source: vbox/trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp@ 83968

/* $Id: DevIommuAmd.cpp 83968 2020-04-24 14:55:49Z vboxsync $ */
/** @file
 * IOMMU - Input/Output Memory Management Unit - AMD implementation.
 */

/*
 * Copyright (C) 2020 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */


/*********************************************************************************************************************************
*   Header Files                                                                                                                 *
*********************************************************************************************************************************/
#define LOG_GROUP LOG_GROUP_DEV_IOMMU
#include <VBox/vmm/pdmdev.h>
#include <VBox/AssertGuest.h>

#include "VBoxDD.h"
#include <iprt/x86.h>
#include <iprt/string.h>


/*********************************************************************************************************************************
*   Defined Constants And Macros                                                                                                 *
*********************************************************************************************************************************/
/**
 * @name PCI configuration register offsets.
 * In accordance with the AMD spec.
 * @{
 */
#define IOMMU_PCI_OFF_CAP_HDR                       0x40
#define IOMMU_PCI_OFF_BASE_ADDR_REG_LO              0x44
#define IOMMU_PCI_OFF_BASE_ADDR_REG_HI              0x48
#define IOMMU_PCI_OFF_RANGE_REG                     0x4c
#define IOMMU_PCI_OFF_MISCINFO_REG_0                0x50
#define IOMMU_PCI_OFF_MISCINFO_REG_1                0x54
#define IOMMU_PCI_OFF_MSI_CAP_HDR                   0x64
#define IOMMU_PCI_OFF_MSI_ADDR_LO                   0x68
#define IOMMU_PCI_OFF_MSI_ADDR_HI                   0x6c
#define IOMMU_PCI_OFF_MSI_DATA                      0x70
#define IOMMU_PCI_OFF_MSI_MAP_CAP_HDR               0x74
/** @} */

/**
 * @name MMIO register offsets.
 * In accordance with the AMD spec.
 * @{
 */
#define IOMMU_MMIO_OFF_DEV_TAB_BAR                  0x00
#define IOMMU_MMIO_OFF_CMD_BUF_BAR                  0x08
#define IOMMU_MMIO_OFF_EVT_LOG_BAR                  0x10
#define IOMMU_MMIO_OFF_CTRL                         0x18
#define IOMMU_MMIO_OFF_EXCL_BAR                     0x20
#define IOMMU_MMIO_OFF_EXCL_RANGE_LIMIT             0x28
#define IOMMU_MMIO_OFF_EXT_FEAT                     0x30

#define IOMMU_MMIO_OFF_PPR_LOG_BAR                  0x38
#define IOMMU_MMIO_OFF_HW_EVT_HI                    0x40
#define IOMMU_MMIO_OFF_HW_EVT_LO                    0x48
#define IOMMU_MMIO_OFF_HW_EVT_STATUS                0x50

#define IOMMU_MMIO_OFF_SMI_FLT_FIRST                0x60
#define IOMMU_MMIO_OFF_SMI_FLT_LAST                 0xd8

#define IOMMU_MMIO_OFF_GALOG_BAR                    0xe0
#define IOMMU_MMIO_OFF_GALOG_TAIL_ADDR              0xe8

#define IOMMU_MMIO_OFF_PPR_LOG_B_BAR                0xf0
#define IOMMU_MMIO_OFF_PPR_EVT_B_BAR                0xf8

#define IOMMU_MMIO_OFF_DEV_TAB_SEG_FIRST            0x100
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_1                0x100
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_2                0x108
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_3                0x110
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_4                0x118
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_5                0x120
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_6                0x128
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_7                0x130
#define IOMMU_MMIO_OFF_DEV_TAB_SEG_LAST             0x130

#define IOMMU_MMIO_OFF_DEV_SPECIFIC_FEAT            0x138
#define IOMMU_MMIO_OFF_DEV_SPECIFIC_CTRL            0x140
#define IOMMU_MMIO_OFF_DEV_SPECIFIC_STATUS          0x148

#define IOMMU_MMIO_OFF_MSI_VECTOR_0                 0x150
#define IOMMU_MMIO_OFF_MSI_VECTOR_1                 0x154
#define IOMMU_MMIO_OFF_MSI_CAP_HDR                  0x158
#define IOMMU_MMIO_OFF_MSI_ADDR_LO                  0x15c
#define IOMMU_MMIO_OFF_MSI_ADDR_HI                  0x160
#define IOMMU_MMIO_OFF_MSI_DATA                     0x164
#define IOMMU_MMIO_OFF_MSI_MAPPING_CAP_HDR          0x168

#define IOMMU_MMIO_OFF_PERF_OPT_CTRL                0x16c

#define IOMMU_MMIO_OFF_XT_GEN_INTR_CTRL             0x170
#define IOMMU_MMIO_OFF_XT_PPR_INTR_CTRL             0x178
#define IOMMU_MMIO_OFF_XT_GALOG_INT_CTRL            0x180

#define IOMMU_MMIO_OFF_MARC_APER_BAR_0              0x200
#define IOMMU_MMIO_OFF_MARC_APER_RELOC_0            0x208
#define IOMMU_MMIO_OFF_MARC_APER_LEN_0              0x210
#define IOMMU_MMIO_OFF_MARC_APER_BAR_1              0x218
#define IOMMU_MMIO_OFF_MARC_APER_RELOC_1            0x220
#define IOMMU_MMIO_OFF_MARC_APER_LEN_1              0x228
#define IOMMU_MMIO_OFF_MARC_APER_BAR_2              0x230
#define IOMMU_MMIO_OFF_MARC_APER_RELOC_2            0x238
#define IOMMU_MMIO_OFF_MARC_APER_LEN_2              0x240
#define IOMMU_MMIO_OFF_MARC_APER_BAR_3              0x248
#define IOMMU_MMIO_OFF_MARC_APER_RELOC_3            0x250
#define IOMMU_MMIO_OFF_MARC_APER_LEN_3              0x258

#define IOMMU_MMIO_OFF_RSVD_REG                     0x1ff8

#define IOMMU_MMIO_CMD_BUF_HEAD_PTR                 0x2000
#define IOMMU_MMIO_CMD_BUF_TAIL_PTR                 0x2008
#define IOMMU_MMIO_EVT_LOG_HEAD_PTR                 0x2010
#define IOMMU_MMIO_EVT_LOG_TAIL_PTR                 0x2018

#define IOMMU_MMIO_OFF_STATUS                       0x2020

#define IOMMU_MMIO_OFF_PPR_LOG_HEAD_PTR             0x2030
#define IOMMU_MMIO_OFF_PPR_LOG_TAIL_PTR             0x2038

#define IOMMU_MMIO_OFF_GALOG_HEAD_PTR               0x2040
#define IOMMU_MMIO_OFF_GALOG_TAIL_PTR               0x2048

#define IOMMU_MMIO_OFF_PPR_LOG_B_HEAD_PTR           0x2050
#define IOMMU_MMIO_OFF_PPR_LOG_B_TAIL_PTR           0x2058

#define IOMMU_MMIO_OFF_EVT_LOG_B_HEAD_PTR           0x2070
#define IOMMU_MMIO_OFF_EVT_LOG_B_TAIL_PTR           0x2078

#define IOMMU_MMIO_OFF_PPR_LOG_AUTO_RESP            0x2080
#define IOMMU_MMIO_OFF_PPR_LOG_OVERFLOW_EARLY       0x2088
#define IOMMU_MMIO_OFF_PPR_LOG_B_OVERFLOW_EARLY     0x2090
/** @} */

/**
 * @name MMIO register-access table offsets.
 * Each table [first..last] (both inclusive) represents the range of registers
 * covered by a distinct register-access table. This is done due to arbitrary large
 * gaps in the MMIO register offsets themselves.
 * @{
 */
#define IOMMU_MMIO_OFF_TABLE_0_FIRST               0x00
#define IOMMU_MMIO_OFF_TABLE_0_LAST                0x258

#define IOMMU_MMIO_OFF_TABLE_1_FIRST               0x1ff8
#define IOMMU_MMIO_OFF_TABLE_1_LAST                0x2090
/** @} */

/**
 * @name Commands.
 * In accordance with the AMD spec.
 * @{
 */
#define IOMMU_CMD_COMPLETION_WAIT                   0x01
#define IOMMU_CMD_INV_DEV_TAB_ENTRY                 0x02
#define IOMMU_CMD_INV_IOMMU_PAGES                   0x03
#define IOMMU_CMD_INV_IOTLB_PAGES                   0x04
#define IOMMU_CMD_INV_INTR_TABLE                    0x05
#define IOMMU_CMD_PREFETCH_IOMMU_PAGES              0x06
#define IOMMU_CMD_COMPLETE_PPR_REQ                  0x07
#define IOMMU_CMD_INV_IOMMU_ALL                     0x08
/** @} */

/**
 * @name Event codes.
 * In accordance with the AMD spec.
 * @{
 */
#define IOMMU_EVT_ILLEGAL_DEV_TAB_ENTRY             0x01
#define IOMMU_EVT_IO_PAGE_FAULT                     0x02
#define IOMMU_EVT_DEV_TAB_HARDWARE_ERROR            0x03
#define IOMMU_EVT_PAGE_TAB_HARDWARE_ERROR           0x04
#define IOMMU_EVT_ILLEGAL_COMMAND_ERROR             0x05
#define IOMMU_EVT_COMMAND_HARDWARE_ERROR            0x06
#define IOMMU_EVT_IOTLB_INV_TIMEOUT                 0x07
#define IOMMU_EVT_INVALID_DEVICE_REQUEST            0x08
#define IOMMU_EVT_INVALID_PPR_REQUEST               0x09
#define IOMMU_EVT_EVENT_COUNTER_ZERO                0x10
#define IOMMU_EVT_GUEST_EVENT_FAULT                 0x11
/** @} */

/**
 * @name IOMMU Capability Header.
 * In accordance with the AMD spec.
 * @{
 */
/** CapId: Capability ID. */
#define IOMMU_BF_CAPHDR_CAP_ID_SHIFT                0
#define IOMMU_BF_CAPHDR_CAP_ID_MASK                 UINT32_C(0x000000ff)
/** CapPtr: Capability Pointer. */
#define IOMMU_BF_CAPHDR_CAP_PTR_SHIFT               8
#define IOMMU_BF_CAPHDR_CAP_PTR_MASK                UINT32_C(0x0000ff00)
/** CapType: Capability Type. */
#define IOMMU_BF_CAPHDR_CAP_TYPE_SHIFT              16
#define IOMMU_BF_CAPHDR_CAP_TYPE_MASK               UINT32_C(0x00070000)
/** CapRev: Capability Revision. */
#define IOMMU_BF_CAPHDR_CAP_REV_SHIFT               19
#define IOMMU_BF_CAPHDR_CAP_REV_MASK                UINT32_C(0x00f80000)
/** IoTlbSup: IO TLB Support. */
#define IOMMU_BF_CAPHDR_IOTLB_SUP_SHIFT             24
#define IOMMU_BF_CAPHDR_IOTLB_SUP_MASK              UINT32_C(0x01000000)
/** HtTunnel: HyperTransport Tunnel translation support. */
#define IOMMU_BF_CAPHDR_HT_TUNNEL_SHIFT             25
#define IOMMU_BF_CAPHDR_HT_TUNNEL_MASK              UINT32_C(0x02000000)
/** NpCache: Not Present table entries Cached. */
#define IOMMU_BF_CAPHDR_NP_CACHE_SHIFT              26
#define IOMMU_BF_CAPHDR_NP_CACHE_MASK               UINT32_C(0x04000000)
/** EFRSup: Extended Feature Register (EFR) Supported. */
#define IOMMU_BF_CAPHDR_EFR_SUP_SHIFT               27
#define IOMMU_BF_CAPHDR_EFR_SUP_MASK                UINT32_C(0x08000000)
/** CapExt: Miscellaneous Information Register Supported . */
#define IOMMU_BF_CAPHDR_CAP_EXT_SHIFT               28
#define IOMMU_BF_CAPHDR_CAP_EXT_MASK                UINT32_C(0x10000000)
/** Bits 31:29 reserved. */
#define IOMMU_BF_CAPHDR_RSVD_29_31_SHIFT            29
#define IOMMU_BF_CAPHDR_RSVD_29_31_MASK             UINT32_C(0xe0000000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_CAPHDR_, UINT32_C(0), UINT32_MAX,
                            (CAP_ID, CAP_PTR, CAP_TYPE, CAP_REV, IOTLB_SUP, HT_TUNNEL, NP_CACHE, EFR_SUP, CAP_EXT, RSVD_29_31));
/** @} */

/**
 * @name IOMMU Base Address Low Register.
 * In accordance with the AMD spec.
 * @{
 */
/** Enable: Enables access to the address specified in the Base Address Register. */
#define IOMMU_BF_BASEADDR_LO_ENABLE_SHIFT           0
#define IOMMU_BF_BASEADDR_LO_ENABLE_MASK            UINT32_C(0x00000001)
/** Bits 13:1 reserved. */
#define IOMMU_BF_BASEADDR_LO_RSVD_1_13_SHIFT        1
#define IOMMU_BF_BASEADDR_LO_RSVD_1_13_MASK         UINT32_C(0x00003ffe)
/** Base Address[31:14]: Low Base address of IOMMU MMIO control registers. */
#define IOMMU_BF_BASEADDR_LO_ADDR_SHIFT             14
#define IOMMU_BF_BASEADDR_LO_ADDR_MASK              UINT32_C(0xffffc000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_BASEADDR_LO_, UINT32_C(0), UINT32_MAX,
                            (ENABLE, RSVD_1_13, ADDR));
/** @} */

/**
 * @name IOMMU Range Register.
 * In accordance with the AMD spec.
 * @{
 */
/** UnitID: HyperTransport Unit ID. */
#define IOMMU_BF_RANGE_UNIT_ID_SHIFT                0
#define IOMMU_BF_RANGE_UNIT_ID_MASK                 UINT32_C(0x0000001f)
/** Bits 6:5 reserved. */
#define IOMMU_BF_RANGE_RSVD_5_6_SHIFT               5
#define IOMMU_BF_RANGE_RSVD_5_6_MASK                UINT32_C(0x00000060)
/** RngValid: Range valid. */
#define IOMMU_BF_RANGE_VALID_SHIFT                  7
#define IOMMU_BF_RANGE_VALID_MASK                   UINT32_C(0x00000080)
/** BusNumber: Device range bus number. */
#define IOMMU_BF_RANGE_BUS_NUMBER_SHIFT             8
#define IOMMU_BF_RANGE_BUS_NUMBER_MASK              UINT32_C(0x0000ff00)
/** First Device. */
#define IOMMU_BF_RANGE_FIRST_DEVICE_SHIFT           16
#define IOMMU_BF_RANGE_FIRST_DEVICE_MASK            UINT32_C(0x00ff0000)
/** Last Device. */
#define IOMMU_BF_RANGE_LAST_DEVICE_SHIFT            24
#define IOMMU_BF_RANGE_LAST_DEVICE_MASK             UINT32_C(0xff000000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_RANGE_, UINT32_C(0), UINT32_MAX,
                            (UNIT_ID, RSVD_5_6, VALID, BUS_NUMBER, FIRST_DEVICE, LAST_DEVICE));
/** @} */

/**
 * @name IOMMU Miscellaneous Information Register 0.
 * In accordance with the AMD spec.
 * @{
 */
/** MsiNum: MSI message number. */
#define IOMMU_BF_MISCINFO_0_MSI_NUM_SHIFT           0
#define IOMMU_BF_MISCINFO_0_MSI_NUM_MASK            UINT32_C(0x0000001f)
/** GvaSize: Guest Virtual Address Size. */
#define IOMMU_BF_MISCINFO_0_GVA_SIZE_SHIFT          5
#define IOMMU_BF_MISCINFO_0_GVA_SIZE_MASK           UINT32_C(0x000000e0)
/** PaSize: Physical Address Size. */
#define IOMMU_BF_MISCINFO_0_PA_SIZE_SHIFT           8
#define IOMMU_BF_MISCINFO_0_PA_SIZE_MASK            UINT32_C(0x00007f00)
/** VaSize: Virtual Address Size. */
#define IOMMU_BF_MISCINFO_0_VA_SIZE_SHIFT           15
#define IOMMU_BF_MISCINFO_0_VA_SIZE_MASK            UINT32_C(0x003f8000)
/** HtAtsResv: HyperTransport ATS Response Address range Reserved. */
#define IOMMU_BF_MISCINFO_0_HT_ATS_RESV_SHIFT       22
#define IOMMU_BF_MISCINFO_0_HT_ATS_RESV_MASK        UINT32_C(0x00400000)
/** Bits 26:23 reserved. */
#define IOMMU_BF_MISCINFO_0_RSVD_23_26_SHIFT        23
#define IOMMU_BF_MISCINFO_0_RSVD_23_26_MASK         UINT32_C(0x07800000)
/** MsiNumPPR: Peripheral Page Request MSI message number. */
#define IOMMU_BF_MISCINFO_0_MSI_NUM_PPR_SHIFT       27
#define IOMMU_BF_MISCINFO_0_MSI_NUM_PPR_MASK        UINT32_C(0xf8000000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_MISCINFO_0_, UINT32_C(0), UINT32_MAX,
                            (MSI_NUM, GVA_SIZE, PA_SIZE, VA_SIZE, HT_ATS_RESV, RSVD_23_26, MSI_NUM_PPR));
/** @} */

/**
 * @name IOMMU Miscellaneous Information Register 1.
 * In accordance with the AMD spec.
 * @{
 */
/** MsiNumGA: MSI message number for guest virtual-APIC log. */
#define IOMMU_BF_MISCINFO_1_MSI_NUM_GA_SHIFT        0
#define IOMMU_BF_MISCINFO_1_MSI_NUM_GA_MASK         UINT32_C(0x0000001f)
/** Bits 31:5 reserved. */
#define IOMMU_BF_MISCINFO_1_RSVD_5_31_SHIFT         5
#define IOMMU_BF_MISCINFO_1_RSVD_5_31_MASK          UINT32_C(0xffffffe0)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_MISCINFO_1_, UINT32_C(0), UINT32_MAX,
                            (MSI_NUM_GA, RSVD_5_31));
/** @} */

/**
 * @name MSI Capability Header Register.
 * In accordance with the AMD spec.
 * @{
 */
/** MsiCapId: Capability ID. */
#define IOMMU_BF_MSI_CAPHDR_CAP_ID_SHIFT            0
#define IOMMU_BF_MSI_CAPHDR_CAP_ID_MASK             UINT32_C(0x000000ff)
/** MsiCapPtr: Pointer (PCI config offset) to the next capability. */
#define IOMMU_BF_MSI_CAPHDR_CAP_PTR_SHIFT           8
#define IOMMU_BF_MSI_CAPHDR_CAP_PTR_MASK            UINT32_C(0x0000ff00)
/** MsiEn: Message Signal Interrupt enable. */
#define IOMMU_BF_MSI_CAPHDR_EN_SHIFT                16
#define IOMMU_BF_MSI_CAPHDR_EN_MASK                 UINT32_C(0x00010000)
/** MsiMultMessCap: MSI Multi-Message Capability. */
#define IOMMU_BF_MSI_CAPHDR_MULTMESS_CAP_SHIFT      17
#define IOMMU_BF_MSI_CAPHDR_MULTMESS_CAP_MASK       UINT32_C(0x000e0000)
/** MsiMultMessEn: MSI Mult-Message Enable. */
#define IOMMU_BF_MSI_CAPHDR_MULTMESS_EN_SHIFT       20
#define IOMMU_BF_MSI_CAPHDR_MULTMESS_EN_MASK        UINT32_C(0x00700000)
/** Msi64BitEn: MSI 64-bit Enabled. */
#define IOMMU_BF_MSI_CAPHDR_64BIT_EN_SHIFT          23
#define IOMMU_BF_MSI_CAPHDR_64BIT_EN_MASK           UINT32_C(0x00800000)
/** Bits 31:24 reserved. */
#define IOMMU_BF_MSI_CAPHDR_RSVD_24_31_SHIFT        24
#define IOMMU_BF_MSI_CAPHDR_RSVD_24_31_MASK         UINT32_C(0xff000000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_MSI_CAPHDR_, UINT32_C(0), UINT32_MAX,
                            (CAP_ID, CAP_PTR, EN, MULTMESS_CAP, MULTMESS_EN, 64BIT_EN, RSVD_24_31));
/** @} */

/**
 * @name MSI Mapping Capability Header Register.
 * In accordance with the AMD spec.
 * @{
 */
/** MsiMapCapId: Capability ID. */
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_ID_SHIFT        0
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_ID_MASK         UINT32_C(0x000000ff)
/** MsiMapCapPtr: Pointer (PCI config offset) to the next capability. */
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_PTR_SHIFT       8
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_PTR_MASK        UINT32_C(0x0000ff00)
/** MsiMapEn: MSI mapping capability enable. */
#define IOMMU_BF_MSI_MAP_CAPHDR_EN_SHIFT            16
#define IOMMU_BF_MSI_MAP_CAPHDR_EN_MASK             UINT32_C(0x00010000)
/** MsiMapFixd: MSI interrupt mapping range is not programmable. */
#define IOMMU_BF_MSI_MAP_CAPHDR_FIXED_SHIFT         17
#define IOMMU_BF_MSI_MAP_CAPHDR_FIXED_MASK          UINT32_C(0x00020000)
/** Bits 18:28 reserved. */
#define IOMMU_BF_MSI_MAP_CAPHDR_RSVD_18_28_SHIFT    18
#define IOMMU_BF_MSI_MAP_CAPHDR_RSVD_18_28_MASK     UINT32_C(0x07fc0000)
/** MsiMapCapType: MSI mapping capability. */
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_TYPE_SHIFT      27
#define IOMMU_BF_MSI_MAP_CAPHDR_CAP_TYPE_MASK       UINT32_C(0xf8000000)
RT_BF_ASSERT_COMPILE_CHECKS(IOMMU_BF_MSI_MAP_CAPHDR_, UINT32_C(0), UINT32_MAX,
                            (CAP_ID, CAP_PTR, EN, FIXED, RSVD_18_28, CAP_TYPE));
/** @} */

/** @name Miscellaneous IOMMU defines.
 * @{ */
/** Log prefix string. */
#define IOMMU_LOG_PFX                               "AMD_IOMMU"
/** The current saved state version. */
#define IOMMU_SAVED_STATE_VERSION                   1
/** AMD's vendor ID. */
#define IOMMU_PCI_VENDOR_ID                         0x1022
/** VirtualBox IOMMU device ID. */
#define IOMMU_PCI_DEVICE_ID                         0xc0de
/** VirtualBox IOMMU device revision ID. */
#define IOMMU_PCI_REVISION_ID                       0x01
/** Size of the MMIO region in bytes. */
#define IOMMU_MMIO_REGION_SIZE                      _16K
/** Number of device table segments supported (power of 2). */
#define IOMMU_MAX_DEV_TAB_SEGMENTS                  3
/** @} */

/**
 * Acquires the IOMMU PDM lock or returns @a a_rcBusy if it's busy.
 */
#define IOMMU_LOCK_RET(a_pDevIns, a_pThis, a_rcBusy)  \
    do { \
        NOREF(pThis); \
        int rcLock = PDMDevHlpCritSectEnter((a_pDevIns), (a_pDevIns)->CTX_SUFF(pCritSectRo), (a_rcBusy)); \
        if (RT_LIKELY(rcLock == VINF_SUCCESS)) \
        { /* likely */ } \
        else \
            return rcLock; \
    } while (0)

/**
 * Releases the IOMMU PDM lock.
 */
#define IOMMU_UNLOCK(a_pDevIns, a_pThis) \
    do { \
        PDMDevHlpCritSectLeave((a_pDevIns), (a_pDevIns)->CTX_SUFF(pCritSectRo)); \
    } while (0)

/**
 * Gets the device table size given the size field.
 */
#define IOMMU_GET_DEV_TAB_SIZE(a_uSize)     (((a_uSize) + 1) << X86_PAGE_4K_SHIFT)

/*********************************************************************************************************************************
*   Structures and Typedefs                                                                                                      *
*********************************************************************************************************************************/
/**
 * The Device ID.
 * In accordance with VirtualBox's PCI configuration.
 */
typedef union
{
    struct
    {
        uint16_t    u3Function : 3;  /**< Bits 2:0   - Function. */
        uint16_t    u9Device : 9;    /**< Bits 11:3  - Device. */
        uint16_t    u4Bus : 4;       /**< Bits 15:12 - Bus. */
    } n;
    /** The unsigned integer view. */
    uint16_t        u;
} DEVICE_ID_T;
AssertCompileSize(DEVICE_ID_T, 2);

/**
 * Device Table Entry (DTE).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1Valid : 1;                      /**< Bit  0       - V: Valid. */
        uint32_t    u1TranslationValid : 1;           /**< Bit  1       - TV: Translation information Valid. */
        uint32_t    u5Rsvd0 : 5;                      /**< Bits 6:2     - Reserved. */
        uint32_t    u2Had : 2;                        /**< Bits 8:7     - HAD: Host Access Dirty. */
        uint32_t    u3Mode : 3;                       /**< Bits 11:9    - Mode: Paging mode. */
        uint32_t    u20PageTableRootPtrLo : 20;       /**< Bits 31:12   - Page Table Root Pointer (Lo). */
        uint32_t    u20PageTableRootPtrHi : 20;       /**< Bits 51:32   - Page Table Root Pointer (Hi). */
        uint32_t    u1Ppr : 1;                        /**< Bit  52      - PPR: Peripheral Page Request. */
        uint32_t    u1GstPprRespPasid : 1;            /**< Bit  53      - GRPR: Guest PPR Response with PASID. */
        uint32_t    u1GstIoValid : 1;                 /**< Bit  54      - GIoV: Guest I/O Protection Valid. */
        uint32_t    u1GstTranslateValid : 1;          /**< Bit  55      - GV: Guest translation Valid. */
        uint32_t    u2GstCr3RootTblTranslated : 2;    /**< Bits 57:56   - GLX: Guest Levels Translated. */
        uint32_t    u3GstCr3TableRootPtrLo : 2;       /**< Bits 60:58   - GCR3 TRP: Guest CR3 Table Root Pointer (Lo). */
        uint32_t    u1IoRead : 1;                     /**< Bit  61      - IR: I/O Read permission. */
        uint32_t    u1IoWrite : 1;                    /**< Bit  62      - IW: I/O Write permission. */
        uint32_t    u1Rsvd0 : 1;                      /**< Bit  63      - Reserved. */
        uint32_t    u16DomainId : 1;                  /**< Bits 79:64   - Domain ID. */
        uint32_t    u16GstCr3TableRootPtrMed : 16;    /**< Bits 95:80   - GCR3 TRP: Guest CR3 Table Root Pointer (Mid). */
        uint32_t    u1IoTlbEnable : 1;                /**< Bit  96      - IOTLB Enable. */
        uint32_t    u1SuppressPfEvents : 1;           /**< Bit  97      - SE: Supress Page-fault events. */
        uint32_t    u1SuppressAllPfEvents : 1;        /**< Bit  98      - SA: Supress All Page-fault events. */
        uint32_t    u2IoCtl : 1;                      /**< Bits 100:99  - IoCtl: Port I/O Control. */
        uint32_t    u1Cache : 1;                      /**< Bit  101     - Cache: IOTLB Cache Hint. */
        uint32_t    u1SnoopDisable : 1;               /**< Bit  102     - SD: Snoop Disable. */
        uint32_t    u1AllowExclusion : 1;             /**< Bit  103     - EX: Allow Exclusion. */
        uint32_t    u2SysMgt : 2;                     /**< Bits 105:104 - SysMgt: System Management message enable. */
        uint32_t    u1Rsvd1 : 1;                      /**< Bit  106     - Reserved. */
        uint32_t    u21GstCr3TableRootPtrHi : 21;     /**< Bits 127:107 - GCR3 TRP: Guest CR3 Table Root Pointer (Hi). */
        uint32_t    u1IntrMapValid : 1;               /**< Bit  128     - IV: Interrupt map Valid. */
        uint32_t    u4IntrTableLength : 4;            /**< Bits 132:129 - IntTabLen: Interrupt Table Length. */
        uint32_t    u1IgnoreUnmappedIntrs : 1;        /**< Bits 133     - IG: Ignore unmapped interrupts. */
        uint32_t    u26IntrTableRootPtr : 26;         /**< Bits 159:134 - Interrupt Root Table Pointer (Lo). */
        uint32_t    u20IntrTableRootPtr : 20;         /**< Bits 179:160 - Interrupt Root Table Pointer (Hi). */
        uint32_t    u4Rsvd0 : 4;                      /**< Bits 183:180 - Reserved. */
        uint32_t    u1InitPassthru : 1;               /**< Bits 184     - INIT Pass-through. */
        uint32_t    u1ExtIntPassthru : 1;             /**< Bits 185     - External Interrupt Pass-through. */
        uint32_t    u1NmiPassthru : 1;                /**< Bits 186     - NMI Pass-through. */
        uint32_t    u1Rsvd2 : 1;                      /**< Bits 187     - Reserved. */
        uint32_t    u2IntrCtrl : 2;                   /**< Bits 189:188 - IntCtl: Interrupt Control. */
        uint32_t    u1Lint0Passthru : 1;              /**< Bit  190     - Lint0Pass: LINT0 (Legacy PIC NMI) Pass-thru. */
        uint32_t    u1Lint1Passthru : 1;              /**< Bit  191     - Lint1Pass: LINT1 (Legacy PIC NMI) Pass-thru. */
        uint32_t    u32Rsvd0;                         /**< Bits 223:192 - Reserved. */
        uint32_t    u22Rsvd0 : 22;                    /**< Bits 245:224 - Reserved. */
        uint32_t    u1AttrOverride : 1;               /**< Bit  246     - AttrV: Attribute Override. */
        uint32_t    u1Mode0FC: 1;                     /**< Bit  247     - Mode0FC. */
        uint32_t    u8SnoopAttr: 1;                   /**< Bits 255:248 - Snoop Attribute. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t        au32[8];
} DEV_TAB_ENTRY_T;
AssertCompileSize(DEV_TAB_ENTRY_T, 32);

/**
 * I/O Page Table Entry.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t    u1Present : 1;             /**< Bit  0      - PR: Present. */
        RT_GCC_EXTENSION uint64_t    u4Ign0 : 4;                /**< Bits 4:1    - Ignored. */
        RT_GCC_EXTENSION uint64_t    u1Accessed : 1;            /**< Bit  5      - A: Accessed. */
        RT_GCC_EXTENSION uint64_t    u1Dirty : 1;               /**< Bit  6      - D: Dirty. */
        RT_GCC_EXTENSION uint64_t    u2Ign0 : 2;                /**< Bits 8:7    - Ignored. */
        RT_GCC_EXTENSION uint64_t    u3NextLevel : 3;           /**< Bits 11:9   - Next Level: Next page translation level. */
        RT_GCC_EXTENSION uint64_t    u40PageAddr : 40;          /**< Bits 51:12  - Page address. */
        RT_GCC_EXTENSION uint64_t    u7Rsvd0 : 7;               /**< Bits 58:52  - Reserved. */
        RT_GCC_EXTENSION uint64_t    u1UntranslatedAccess : 1;  /**< Bit 59      - U: Untranslated Access Only. */
        RT_GCC_EXTENSION uint64_t    u1ForceCoherent : 1;       /**< Bit 60      - FC: Force Coherent. */
        RT_GCC_EXTENSION uint64_t    u1IoRead : 1;              /**< Bit 61      - IR: I/O Read permission. */
        RT_GCC_EXTENSION uint64_t    u1IoWrite : 1;             /**< Bit 62      - IW: I/O Wead permission. */
        RT_GCC_EXTENSION uint64_t    u1Ign0 : 1;                /**< Bit 63      - Ignored. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t        u;
} IOPTE_T;
AssertCompileSize(IOPTE_T, 8);

/**
 * I/O Page Directory Entry.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t    u1Present : 1;         /**< Bit  0      - PR: Present. */
        RT_GCC_EXTENSION uint64_t    u4Ign0 : 4;            /**< Bits 4:1    - Ignored. */
        RT_GCC_EXTENSION uint64_t    u1Accessed : 1;        /**< Bit  5      - A: Accessed. */
        RT_GCC_EXTENSION uint64_t    u3Ign0 : 3;            /**< Bits 8:6    - Ignored. */
        RT_GCC_EXTENSION uint64_t    u3NextLevel : 3;       /**< Bits 11:9   - Next Level: Next page translation level. */
        RT_GCC_EXTENSION uint64_t    u40PageAddr : 40;      /**< Bits 51:12  - Page address (Next Table Address). */
        RT_GCC_EXTENSION uint64_t    u9Rsvd0 : 9;           /**< Bits 60:52  - Reserved. */
        RT_GCC_EXTENSION uint64_t    u1IoRead : 1;          /**< Bit 61      - IR: I/O Read permission. */
        RT_GCC_EXTENSION uint64_t    u1IoWrite : 1;         /**< Bit 62      - IW: I/O Wead permission. */
        RT_GCC_EXTENSION uint64_t    u1Ign0 : 1;            /**< Bit 63      - Ignored. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t        u;
} IOPDE_T;
AssertCompileSize(IOPDE_T, 8);

/**
 * Interrupt Remapping Table Entry.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1RemapEnable : 1;      /**< Bit  0     - RemapEn: Remap Enable. */
        uint32_t    u1SuppressPf : 1;       /**< Bit  1     - SupIOPF: Supress I/O Page Fault. */
        uint32_t    u3IntrType : 1;         /**< Bits 4:2   - IntType: Interrupt Type. */
        uint32_t    u1ReqEoi : 1;           /**< Bit  5     - RqEoi: Request EOI. */
        uint32_t    u1DstMode : 1;          /**< Bit  6     - DM: Destination Mode. */
        uint32_t    u1GuestMode : 1;        /**< Bit  7     - GuestMode. */
        uint32_t    u8Dst : 8;              /**< Bits 15:8  - Destination. */
        uint32_t    u8Vector : 8;           /**< Bits 23:16 - Vector. */
        uint32_t    u8Rsvd0 : 8;            /**< Bits 31:24 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t        u;
} IRTE_T;
AssertCompileSize(IRTE_T, 4);

/**
 * Command: Generic Command Buffer Entry.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Operand1Lo;          /**< Bits 31:0   - Operand 1 (Lo). */
        uint32_t    u32Operand1Hi : 28;     /**< Bits 59:32  - Operand 1 (Hi). */
        uint32_t    u4Opcode : 4;           /**< Bits 63:60  - Op Code. */
        uint64_t    u64Operand2;            /**< Bits 127:64 - Operand 2. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_GENERIC_T;
AssertCompileSize(CMD_GENERIC_T, 16);

/**
 * Command: COMPLETION_WAIT.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1Store : 1;           /**< Bit  0      - S: Completion Store. */
        uint32_t    u1Interrupt : 1;       /**< Bit  1      - I: Completion Interrupt. */
        uint32_t    u1Flush : 1;           /**< Bit  2      - F: Flush Queue. */
        uint32_t    u29StoreAddrLo : 29;   /**< Bits 31:3   - Store Address (Lo). */
        uint32_t    u20StoreAddrHi : 20;   /**< Bits 51:32  - Store Address (Hi). */
        uint32_t    u8Rsvd0 : 8;           /**< Bits 59:52  - Reserved. */
        uint32_t    u4OpCode : 4;          /**< Bits 63:60  - OpCode (Command). */
        uint64_t    u64StoreData;          /**< Bits 127:64 - Store Data. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint32_t    au64[2];
} CMD_COMPLETION_WAIT_T;
AssertCompileSize(CMD_COMPLETION_WAIT_T, 16);

/**
 * Command: INVALIDATE_DEVTAB_ENTRY.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t                     u16DeviceId;       /**< Bits 15:0   - DeviceID. */
        uint16_t                     u16Rsvd0;          /**< Bits 31:16  - Reserved. */
        uint32_t                     u28Rsvd0 : 28;     /**< Bits 59:32  - Reserved. */
        uint32_t                     u4OpCode : 4;      /**< Bits 63:60  - Op Code (Command). */
        uint64_t                     u64Rsvd0;          /**< Bits 127:64 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_INV_DEV_TAB_ENTRY_T;
AssertCompileSize(CMD_INV_DEV_TAB_ENTRY_T, 16);

/**
 * Command: INVALIDATE_IOMMU_PAGES.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u20Pasid : 20;          /**< Bits 19:0   - PASID: Process Address-Space ID. */
        uint32_t    u12Rsvd0 : 12;          /**< Bits 31:20  - Reserved. */
        uint32_t    u16DomainId : 16;       /**< Bits 47:32  - Domain ID. */
        uint32_t    u12Rsvd1 : 12;          /**< Bits 59:48  - Reserved. */
        uint32_t    u4OpCode : 4;           /**< Bits 63:60  - Op Code (Command). */
        uint32_t    u1Size : 1;             /**< Bit  64     - S: Size. */
        uint32_t    u1PageDirEntries : 1;   /**< Bit  65     - PDE: Page Directory Entries. */
        uint32_t    u1GuestOrNested : 1;    /**< Bit  66     - GN: Guest (GPA) or Nested (GVA). */
        uint32_t    u9Rsvd0 : 9;            /**< Bits 75:67  - Reserved. */
        uint32_t    u20AddrLo : 20;         /**< Bits 95:76  - Address (Lo). */
        uint32_t    u32AddrHi;              /**< Bits 127:96 - Address (Hi). */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_INV_IOMMU_PAGES_T;
AssertCompileSize(CMD_INV_IOMMU_PAGES_T, 16);

/**
 * Command: INVALIDATE_IOTLB_PAGES.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;            /**< Bits 15:0   - Device ID. */
        uint8_t     u8PasidLo;              /**< Bits 23:16  - PASID: Process Address-Space ID (Lo). */
        uint8_t     u8MaxPend;              /**< Bits 31:24  - Maxpend: Maximum simultaneous in-flight transactions. */
        uint32_t    u16QueueId : 16;        /**< Bits 47:32  - Queue ID. */
        uint32_t    u12PasidHi : 12;        /**< Bits 59:48  - PASID: Process Address-Space ID (Hi). */
        uint32_t    u4OpCode : 4;           /**< Bits 63:60  - Op Code (Command). */
        uint32_t    u1Size : 1;             /**< Bit  64     - S: Size. */
        uint32_t    u1Rsvd0: 1;             /**< Bit  65     - Reserved. */
        uint32_t    u1GuestOrNested : 1;    /**< Bit  66     - GN: Guest (GPA) or Nested (GVA). */
        uint32_t    u1Rsvd1 : 1;            /**< Bit  67     - Reserved. */
        uint32_t    u2Type : 2;             /**< Bit  69:68  - Type. */
        uint32_t    u6Rsvd0 : 6;            /**< Bits 75:70  - Reserved. */
        uint32_t    u20AddrLo : 20;         /**< Bits 95:76  - Address (Lo). */
        uint32_t    u32AddrHi;              /**< Bits 127:96 - Address (Hi). */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_INV_IOTLB_PAGES_T;
AssertCompileSize(CMD_INV_IOTLB_PAGES_T, 16);

/**
 * Command: INVALIDATE_INTR_TABLE.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;        /**< Bits 15:0   - Device ID. */
        uint16_t    u16Rsvd0;           /**< Bits 31:16  - Reserved. */
        uint32_t    u32Rsvd0 : 28;      /**< Bits 59:32  - Reserved. */
        uint32_t    u4OpCode : 4;       /**< Bits 63:60  - Op Code (Command). */
        uint64_t    u64Rsvd0;           /**< Bits 127:64 - Reserved. */
    } u;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_INV_INTR_TABLE_T;
AssertCompileSize(CMD_INV_INTR_TABLE_T, 16);

/**
 * Command: COMPLETE_PPR_REQ.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;            /**< Bits 15:0    - Device ID. */
        uint16_t    u16Rsvd0;               /**< Bits 31:16   - Reserved. */
        uint32_t    u20Pasid : 20;          /**< Bits 51:32   - PASID: Process Address-Space ID. */
        uint32_t    u8Rsvd0 : 8;            /**< Bits 59:52   - Reserved. */
        uint32_t    u4OpCode : 4;           /**< Bits 63:60   - Op Code (Command). */
        uint32_t    u2Rsvd0 : 2;            /**< Bits 65:64   - Reserved. */
        uint32_t    u1GuestOrNested : 1;    /**< Bit  66      - GN: Guest (GPA) or Nested (GVA). */
        uint32_t    u29Rsvd0 : 29;          /**< Bits 95:67   - Reserved. */
        uint32_t    u16CompletionTag : 16;  /**< Bits 111:96  - Completion Tag. */
        uint32_t    u16Rsvd1 : 16;          /**< Bits 127:112 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_COMPLETE_PPR_REQ_T;
AssertCompileSize(CMD_COMPLETE_PPR_REQ_T, 16);

/**
 * Command: INV_IOMMU_ALL.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Rsvd0;           /**< Bits 31:0   - Reserved. */
        uint32_t    u28Rsvd0 : 28;      /**< Bits 59:32  - Reserved. */
        uint32_t    u4OpCode : 4;       /**< Bits 63:60  - Op Code (Command). */
        uint64_t    u64Rsvd0;           /**< Bits 127:64 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    au64[2];
} CMD_IOMMU_ALL_T;
AssertCompileSize(CMD_IOMMU_ALL_T, 16);

/**
 * Event Log Entry: Generic.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Operand1Lo;          /**< Bits 31:0   - Operand 1 (Lo). */
        uint32_t    u32Operand1Hi : 28;     /**< Bits 59:32  - Operand 1 (Hi). */
        uint32_t    u4EventCode : 4;        /**< Bits 63:60  - Event code. */
        uint32_t    u32Operand2Lo;          /**< Bits 95:64  - Operand 2 (Lo). */
        uint32_t    u32Operand2Hi;          /**< Bits 127:96 - Operand 2 (Hi). */
    } n;
    /** The 32-bit unsigned integer view.  */
    uint32_t    au32[4];
} EVT_GENERIC_T;
AssertCompileSize(EVT_GENERIC_T, 16);

/**
 * Event Log Entry: ILLEGAL_DEV_TAB_ENTRY.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;            /**< Bits 15:0   - Device ID. */
        uint16_t    u4PasidHi : 4;          /**< Bits 19:16  - PASID: Process Address-Space ID (Hi). */
        uint16_t    u12Rsvd0 : 12;          /**< Bits 31:20  - Reserved. */
        uint16_t    u16PasidLo;             /**< Bits 47:32  - PASID: Process Address-Space ID (Lo). */
        uint16_t    u1GuestOrNested : 1;    /**< Bit  48     - GN: Guest (GPA) or Nested (GVA). */
        uint16_t    u2Rsvd0 : 2;            /**< Bits 50:49  - Reserved. */
        uint16_t    u1Interrupt : 1;        /**< Bit  51     - I: Interrupt. */
        uint16_t    u1Rsvd0 : 1;            /**< Bit  52     - Reserved. */
        uint16_t    u1ReadWrite : 1;        /**< Bit  53     - RW: Read/Write. */
        uint16_t    u1Rsvd1 : 1;            /**< Bit  54     - Reserved. */
        uint16_t    u1RsvdZero : 1;         /**< Bit  55     - RZ: Reserved bit not Zero or invalid level encoding. */
        uint16_t    u1Translation : 1;      /**< Bit  56     - TN: Translation. */
        uint16_t    u3Rsvd0 : 3;            /**< Bits 59:57  - Reserved. */
        uint16_t    u4EventCode : 4;        /**< Bits 63:60  - Event code. */
        uint32_t    u2Rsvd1 : 2;            /**< Bits 65:64  - Reserved. */
        uint32_t    u30AddrLo : 2;          /**< Bits 95:66  - Address: Device Virtual Address (Lo). */
        uint32_t    u30AddrHi;              /**< Bits 127:96 - Address: Device Virtual Address (Hi). */
    } n;
    /** The 32-bit unsigned integer view.  */
    uint32_t    au32[4];
} EVT_ILLEGAL_DEV_TAB_ENTRY_T;
AssertCompileSize(EVT_ILLEGAL_DEV_TAB_ENTRY_T, 16);

/**
 * Event Log Entry: IO_PAGE_FAULT_EVENT.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;            /**< Bits 15:0   - Device ID. */
        uint16_t    u4PasidHi : 4;          /**< Bits 19:16  - PASID: Process Address-Space ID (Hi). */
        uint16_t    u16DomainOrPasidLo;     /**< Bits 47:32  - D/P: Domain ID or Process Address-Space ID (Lo). */
        uint16_t    u1GuestOrNested : 1;    /**< Bit  48     - GN: Guest (GPA) or Nested (GVA). */
        uint16_t    u1NoExecute : 1;        /**< Bit  49     - NX: No Execute. */
        uint16_t    u1User : 1;             /**< Bit  50     - US: User/Supervisor. */
        uint16_t    u1Interrupt : 1;        /**< Bit  51     - I: Interrupt. */
        uint16_t    u1Present : 1;          /**< Bit  52     - PR: Present. */
        uint16_t    u1ReadWrite : 1;        /**< Bit  53     - RW: Read/Write. */
        uint16_t    u1Perm : 1;             /**< Bit  54     - PE: Permission Indicator. */
        uint16_t    u1RsvdZero : 1;         /**< Bit  55     - RZ: Reserved bit not Zero or invalid level encoding. */
        uint16_t    u1Translation : 1;      /**< Bit  56     - TN: Translation. */
        uint16_t    u3Rsvd0 : 3;            /**< Bit  59:57  - Reserved. */
        uint16_t    u4EventCode : 4;        /**< Bits 63:60  - Event code. */
        uint64_t    u64Addr;                /**< Bits 127:64 - Address: Device Virtual Address. */
    } n;
    /** The 32-bit unsigned integer view.  */
    uint32_t    au32[4];
} EVT_IO_PAGE_FAULT_T;
AssertCompileSize(EVT_IO_PAGE_FAULT_T, 16);

/**
 * Event Log Entry: DEV_TAB_HARDWARE_ERROR.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;            /**< Bits 15:0   - Device ID. */
        uint16_t    u16Rsvd0;               /**< Bits 31:16  - Reserved. */
        uint32_t    u19Rsvd0 : 19;          /**< Bits 50:32  - Reserved. */
        uint32_t    u1Intr : 1;             /**< Bit  51     - I: Interrupt. */
        uint32_t    u1Rsvd0 : 1;            /**< Bit  52     - Reserved. */
        uint32_t    u1ReadWrite : 1;        /**< Bit  53     - RW: Read/Write. */
        uint32_t    u2Rsvd0 : 2;            /**< Bits 55:54  - Reserved. */
        uint32_t    u1Translation : 1;      /**< Bit  56     - TR: Translation. */
        uint32_t    u2Type : 2;             /**< Bits 58:57  - Type: The type of hardware error. */
        uint32_t    u1Rsvd1 : 1;            /**< Bit  59     - Reserved. */
        uint32_t    u4EventCode : 4;        /**< Bits 63:60  - Event code. */
        uint32_t    u4Rsvd0 : 4;            /**< Bits 67:64  - Reserved. */
        uint32_t    u28AddrLo : 28;         /**< Bits 95:68  - Address: System Physical Address (Lo). */
        uint32_t    u32AddrHi;              /**< Bits 127:96 - Address: System Physical Address (Hi). */
    } n;
    /** The 32-bit unsigned integer view.  */
    uint32_t    au32[4];
} EVT_DEV_TAB_HARDWARE_ERROR;
AssertCompileSize(EVT_DEV_TAB_HARDWARE_ERROR, 16);

/**
 * Event Log Entry: EVT_PAGE_TAB_HARDWARE_ERROR.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;                /**< Bits 15:0   - Device ID. */
        uint16_t    u16Rsvd0;                   /**< Bits 31:16  - Reserved. */
        uint32_t    u16DomainOrPasidLo : 16;    /**< Bits 47:32  - D/P: Domain ID or Process Address-Space ID (Lo). */
        uint32_t    u1GuestOrNested : 1;        /**< Bit  48     - GN: Guest (GPA) or Nested (GVA). */
        uint32_t    u2Rsvd0 : 2;                /**< Bits 50:49  - Reserved. */
        uint32_t    u1Interrupt : 1;            /**< Bit  51     - I: Interrupt. */
        uint32_t    u1Rsvd0 : 1;                /**< Bit  52     - Reserved. */
        uint32_t    u1ReadWrite : 1;            /**< Bit  53     - RW: Read/Write. */
        uint32_t    u2Rsvd1 : 2;                /**< Bit  55:54  - Reserved. */
        uint32_t    u1Translation : 1;          /**< Bit  56     - TR: Translation. */
        uint32_t    u2Type : 2;                 /**< Bits 58:57  - Type: The type of hardware error. */
        uint32_t    u1Rsvd1 : 1;                /**< Bit  59     - Reserved. */
        uint32_t    u4EventCode : 4;            /**< Bit  63:60  - Event code. */
        /** @todo r=ramshankar: Figure 55: PAGE_TAB_HARDWARE_ERROR says Addr[31:3] but
         *        table 58 mentions Addr[31:4]. Looks like a typo in the figure. Use
         *        table as it makes more sense and matches address size in
         *        EVT_DEV_TAB_HARDWARE_ERROR. See AMD AMD IOMMU spec (3.05-PUB, Jan
         *        2020). */
        uint32_t    u4Rsvd0 : 4;                /**< Bits 67:64  - Reserved. */
        uint32_t    u28AddrLo : 28;             /**< Bits 95:68  - Address: SPA of page table entry (Lo). */
        uint32_t    u32AddrHi;                  /**< Bits 127:96 - Address: SPA of page table entry (Hi). */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[4];
} EVT_PAGE_TAB_HARDWARE_ERROR;
AssertCompileSize(EVT_PAGE_TAB_HARDWARE_ERROR, 16);

/**
 * Event Log Entry: ILLEGAL_COMMAND_ERROR.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Rsvd0;           /**< Bits 31:0   - Reserved. */
        uint32_t    u28Rsvd0 : 28;      /**< Bits 47:32  - Reserved. */
        uint32_t    u4EventCode : 4;    /**< Bits 63:60  - Event code. */
        uint32_t    u4Rsvd0 : 4;        /**< Bits 67:64  - Reserved. */
        uint32_t    u28AddrLo : 28;     /**< Bits 95:68  - Address: SPA of the invalid command (Lo). */
        uint32_t    u32AddrHi;          /**< Bits 127:96 - Address: SPA of the invalid command (Hi). */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[4];
} EVT_ILLEGAL_COMMAND_ENTRY;
AssertCompileSize(EVT_ILLEGAL_COMMAND_ENTRY, 16);

/**
 * Event Log Entry: COMMAND_HARDWARE_ERROR.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Rsvd0;           /**< Bits 31:0  - Reserved. */
        uint32_t    u4Rsvd0 : 4;        /**< Bits 35:32 - Reserved. */
        uint32_t    u28AddrLo : 28;     /**< Bits 63:36 - Address: SPA of the attempted access (Lo). */
        uint32_t    u32AddrHi;          /**< Bits 95:64 - Address: SPA of the attempted access (Hi). */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[3];
} EVT_COMMAND_HARDWARE_ERROR;
AssertCompileSize(EVT_COMMAND_HARDWARE_ERROR, 12);

/**
 * Event Log Entry: IOTLB_INV_TIMEOUT.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16DeviceId;        /**< Bits 15:0   - Device ID. */
        uint16_t    u16Rsvd0;           /**< Bits 31:16  - Reserved.*/
        uint32_t    u28Rsvd0 : 28;      /**< Bits 59:32  - Reserved. */
        uint32_t    u4EventCode : 4;    /**< Bits 63:60  - Event code. */
        uint32_t    u4Rsvd0 : 4;        /**< Bits 67:64  - Reserved. */
        uint32_t    u28AddrLo : 28;     /**< Bits 95:68  - Address: SPA of the invalidation command that timedout (Lo). */
        uint32_t    u32AddrHi;          /**< Bits 127:96 - Address: SPA of the invalidation command that timedout (Hi). */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[4];
} EVT_IOTLB_INV_TIMEOUT;
AssertCompileSize(EVT_IOTLB_INV_TIMEOUT, 16);

/**
 * Event Log Entry: INVALID_DEVICE_REQUEST.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u16DeviceId : 16;       /***< Bits 15:0   - Device ID. */
        uint32_t    u4PasidHi : 4;          /***< Bits 19:16  - PASID: Process Address-Space ID (Hi). */
        uint32_t    u12Rsvd0 : 12;          /***< Bits 31:20  - Reserved. */
        uint32_t    u16PasidLo : 16;        /***< Bits 47:32  - PASID: Process Address-Space ID (Lo). */
        uint32_t    u1GuestOrNested : 1;    /***< Bit  48     - GN: Guest (GPA) or Nested (GVA). */
        uint32_t    u1User : 1;             /***< Bit  49     - US: User/Supervisor. */
        uint32_t    u6Rsvd0 : 6;            /***< Bits 55:50  - Reserved. */
        uint32_t    u1Translation: 1;       /***< Bit  56     - TR: Translation. */
        uint32_t    u3Type: 3;              /***< Bits 59:57  - Type: The type of hardware error. */
        uint32_t    u4EventCode : 4;        /***< Bits 63:60  - Event code. */
        uint64_t    u64Addr;                /***< Bits 127:64 - Address: Translation or access address. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[4];
} EVT_INVALID_DEVICE_REQUEST;
AssertCompileSize(EVT_INVALID_DEVICE_REQUEST, 16);

/**
 * Event Log Entry: EVENT_COUNTER_ZERO.
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u32Rsvd0;               /**< Bits 31:0   - Reserved. */
        uint32_t    u28Rsvd0 : 28;          /**< Bits 59:32  - Reserved. */
        uint32_t    u4EventCode : 4;        /**< Bits 63:60  - Event code. */
        uint32_t    u20CounterNoteHi : 20;  /**< Bits 83:64  - CounterNote: Counter value for the event counter register (Hi). */
        uint32_t    u12Rsvd0 : 12;          /**< Bits 95:84  - Reserved. */
        uint32_t    u32CounterNoteLo;       /**< Bits 127:96 - CounterNote: Counter value for the event cuonter register (Lo). */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[4];
} EVT_EVENT_COUNTER_ZERO;
AssertCompileSize(EVT_EVENT_COUNTER_ZERO, 16);

/**
 * IOMMU Capability Header (PCI).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u8CapId : 8;        /**< Bits 7:0   - CapId: Capability ID. */
        uint32_t    u8CapPtr : 8;       /**< Bits 15:8  - CapPtr: Pointer (PCI config offset) to the next capability. */
        uint32_t    u3CapType : 3;      /**< Bits 18:16 - CapType: Capability Type. */
        uint32_t    u5CapRev : 5;       /**< Bits 23:19 - CapRev: Capability revision. */
        uint32_t    u1IoTlbSup : 1;     /**< Bit  24    - IotlbSup: IOTLB Support. */
        uint32_t    u1HtTunnel : 1;     /**< Bit  25    - HtTunnel: HyperTransport Tunnel translation support. */
        uint32_t    u1NpCache : 1;      /**< Bit  26    - NpCache: Not Present table entries are cached. */
        uint32_t    u1EfrSup : 1;       /**< Bit  27    - EFRSup: Extended Feature Register Support. */
        uint32_t    u1CapExt : 1;       /**< Bit  28    - CapExt: Misc. Information Register 1 Support. */
        uint32_t    u3Rsvd0 : 3;        /**< Bits 31:29 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} IOMMU_CAP_HDR_T;
AssertCompileSize(IOMMU_CAP_HDR_T, 4);

/**
 * IOMMU Base Address (Lo and Hi) Register (PCI).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t   u1Enable : 1;       /**< Bit  1     - Enable: RW1S - Enable IOMMU MMIO region. */
        uint32_t   u12Rsvd0 : 12;      /**< Bits 13:1  - Reserved. */
        uint32_t   u18BaseAddrLo : 18; /**< Bits 31:14 - Base address (Lo) of the MMIO region. */
        uint32_t   u32BaseAddrHi;      /**< Bits 63:32 - Base address (Hi) of the MMIO region. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_BAR_T;
AssertCompileSize(IOMMU_BAR_T, 8);
#define IOMMU_BAR_VALID_MASK    UINT64_C(0xffffffffffffc001)

/**
 * IOMMU Range Register (PCI).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u5HtUnitId : 5;     /**< Bits 4:0   - UnitID: IOMMU HyperTransport Unit ID (not used). */
        uint32_t    u2Rsvd0 : 2;        /**< Bits 6:5   - Reserved. */
        uint32_t    u1RangeValid : 1;   /**< Bit  7     - RngValid: Range Valid. */
        uint32_t    u8Bus : 8;          /**< Bits 15:8  - BusNumber: Bus number of the first and last device. */
        uint32_t    u8FirstDevice : 8;  /**< Bits 23:16 - FirstDevice: Device and function number of the first device. */
        uint32_t    u8LastDevice: 8;    /**< Bits 31:24 - LastDevice: Device and function number of the last device. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} IOMMU_RANGE_T;
AssertCompileSize(IOMMU_RANGE_T, 4);

/**
 * Device Table Base Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u9Size : 9;     /**< Bits 8:0   - Size: Size of the device table. */
        RT_GCC_EXTENSION uint64_t   u3Rsvd0 : 3;    /**< Bits 11:9  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;   /**< Bits 51:12 - DevTabBase: Device table base address. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;  /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} DEV_TAB_BAR_T;
AssertCompileSize(DEV_TAB_BAR_T, 8);
#define IOMMU_DEV_TAB_BAR_VALID_MASK      UINT64_C(0x000ffffffffff1ff)

/**
 * Command Buffer Base Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;      /**< Bits 11:0  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;       /**< Bits 51:12 - ComBase: Command buffer base address. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd0 : 4;        /**< Bits 55:52 - Reserved. */
        RT_GCC_EXTENSION uint64_t   u4Len : 4;          /**< Bits 59:56 - ComLen: Command buffer length. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd1 : 4;        /**< Bits 63:60 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} CMD_BUF_BAR_T;
AssertCompileSize(CMD_BUF_BAR_T, 8);
#define IOMMU_CMD_BUF_BAR_VALID_MASK      UINT64_C(0x0f0ffffffffff000)

/**
 * Event Log Base Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;      /**< Bits 11:0  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;       /**< Bits 51:12 - EventBase: Event log base address. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd0 : 4;        /**< Bits 55:52 - Reserved. */
        RT_GCC_EXTENSION uint64_t   u4Len : 4;          /**< Bits 59:56 - EventLen: Event log length. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd1 : 4;        /**< Bits 63:60 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} EVT_LOG_BAR_T;
AssertCompileSize(EVT_LOG_BAR_T, 8);
#define IOMMU_EVT_LOG_BAR_VALID_MASK      UINT64_C(0x0f0ffffffffff000)

/**
 * IOMMU Control Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1IommuEn : 1;               /**< Bit  0     - IommuEn: IOMMU Enable. */
        uint32_t    u1HtTunEn : 1;               /**< Bit  1     - HtTunEn: HyperTransport Tunnel Enable. */
        uint32_t    u1EvtLogEn : 1;              /**< Bit  2     - EventLogEn: Event Log Enable. */
        uint32_t    u1EvtIntrEn : 1;             /**< Bit  3     - EventIntEn: Event Log Interrupt Enable. */
        uint32_t    u1CompWaitIntrEn : 1;        /**< Bit  4     - ComWaitIntEn: Completion Wait Interrupt Enable. */
        uint32_t    u3InvTimeOut : 3;            /**< Bits 7:5   - InvTimeOut: Invalidation Timeout. */
        uint32_t    u1PassPW : 1;                /**< Bit  8     - PassPW: Pass Posted Write. */
        uint32_t    u1ResPassPW : 1;             /**< Bit  9     - ResPassPW: Response Pass Posted Write. */
        uint32_t    u1Coherent : 1;              /**< Bit  10    - Coherent: HT read request packet Coherent bit. */
        uint32_t    u1Isoc : 1;                  /**< Bit  11    - Isoc: HT read request packet Isochronous bit. */
        uint32_t    u1CmdBufEn : 1;              /**< Bit  12    - CmdBufEn: Command Buffer Enable. */
        uint32_t    u1PprLogEn : 1;              /**< Bit  13    - PprLogEn: Peripheral Page Request (PPR) Log Enable. */
        uint32_t    u1PprIntrEn : 1;             /**< Bit  14    - PprIntrEn: Peripheral Page Request Interrupt Enable. */
        uint32_t    u1PprEn : 1;                 /**< Bit  15    - PprEn: Peripheral Page Request processing Enable. */
        uint32_t    u1GstTranslateEn : 1;        /**< Bit  16    - GTEn: Guest Translate Enable. */
        uint32_t    u1GstVirtApicEn : 1;         /**< Bit  17    - GAEn: Guest Virtual-APIC Enable. */
        uint32_t    u4Crw : 1;                   /**< Bits 21:18 - CRW: Intended for future use (not documented). */
        uint32_t    u1SmiFilterEn : 1;           /**< Bit  22    - SmiFEn: SMI Filter Enable. */
        uint32_t    u1SelfWriteBackDis : 1;      /**< Bit  23    - SlfWBDis: Self Write-Back Disable. */
        uint32_t    u1SmiFilterLogEn : 1;        /**< Bit  24    - SmiFLogEn: SMI Filter Log Enable. */
        uint32_t    u3GstVirtApicModeEn : 3;     /**< Bits 27:25 - GAMEn: Guest Virtual-APIC Mode Enable. */
        uint32_t    u1GstLogEn : 1;              /**< Bit  28    - GALogEn: Guest Virtual-APIC GA Log Enable. */
        uint32_t    u1GstIntrEn : 1;             /**< Bit  29    - GAIntEn: Guest Virtual-APIC Interrupt Enable. */
        uint32_t    u2DualPprLogEn : 2;          /**< Bits 31:30 - DualPprLogEn: Dual Peripheral Page Request Log Enable. */
        uint32_t    u2DualEvtLogEn : 2;          /**< Bits 33:32 - DualEventLogEn: Dual Event Log Enable. */
        uint32_t    u3DevTabSegEn : 3;           /**< Bits 36:34 - DevTblSegEn: Device Table Segment Enable. */
        uint32_t    u2PrivAbortEn : 2;           /**< Bits 38:37 - PrivAbrtEn: Privilege Abort Enable. */
        uint32_t    u1PprAutoRespEn : 1;         /**< Bit  39    - PprAutoRspEn: Peripheral Page Request Auto Response Enable. */
        uint32_t    u1MarcEn : 1;                /**< Bit  40    - MarcEn: Memory Address Routing and Control Enable. */
        uint32_t    u1BlockStopMarkEn : 1;       /**< Bit  41    - BlkStopMarkEn: Block StopMark messages Enable. */
        uint32_t    u1PprAutoRespAlwaysOnEn : 1; /**< Bit  42    - PprAutoRspAon:: PPR Auto Response - Always On Enable. */
        uint32_t    u1DomainIDPNE : 1;           /**< Bit  43    - DomainIDPE: Reserved (not documented). */
        uint32_t    u1Rsvd0 : 1;                 /**< Bit  44    - Reserved. */
        uint32_t    u1EnhancedPpr : 1;           /**< Bit  45    - EPHEn: Enhanced Peripheral Page Request Handling Enable. */
        uint32_t    u2HstAccDirtyBitUpdate : 2;  /**< Bits 47:46 - HADUpdate: Access and Dirty Bit updated in host page table. */
        uint32_t    u1GstDirtyUpdateDis : 1;     /**< Bit  48    - GDUpdateDis: Disable hardare update of Dirty bit in GPT. */
        uint32_t    u1Rsvd1 : 1;                 /**< Bit  49    - Reserved. */
        uint32_t    u1X2ApicEn : 1;              /**< Bit  50    - XTEn: Enable X2APIC. */
        uint32_t    u1X2ApicIntrGenEn : 1;       /**< Bit  51    - IntCapXTEn: Enable IOMMU X2APIC Interrupt generation. */
        uint32_t    u2Rsvd0 : 2;                 /**< Bits 53:52 - Reserved. */
        uint32_t    u1GstAccessUpdateDis : 1;    /**< Bit  54    - GAUpdateDis: Disable hardare update of Access bit in GPT. */
        uint32_t    u8Rsvd0 : 8;                 /**< Bits 63:55 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_CTRL_T;
AssertCompileSize(IOMMU_CTRL_T, 8);

/**
 * IOMMU Exclusion Base Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u1ExclEnable : 1;       /**< Bit 0      - ExEn: Exclusion Range Enable. */
        RT_GCC_EXTENSION uint64_t   u1AllowAll : 1;         /**< Bit 1      - Allow: Allow All Devices. */
        RT_GCC_EXTENSION uint64_t   u10Rsvd0 : 10;          /**< Bits 11:2  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40ExclRangeBase : 40;  /**< Bits 51:12 - Exclusion Range Base Address. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;          /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_EXCL_RANGE_BAR_T;
AssertCompileSize(IOMMU_EXCL_RANGE_BAR_T, 8);
#define IOMMU_EXCL_RANGE_BAR_VALID_MASK     UINT64_C(0x000ffffffffff003)

/**
 * IOMMU Exclusion Range Limit Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;      /**< Bits 11:0  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40ExclLimit : 40;  /**< Bits 51:12 - Exclusion Range Limit. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd1 : 12;      /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_EXCL_RANGE_LIMIT_T;
AssertCompileSize(IOMMU_EXCL_RANGE_LIMIT_T, 8);
#define IOMMU_EXCL_RANGE_LIMIT_VALID_MASK   UINT64_C(0x000ffffffffff000)

/**
 * IOMMU Extended Feature Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1PrefetchSup : 1;            /**< Bit  0     - PreFSup: Prefetch Support. */
        uint32_t    u1PprSup : 1;                 /**< Bit  1     - PPRSup: Peripheral Page Request Support. */
        uint32_t    u1X2ApicSup : 1;              /**< Bit  2     - XTSup: x2Apic Support. */
        uint32_t    u1NoExecuteSup : 1;           /**< Bit  3     - NXSup: No-Execute and Privilege Level Support. */
        uint32_t    u1GstTranslateSup : 1;        /**< Bit  4     - GTSup: Guest Translations Support. */
        uint32_t    u1Rsvd0 : 1;                  /**< Bit  5     - Reserved. */
        uint32_t    u1InvAllSup : 1;              /**< Bit  6     - IASup: Invalidate-All Support. */
        uint32_t    u1GstVirtApicSup : 1;         /**< Bit  7     - GASup: Guest Virtual-APIC Support. */
        uint32_t    u1HwErrorSup : 1;             /**< Bit  8     - HESup: Hardware Error registers Support. */
        uint32_t    u1PerfCounterSup : 1;         /**< Bit  8     - PCSup: Performance Counter Support. */
        uint32_t    u2HostAddrTranslateSize : 2;  /**< Bits 11:10 - HATS: Host Address Translation Size. */
        uint32_t    u2GstAddrTranslateSize : 2;   /**< Bits 13:12 - GATS: Guest Address Translation Size. */
        uint32_t    u2GstCr3RootTblLevel : 2;     /**< Bits 15:14 - GLXSup: Guest CR3 Root Table Level (Max) Size Support. */
        uint32_t    u2SmiFilterSup : 2;           /**< Bits 17:16 - SmiFSup: SMI Filter Register Support. */
        uint32_t    u3SmiFilterCount : 3;         /**< Bits 20:18 - SmiFRC: SMI Filter Register Count. */
        uint32_t    u3GstVirtApicModeSup : 3;     /**< Bits 23:21 - GAMSup: Guest Virtual-APIC Modes Supported. */
        uint32_t    u2DualPprLogSup : 2;          /**< Bits 25:24 - DualPprLogSup: Dual Peripheral Page Request Log Support. */
        uint32_t    u2Rsvd0 : 2;                  /**< Bits 27:26 - Reserved. */
        uint32_t    u2DualEvtLogSup : 2;          /**< Bits 29:28 - DualEventLogSup: Dual Event Log Support. */
        uint32_t    u2Rsvd1 : 2;                  /**< Bits 31:30 - Reserved. */
        uint32_t    u5MaxPasidSup : 5;            /**< Bits 36:32 - PASMax: Maximum PASID Supported. */
        uint32_t    u1UserSupervisorSup : 1;      /**< Bit  37    - USSup: User/Supervisor Page Protection Support. */
        uint32_t    u2DevTabSegSup : 2;           /**< Bits 39:38 - DevTlbSegSup: Segmented Device Table Support. */
        uint32_t    u1PprLogOverflowWarn : 1;     /**< Bit  40    - PprOvrflwEarlySup: PPR Log Overflow Early Warning Support. */
        uint32_t    u1PprAutoRespSup : 1;         /**< Bit  41    - PprAutoRspSup: PPR Automatic Response Support. */
        uint32_t    u2MarcSup : 2;                /**< Bit  43:42 - MarcSup: Memory Access Routing and Control Support. */
        uint32_t    u1BlockStopMarkSup : 1;       /**< Bit  44    - BlkStopMarkSup: Block StopMark messages Support. */
        uint32_t    u1PerfOptSup : 1;             /**< Bit  45    - PerfOptSup: IOMMU Performance Optimization Support. */
        uint32_t    u1MsiCapMmioSup : 1;          /**< Bit  46    - MsiCapMmioSup: MSI Capability Register MMIO Access Support. */
        uint32_t    u1Rsvd1 : 1;                  /**< Bit  47    - Reserved. */
        uint32_t    u1GstIoSup : 1;               /**< Bit  48    - GIoSup: Guest I/O Protection Support. */
        uint32_t    u1HostAccessSup : 1;          /**< Bit  49    - HASup: Host Access Support. */
        uint32_t    u1EnhancedPprSup : 1;         /**< Bit  50    - EPHSup: Enhanced Peripheral Page Request Handling Support. */
        uint32_t    u1AttrForwardSup : 1;         /**< Bit  51    - AttrFWSup: Attribute Forward Support. */
        uint32_t    u1HostDirtySup : 1;           /**< Bit  52    - HDSup: Host Dirty Support. */
        uint32_t    u1Rsvd2 : 1;                  /**< Bit  53    - Reserved. */
        uint32_t    u1InvIoTlbTypeSup : 1;        /**< Bit  54    - InvIotlbTypeSup: Invalidate IOTLB Type Support. */
        uint32_t    u6Rsvd0 : 6;                  /**< Bit  60:55 - Reserved. */
        uint32_t    u1GstUpdateDisSup : 1;        /**< Bit  61    - GAUpdateDisSup: Disable hardware update on GPT Support. */
        uint32_t    u1ForcePhysDstSup : 1;        /**< Bit  62    - ForcePhyDestSup: Force Phys. Dst. Mode for Remapped Intr. */
        uint32_t    u1Rsvd3 : 1;                  /**< Bit  63    - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_EXT_FEAT_T;
AssertCompileSize(IOMMU_EXT_FEAT_T, 8);

/**
 * Peripheral Page Request Log Base Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;      /**< Bit 11:0   - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;       /**< Bits 51:12 - PPRLogBase: Peripheral Page Request Log Base Address. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd0 : 4;        /**< Bits 55:52 - Reserved. */
        RT_GCC_EXTENSION uint64_t   u4Len : 4;          /**< Bits 59:56 - PPRLogLen: Peripheral Page Request Log Length. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd1 : 4;        /**< Bits 63:60 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} PPR_LOG_BAR_T;
AssertCompileSize(PPR_LOG_BAR_T, 8);
#define IOMMU_PPR_LOG_BAR_VALID_MASK    UINT64_C(0x0f0ffffffffff000)

/**
 * IOMMU Hardware Event Upper Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u60FirstOperand : 60;   /**< Bits 59:0  - First event code dependent operand. */
        RT_GCC_EXTENSION uint64_t   u4EvtCode : 4;          /**< Bits 63:60 - Event Code. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_HW_EVT_HI_T;
AssertCompileSize(IOMMU_HW_EVT_HI_T, 8);

/**
 * IOMMU Hardware Event Lower Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef uint64_t IOMMU_HW_EVT_LO_T;

/**
 * IOMMU Hardware Event Status (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t   u1Valid : 1;     /**< Bit 0      - HEV: Hardware Event Valid. */
        uint32_t   u1Overflow : 1;  /**< Bit 1      - HEO: Hardware Event Overflow. */
        uint32_t   u30Rsvd0 : 30;   /**< Bits 31:2  - Reserved. */
        uint32_t   u32Rsvd0;        /**< Bits 63:32 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_HW_EVT_STATUS_T;
AssertCompileSize(IOMMU_HW_EVT_STATUS_T, 8);
#define IOMMU_HW_EVT_STATUS_VALID_MASK      UINT64_C(0x0000000000000003)

/**
 * Guest Virtual-APIC Log Base Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;  /**< Bit 11:0   - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;   /**< Bits 51:12 - GALogBase: Guest Virtual-APIC Log Base Address. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd0 : 4;    /**< Bits 55:52 - Reserved. */
        RT_GCC_EXTENSION uint64_t   u4Len : 4;      /**< Bits 59:56 - GALogLen: Guest Virtual-APIC Log Length. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd1 : 4;    /**< Bits 63:60 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} GALOG_BAR_T;
AssertCompileSize(GALOG_BAR_T, 8);

/**
 * Guest Virtual-APIC Log Tail Address Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u3Rsvd0 : 3;            /**< Bits 2:0   - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40GALogTailAddr : 48;  /**< Bits 51:3  - GATAddr: Guest Virtual-APIC Tail Log Address. */
        RT_GCC_EXTENSION uint64_t   u11Rsvd1 : 11;          /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} GALOG_TAIL_ADDR_T;
AssertCompileSize(GALOG_TAIL_ADDR_T, 8);

/**
 * PPR Log B Base Address Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to PPR_LOG_BAR_T.
 */
typedef PPR_LOG_BAR_T       PPR_LOG_B_BAR_T;

/**
 * Event Log B Base Address Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to EVT_LOG_BAR_T.
 */
typedef EVT_LOG_BAR_T       EVT_LOG_B_BAR_T;

/**
 * Device Table Segment Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u8Size : 8;     /**< Bits 7:0   - Size: Size of the Device Table segment. */
        RT_GCC_EXTENSION uint64_t   u4Rsvd0 : 4;    /**< Bits 11:8  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40Base : 40;   /**< Bits 51:12 - DevTabBase: Device Table Segment Base Address. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;  /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} DEV_TAB_SEG_BAR_T;
AssertCompileSize(DEV_TAB_SEG_BAR_T, 8);
#define IOMMU_DEV_TAB_SEG_BAR_VALID_MASK      UINT64_C(0x000ffffffffff0ff)

/**
 * Device-specific Feature Extension (DSFX) Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u24DevSpecFeat : 24;     /**< Bits 23:0  - DevSpecificFeatSupp: Implementation specific features. */
        uint32_t    u4RevMinor : 4;          /**< Bits 27:24 - RevMinor: Minor revision identifier. */
        uint32_t    u4RevMajor : 4;          /**< Bits 31:28 - RevMajor: Major revision identifier. */
        uint32_t    u32Rsvd0;                /**< Bits 63:32 - Reserved.*/
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} DEV_SPECIFIC_FEAT_T;
AssertCompileSize(DEV_SPECIFIC_FEAT_T, 8);

/**
 * Device-specific Control Extension (DSCX) Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u24DevSpecCtrl : 24;     /**< Bits 23:0  - DevSpecificFeatCntrl: Implementation specific control. */
        uint32_t    u4RevMinor : 4;          /**< Bits 27:24 - RevMinor: Minor revision identifier. */
        uint32_t    u4RevMajor : 4;          /**< Bits 31:28 - RevMajor: Major revision identifier. */
        uint32_t    u32Rsvd0;                /**< Bits 63:32 - Reserved.*/
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} DEV_SPECIFIC_CTRL_T;
AssertCompileSize(DEV_SPECIFIC_CTRL_T, 8);

/**
 * Device-specific Status Extension (DSSX) Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u24DevSpecStatus : 24;      /**< Bits 23:0  - DevSpecificFeatStatus: Implementation specific status. */
        uint32_t    u4RevMinor : 4;             /**< Bits 27:24 - RevMinor: Minor revision identifier. */
        uint32_t    u4RevMajor : 4;             /**< Bits 31:28 - RevMajor: Major revision identifier. */
        uint32_t    u32Rsvd0;                   /**< Bits 63:32 - Reserved.*/
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} DEV_SPECIFIC_STATUS_T;
AssertCompileSize(DEV_SPECIFIC_STATUS_T, 8);

/**
 * MSI Information Register 0 and 1 (PCI) / MSI Vector Register 0 and 1 (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u5MsiNumEvtLog : 5;     /**< Bits 4:0   - MsiNum: Event Log MSI message number. */
        uint32_t    u3GstVirtAddrSize: 3;   /**< Bits 7:5   - GVAsize: Guest Virtual Address Size. */
        uint32_t    u7PhysAddrSize : 7;     /**< Bits 14:8  - PAsize: Physical Address Size. */
        uint32_t    u7VirtAddrSize : 7;     /**< Bits 21:15 - VAsize: Virtual Address Size. */
        uint32_t    u1HtAtsResv: 1;         /**< Bit  22    - HtAtsResv: HyperTransport ATS Response Address range Reserved. */
        uint32_t    u4Rsvd0 : 4;            /**< Bits 26:23 - Reserved. */
        uint32_t    u5MsiNumPpr : 5;        /**< Bits 31:27 - MsiNumPPR: Peripheral Page Request MSI message number. */
        uint32_t    u5MsiNumGa : 5;         /**< Bits 36:32 - MsiNumGa: MSI message number for guest virtual-APIC log. */
        uint32_t    u27Rsvd0: 27;           /**< Bits 63:37 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} MSI_MISC_INFO_T;
AssertCompileSize(MSI_MISC_INFO_T, 8);
/** MSI Vector Register 0 and 1 (MMIO). */
typedef MSI_MISC_INFO_T       MSI_VECTOR_T;

/**
 * MSI Capability Header Register (PCI + MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u8MsiCapId : 8;         /**< Bits 7:0   - MsiCapId: Capability ID. */
        uint32_t    u8MsiCapPtr : 8;        /**< Bits 15:8  - MsiCapPtr: Pointer (PCI config offset) to the next capability. */
        uint32_t    u1MsiEnable : 1;        /**< Bit  16    - MsiEn: Message Signal Interrupt Enable. */
        uint32_t    u3MsiMultiMessCap : 3;  /**< Bits 19:17 - MsiMultMessCap: MSI Multi-Message Capability. */
        uint32_t    u3MsiMultiMessEn : 3;   /**< Bits 22:20 - MsiMultMessEn: MSI Multi-Message Enable. */
        uint32_t    u1Msi64BitEn : 1;       /**< Bit  23    - Msi64BitEn: MSI 64-bit Enable. */
        uint32_t    u8Rsvd0 : 8;            /**< Bits 31:24 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} MSI_CAP_HDR_T;
AssertCompileSize(MSI_CAP_HDR_T, 4);

/**
 * MSI Address Register (PCI + MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u2Rsvd : 2;       /**< Bits 1:0   - Reserved. */
        RT_GCC_EXTENSION uint64_t   u62MsiAddr : 62;  /**< Bits 31:2  - MsiAddr: MSI Address. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} MSI_ADDR_T;
AssertCompileSize(MSI_ADDR_T, 8);
#define IOMMU_MSI_ADDR_VALID_MASK           UINT64_C(0xfffffffffffffffc)

/**
 * MSI Data Register (PCI + MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint16_t    u16MsiData;     /**< Bits 15:0  - MsiData: MSI Data. */
        uint16_t    u16Rsvd0;       /**< Bits 31:16 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} MSI_DATA_T;
AssertCompileSize(MSI_DATA_T, 4);
#define IOMMU_MSI_DATA_VALID_MASK       UINT64_C(0x000000000000ffff)

/**
 * MSI Mapping Capability Header Register (PCI + MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u8MsiMapCapId : 8;  /**< Bits 7:0   - MsiMapCapId: MSI Map capability ID. */
        uint32_t    u8Rsvd0 : 8;        /**< Bits 15:8  - Reserved. */
        uint32_t    u1MsiMapEn : 1;     /**< Bit  16    - MsiMapEn: MSI Map enable. */
        uint32_t    u1MsiMapFixed : 1;  /**< Bit  17    - MsiMapFixd: MSI Map fixed. */
        uint32_t    u9Rsvd0 : 9;        /**< Bits 26:18 - Reserved. */
        uint32_t    u5MapCapType : 5;   /**< Bits 31:27 - MsiMapCapType: MSI Mapping capability type. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} MSI_MAP_CAP_HDR_T;
AssertCompileSize(MSI_MAP_CAP_HDR_T, 4);

/**
 * Performance Optimization Control Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u13Rsvd0 : 13;      /**< Bits 12:0  - Reserved. */
        uint32_t    u1PerfOptEn : 1;    /**< Bit  13    - PerfOptEn: Performance Optimization Enable. */
        uint32_t    u17Rsvd0 : 18;      /**< Bits 31:14 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    u32;
} IOMMU_PERF_OPT_CTRL_T;
AssertCompileSize(IOMMU_PERF_OPT_CTRL_T, 4);

/**
 * XT (x2APIC) IOMMU General Interrupt Control Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u2Rsvd0 : 2;                    /**< Bits 1:0   - Reserved.*/
        uint32_t    u1X2ApicIntrDstMode : 1;        /**< Bit  2     - Destination Mode for general interrupt.*/
        uint32_t    u4Rsvd0 : 4;                    /**< Bits 7:3   - Reserved.*/
        uint32_t    u24X2ApicIntrDstLo : 24;        /**< Bits 31:8  - Destination for general interrupt (Lo).*/
        uint32_t    u8X2ApicIntrVector : 8;         /**< Bits 39:32 - Vector for general interrupt.*/
        uint32_t    u1X2ApicIntrDeliveryMode : 1;   /**< Bit  40    - Delivery Mode for general interrupt.*/
        uint32_t    u15Rsvd0 : 15;                  /**< Bits 55:41 - Reserved.*/
        uint32_t    u7X2ApicIntrDstHi : 7;          /**< Bits 63:56 - Destination for general interrupt (Hi) .*/
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_XT_GEN_INTR_CTRL_T;
AssertCompileSize(IOMMU_XT_GEN_INTR_CTRL_T, 8);

/**
 * XT (x2APIC) IOMMU General Interrupt Control Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u2Rsvd0 : 2;                    /**< Bits 1:0   - Reserved.*/
        uint32_t    u1X2ApicIntrDstMode : 1;        /**< Bit  2     - Destination Mode for the interrupt.*/
        uint32_t    u4Rsvd0 : 4;                    /**< Bits 7:3   - Reserved.*/
        uint32_t    u24X2ApicIntrDstLo : 24;        /**< Bits 31:8  - Destination for the interrupt (Lo).*/
        uint32_t    u8X2ApicIntrVector : 8;         /**< Bits 39:32 - Vector for the interrupt.*/
        uint32_t    u1X2ApicIntrDeliveryMode : 1;   /**< Bit  40    - Delivery Mode for the interrupt.*/
        uint32_t    u15Rsvd0 : 15;                  /**< Bits 55:41 - Reserved.*/
        uint32_t    u7X2ApicIntrDstHi : 7;          /**< Bits 63:56 - Destination for the interrupt (Hi) .*/
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_XT_INTR_CTRL_T;
AssertCompileSize(IOMMU_XT_INTR_CTRL_T, 8);

/**
 * XT (x2APIC) IOMMU PPR Interrupt Control Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to IOMMU_XT_INTR_CTRL_T.
 */
typedef IOMMU_XT_INTR_CTRL_T    IOMMU_XT_PPR_INTR_CTRL_T;

/**
 * XT (x2APIC) IOMMU GA (Guest Address) Log Control Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to IOMMU_XT_INTR_CTRL_T.
 */
typedef IOMMU_XT_INTR_CTRL_T    IOMMU_XT_GALOG_INTR_CTRL_T;

/**
 * Memory Access and Routing Control (MARC) Aperture Base Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;          /**< Bits 11:0  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40MarcBaseAddr : 40;   /**< Bits 51:12 - MarcBaseAddr: MARC Aperture Base Address. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd1 : 12;          /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} MARC_APER_BAR_T;
AssertCompileSize(MARC_APER_BAR_T, 8);

/**
 * Memory Access and Routing Control (MARC) Relocation Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u1RelocEn : 1;          /**< Bit  0     - RelocEn: Relocation Enabled. */
        RT_GCC_EXTENSION uint64_t   u1ReadOnly : 1;         /**< Bit  1     - ReadOnly: Whether only read-only acceses allowed. */
        RT_GCC_EXTENSION uint64_t   u10Rsvd0 : 10;          /**< Bits 11:2  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40MarcRelocAddr : 40;  /**< Bits 51:12 - MarcRelocAddr: MARC Aperture Relocation Address. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd1 : 12;          /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} MARC_APER_RELOC_T;
AssertCompileSize(MARC_APER_RELOC_T, 8);

/**
 * Memory Access and Routing Control (MARC) Length Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        RT_GCC_EXTENSION uint64_t   u12Rsvd0 : 12;          /**< Bits 11:0  - Reserved. */
        RT_GCC_EXTENSION uint64_t   u40MarcLength : 40;     /**< Bits 51:12 - MarcLength: MARC Aperture Length. */
        RT_GCC_EXTENSION uint64_t   u12Rsvd1 : 12;          /**< Bits 63:52 - Reserved. */
    } n;
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} MARC_APER_LEN_T;

/**
 * Memory Access and Routing Control (MARC) Aperture Register.
 * This combines other registers to match the MMIO layout for convenient access.
 */
typedef struct
{
    MARC_APER_BAR_T     Base;
    MARC_APER_RELOC_T   Reloc;
    MARC_APER_LEN_T     Length;
} MARC_APER_T;
AssertCompileSize(MARC_APER_T, 24);

/**
 * IOMMU Reserved Register (MMIO).
 * In accordance with the AMD spec.
 * This register is reserved for hardware use (although RW?).
 */
typedef uint64_t    IOMMU_RSVD_REG_T;

/**
 * Command Buffer Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u4Rsvd0 : 4;    /**< Bits 3:0   - Reserved. */
        uint32_t    u15Ptr : 15;    /**< Bits 18:4  - Buffer pointer. */
        uint32_t    u13Rsvd0 : 13;  /**< Bits 31:19 - Reserved. */
        uint32_t    u32Rsvd0;       /**< Bits 63:32 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} CMD_BUF_HEAD_PTR_T;
AssertCompileSize(CMD_BUF_HEAD_PTR_T, 8);
#define IOMMU_CMD_BUF_HEAD_PTR_VALID_MASK       UINT64_C(0x000000000007fff0)

/**
 * Command Buffer Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T    CMD_BUF_TAIL_PTR_T;
#define IOMMU_CMD_BUF_TAIL_PTR_VALID_MASK       UINT64_C(0x000000000007fff0)


/**
 * Event Log Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T    EVT_LOG_HEAD_PTR_T;

/**
 * Event Log Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T    EVT_LOG_TAIL_PTR_T;

/**
 * IOMMU Status Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u1EvtOverflow : 1;          /**< Bit  0     - EventOverflow: Event log overflow. */
        uint32_t    u1EvtLogIntr : 1;           /**< Bit  1     - EventLogInt: Event log interrupt. */
        uint32_t    u1CompWaitIntr : 1;         /**< Bit  2     - ComWaitInt: Completion wait interrupt . */
        uint32_t    u1EvtLogRunning : 1;        /**< Bit  3     - EventLogRun: Event logging is running. */
        uint32_t    u1CmdBufRunning : 1;        /**< Bit  4     - CmdBufRun: Command buffer is running. */
        uint32_t    u1PprOverflow : 1;          /**< Bit  5     - PprOverflow: Peripheral Page Request Log (PPR) overflow. */
        uint32_t    u1PprIntr : 1;              /**< Bit  6     - PprInt: PPR interrupt. */
        uint32_t    u1PprLogRunning : 1;        /**< Bit  7     - PprLogRun: PPR logging is running. */
        uint32_t    u1GstLogRunning : 1;        /**< Bit  8     - GALogRun: Guest virtual-APIC logging is running. */
        uint32_t    u1GstLogOverflow : 1;       /**< Bit  9     - GALOverflow: Guest virtual-APIC log overflow. */
        uint32_t    u1GstLogIntr : 1;           /**< Bit  10    - GAInt: Guest virtual-APIC log interrupt. */
        uint32_t    u1PprOverflowB : 1;         /**< Bit  11    - PprOverflowB: PPR log B overflow. */
        uint32_t    u1PprLogActive : 1;         /**< Bit  12    - PprLogActive: PPR log A is active. */
        uint32_t    u2Rsvd0 : 2;                /**< Bits 14:13 - Reserved. */
        uint32_t    u1EvtOverflowB : 1;         /**< Bit  15    - EvtOverflowB: Event log B overflow. */
        uint32_t    u1EvtLogActive : 1;         /**< Bit  16    - EvtLogActive: Event log A active. */
        uint32_t    u1PprOverflowEarlyB : 1;    /**< Bit  17    - PprOverflowEarlyB: PPR log B overflow early warning. */
        uint32_t    u1PprOverflowEarly : 1;     /**< Bit  18    - PprOverflowEarly: PPR log overflow early warning. */
        uint32_t    u13Rsvd0 : 13;              /**< Bits 31:19 - Reserved. */
        uint32_t    u32Rsvd0;                   /**< Bits 63:32 - Reserved . */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} IOMMU_STATUS_T;
AssertCompileSize(IOMMU_STATUS_T, 8);

/**
 * PPR Log Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      PPR_LOG_HEAD_PTR_T;

/**
 * PPR Log Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      PPR_LOG_TAIL_PTR_T;

/**
 * Guest Virtual-APIC Log Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u2Rsvd0 : 2;            /**< Bits  2:0  - Reserved. */
        uint32_t    u12GALogPtr : 12;       /**< Bits 15:3  - Guest Virtual-APIC Log Head or Tail Pointer. */
        uint32_t    u16Rsvd0 : 16;          /**< Bits 31:16 - Reserved. */
        uint32_t    u32Rsvd0;               /**< Bits 63:32 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} GALOG_HEAD_PTR_T;
AssertCompileSize(GALOG_HEAD_PTR_T, 8);

/**
 * Guest Virtual-APIC Log Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to GALOG_HEAD_PTR_T.
 */
typedef GALOG_HEAD_PTR_T        GALOG_TAIL_PTR_T;

/**
 * PPR Log B Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      PPR_LOG_B_HEAD_PTR_T;

/**
 * PPR Log B Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      PPR_LOG_B_TAIL_PTR_T;

/**
 * Event Log B Head Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      EVT_LOG_B_HEAD_PTR_T;

/**
 * Event Log B Tail Pointer Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to CMD_BUF_HEAD_PTR_T.
 */
typedef CMD_BUF_HEAD_PTR_T      EVT_LOG_B_TAIL_PTR_T;

/**
 * PPR Log Auto Response Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u4AutoRespCode : 4;     /**< Bits 3:0   - PprAutoRespCode: PPR log Auto Response Code. */
        uint32_t    u1AutoRespMaskGen : 1;  /**< Bit  4     - PprAutoRespMaskGn: PPR log Auto Response Mask Gen. */
        uint32_t    u27Rsvd0 : 27;          /**< Bits 31:5  - Reserved. */
        uint32_t    u32Rsvd0;               /**< Bits 63:32 - Reserved.*/
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} PPR_LOG_AUTO_RESP_T;
AssertCompileSize(PPR_LOG_AUTO_RESP_T, 8);

/**
 * PPR Log Overflow Early Indicator Register (MMIO).
 * In accordance with the AMD spec.
 */
typedef union
{
    struct
    {
        uint32_t    u15Threshold : 15;  /**< Bits 14:0  - PprOvrflwEarlyThreshold: Overflow early indicator threshold. */
        uint32_t    u15Rsvd0 : 15;      /**< Bits 29:15 - Reserved. */
        uint32_t    u1IntrEn : 1;       /**< Bit  30    - PprOvrflwEarlyIntEn: Overflow early indicator interrupt enable. */
        uint32_t    u1Enable : 1;       /**< Bit  31    - PprOvrflwEarlyEn: Overflow early indicator enable. */
        uint32_t    u32Rsvd0;           /**< Bits 63:32 - Reserved. */
    } n;
    /** The 32-bit unsigned integer view. */
    uint32_t    au32[2];
    /** The 64-bit unsigned integer view. */
    uint64_t    u64;
} PPR_LOG_OVERFLOW_EARLY_T;
AssertCompileSize(PPR_LOG_OVERFLOW_EARLY_T, 8);

/**
 * PPR Log B Overflow Early Indicator Register (MMIO).
 * In accordance with the AMD spec.
 * Currently identical to PPR_LOG_OVERFLOW_EARLY_T.
 */
typedef PPR_LOG_OVERFLOW_EARLY_T        PPR_LOG_B_OVERFLOW_EARLY_T;


/**
 * The shared IOMMU device state.
 */
typedef struct IOMMU
{
    /** IOMMU device index (0 is at the top of the PCI tree hierarchy). */
    uint32_t                    idxIommu;
    /** Alignment padding. */
    uint32_t                    uPadding0;
    /** The event semaphore the command thread waits on. */
    SUPSEMEVENT                 hEvtCmdThread;
    /** The MMIO handle. */
    IOMMMIOHANDLE               hMmio;

    /** @name PCI: Base capability block registers.
     * @{ */
    IOMMU_BAR_T                 IommuBar;           /**< IOMMU base address register. */
    /** @} */

    /** @name MMIO: Control and status registers.
     * @{ */
    DEV_TAB_BAR_T               DevTabBaseAddr;     /**< Device table base address register. */
    CMD_BUF_BAR_T               CmdBufBaseAddr;     /**< Command buffer base address register. */
    EVT_LOG_BAR_T               EvtLogBaseAddr;     /**< Event log base address register. */
    IOMMU_CTRL_T                Ctrl;               /**< IOMMU control register. */
    IOMMU_EXCL_RANGE_BAR_T      ExclRangeBaseAddr;  /**< IOMMU exclusion range base register. */
    IOMMU_EXCL_RANGE_LIMIT_T    ExclRangeLimit;     /**< IOMMU exclusion range limit. */
    IOMMU_EXT_FEAT_T            ExtFeat;            /**< IOMMU extended feature register. */
    /** @} */

    /** @name MMIO: PPR Log registers.
     * @{ */
    PPR_LOG_BAR_T               PprLogBaseAddr;     /**< PPR Log base address register. */
    IOMMU_HW_EVT_HI_T           HwEvtHi;            /**< IOMMU hardware event register (Hi). */
    IOMMU_HW_EVT_LO_T           HwEvtLo;            /**< IOMMU hardware event register (Lo). */
    IOMMU_HW_EVT_STATUS_T       HwEvtStatus;        /**< IOMMU hardware event status. */
    /** @} */

    /** @todo IOMMU: SMI filter. */

    /** @name MMIO: Guest Virtual-APIC Log registers.
     * @{ */
    GALOG_BAR_T                 GALogBaseAddr;      /**< Guest Virtual-APIC Log base address register. */
    GALOG_TAIL_ADDR_T           GALogTailAddr;      /**< Guest Virtual-APIC Log Tail address register. */
    /** @} */

    /** @name MMIO: Alternate PPR and Event Log registers.
     *  @{ */
    PPR_LOG_B_BAR_T             PprLogBBaseAddr;    /**< PPR Log B base address register. */
    EVT_LOG_B_BAR_T             EvtLogBBaseAddr;    /**< Event Log B base address register. */
    /** @} */

    /** @name MMIO: Device table segment registers.
     * @{ */
    DEV_TAB_SEG_BAR_T           DevTabSeg[7];       /**< Device Table Segment base address register. */
    /** @} */

    /** @name MMIO: Device-specific feature registers.
     * @{ */
    DEV_SPECIFIC_FEAT_T         DevSpecificFeat;    /**< Device-specific feature extension register (DSFX). */
    DEV_SPECIFIC_CTRL_T         DevSpecificCtrl;    /**< Device-specific control extension register (DSCX). */
    DEV_SPECIFIC_STATUS_T       DevSpecificStatus;  /**< Device-specific status extension register (DSSX). */
    /** @} */

    /** @name MMIO: MSI Capability Block registers.
     * @{ */
    MSI_MISC_INFO_T             MsiMiscInfo;        /**< MSI Misc. info registers / MSI Vector registers. */
    /** @} */

    /** @name MMIO: Performance Optimization Control registers.
     *  @{ */
    IOMMU_PERF_OPT_CTRL_T       PerfOptCtrl;       /**< IOMMU Performance optimization control register. */
    /** @} */

    /** @name MMIO: x2APIC Control registers.
     * @{ */
    IOMMU_XT_GEN_INTR_CTRL_T    XtGenIntrCtrl;      /**< IOMMU X2APIC General interrupt control register. */
    IOMMU_XT_PPR_INTR_CTRL_T    XtPprIntrCtrl;      /**< IOMMU X2APIC PPR interrupt control register. */
    IOMMU_XT_GALOG_INTR_CTRL_T  XtGALogIntrCtrl;    /**< IOMMU X2APIC Guest Log interrupt control register. */
    /** @} */

    /** @name MMIO: MARC registers.
     * @{ */
    MARC_APER_T                 aMarcApers[4];      /**< MARC Aperture Registers. */
    /** @} */

    /** @name MMIO: Reserved register.
     *  @{ */
    IOMMU_RSVD_REG_T            RsvdReg;            /**< IOMMU Reserved Register. */
    /** @} */

    /** @name MMIO: Command and Event Log pointer registers.
     * @{ */
    CMD_BUF_HEAD_PTR_T          CmdBufHeadPtr;      /**< Command buffer head pointer register. */
    CMD_BUF_TAIL_PTR_T          CmdBufTailPtr;      /**< Command buffer tail pointer register. */
    EVT_LOG_HEAD_PTR_T          EvtLogHeadPtr;      /**< Event log head pointer register. */
    EVT_LOG_TAIL_PTR_T          EvtLogTailPtr;      /**< Event log tail pointer register. */
    /** @} */

    /** @name MMIO: Command and Event Status register.
     * @{ */
    IOMMU_STATUS_T              Status;             /**< IOMMU status register. */
    /** @} */

    /** @name MMIO: PPR Log Head and Tail pointer registers.
     * @{ */
    PPR_LOG_HEAD_PTR_T          PprLogHeadPtr;      /**< IOMMU PPR log head pointer register. */
    PPR_LOG_TAIL_PTR_T          PprLogTailPtr;      /**< IOMMU PPR log tail pointer register. */
    /** @} */

    /** @name MMIO: Guest Virtual-APIC Log Head and Tail pointer registers.
     * @{ */
    GALOG_HEAD_PTR_T            GALogHeadPtr;       /**< Guest Virtual-APIC log head pointer register. */
    GALOG_TAIL_PTR_T            GALogTailPtr;       /**< Guest Virtual-APIC log tail pointer register. */
    /** @} */

    /** @name MMIO: PPR Log B Head and Tail pointer registers.
     *  @{ */
    PPR_LOG_B_HEAD_PTR_T        PprLogBHeadPtr;     /**< PPR log B head pointer register. */
    PPR_LOG_B_TAIL_PTR_T        PprLogBTailPtr;     /**< PPR log B tail pointer register. */
    /** @} */

    /** @name MMIO: Event Log B Head and Tail pointer registers.
     * @{ */
    EVT_LOG_B_HEAD_PTR_T        EvtLogBHeadPtr;     /**< Event log B head pointer register. */
    EVT_LOG_B_TAIL_PTR_T        EvtLogBTailPtr;     /**< Event log B tail pointer register. */
    /** @} */

    /** @name MMIO: PPR Log Overflow protection registers.
     * @{ */
    PPR_LOG_AUTO_RESP_T         PprLogAutoResp;         /**< PPR Log Auto Response register. */
    PPR_LOG_OVERFLOW_EARLY_T    PprLogOverflowEarly;    /**< PPR Log Overflow Early Indicator register. */
    PPR_LOG_B_OVERFLOW_EARLY_T  PprLogBOverflowEarly;   /**< PPR Log B Overflow Early Indicator register. */
    /** @} */

    /** @todo IOMMU: IOMMU Event counter registers. */

    /** @todo IOMMU: Stat counters. */
} IOMMU;
/** Pointer to the IOMMU device state. */
typedef struct IOMMU *PIOMMU;
/** Pointer to the const IOMMU device state. */
typedef const struct IOMMU *PCIOMMU;
AssertCompileMemberAlignment(IOMMU, hEvtCmdThread, 8);
AssertCompileMemberAlignment(IOMMU, hMmio, 8);
AssertCompileMemberAlignment(IOMMU, IommuBar, 8);


/**
 * The ring-3 IOMMU device state.
 */
typedef struct IOMMUR3
{
    /** Device instance. */
    PPDMDEVINSR3            pDevInsR3;
    /** The IOMMU helpers. */
    PCPDMIOMMUHLPR3         pIommuHlpR3;
    /** The command thread handle. */
    R3PTRTYPE(PPDMTHREAD)   pCmdThread;
} IOMMUR3;
/** Pointer to the ring-3 IOMMU device state. */
typedef IOMMUR3 *PIOMMUR3;

/**
 * The ring-0 IOMMU device state.
 */
typedef struct IOMMUR0
{
    /** Device instance. */
    PPDMDEVINSR0            pDevInsR0;
    /** The IOMMU helpers. */
    PCPDMIOMMUHLPR0         pIommuHlpR0;
} IOMMUR0;
/** Pointer to the ring-0 IOMMU device state. */
typedef IOMMUR0 *PIOMMUR0;

/**
 * The raw-mode IOMMU device state.
 */
typedef struct IOMMURC
{
    /** Device instance. */
    PPDMDEVINSR0            pDevInsRC;
    /** The IOMMU helpers. */
    PCPDMIOMMUHLPRC         pIommuHlpRC;
} IOMMURC;
/** Pointer to the raw-mode IOMMU device state. */
typedef IOMMURC *PIOMMURC;

/** The IOMMU device state for the current context. */
typedef CTX_SUFF(IOMMU)  IOMMUCC;
/** Pointer to the IOMMU device state for the current context. */
typedef CTX_SUFF(PIOMMU) PIOMMUCC;

/**
 * IOMMU register access routines.
 */
typedef struct
{
    const char   *pszName;
    VBOXSTRICTRC (*pfnRead )(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t *pu64Value);
    VBOXSTRICTRC (*pfnWrite)(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t  u64Value);
    bool         f64BitReg;
} IOMMUREGACC;


/*********************************************************************************************************************************
*   Global Variables                                                                                                             *
*********************************************************************************************************************************/
/**
 * An array of the number of device table segments supported.
 * Indexed by u2DevTabSegSup.
 */
static uint8_t const g_acDevTabSegs[] = { 0, 2, 4, 8 };

/**
 * The maximum size (inclusive) of each device table segment (0 to 7).
 * Indexed by the device table segment index.
 */
static uint16_t const g_auDevTabSegSizes[] = { 0x1ff, 0xff, 0x7f, 0x7f, 0x3f, 0x3f, 0x3f, 0x3f };


#ifndef VBOX_DEVICE_STRUCT_TESTCASE

/**
 * Gets the buffer length length corresponding to a base address.
 *
 * @param   uEncodedLen     The length to decode (power-of-2 encoded).
 * @param   pcEntries       Where to store the number of entries. Optional, can be
 *                          NULL.
 * @param   pcbBuffer       Where to store the size of the buffer. Optional, can be
 *                          NULL.
 *
 * @remarks Both @a pcEntries and @a pcbBuffer cannot both be NULL.
 */
static void iommuAmdGetBaseBufferLength(uint8_t uEncodedLen, uint32_t *pcEntries, uint32_t *pcbBuffer)
{
    uint32_t cEntries;
    uint32_t cbBuffer;
    if (uEncodedLen > 7)
    {
        cEntries = 2 << (uEncodedLen - 1);
        cbBuffer = *pcEntries << 4;
    }
    else
        cEntries = cbBuffer = 0;

    Assert(pcEntries || pcbBuffer);
    if (pcEntries)
        *pcEntries = cEntries;
    if (pcbBuffer)
        *pcbBuffer = cbBuffer;
}


DECL_FORCE_INLINE(IOMMU_STATUS_T) iommuAmdGetStatus(PCIOMMU pThis)
{
    IOMMU_STATUS_T Status;
    Status.u64 = ASMAtomicReadU64((volatile uint64_t *)&pThis->Status.u64);
    return Status;
}


DECL_FORCE_INLINE(IOMMU_CTRL_T) iommuAmdGetCtrl(PCIOMMU pThis)
{
    IOMMU_CTRL_T Ctrl;
    Ctrl.u64 = ASMAtomicReadU64((volatile uint64_t *)&pThis->Ctrl.u64);
    return Ctrl;
}


/**
 * Writes to a read-only register.
 */
static VBOXSTRICTRC iommuAmdIgnore_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, pThis, iReg, u64Value);
    Log((IOMMU_LOG_PFX ": Write to read-only register (%#x) with value %#RX64 ignored\n", iReg, u64Value));
    return VINF_SUCCESS;
}


/**
 * Writes the Device Table Base Address Register.
 */
static VBOXSTRICTRC iommuAmdDevTabBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /* Mask out all unrecognized bits. */
    u64Value &= IOMMU_DEV_TAB_BAR_VALID_MASK;
    DEV_TAB_BAR_T DevTabBaseAddr;
    DevTabBaseAddr.u64 = u64Value;

    /* Validate the base address. */
    RTGCPHYS const GCPhysDevTab = DevTabBaseAddr.n.u40Base;
    if (!(GCPhysDevTab & X86_PAGE_4K_OFFSET_MASK))
        pThis->DevTabBaseAddr.u64 = DevTabBaseAddr.u64;
    else
        Log((IOMMU_LOG_PFX ": Device table base address (%#RX64) misaligned -> Ignored\n", GCPhysDevTab));
    return VINF_SUCCESS;
}


/**
 * Writes the Command Buffer Base Address Register.
 */
static VBOXSTRICTRC iommuAmdCmdBufBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /*
     * While this is not explicitly specified like the event log base address register,
     * the AMD spec. does specify "CmdBufRun must be 0b to modify the command buffer registers properly".
     * Inconsistent specs :/
     */
    IOMMU_STATUS_T const Status = iommuAmdGetStatus(pThis);
    if (Status.n.u1CmdBufRunning)
    {
        Log((IOMMU_LOG_PFX ": Setting CmdBufBar (%#RX64) when command buffer is running -> Ignored\n", u64Value));
        return VINF_SUCCESS;
    }

    /* Mask out all unrecognized bits. */
    CMD_BUF_BAR_T CmdBufBaseAddr;
    CmdBufBaseAddr.u64 = u64Value & IOMMU_CMD_BUF_BAR_VALID_MASK;

    /* Validate the base address. */
    RTGCPHYS const GCPhysCmdBuf = CmdBufBaseAddr.n.u40Base;
    if (!(GCPhysCmdBuf & X86_PAGE_4K_OFFSET_MASK))
    {
        /* Validate the length. */
        if (CmdBufBaseAddr.n.u4Len >= 8)
            pThis->CmdBufBaseAddr.u64 = CmdBufBaseAddr.u64;
        else
            Log((IOMMU_LOG_PFX ": Command buffer length (%#x) invalid -> Ignored\n", CmdBufBaseAddr.n.u4Len));
    }
    else
        Log((IOMMU_LOG_PFX ": Command buffer base address (%#RX64) misaligned -> Ignored\n", CmdBufBaseAddr.n.u40Base));

    /*
     * Writing the command log base address, clears the command buffer head and tail pointers.
     * See AMD spec. 2.4 "Commands".
     */
    pThis->CmdBufHeadPtr.u64 = 0;
    pThis->CmdBufTailPtr.u64 = 0;

    return VINF_SUCCESS;
}


/**
 * Writes the Event Log Base Address Register.
 */
static VBOXSTRICTRC iommuAmdEvtLogBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /*
     * IOMMU behavior is undefined when software writes this register when event logging is running.
     * In our emulation, we ignore the write entirely.
     * See AMD IOMMU spec. "Event Log Base Address Register".
     */
    IOMMU_STATUS_T const Status = iommuAmdGetStatus(pThis);
    if (Status.n.u1EvtLogRunning)
    {
        Log((IOMMU_LOG_PFX ": Setting EvtLogBar (%#RX64) when event logging is running -> Ignored\n", u64Value));
        return VINF_SUCCESS;
    }

    /* Mask out all unrecognized bits. */
    u64Value &= IOMMU_EVT_LOG_BAR_VALID_MASK;
    EVT_LOG_BAR_T EvtLogBaseAddr;
    EvtLogBaseAddr.u64 = u64Value;

    /* Validate the base address. */
    RTGCPHYS const GCPhysEvtLog = EvtLogBaseAddr.n.u40Base;
    if (!(GCPhysEvtLog & X86_PAGE_4K_OFFSET_MASK))
    {
        /* Validate the length. */
        if (EvtLogBaseAddr.n.u4Len >= 8)
            pThis->EvtLogBaseAddr.u64 = EvtLogBaseAddr.u64;
        else
            Log((IOMMU_LOG_PFX ": Event log length (%#x) invalid -> Ignored\n", EvtLogBaseAddr.n.u4Len));
    }
    else
        Log((IOMMU_LOG_PFX ": Event log base address (%#RX64) misaligned -> Ignored\n", EvtLogBaseAddr.n.u40Base));

    /*
     * Writing the event log base address, clears the event log head and tail pointers.
     * See AMD spec. 2.5 "Event Logging".
     */
    pThis->EvtLogHeadPtr.u64 = 0;
    pThis->EvtLogTailPtr.u64 = 0;

    return VINF_SUCCESS;
}


/**
 * Writes to the Excluse Range Base Address Register.
 */
static VBOXSTRICTRC iommuAmdExclRangeBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);
    pThis->ExclRangeBaseAddr.u64 = u64Value & IOMMU_EXCL_RANGE_BAR_VALID_MASK;
    return VINF_SUCCESS;
}


/**
 * Writes to the Excluse Range Limit Register.
 */
static VBOXSTRICTRC iommuAmdExclRangeLimit_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);
    pThis->ExclRangeLimit.u64 = u64Value & IOMMU_EXCL_RANGE_LIMIT_VALID_MASK;
    return VINF_SUCCESS;
}


/**
 * Writes the PPR Log Base Address Register.
 */
static VBOXSTRICTRC iommuAmdPprLogBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /*
     * IOMMU behavior is undefined when software writes this register when PPR logging is running.
     * In our emulation, we ignore the write entirely.
     * See AMD IOMMU spec. 3.3.2 "PPR Log Registers".
     */
    IOMMU_STATUS_T const Status = iommuAmdGetStatus(pThis);
    if (Status.n.u1PprLogRunning)
    {
        Log((IOMMU_LOG_PFX ": Setting PprLogBar (%#RX64) when PPR logging is running -> Ignored\n", u64Value));
        return VINF_SUCCESS;
    }

    /* Mask out all unrecognized bits. */
    u64Value &= IOMMU_PPR_LOG_BAR_VALID_MASK;
    PPR_LOG_BAR_T PprLogBaseAddr;
    PprLogBaseAddr.u64 = u64Value;

    /* Validate the base address. */
    RTGCPHYS const GCPhysPprLog = PprLogBaseAddr.n.u40Base;
    if (!(GCPhysPprLog & X86_PAGE_4K_OFFSET_MASK))
    {
        /* Validate the length. */
        if (PprLogBaseAddr.n.u4Len >= 8)
            pThis->PprLogBaseAddr.u64 = PprLogBaseAddr.u64;
        else
            Log((IOMMU_LOG_PFX ": PPR log length (%#x) invalid -> Ignored\n", PprLogBaseAddr.n.u4Len));
    }
    else
        Log((IOMMU_LOG_PFX ": PPR log base address (%#RX64) misaligned -> Ignored\n", PprLogBaseAddr.n.u40Base));

    /*
     * Writing the event log base address, clears the PPR log head and tail pointers.
     * See AMD spec. 2.6 "Peripheral Page Request (PPR) Logging"
     */
    pThis->PprLogHeadPtr.u64 = 0;
    pThis->PprLogTailPtr.u64 = 0;

    return VINF_SUCCESS;
}


/**
 * Writes the Hardware Event Register (Hi).
 */
static VBOXSTRICTRC iommuAmdHwEvtHi_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    /** @todo IOMMU: Why the heck is this marked read/write by the AMD IOMMU spec? */
    RT_NOREF(pDevIns, iReg);
    Log((IOMMU_LOG_PFX ": Writing %#RX64 to hardware event (Hi) register!\n", u64Value));
    pThis->HwEvtHi.u64 = u64Value;
    return VINF_SUCCESS;
}


/**
 * Writes the Hardware Event Register (Lo).
 */
static VBOXSTRICTRC iommuAmdHwEvtLo_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    /** @todo IOMMU: Why the heck is this marked read/write by the AMD IOMMU spec? */
    RT_NOREF(pDevIns, iReg);
    Log((IOMMU_LOG_PFX ": Writing %#RX64 to hardware event (Lo) register!\n", u64Value));
    pThis->HwEvtLo = u64Value;
    return VINF_SUCCESS;
}


/**
 * Writes the Hardware Event Status Register.
 */
static VBOXSTRICTRC iommuAmdHwEvtStatus_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /* Mask out all unrecognized bits. */
    u64Value &= IOMMU_HW_EVT_STATUS_VALID_MASK;

    /*
     * The two bits (HEO and HEV) are RW1C (Read/Write 1-to-Clear; writing 0 has no effect).
     * If the current status bits or the bits being written are both 0, we've nothing to do.
     * The Overflow bit (bit 1) is only valid when the Valid bit (bit 0) is 1.
     */
    uint64_t HwStatus = pThis->HwEvtStatus.u64;
    if (!(HwStatus & RT_BIT(0)))
        return VINF_SUCCESS;
    if (u64Value & HwStatus & RT_BIT_64(0))
        HwStatus &= ~RT_BIT_64(0);
    if (u64Value & HwStatus & RT_BIT_64(1))
        HwStatus &= ~RT_BIT_64(1);
    pThis->HwEvtStatus.u64 = HwStatus;
    return VINF_SUCCESS;
}


/**
 * Writes the Device Table Segment Base Address Register.
 */
static VBOXSTRICTRC iommuAmdDevTabSegBar_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns);

    /* Figure out which segment is being written. */
    uint8_t const idxDevTabSeg = (iReg - IOMMU_MMIO_OFF_DEV_TAB_SEG_FIRST) >> 3;
    uint8_t const idxSegment   = idxDevTabSeg + 1;
    Assert(idxDevTabSeg < RT_ELEMENTS(pThis->DevTabSeg));

    /* Mask out all unrecognized bits. */
    u64Value &= IOMMU_DEV_TAB_SEG_BAR_VALID_MASK;
    DEV_TAB_SEG_BAR_T DevTabSegBar;
    DevTabSegBar.u64 = u64Value;

    /* Validate the base address. */
    RTGCPHYS const GCPhysDevTab = DevTabSegBar.n.u40Base;
    if (!(GCPhysDevTab & X86_PAGE_4K_OFFSET_MASK))
    {
        /* Validate the size. */
        uint16_t const uSegSize    = DevTabSegBar.n.u8Size;
        uint16_t const uMaxSegSize = g_auDevTabSegSizes[idxSegment];
        if (uSegSize <= uMaxSegSize)
        {
            /* Finally, update the segment register. */
            pThis->DevTabSeg[idxDevTabSeg].u64 = u64Value;
        }
        else
            Log((IOMMU_LOG_PFX ": Device table segment (%u) size invalid (%#RX32) -> Ignored\n", idxSegment, uSegSize));
    }
    else
        Log((IOMMU_LOG_PFX ": Device table segment (%u) address misaligned (%#RX64) -> Ignored\n", idxSegment, GCPhysDevTab));

    return VINF_SUCCESS;
}


/**
 * Writes the MSI Address (Lo) Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdMsiAddrLo_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pThis, iReg);
    Assert(!RT_HI_U32(u64Value));
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_LO, u64Value & IOMMU_MSI_ADDR_VALID_MASK);
    return VINF_SUCCESS;
}


/**
 * Writes the MSI Address (Hi) Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdMsiAddrHi_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pThis, iReg);
    Assert(!RT_HI_U32(u64Value));
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_HI, u64Value);
    return VINF_SUCCESS;
}


/**
 * Writes the MSI Data Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdMsiData_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pThis, iReg);
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_DATA, u64Value & IOMMU_MSI_DATA_VALID_MASK);
    return VINF_SUCCESS;
}


/**
 * Writes the Command Buffer Head Pointer Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdCmdBufHeadPtr_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /*
     * IOMMU behavior is undefined when software writes this register when the command buffer is running.
     * In our emulation, we ignore the write entirely.
     * See AMD IOMMU spec. 3.3.13 "Command and Event Log Pointer Registers".
     */
    IOMMU_STATUS_T const Status = iommuAmdGetStatus(pThis);
    if (Status.n.u1CmdBufRunning)
    {
        Log((IOMMU_LOG_PFX ": Setting CmdBufHeadPtr (%#RX64) when command buffer is running -> Ignored\n", u64Value));
        return VINF_SUCCESS;
    }

    /*
     * IOMMU behavior is undefined when software writes a value outside the buffer length.
     * In our emulation, we ignore the write entirely.
     */
    uint32_t const      offBuf     = u64Value & IOMMU_CMD_BUF_HEAD_PTR_VALID_MASK;
    CMD_BUF_BAR_T const CmdBufBar  = pThis->CmdBufBaseAddr;
    uint32_t            cbBuf;
    iommuAmdGetBaseBufferLength(CmdBufBar.n.u4Len, NULL, &cbBuf);
    if (offBuf >= cbBuf)
    {
        Log((IOMMU_LOG_PFX ": Setting CmdBufHeadPtr (%#RX32) to a value that exceeds buffer length (%#RX23) -> Ignored\n",
             offBuf, cbBuf));
        return VINF_SUCCESS;
    }

    pThis->CmdBufHeadPtr.u64 = offBuf;
    LogFlow((IOMMU_LOG_PFX ": Set CmdBufHeadPtr to %#RX32\n", offBuf));
    return VINF_SUCCESS;
}


/**
 * Writes the Command Buffer Tail Pointer Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdCmdBufTailPtr_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);

    /*
     * IOMMU behavior is undefined when software advances this register equal or beyond its head pointer.
     * In our emulation, we ignore the write entirely.
     * See AMD IOMMU spec. 3.3.13 "Command and Event Log Pointer Registers".
     */
    uint32_t const offBufTail = u64Value & IOMMU_CMD_BUF_HEAD_PTR_VALID_MASK;
    NOREF(offBufTail);
    NOREF(pThis);
    return VINF_SUCCESS;
}


/**
 * Writes the Event Log Head Pointer Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdEvtLogHeadPtr_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);
    NOREF(pThis);
    NOREF(u64Value);
    return VINF_SUCCESS;
}


/**
 * Writes the Event Log Tail Pointer Register (32-bit).
 */
static VBOXSTRICTRC iommuAmdEvtLogTailPtr_w(PPDMDEVINS pDevIns, PIOMMU pThis, uint32_t iReg, uint64_t u64Value)
{
    RT_NOREF(pDevIns, iReg);
    NOREF(pThis);
    NOREF(u64Value);
    return VINF_SUCCESS;
}


/**
 * The IOMMU command thread.
 *
 * @returns VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   pThread     The command thread.
 */
static DECLCALLBACK(int) iommuAmdR3CmdThread(PPDMDEVINS pDevIns, PPDMTHREAD pThread)
{
    RT_NOREF(pDevIns, pThread);
}


/**
 * Unblocks the command thread so it can respond to a state change.
 *
 * @returns VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   pThread     The command thread.
 */
static DECLCALLBACK(int) iommuAmdR3CmdThreadWakeUp(PPDMDEVINS pDevIns, PPDMTHREAD pThread)
{
    RT_NOREF(pThread);
    PIOMMU pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    return PDMDevHlpSUPSemEventSignal(pDevIns, pThis->hEvtCmdThread);
}


#if 0
/**
 * Table 0: Registers-access table.
 */
static const IOMMUREGACC g_aTable0Regs[] =
{

};

/**
 * Table 1: Registers-access table.
 */
static const IOMMUREGACC g_aTable1Regs[] =
{
};
#endif

/**
 * Writes an IOMMU register (32-bit and 64-bit).
 *
 * @returns Strict VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   off         MMIO byte offset to the register.
 * @param   cb          The size of the write access.
 * @param   uValue      The value being written.
 */
static VBOXSTRICTRC iommuAmdWriteRegister(PPDMDEVINS pDevIns, uint32_t off, uint8_t cb, uint64_t uValue)
{
    Assert(off < IOMMU_MMIO_REGION_SIZE);
    Assert(cb == 4 || cb == 8);
    Assert(!(off & (cb - 1)));

    PIOMMU pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    switch (off)
    {
        case IOMMU_MMIO_OFF_DEV_TAB_BAR:         return iommuAmdDevTabBar_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_CMD_BUF_BAR:         return iommuAmdCmdBufBar_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_EVT_LOG_BAR:         return iommuAmdEvtLogBar_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_CTRL:                /** @todo IOMMU: Control register. */
        case IOMMU_MMIO_OFF_EXCL_BAR:            return iommuAmdExclRangeBar_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_EXCL_RANGE_LIMIT:    return iommuAmdExclRangeLimit_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_EXT_FEAT:            return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_PPR_LOG_BAR:         return iommuAmdPprLogBar_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_HW_EVT_HI:           return iommuAmdHwEvtHi_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_HW_EVT_LO:           return iommuAmdHwEvtLo_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_HW_EVT_STATUS:       return iommuAmdHwEvtStatus_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_GALOG_BAR:
        case IOMMU_MMIO_OFF_GALOG_TAIL_ADDR:     return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_PPR_LOG_B_BAR:
        case IOMMU_MMIO_OFF_PPR_EVT_B_BAR:       return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_DEV_TAB_SEG_1:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_2:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_3:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_4:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_5:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_6:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_7:       return iommuAmdDevTabSegBar_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_DEV_SPECIFIC_FEAT:
        case IOMMU_MMIO_OFF_DEV_SPECIFIC_CTRL:
        case IOMMU_MMIO_OFF_DEV_SPECIFIC_STATUS: return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_MSI_VECTOR_0:
        case IOMMU_MMIO_OFF_MSI_VECTOR_1:        return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_MSI_CAP_HDR:
        {
            VBOXSTRICTRC rcStrict = iommuAmdIgnore_w(pDevIns, pThis, off, (uint32_t)uValue);
            if (cb == 4 || RT_FAILURE(rcStrict))
                return rcStrict;
            uValue >>= 32;
            RT_FALL_THRU();
        }
        case IOMMU_MMIO_OFF_MSI_ADDR_LO:         return iommuAmdMsiAddrLo_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_MSI_ADDR_HI:
        {
            VBOXSTRICTRC rcStrict = iommuAmdMsiAddrHi_w(pDevIns, pThis, off, (uint32_t)uValue);
            if (cb == 4 || RT_FAILURE(rcStrict))
                return rcStrict;
            uValue >>= 32;
            RT_FALL_THRU();
        }
        case IOMMU_MMIO_OFF_MSI_DATA:            return iommuAmdMsiData_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_OFF_MSI_MAPPING_CAP_HDR: return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_PERF_OPT_CTRL:       return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_XT_GEN_INTR_CTRL:
        case IOMMU_MMIO_OFF_XT_PPR_INTR_CTRL:
        case IOMMU_MMIO_OFF_XT_GALOG_INT_CTRL:   return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_MARC_APER_BAR_0:
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_0:
        case IOMMU_MMIO_OFF_MARC_APER_LEN_0:
        case IOMMU_MMIO_OFF_MARC_APER_BAR_1:
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_1:
        case IOMMU_MMIO_OFF_MARC_APER_LEN_1:
        case IOMMU_MMIO_OFF_MARC_APER_BAR_2:
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_2:
        case IOMMU_MMIO_OFF_MARC_APER_LEN_2:
        case IOMMU_MMIO_OFF_MARC_APER_BAR_3:
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_3:
        case IOMMU_MMIO_OFF_MARC_APER_LEN_3:     return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_RSVD_REG:            return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_CMD_BUF_HEAD_PTR:        return iommuAmdCmdBufHeadPtr_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_CMD_BUF_TAIL_PTR:        return iommuAmdCmdBufTailPtr_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_EVT_LOG_HEAD_PTR:        return iommuAmdEvtLogHeadPtr_w(pDevIns, pThis, off, uValue);
        case IOMMU_MMIO_EVT_LOG_TAIL_PTR:        return iommuAmdEvtLogTailPtr_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_STATUS:

        case IOMMU_MMIO_OFF_PPR_LOG_HEAD_PTR:
        case IOMMU_MMIO_OFF_PPR_LOG_TAIL_PTR:

        case IOMMU_MMIO_OFF_GALOG_HEAD_PTR:
        case IOMMU_MMIO_OFF_GALOG_TAIL_PTR:

        case IOMMU_MMIO_OFF_PPR_LOG_B_HEAD_PTR:
        case IOMMU_MMIO_OFF_PPR_LOG_B_TAIL_PTR:

        case IOMMU_MMIO_OFF_EVT_LOG_B_HEAD_PTR:
        case IOMMU_MMIO_OFF_EVT_LOG_B_TAIL_PTR:  return iommuAmdIgnore_w(pDevIns, pThis, off, uValue);

        case IOMMU_MMIO_OFF_PPR_LOG_AUTO_RESP:
        case IOMMU_MMIO_OFF_PPR_LOG_OVERFLOW_EARLY:
        case IOMMU_MMIO_OFF_PPR_LOG_B_OVERFLOW_EARLY:

        /* Not implemented. */
        case IOMMU_MMIO_OFF_SMI_FLT_FIRST:
        case IOMMU_MMIO_OFF_SMI_FLT_LAST:
        {
            Log((IOMMU_LOG_PFX ": Writing unsupported register: SMI filter %u -> Ignored\n",
                 (off - IOMMU_MMIO_OFF_SMI_FLT_FIRST) >> 3));
            return VINF_SUCCESS;
        }

        /* Unknown. */
        default:
        {
            Log((IOMMU_LOG_PFX ": Writing unknown register %u (%#x) with %#RX64 -> Ignored\n", off, off, uValue));
            return VINF_SUCCESS;
        }
    }
}


/**
 * Reads an IOMMU register (64-bit).
 *
 * All reads are 64-bit but reads to 32-bit registers that are aligned on an 8-byte
 * boundary include the lower half of the subsequent register.
 *
 * This is because most registers are 64-bit and aligned on 8-byte boundaries but
 * some are really 32-bit registers aligned on an 8-byte boundary. We cannot assume
 * guests will only perform 32-bit reads on those 32-bit registers that are aligned
 * on 8-byte boundaries.
 *
 * @returns Strict VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   off         Offset in bytes.
 * @param   puResult    Where to store the value being read.
 */
static VBOXSTRICTRC iommuAmdReadRegister(PPDMDEVINS pDevIns, uint32_t off, uint64_t *puResult)
{
    Assert(off < IOMMU_MMIO_REGION_SIZE);
    Assert(!(off & 7) || !(off & 3));

    PIOMMU     pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);

    /** @todo IOMMU: fine-grained locking? */
    uint64_t uReg;
    switch (off)
    {
        case IOMMU_MMIO_OFF_DEV_TAB_BAR:              uReg = pThis->DevTabBaseAddr.u64;         break;
        case IOMMU_MMIO_OFF_CMD_BUF_BAR:              uReg = pThis->CmdBufBaseAddr.u64;         break;
        case IOMMU_MMIO_OFF_EVT_LOG_BAR:              uReg = pThis->EvtLogBaseAddr.u64;         break;
        case IOMMU_MMIO_OFF_CTRL:                     uReg = pThis->Ctrl.u64;                   break;
        case IOMMU_MMIO_OFF_EXCL_BAR:                 uReg = pThis->ExclRangeBaseAddr.u64;      break;
        case IOMMU_MMIO_OFF_EXCL_RANGE_LIMIT:         uReg = pThis->ExclRangeLimit.u64;         break;
        case IOMMU_MMIO_OFF_EXT_FEAT:                 uReg = pThis->ExtFeat.u64;                break;

        case IOMMU_MMIO_OFF_PPR_LOG_BAR:              uReg = pThis->PprLogBaseAddr.u64;         break;
        case IOMMU_MMIO_OFF_HW_EVT_HI:                uReg = pThis->HwEvtHi.u64;                break;
        case IOMMU_MMIO_OFF_HW_EVT_LO:                uReg = pThis->HwEvtLo;                    break;
        case IOMMU_MMIO_OFF_HW_EVT_STATUS:            uReg = pThis->HwEvtStatus.u64;            break;

        case IOMMU_MMIO_OFF_GALOG_BAR:                uReg = pThis->GALogBaseAddr.u64;          break;
        case IOMMU_MMIO_OFF_GALOG_TAIL_ADDR:          uReg = pThis->GALogTailAddr.u64;          break;

        case IOMMU_MMIO_OFF_PPR_LOG_B_BAR:            uReg = pThis->PprLogBBaseAddr.u64;        break;
        case IOMMU_MMIO_OFF_PPR_EVT_B_BAR:            uReg = pThis->EvtLogBBaseAddr.u64;        break;

        case IOMMU_MMIO_OFF_DEV_TAB_SEG_FIRST:
        case IOMMU_MMIO_OFF_DEV_TAB_SEG_LAST:
        {
            uint8_t const idxDevTabSeg = (off - IOMMU_MMIO_OFF_DEV_TAB_SEG_FIRST) >> 3;
            Assert(idxDevTabSeg < RT_ELEMENTS(pThis->DevTabSeg));
            uReg = pThis->DevTabSeg[idxDevTabSeg].u64;
            break;
        }

        case IOMMU_MMIO_OFF_DEV_SPECIFIC_FEAT:        uReg = pThis->DevSpecificFeat.u64;        break;
        case IOMMU_MMIO_OFF_DEV_SPECIFIC_CTRL:        uReg = pThis->DevSpecificCtrl.u64;        break;
        case IOMMU_MMIO_OFF_DEV_SPECIFIC_STATUS:      uReg = pThis->DevSpecificStatus.u64;      break;

        case IOMMU_MMIO_OFF_MSI_VECTOR_0:             uReg = pThis->MsiMiscInfo.u64;            break;
        case IOMMU_MMIO_OFF_MSI_VECTOR_1:             uReg = pThis->MsiMiscInfo.au32[1];        break;
        case IOMMU_MMIO_OFF_MSI_CAP_HDR:
        {
            uint32_t const uMsiCapHdr = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_CAP_HDR);
            uint32_t const uMsiAddrLo = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_LO);
            uReg = RT_MAKE_U64(uMsiCapHdr, uMsiAddrLo);
            break;
        }
        case IOMMU_MMIO_OFF_MSI_ADDR_LO:
        {
            uReg = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_LO);
            break;
        }
        case IOMMU_MMIO_OFF_MSI_ADDR_HI:
        {
            uint32_t const uMsiAddrHi = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_HI);
            uint32_t const uMsiData   = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_DATA);
            uReg = RT_MAKE_U64(uMsiAddrHi, uMsiData);
            break;
        }
        case IOMMU_MMIO_OFF_MSI_DATA:
        {
            uReg = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_DATA);
            break;
        }
        case IOMMU_MMIO_OFF_MSI_MAPPING_CAP_HDR:
        {
            /*
             * The PCI spec. lists MSI Mapping Capability 08H as related to HyperTransport capability.
             * The AMD IOMMU spec. fails to mention it explicitly and lists values for this register as
             * though HyperTransport is supported. We don't support HyperTransport, we thus just return
             * 0 for this register.
             */
            uReg = RT_MAKE_U64(0, pThis->PerfOptCtrl.u32);
            break;
        }

        case IOMMU_MMIO_OFF_PERF_OPT_CTRL:            uReg = pThis->PerfOptCtrl.u32;            break;

        case IOMMU_MMIO_OFF_XT_GEN_INTR_CTRL:         uReg = pThis->XtGenIntrCtrl.u64;          break;
        case IOMMU_MMIO_OFF_XT_PPR_INTR_CTRL:         uReg = pThis->XtPprIntrCtrl.u64;          break;
        case IOMMU_MMIO_OFF_XT_GALOG_INT_CTRL:        uReg = pThis->XtGALogIntrCtrl.u64;        break;

        case IOMMU_MMIO_OFF_MARC_APER_BAR_0:          uReg = pThis->aMarcApers[0].Base.u64;     break;
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_0:        uReg = pThis->aMarcApers[0].Reloc.u64;    break;
        case IOMMU_MMIO_OFF_MARC_APER_LEN_0:          uReg = pThis->aMarcApers[0].Length.u64;   break;
        case IOMMU_MMIO_OFF_MARC_APER_BAR_1:          uReg = pThis->aMarcApers[1].Base.u64;     break;
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_1:        uReg = pThis->aMarcApers[1].Reloc.u64;    break;
        case IOMMU_MMIO_OFF_MARC_APER_LEN_1:          uReg = pThis->aMarcApers[1].Length.u64;   break;
        case IOMMU_MMIO_OFF_MARC_APER_BAR_2:          uReg = pThis->aMarcApers[2].Base.u64;     break;
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_2:        uReg = pThis->aMarcApers[2].Reloc.u64;    break;
        case IOMMU_MMIO_OFF_MARC_APER_LEN_2:          uReg = pThis->aMarcApers[2].Length.u64;   break;
        case IOMMU_MMIO_OFF_MARC_APER_BAR_3:          uReg = pThis->aMarcApers[3].Base.u64;     break;
        case IOMMU_MMIO_OFF_MARC_APER_RELOC_3:        uReg = pThis->aMarcApers[3].Reloc.u64;    break;
        case IOMMU_MMIO_OFF_MARC_APER_LEN_3:          uReg = pThis->aMarcApers[3].Length.u64;   break;

        case IOMMU_MMIO_OFF_RSVD_REG:                 uReg = pThis->RsvdReg;                    break;

        case IOMMU_MMIO_CMD_BUF_HEAD_PTR:             uReg = pThis->CmdBufHeadPtr.u64;          break;
        case IOMMU_MMIO_CMD_BUF_TAIL_PTR:             uReg = pThis->CmdBufTailPtr.u64;          break;
        case IOMMU_MMIO_EVT_LOG_HEAD_PTR:             uReg = pThis->EvtLogHeadPtr.u64;          break;
        case IOMMU_MMIO_EVT_LOG_TAIL_PTR:             uReg = pThis->EvtLogTailPtr.u64;          break;

        case IOMMU_MMIO_OFF_STATUS:                   uReg = pThis->Status.u64;                 break;

        case IOMMU_MMIO_OFF_PPR_LOG_HEAD_PTR:         uReg = pThis->PprLogHeadPtr.u64;          break;
        case IOMMU_MMIO_OFF_PPR_LOG_TAIL_PTR:         uReg = pThis->PprLogTailPtr.u64;          break;

        case IOMMU_MMIO_OFF_GALOG_HEAD_PTR:           uReg = pThis->GALogHeadPtr.u64;           break;
        case IOMMU_MMIO_OFF_GALOG_TAIL_PTR:           uReg = pThis->GALogTailPtr.u64;           break;

        case IOMMU_MMIO_OFF_PPR_LOG_B_HEAD_PTR:       uReg = pThis->PprLogBHeadPtr.u64;         break;
        case IOMMU_MMIO_OFF_PPR_LOG_B_TAIL_PTR:       uReg = pThis->PprLogBTailPtr.u64;         break;

        case IOMMU_MMIO_OFF_EVT_LOG_B_HEAD_PTR:       uReg = pThis->EvtLogBHeadPtr.u64;         break;
        case IOMMU_MMIO_OFF_EVT_LOG_B_TAIL_PTR:       uReg = pThis->EvtLogBTailPtr.u64;         break;

        case IOMMU_MMIO_OFF_PPR_LOG_AUTO_RESP:        uReg = pThis->PprLogAutoResp.u64;         break;
        case IOMMU_MMIO_OFF_PPR_LOG_OVERFLOW_EARLY:   uReg = pThis->PprLogOverflowEarly.u64;    break;
        case IOMMU_MMIO_OFF_PPR_LOG_B_OVERFLOW_EARLY: uReg = pThis->PprLogBOverflowEarly.u64;   break;

        /* Not implemented. */
        case IOMMU_MMIO_OFF_SMI_FLT_FIRST:
        case IOMMU_MMIO_OFF_SMI_FLT_LAST:
        {
            Log((IOMMU_LOG_PFX ": Reading unsupported register: SMI filter %u\n", (off - IOMMU_MMIO_OFF_SMI_FLT_FIRST) >> 3));
            uReg = 0;
            break;
        }

        /* Unknown. */
        default:
        {
            Log((IOMMU_LOG_PFX ": Reading unknown register %u (%#x) -> 0\n", off, off));
            uReg = 0;
            return VINF_IOM_MMIO_UNUSED_00;
        }
    }

    *puResult = uReg;
    return VINF_SUCCESS;
}


/**
 * Reads a device table segment (0-7) from guest memory.
 *
 * @returns VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   idxSeg      The device table segment index.
 * @param   pvBuf       Where to store the device table segment.
 * @param   cbBuf       The size of the buffer in bytes.
 *
 * @thread  Any.
 */
static int iommuAmdReadDeviceTableSegment(PPDMDEVINS pDevIns, uint8_t idxSeg, void *pvBuf, uint32_t cbBuf)
{
    PIOMMU pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);

    /* Validate. */
    Assert(pvBuf);
    Assert(cbBuf <= _2M);
    Assert(!idxSeg || pThis->ExtFeat.n.u2DevTabSegSup);
    Assert(!idxSeg || idxSeg < g_acDevTabSegs[pThis->ExtFeat.n.u2DevTabSegSup]);

    /* Get the base address and size of the segment. */
    RTGCPHYS GCPhysDevTab;
    uint32_t cbDevTab;
    if (!idxSeg)
    {
        GCPhysDevTab = pThis->DevTabBaseAddr.n.u40Base;
        cbDevTab     = IOMMU_GET_DEV_TAB_SIZE(pThis->DevTabBaseAddr.n.u9Size);
    }
    else
    {
        GCPhysDevTab = pThis->DevTabSeg[idxSeg].n.u40Base;
        cbDevTab     = IOMMU_GET_DEV_TAB_SIZE(pThis->DevTabSeg[idxSeg].n.u8Size);
    }

    /* Validate that the destination buffer is large enough to hold the segment. */
    Assert(cbBuf >= cbDevTab);

    /* Copy the device table to the buffer. */
    int rc = PDMDevHlpPCIPhysRead(pDevIns, GCPhysDevTab, pvBuf, cbDevTab);
    if (RT_FAILURE(rc))
    {
        Log((IOMMU_LOG_PFX ": iommuAmdFetchDeviceTable: Failed to read device table segment. idxSeg=%u GCPhys=%#RGp rc=%Rrc",
             idxSeg, GCPhysDevTab, rc));
    }

    return rc;
}


/**
 * Calculates and returns the total size of the device table.
 * This includes device table segments if they are used.
 *
 * @returns The size of the device table in bytes.
 * @param   pDevIns     The IOMMU device instance.
 *
 * @thread  Any.
 */
static uint32_t iommuAmdCalcTotalDevTabSize(PPDMDEVINS pDevIns)
{
    PCIOMMU pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    IOMMU_CTRL_T const Ctrl = iommuAmdGetCtrl(pThis);

    /* The base address register always exists. */
    uint32_t cbDevTabSize = IOMMU_GET_DEV_TAB_SIZE(pThis->DevTabBaseAddr.n.u9Size);

    /* If segmentation is enabled, add the size of each segments. */
    uint8_t const uSegmentsEnabled = Ctrl.n.u3DevTabSegEn;
    if (uSegmentsEnabled)
    {
        Assert(uSegmentsEnabled < RT_ELEMENTS(g_acDevTabSegs));
        uint8_t const cSegments = g_acDevTabSegs[uSegmentsEnabled] - 1;
        for (uint8_t idxSegment = 0; idxSegment < cSegments - 1; idxSegment++)
            cbDevTabSize += IOMMU_GET_DEV_TAB_SIZE(pThis->DevTabSeg[idxSegment].n.u8Size);
    }

    return cbDevTabSize;
}


/**
 * Memory read transaction from a device.
 *
 * @returns VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   uDeviceId   The device identifier (bus, device, function).
 * @param   uDva        The device virtual address being read.
 * @param   cbRead      The number of bytes being read.
 * @param   pGCPhysOut  Where to store the translated physical address.
 *
 * @thread  Any.
 */
static int iommuAmdDeviceMemRead(PPDMDEVINS pDevIns, uint16_t uDeviceId, uint64_t uDva, size_t cbRead, PRTGCPHYS pGCPhysOut)
{
    RT_NOREF(pDevIns, uDeviceId, uDva, cbRead, pGCPhysOut);
    return VERR_NOT_IMPLEMENTED;
}


/**
 * Memory write transaction from a device.
 *
 * @returns VBox status code.
 * @param   pDevIns     The IOMMU device instance.
 * @param   uDeviceId   The device identifier (bus, device, function).
 * @param   uDva        The device virtual address being written.
 * @param   cbWrite     The number of bytes being written.
 * @param   pGCPhysOut  Where to store the translated physical address.
 *
 * @thread  Any.
 */
static int iommuAmdDeviceMemWrite(PPDMDEVINS pDevIns, uint16_t uDeviceId, uint64_t uDva, size_t cbWrite, PRTGCPHYS pGCPhysOut)
{
    RT_NOREF(pDevIns, uDeviceId, uDva, cbWrite, pGCPhysOut);
    return VERR_NOT_IMPLEMENTED;
}


/**
 * @callback_method_impl{FNIOMMMIONEWWRITE}
 */
static DECLCALLBACK(VBOXSTRICTRC) iommuAmdMmioWrite(PPDMDEVINS pDevIns, void *pvUser, RTGCPHYS off, void const *pv, unsigned cb)
{
    NOREF(pvUser);
    Assert(cb == 4 || cb == 8);
    Assert(!(off & (cb - 1)));

    uint64_t const uValue = cb == 8 ? *(uint64_t const *)pv : *(uint32_t const *)pv;
    return iommuAmdWriteRegister(pDevIns, off, cb, uValue);
}


/**
 * @callback_method_impl{FNIOMMMIONEWREAD}
 */
static DECLCALLBACK(VBOXSTRICTRC) iommuAmdMmioRead(PPDMDEVINS pDevIns, void *pvUser, RTGCPHYS off, void *pv, unsigned cb)
{
    NOREF(pvUser);
    Assert(cb == 4 || cb == 8);
    Assert(!(off & (cb - 1)));

    uint64_t uResult;
    VBOXSTRICTRC rcStrict = iommuAmdReadRegister(pDevIns, off, &uResult);
    if (cb == 8)
        *(uint64_t *)pv = uResult;
    else
        *(uint32_t *)pv = (uint32_t)uResult;

    return rcStrict;
}


# ifdef IN_RING3
/**
 * @callback_method_impl{FNPCICONFIGREAD}
 */
static DECLCALLBACK(VBOXSTRICTRC) iommuAmdR3PciConfigRead(PPDMDEVINS pDevIns, PPDMPCIDEV pPciDev, uint32_t uAddress,
                                                          unsigned cb, uint32_t *pu32Value)
{
    /** @todo IOMMU: PCI config read stat counter. */
    VBOXSTRICTRC rcStrict = PDMDevHlpPCIConfigRead(pDevIns, pPciDev, uAddress, cb, pu32Value);
    Log3((IOMMU_LOG_PFX ": Reading PCI config register %#x (cb=%u) -> %#x %Rrc\n", uAddress, cb, *pu32Value,
          VBOXSTRICTRC_VAL(rcStrict)));
    return rcStrict;
}


/**
 * @callback_method_impl{FNPCICONFIGWRITE}
 */
static DECLCALLBACK(VBOXSTRICTRC) iommuAmdR3PciConfigWrite(PPDMDEVINS pDevIns, PPDMPCIDEV pPciDev, uint32_t uAddress,
                                                           unsigned cb, uint32_t u32Value)
{
    PIOMMU pThis = PDMDEVINS_2_DATA(pDevIns, PIOMMU);

    /*
     * Discard writes to read-only registers that are specific to the IOMMU.
     * Other common PCI registers are handled by the generic code, see devpciR3IsConfigByteWritable().
     * See PCI spec. 6.1. "Configuration Space Organization".
     */
    switch (uAddress)
    {
        case IOMMU_PCI_OFF_CAP_HDR:         /* All bits are read-only. */
        case IOMMU_PCI_OFF_RANGE_REG:       /* We don't have any devices integrated with the IOMMU. */
        case IOMMU_PCI_OFF_MISCINFO_REG_0:  /* We don't support MSI-X. */
        case IOMMU_PCI_OFF_MISCINFO_REG_1:  /* We don't support guest-address translation. */
        {
            Log((IOMMU_LOG_PFX ": PCI config write (%#RX32) to read-only register %#x -> Ignored\n", u32Value, uAddress));
            return VINF_SUCCESS;
        }
    }

    IOMMU_LOCK_RET(pDevIns, pThis, VERR_IGNORED);

    VBOXSTRICTRC rcStrict;
    switch (uAddress)
    {
        case IOMMU_PCI_OFF_BASE_ADDR_REG_LO:
        {
            IOMMU_BAR_T const IommuBar = pThis->IommuBar;
            if (!IommuBar.n.u1Enable)
            {
                pThis->IommuBar.au32[0] = u32Value & IOMMU_BAR_VALID_MASK;
                Assert(pThis->hMmio == NIL_IOMMMIOHANDLE);
                RTGCPHYS const GCPhysMmioBase = RT_MAKE_U64(pThis->IommuBar.n.u18BaseAddrLo, pThis->IommuBar.n.u32BaseAddrHi);
                rcStrict = PDMDevHlpMmioMap(pDevIns, pThis->hMmio, GCPhysMmioBase);
                if (RT_FAILURE(rcStrict))
                    Log((IOMMU_LOG_PFX ": Failed to map IOMMU MMIO region at %#RGp. rc=%Rrc\n", GCPhysMmioBase, rcStrict));
            }
            else
            {
                rcStrict = VINF_SUCCESS;
                Log((IOMMU_LOG_PFX ": Writing Base Address (Lo) when it's already enabled -> Ignored\n"));
            }
            break;
        }

        case IOMMU_PCI_OFF_BASE_ADDR_REG_HI:
        {
            IOMMU_BAR_T const IommuBar = pThis->IommuBar;
            if (!IommuBar.n.u1Enable)
                pThis->IommuBar.au32[1] = u32Value;
            else
            {
                rcStrict = VINF_SUCCESS;
                Log((IOMMU_LOG_PFX ": Writing Base Address (Hi) when it's already enabled -> Ignored\n"));
            }
            break;
        }

        case IOMMU_PCI_OFF_MSI_CAP_HDR:
        {
            u32Value |= RT_BIT(23);     /* 64-bit MSI addressess must always be enabled for IOMMU. */
            RT_FALL_THRU();
        }

        default:
        {
            rcStrict = PDMDevHlpPCIConfigWrite(pDevIns, pPciDev, uAddress, cb, u32Value);
            break;
        }
    }

    IOMMU_UNLOCK(pDevIns, pThis);

    Log3((IOMMU_LOG_PFX ": PCI config write: %#x -> To %#x (%u) %Rrc\n", u32Value, uAddress, cb, VBOXSTRICTRC_VAL(rcStrict)));
    return rcStrict;
}


/**
 * @callback_method_impl{FNDBGFHANDLERDEV}
 */
static DECLCALLBACK(void) iommuAmdR3DbgInfo(PPDMDEVINS pDevIns, PCDBGFINFOHLP pHlp, const char *pszArgs)
{
    PCIOMMU    pThis   = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);

    LogFlow((IOMMU_LOG_PFX ": %s: pThis=%p pszArgs=%s\n", __PRETTY_FUNCTION__, pThis, pszArgs));
    bool const fVerbose = !strncmp(pszArgs, RT_STR_TUPLE("verbose")) ? true : false;

    pHlp->pfnPrintf(pHlp, "AMD-IOMMU:\n");
    /* Device Table Base Address. */
    {
        DEV_TAB_BAR_T const DevTabBar = pThis->DevTabBaseAddr;
        pHlp->pfnPrintf(pHlp, "  Device Table BAR                        = %#RX64\n", DevTabBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Size                                    = %#x (%u bytes)\n", DevTabBar.n.u9Size,
                            IOMMU_GET_DEV_TAB_SIZE(DevTabBar.n.u9Size));
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", DevTabBar.n.u40Base);
        }
    }
    /* Command Buffer Base Address Register. */
    {
        CMD_BUF_BAR_T const CmdBufBar = pThis->CmdBufBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = CmdBufBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  Command buffer BAR                      = %#RX64\n", CmdBufBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", CmdBufBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* Event Log Base Address Register. */
    {
        EVT_LOG_BAR_T const EvtLogBar = pThis->EvtLogBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = EvtLogBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  Event log BAR                           = %#RX64\n", EvtLogBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", EvtLogBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* IOMMU Control Register. */
    {
        IOMMU_CTRL_T const Ctrl = pThis->Ctrl;
        pHlp->pfnPrintf(pHlp, "  Control                                 = %#RX64\n", Ctrl.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    IOMMU enable                            = %RTbool\n", Ctrl.n.u1IommuEn);
            pHlp->pfnPrintf(pHlp, "    HT Tunnel translation enable            = %RTbool\n", Ctrl.n.u1HtTunEn);
            pHlp->pfnPrintf(pHlp, "    Event log enable                        = %RTbool\n", Ctrl.n.u1EvtLogEn);
            pHlp->pfnPrintf(pHlp, "    Event log interrupt enable              = %RTbool\n", Ctrl.n.u1EvtIntrEn);
            pHlp->pfnPrintf(pHlp, "    Completion wait interrupt enable        = %RTbool\n", Ctrl.n.u1EvtIntrEn);
            pHlp->pfnPrintf(pHlp, "    Invalidation timeout                    = %u\n",      Ctrl.n.u3InvTimeOut);
            pHlp->pfnPrintf(pHlp, "    Pass posted write                       = %RTbool\n", Ctrl.n.u1PassPW);
            pHlp->pfnPrintf(pHlp, "    Respose Pass posted write               = %RTbool\n", Ctrl.n.u1ResPassPW);
            pHlp->pfnPrintf(pHlp, "    Coherent                                = %RTbool\n", Ctrl.n.u1Coherent);
            pHlp->pfnPrintf(pHlp, "    Isochronous                             = %RTbool\n", Ctrl.n.u1Isoc);
            pHlp->pfnPrintf(pHlp, "    Command buffer enable                   = %RTbool\n", Ctrl.n.u1CmdBufEn);
            pHlp->pfnPrintf(pHlp, "    PPR log enable                          = %RTbool\n", Ctrl.n.u1PprLogEn);
            pHlp->pfnPrintf(pHlp, "    PPR interrupt enable                    = %RTbool\n", Ctrl.n.u1PprIntrEn);
            pHlp->pfnPrintf(pHlp, "    PPR enable                              = %RTbool\n", Ctrl.n.u1PprEn);
            pHlp->pfnPrintf(pHlp, "    Guest translation eanble                = %RTbool\n", Ctrl.n.u1GstTranslateEn);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC enable               = %RTbool\n", Ctrl.n.u1GstVirtApicEn);
            pHlp->pfnPrintf(pHlp, "    CRW                                     = %#x\n",     Ctrl.n.u4Crw);
            pHlp->pfnPrintf(pHlp, "    SMI filter enable                       = %RTbool\n", Ctrl.n.u1SmiFilterEn);
            pHlp->pfnPrintf(pHlp, "    Self-writeback disable                  = %RTbool\n", Ctrl.n.u1SelfWriteBackDis);
            pHlp->pfnPrintf(pHlp, "    SMI filter log enable                   = %RTbool\n", Ctrl.n.u1SmiFilterLogEn);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC mode enable          = %#x\n",     Ctrl.n.u3GstVirtApicModeEn);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC GA log enable        = %RTbool\n", Ctrl.n.u1GstLogEn);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC interrupt enable     = %RTbool\n", Ctrl.n.u1GstIntrEn);
            pHlp->pfnPrintf(pHlp, "    Dual PPR log enable                     = %#x\n",     Ctrl.n.u2DualPprLogEn);
            pHlp->pfnPrintf(pHlp, "    Dual event log enable                   = %#x\n",     Ctrl.n.u2DualEvtLogEn);
            pHlp->pfnPrintf(pHlp, "    Device table segmentation enable        = %#x\n",     Ctrl.n.u3DevTabSegEn);
            pHlp->pfnPrintf(pHlp, "    Privilege abort enable                  = %#x\n",     Ctrl.n.u2PrivAbortEn);
            pHlp->pfnPrintf(pHlp, "    PPR auto response enable                = %RTbool\n", Ctrl.n.u1PprAutoRespEn);
            pHlp->pfnPrintf(pHlp, "    MARC enable                             = %RTbool\n", Ctrl.n.u1MarcEn);
            pHlp->pfnPrintf(pHlp, "    Block StopMark enable                   = %RTbool\n", Ctrl.n.u1BlockStopMarkEn);
            pHlp->pfnPrintf(pHlp, "    PPR auto response always-on enable      = %RTbool\n", Ctrl.n.u1PprAutoRespAlwaysOnEn);
            pHlp->pfnPrintf(pHlp, "    Domain IDPNE                            = %RTbool\n", Ctrl.n.u1DomainIDPNE);
            pHlp->pfnPrintf(pHlp, "    Enhanced PPR handling                   = %RTbool\n", Ctrl.n.u1EnhancedPpr);
            pHlp->pfnPrintf(pHlp, "    Host page table access/dirty bit update = %#x\n",     Ctrl.n.u2HstAccDirtyBitUpdate);
            pHlp->pfnPrintf(pHlp, "    Guest page table dirty bit disable      = %RTbool\n", Ctrl.n.u1GstDirtyUpdateDis);
            pHlp->pfnPrintf(pHlp, "    x2APIC enable                           = %RTbool\n", Ctrl.n.u1X2ApicEn);
            pHlp->pfnPrintf(pHlp, "    x2APIC interrupt enable                 = %RTbool\n", Ctrl.n.u1X2ApicIntrGenEn);
            pHlp->pfnPrintf(pHlp, "    Guest page table access bit update      = %RTbool\n", Ctrl.n.u1GstAccessUpdateDis);
        }
    }
    /* Exclusion Base Address Register. */
    {
        IOMMU_EXCL_RANGE_BAR_T const ExclRangeBar = pThis->ExclRangeBaseAddr;
        pHlp->pfnPrintf(pHlp, "  Exclusion BAR                           = %#RX64\n", ExclRangeBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Exclusion enable                        = %RTbool\n", ExclRangeBar.n.u1ExclEnable);
            pHlp->pfnPrintf(pHlp, "    Allow all devices                       = %RTbool\n", ExclRangeBar.n.u1AllowAll);
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", ExclRangeBar.n.u40ExclRangeBase);
        }
    }
    /* Exclusion Range Limit Register. */
    {
        IOMMU_EXCL_RANGE_LIMIT_T const ExclRangeLimit = pThis->ExclRangeLimit;
        pHlp->pfnPrintf(pHlp, "  Exclusion Range Limit                   = %#RX64\n", ExclRangeLimit.u64);
        if (fVerbose)
            pHlp->pfnPrintf(pHlp, "    Range limit                             = %#RX64\n", ExclRangeLimit.n.u40ExclLimit);
    }
    /* Extended Feature Register. */
    {
        IOMMU_EXT_FEAT_T ExtFeat = pThis->ExtFeat;
        pHlp->pfnPrintf(pHlp, "  Extended Feature Register               = %#RX64\n", ExtFeat.u64);
        pHlp->pfnPrintf(pHlp, "    Prefetch support                        = %RTbool\n", ExtFeat.n.u1PrefetchSup);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    PPR support                             = %RTbool\n",  ExtFeat.n.u1PprSup);
            pHlp->pfnPrintf(pHlp, "    x2APIC support                          = %RTbool\n",  ExtFeat.n.u1X2ApicSup);
            pHlp->pfnPrintf(pHlp, "    NX and privilege level support          = %RTbool\n",  ExtFeat.n.u1NoExecuteSup);
            pHlp->pfnPrintf(pHlp, "    Guest translation support               = %RTbool\n",  ExtFeat.n.u1GstTranslateSup);
            pHlp->pfnPrintf(pHlp, "    Invalidate-All command support          = %RTbool\n",  ExtFeat.n.u1InvAllSup);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC support              = %RTbool\n",  ExtFeat.n.u1GstVirtApicSup);
            pHlp->pfnPrintf(pHlp, "    Hardware error register support         = %RTbool\n",  ExtFeat.n.u1HwErrorSup);
            pHlp->pfnPrintf(pHlp, "    Performance counters support            = %RTbool\n",  ExtFeat.n.u1PerfCounterSup);
            pHlp->pfnPrintf(pHlp, "    Host address translation size           = %#x\n",      ExtFeat.n.u2HostAddrTranslateSize);
            pHlp->pfnPrintf(pHlp, "    Guest address translation size          = %#x\n",      ExtFeat.n.u2GstAddrTranslateSize);
            pHlp->pfnPrintf(pHlp, "    Guest CR3 root table level support      = %#x\n",      ExtFeat.n.u2GstCr3RootTblLevel);
            pHlp->pfnPrintf(pHlp, "    SMI filter register support             = %#x\n",      ExtFeat.n.u2SmiFilterSup);
            pHlp->pfnPrintf(pHlp, "    SMI filter register count               = %#x\n",      ExtFeat.n.u3SmiFilterCount);
            pHlp->pfnPrintf(pHlp, "    Guest virtual-APIC modes support        = %#x\n",      ExtFeat.n.u3GstVirtApicModeSup);
            pHlp->pfnPrintf(pHlp, "    Dual PPR log support                    = %#x\n",      ExtFeat.n.u2DualPprLogSup);
            pHlp->pfnPrintf(pHlp, "    Dual event log support                  = %#x\n",      ExtFeat.n.u2DualEvtLogSup);
            pHlp->pfnPrintf(pHlp, "    Maximum PASID                           = %#x\n",      ExtFeat.n.u5MaxPasidSup);
            pHlp->pfnPrintf(pHlp, "    User/supervisor page protection support = %RTbool\n",  ExtFeat.n.u1UserSupervisorSup);
            pHlp->pfnPrintf(pHlp, "    Device table segments supported         = %#x (%u)\n", ExtFeat.n.u2DevTabSegSup,
                            g_acDevTabSegs[ExtFeat.n.u2DevTabSegSup]);
            pHlp->pfnPrintf(pHlp, "    PPR log overflow early warning support  = %RTbool\n",  ExtFeat.n.u1PprLogOverflowWarn);
            pHlp->pfnPrintf(pHlp, "    PPR auto response support               = %RTbool\n",  ExtFeat.n.u1PprAutoRespSup);
            pHlp->pfnPrintf(pHlp, "    MARC support                            = %#x\n",      ExtFeat.n.u2MarcSup);
            pHlp->pfnPrintf(pHlp, "    Block StopMark message support          = %RTbool\n",  ExtFeat.n.u1BlockStopMarkSup);
            pHlp->pfnPrintf(pHlp, "    Performance optimization support        = %RTbool\n",  ExtFeat.n.u1PerfOptSup);
            pHlp->pfnPrintf(pHlp, "    MSI capability MMIO access support      = %RTbool\n",  ExtFeat.n.u1MsiCapMmioSup);
            pHlp->pfnPrintf(pHlp, "    Guest I/O protection support            = %RTbool\n",  ExtFeat.n.u1GstIoSup);
            pHlp->pfnPrintf(pHlp, "    Host access support                     = %RTbool\n",  ExtFeat.n.u1HostAccessSup);
            pHlp->pfnPrintf(pHlp, "    Enhanced PPR handling support           = %RTbool\n",  ExtFeat.n.u1EnhancedPprSup);
            pHlp->pfnPrintf(pHlp, "    Attribute forward supported             = %RTbool\n",  ExtFeat.n.u1AttrForwardSup);
            pHlp->pfnPrintf(pHlp, "    Host dirty support                      = %RTbool\n",  ExtFeat.n.u1HostDirtySup);
            pHlp->pfnPrintf(pHlp, "    Invalidate IOTLB type support           = %RTbool\n",  ExtFeat.n.u1InvIoTlbTypeSup);
            pHlp->pfnPrintf(pHlp, "    Guest page table access bit hw disable  = %RTbool\n",  ExtFeat.n.u1GstUpdateDisSup);
            pHlp->pfnPrintf(pHlp, "    Force physical dest for remapped intr.  = %RTbool\n",  ExtFeat.n.u1ForcePhysDstSup);
        }
    }
    /* PPR Log Base Address Register. */
    {
        PPR_LOG_BAR_T PprLogBar = pThis->PprLogBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = PprLogBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  PPR Log BAR                             = %#RX64\n",   PprLogBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", PprLogBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* Hardware Event (Hi) Register. */
    {
        IOMMU_HW_EVT_HI_T HwEvtHi = pThis->HwEvtHi;
        pHlp->pfnPrintf(pHlp, "  Hardware Event (Hi)                     = %#RX64\n",   HwEvtHi.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    First operand                           = %#RX64\n", HwEvtHi.n.u60FirstOperand);
            pHlp->pfnPrintf(pHlp, "    Event code                              = %#RX8\n",  HwEvtHi.n.u4EvtCode);
        }
    }
    /* Hardware Event (Lo) Register. */
    pHlp->pfnPrintf(pHlp, "  Hardware Event (Lo)                         = %#RX64\n", pThis->HwEvtLo);
    /* Hardware Event Status. */
    {
        IOMMU_HW_EVT_STATUS_T HwEvtStatus = pThis->HwEvtStatus;
        pHlp->pfnPrintf(pHlp, "  Hardware Event Status                   = %#RX64\n",    HwEvtStatus.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Valid                                   = %RTbool\n", HwEvtStatus.n.u1Valid);
            pHlp->pfnPrintf(pHlp, "    Overflow                                = %RTbool\n", HwEvtStatus.n.u1Overflow);
        }
    }
    /* Guest Virtual-APIC Log Base Address Register. */
    {
        GALOG_BAR_T const GALogBar = pThis->GALogBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = GALogBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  Guest Log BAR                           = %#RX64\n",    GALogBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %RTbool\n", GALogBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* Guest Virtual-APIC Log Tail Address Register. */
    {
        GALOG_TAIL_ADDR_T GALogTail = pThis->GALogTailAddr;
        pHlp->pfnPrintf(pHlp, "  Guest Log Tail Address                  = %#RX64\n",   GALogTail.u64);
        if (fVerbose)
            pHlp->pfnPrintf(pHlp, "    Tail address                            = %#RX64\n", GALogTail.n.u40GALogTailAddr);
    }
    /* PPR Log B Base Address Register. */
    {
        PPR_LOG_B_BAR_T PprLogBBar = pThis->PprLogBBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = PprLogBBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  PPR Log B BAR                           = %#RX64\n",   PprLogBBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", PprLogBBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* Event Log B Base Address Register. */
    {
        EVT_LOG_B_BAR_T EvtLogBBar = pThis->EvtLogBBaseAddr;
        uint32_t      cEntries;
        uint32_t      cbBuffer;
        uint8_t const uEncodedLen = EvtLogBBar.n.u4Len;
        iommuAmdGetBaseBufferLength(uEncodedLen, &cEntries, &cbBuffer);
        pHlp->pfnPrintf(pHlp, "  Event Log B BAR                         = %#RX64\n",   EvtLogBBar.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", EvtLogBBar.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Length                                  = %u (%u entries, %u bytes)\n", uEncodedLen,
                            cEntries, cbBuffer);
        }
    }
    /* Device Table Segment Registers. */
    for (unsigned i = 0; i < RT_ELEMENTS(pThis->DevTabSeg); i++)
    {
        DEV_TAB_SEG_BAR_T const DevTabSeg = pThis->DevTabSeg[i];
        pHlp->pfnPrintf(pHlp, "  Device Table Segment BAR [%u]            = %#RX64\n",  DevTabSeg.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Base address                            = %#RX64\n", DevTabSeg.n.u40Base);
            pHlp->pfnPrintf(pHlp, "    Size                                    = %#x (%u bytes)\n", DevTabSeg.n.u8Size,
                            IOMMU_GET_DEV_TAB_SIZE(DevTabSeg.n.u8Size));
        }
    }
    /* Device-Specific Feature Extension Register. */
    {
        DEV_SPECIFIC_FEAT_T const DevSpecificFeat = pThis->DevSpecificFeat;
        pHlp->pfnPrintf(pHlp, "  Device-specific Feature                 = %#RX64\n",   DevSpecificFeat.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Feature                                 = %#RX32\n", DevSpecificFeat.n.u24DevSpecFeat);
            pHlp->pfnPrintf(pHlp, "    Minor revision ID                       = %#x\n",    DevSpecificFeat.n.u4RevMinor);
            pHlp->pfnPrintf(pHlp, "    Major revision ID                       = %#x\n",    DevSpecificFeat.n.u4RevMajor);
        }
    }
    /* Device-Specific Control Extension Register. */
    {
        DEV_SPECIFIC_CTRL_T const DevSpecificCtrl = pThis->DevSpecificCtrl;
        pHlp->pfnPrintf(pHlp, "  Device-specific Control                 = %#RX64\n",   DevSpecificCtrl.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Control                                 = %#RX32\n", DevSpecificCtrl.n.u24DevSpecCtrl);
            pHlp->pfnPrintf(pHlp, "    Minor revision ID                       = %#x\n",    DevSpecificCtrl.n.u4RevMinor);
            pHlp->pfnPrintf(pHlp, "    Major revision ID                       = %#x\n",    DevSpecificCtrl.n.u4RevMajor);
        }
    }
    /* Device-Specific Status Extension Register. */
    {
        DEV_SPECIFIC_STATUS_T const DevSpecificStatus = pThis->DevSpecificStatus;
        pHlp->pfnPrintf(pHlp, "  Device-specific Control                 = %#RX64\n",   DevSpecificStatus.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Status                                  = %#RX32\n", DevSpecificStatus.n.u24DevSpecStatus);
            pHlp->pfnPrintf(pHlp, "    Minor revision ID                       = %#x\n",    DevSpecificStatus.n.u4RevMinor);
            pHlp->pfnPrintf(pHlp, "    Major revision ID                       = %#x\n",    DevSpecificStatus.n.u4RevMajor);
        }
    }
    /* MSI Miscellaneous Information Register (Lo and Hi). */
    {
        MSI_MISC_INFO_T const MsiMiscInfo = pThis->MsiMiscInfo;
        pHlp->pfnPrintf(pHlp, "  MSI Misc. Info. Register                = %#RX64\n",    MsiMiscInfo.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Event Log MSI number                    = %#x\n",     MsiMiscInfo.n.u5MsiNumEvtLog);
            pHlp->pfnPrintf(pHlp, "    Guest Virtual-Address Size              = %#x\n",     MsiMiscInfo.n.u3GstVirtAddrSize);
            pHlp->pfnPrintf(pHlp, "    Physical Address Size                   = %#x\n",     MsiMiscInfo.n.u7PhysAddrSize);
            pHlp->pfnPrintf(pHlp, "    Virtual-Address Size                    = %#x\n",     MsiMiscInfo.n.u7VirtAddrSize);
            pHlp->pfnPrintf(pHlp, "    HT Transport ATS Range Reserved         = %RTbool\n", MsiMiscInfo.n.u1HtAtsResv);
            pHlp->pfnPrintf(pHlp, "    PPR MSI number                          = %#x\n",     MsiMiscInfo.n.u5MsiNumPpr);
            pHlp->pfnPrintf(pHlp, "    GA Log MSI number                       = %#x\n",     MsiMiscInfo.n.u5MsiNumGa);
        }
    }
    /* MSI Capability Header. */
    {
        MSI_CAP_HDR_T MsiCapHdr;
        MsiCapHdr.u32 = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_CAP_HDR);
        pHlp->pfnPrintf(pHlp, "  MSI Capability Header                   = %#RX32\n",    MsiCapHdr.u32);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Capability ID                           = %#x\n",     MsiCapHdr.n.u8MsiCapId);
            pHlp->pfnPrintf(pHlp, "    Capability Ptr (PCI config offset)      = %#x\n",     MsiCapHdr.n.u8MsiCapPtr);
            pHlp->pfnPrintf(pHlp, "    Enable                                  = %RTbool\n", MsiCapHdr.n.u1MsiEnable);
            pHlp->pfnPrintf(pHlp, "    Multi-message capability                = %#x\n",     MsiCapHdr.n.u3MsiMultiMessCap);
            pHlp->pfnPrintf(pHlp, "    Multi-message enable                    = %#x\n",     MsiCapHdr.n.u3MsiMultiMessEn);
        }
    }
    /* MSI Address Register (Lo and Hi). */
    {
        uint32_t const uMsiAddrLo = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_LO);
        uint32_t const uMsiAddrHi = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_HI);
        MSI_ADDR_T MsiAddr;
        MsiAddr.u64 = RT_MAKE_U64(uMsiAddrLo, uMsiAddrHi);
        pHlp->pfnPrintf(pHlp, "  MSI Address                             = %#RX64\n",   MsiAddr.u64);
        if (fVerbose)
            pHlp->pfnPrintf(pHlp, "    Address                                 = %#RX64\n", MsiAddr.n.u62MsiAddr);
    }
    /* MSI Data. */
    {
        MSI_DATA_T MsiData;
        MsiData.u32 = PDMPciDevGetDWord(pPciDev, IOMMU_PCI_OFF_MSI_DATA);
        pHlp->pfnPrintf(pHlp, "  MSI Data                                = %#RX32\n", MsiData.u32);
        if (fVerbose)
            pHlp->pfnPrintf(pHlp, "    Data                                    = %#x\n",  MsiData.n.u16MsiData);
    }
    /* MSI Mapping Capability Header (HyperTransport, reporting all 0s currently). */
    {
        MSI_MAP_CAP_HDR_T MsiMapCapHdr;
        MsiMapCapHdr.u32 = 0;
        pHlp->pfnPrintf(pHlp, "  MSI Mapping Capability Header           = %#RX32\n",    MsiMapCapHdr.u32);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Capability ID                           = %#x\n",     MsiMapCapHdr.n.u8MsiMapCapId);
            pHlp->pfnPrintf(pHlp, "    Map enable                              = %RTbool\n", MsiMapCapHdr.n.u1MsiMapEn);
            pHlp->pfnPrintf(pHlp, "    Map fixed                               = %RTbool\n", MsiMapCapHdr.n.u1MsiMapFixed);
            pHlp->pfnPrintf(pHlp, "    Map capability type                     = %#x\n",     MsiMapCapHdr.n.u5MapCapType);
        }
    }
    /* Performance Optimization Control Register. */
    {
        IOMMU_PERF_OPT_CTRL_T const PerfOptCtrl = pThis->PerfOptCtrl;
        pHlp->pfnPrintf(pHlp, "  Performance Optimization Control        = %#RX32\n",    PerfOptCtrl.u32);
        if (fVerbose)
            pHlp->pfnPrintf(pHlp, "    Enable                                  = %RTbool\n", PerfOptCtrl.n.u1PerfOptEn);
    }
    /* XT (x2APIC) General Interrupt Control Register. */
    {
        IOMMU_XT_GEN_INTR_CTRL_T const XtGenIntrCtrl = pThis->XtGenIntrCtrl;
        pHlp->pfnPrintf(pHlp, "  XT General Interrupt Control            = %#RX64\n", XtGenIntrCtrl.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Interrupt destination mode              = %s\n",
                            !XtGenIntrCtrl.n.u1X2ApicIntrDstMode ? "physical" : "logical");
            pHlp->pfnPrintf(pHlp, "    Interrupt destination                   = %#RX64\n",
                            RT_MAKE_U64(XtGenIntrCtrl.n.u24X2ApicIntrDstLo, XtGenIntrCtrl.n.u7X2ApicIntrDstHi));
            pHlp->pfnPrintf(pHlp, "    Interrupt vector                        = %#x\n", XtGenIntrCtrl.n.u8X2ApicIntrVector);
            pHlp->pfnPrintf(pHlp, "    Interrupt delivery mode                 = %#x\n",
                            !XtGenIntrCtrl.n.u8X2ApicIntrVector ? "fixed" : "arbitrated");
        }
    }
    /* XT (x2APIC) PPR Interrupt Control Register. */
    {
        IOMMU_XT_PPR_INTR_CTRL_T const XtPprIntrCtrl = pThis->XtPprIntrCtrl;
        pHlp->pfnPrintf(pHlp, "  XT PPR Interrupt Control                = %#RX64\n", XtPprIntrCtrl.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "   Interrupt destination mode               = %s\n",
                            !XtPprIntrCtrl.n.u1X2ApicIntrDstMode ? "physical" : "logical");
            pHlp->pfnPrintf(pHlp, "   Interrupt destination                    = %#RX64\n",
                            RT_MAKE_U64(XtPprIntrCtrl.n.u24X2ApicIntrDstLo, XtPprIntrCtrl.n.u7X2ApicIntrDstHi));
            pHlp->pfnPrintf(pHlp, "   Interrupt vector                         = %#x\n", XtPprIntrCtrl.n.u8X2ApicIntrVector);
            pHlp->pfnPrintf(pHlp, "   Interrupt delivery mode                  = %#x\n",
                            !XtPprIntrCtrl.n.u8X2ApicIntrVector ? "fixed" : "arbitrated");
        }
    }
    /* XT (X2APIC) GA Log Interrupt Control Register. */
    {
        IOMMU_XT_GALOG_INTR_CTRL_T const XtGALogIntrCtrl = pThis->XtGALogIntrCtrl;
        pHlp->pfnPrintf(pHlp, "  XT PPR Interrupt Control                = %#RX64\n", XtGALogIntrCtrl.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Interrupt destination mode              = %s\n",
                            !XtGALogIntrCtrl.n.u1X2ApicIntrDstMode ? "physical" : "logical");
            pHlp->pfnPrintf(pHlp, "    Interrupt destination                   = %#RX64\n",
                            RT_MAKE_U64(XtGALogIntrCtrl.n.u24X2ApicIntrDstLo, XtGALogIntrCtrl.n.u7X2ApicIntrDstHi));
            pHlp->pfnPrintf(pHlp, "    Interrupt vector                        = %#x\n", XtGALogIntrCtrl.n.u8X2ApicIntrVector);
            pHlp->pfnPrintf(pHlp, "    Interrupt delivery mode                 = %#x\n",
                            !XtGALogIntrCtrl.n.u8X2ApicIntrVector ? "fixed" : "arbitrated");
        }
    }
    /* MARC Registers. */
    {
        for (unsigned i = 0; i < RT_ELEMENTS(pThis->aMarcApers); i++)
        {
            pHlp->pfnPrintf(pHlp, " MARC Aperature %u:\n", i);
            MARC_APER_BAR_T const MarcAperBar = pThis->aMarcApers[i].Base;
            pHlp->pfnPrintf(pHlp, "   Base    = %#RX64 (addr: %#RX64)\n", MarcAperBar.u64, MarcAperBar.n.u40MarcBaseAddr);

            MARC_APER_RELOC_T const MarcAperReloc = pThis->aMarcApers[i].Reloc;
            pHlp->pfnPrintf(pHlp, "   Reloc   = %#RX64 (addr: %#RX64, read-only: %RTbool, enable: %RTbool)\n",
                            MarcAperReloc.u64, MarcAperReloc.n.u40MarcRelocAddr, MarcAperReloc.n.u1ReadOnly,
                            MarcAperReloc.n.u1RelocEn);

            MARC_APER_LEN_T const MarcAperLen = pThis->aMarcApers[i].Length;
            pHlp->pfnPrintf(pHlp, "   Length  = %u pages\n", MarcAperLen.n.u40MarcLength);
        }
    }
    /* Reserved Register. */
    pHlp->pfnPrintf(pHlp, "  Reserved Register                           = %#RX64\n", pThis->RsvdReg);
    /* Command Buffer Head Pointer Register. */
    {
        CMD_BUF_HEAD_PTR_T const CmdBufHeadPtr = pThis->CmdBufHeadPtr;
        pHlp->pfnPrintf(pHlp, "  Command Buffer Head Pointer             = %#RX64\n", CmdBufHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  CmdBufHeadPtr.n.u15Ptr);
    }
    /* Command Buffer Tail Pointer Register. */
    {
        CMD_BUF_HEAD_PTR_T const CmdBufTailPtr = pThis->CmdBufTailPtr;
        pHlp->pfnPrintf(pHlp, "  Command Buffer Tail Pointer             = %#RX64\n", CmdBufTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  CmdBufTailPtr.n.u15Ptr);
    }
    /* Event Log Head Pointer Register. */
    {
        EVT_LOG_HEAD_PTR_T const EvtLogHeadPtr = pThis->EvtLogHeadPtr;
        pHlp->pfnPrintf(pHlp, "  Event Log Head Pointer                  = %#RX64\n", EvtLogHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  EvtLogHeadPtr.n.u15Ptr);
    }
    /* Event Log Tail Pointer Register. */
    {
        EVT_LOG_TAIL_PTR_T const EvtLogTailPtr = pThis->EvtLogTailPtr;
        pHlp->pfnPrintf(pHlp, "  Event Log Head Pointer                  = %#RX64\n", EvtLogTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  EvtLogTailPtr.n.u15Ptr);
    }
    /* Status Register. */
    {
        IOMMU_STATUS_T const Status = pThis->Status;
        pHlp->pfnPrintf(pHlp, "  Status Register                         = %#RX64\n", Status.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Event log overflow                      = %RTbool\n", Status.n.u1EvtOverflow);
            pHlp->pfnPrintf(pHlp, "    Event log interrupt                     = %RTbool\n", Status.n.u1EvtLogIntr);
            pHlp->pfnPrintf(pHlp, "    Completion wait interrupt               = %RTbool\n", Status.n.u1CompWaitIntr);
            pHlp->pfnPrintf(pHlp, "    Event log running                       = %RTbool\n", Status.n.u1EvtLogRunning);
            pHlp->pfnPrintf(pHlp, "    Command buffer running                  = %RTbool\n", Status.n.u1CmdBufRunning);
            pHlp->pfnPrintf(pHlp, "    PPR overflow                            = %RTbool\n", Status.n.u1PprOverflow);
            pHlp->pfnPrintf(pHlp, "    PPR interrupt                           = %RTbool\n", Status.n.u1PprIntr);
            pHlp->pfnPrintf(pHlp, "    PPR log running                         = %RTbool\n", Status.n.u1PprLogRunning);
            pHlp->pfnPrintf(pHlp, "    Guest log running                       = %RTbool\n", Status.n.u1GstLogRunning);
            pHlp->pfnPrintf(pHlp, "    Guest log interrupt                     = %RTbool\n", Status.n.u1GstLogIntr);
            pHlp->pfnPrintf(pHlp, "    PPR log B overflow                      = %RTbool\n", Status.n.u1PprOverflowB);
            pHlp->pfnPrintf(pHlp, "    PPR log active                          = %RTbool\n", Status.n.u1PprLogActive);
            pHlp->pfnPrintf(pHlp, "    Event log B overflow                    = %RTbool\n", Status.n.u1EvtOverflowB);
            pHlp->pfnPrintf(pHlp, "    Event log active                        = %RTbool\n", Status.n.u1EvtLogActive);
            pHlp->pfnPrintf(pHlp, "    PPR log B overflow early warning        = %RTbool\n", Status.n.u1PprOverflowEarlyB);
            pHlp->pfnPrintf(pHlp, "    PPR log overflow early warning          = %RTbool\n", Status.n.u1PprOverflowEarly);
        }
    }
    /* PPR Log Head Pointer. */
    {
        PPR_LOG_HEAD_PTR_T const PprLogHeadPtr = pThis->PprLogHeadPtr;
        pHlp->pfnPrintf(pHlp, "  PPR Log Head Pointer                    = %#RX64\n", PprLogHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  PprLogHeadPtr.n.u15Ptr);
    }
    /* PPR Log Tail Pointer. */
    {
        PPR_LOG_TAIL_PTR_T const PprLogTailPtr = pThis->PprLogTailPtr;
        pHlp->pfnPrintf(pHlp, "  PPR Log Tail Pointer                    = %#RX64\n", PprLogTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  PprLogTailPtr.n.u15Ptr);
    }
    /* Guest Virtual-APIC Log Head Pointer. */
    {
        GALOG_HEAD_PTR_T const GALogHeadPtr = pThis->GALogHeadPtr;
        pHlp->pfnPrintf(pHlp, "  Guest Virtual-APIC Log Head Pointer     = %#RX64\n", GALogHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  GALogHeadPtr.n.u12GALogPtr);
    }
    /* Guest Virtual-APIC Log Tail Pointer. */
    {
        GALOG_HEAD_PTR_T const GALogTailPtr = pThis->GALogTailPtr;
        pHlp->pfnPrintf(pHlp, "  Guest Virtual-APIC Log Tail Pointer     = %#RX64\n", GALogTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  GALogTailPtr.n.u12GALogPtr);
    }
    /* PPR Log B Head Pointer. */
    {
        PPR_LOG_B_HEAD_PTR_T const PprLogBHeadPtr = pThis->PprLogBHeadPtr;
        pHlp->pfnPrintf(pHlp, "  PPR Log B Head Pointer                  = %#RX64\n", PprLogBHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  PprLogBHeadPtr.n.u15Ptr);
    }
    /* PPR Log B Tail Pointer. */
    {
        PPR_LOG_B_TAIL_PTR_T const PprLogBTailPtr = pThis->PprLogBTailPtr;
        pHlp->pfnPrintf(pHlp, "  PPR Log B Tail Pointer                  = %#RX64\n", PprLogBTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  PprLogBTailPtr.n.u15Ptr);
    }
    /* Event Log B Head Pointer. */
    {
        EVT_LOG_B_HEAD_PTR_T const EvtLogBHeadPtr = pThis->EvtLogBHeadPtr;
        pHlp->pfnPrintf(pHlp, "  Event Log B Head Pointer                = %#RX64\n", EvtLogBHeadPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  EvtLogBHeadPtr.n.u15Ptr);
    }
    /* Event Log B Tail Pointer. */
    {
        EVT_LOG_B_TAIL_PTR_T const EvtLogBTailPtr = pThis->EvtLogBTailPtr;
        pHlp->pfnPrintf(pHlp, "  Event Log B Tail Pointer                = %#RX64\n", EvtLogBTailPtr.u64);
        pHlp->pfnPrintf(pHlp, "    Pointer                                 = %#x\n",  EvtLogBTailPtr.n.u15Ptr);
    }
    /* PPR Log Auto Response Register. */
    {
        PPR_LOG_AUTO_RESP_T const PprLogAutoResp = pThis->PprLogAutoResp;
        pHlp->pfnPrintf(pHlp, "  PPR Log Auto Response Register          = %#RX64\n",     PprLogAutoResp.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Code                                    = %#x\n",      PprLogAutoResp.n.u4AutoRespCode);
            pHlp->pfnPrintf(pHlp, "    Mask Gen.                               = %RTbool\n",  PprLogAutoResp.n.u1AutoRespMaskGen);
        }
    }
    /* PPR Log Overflow Early Warning Indicator Register. */
    {
        PPR_LOG_OVERFLOW_EARLY_T const PprLogOverflowEarly = pThis->PprLogOverflowEarly;
        pHlp->pfnPrintf(pHlp, "  PPR Log overflow early warning          = %#RX64\n",    PprLogOverflowEarly.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Threshold                               = %#x\n",     PprLogOverflowEarly.n.u15Threshold);
            pHlp->pfnPrintf(pHlp, "    Interrupt enable                        = %RTbool\n", PprLogOverflowEarly.n.u1IntrEn);
            pHlp->pfnPrintf(pHlp, "    Enable                                  = %RTbool\n", PprLogOverflowEarly.n.u1Enable);
        }
    }
    /* PPR Log Overflow Early Warning Indicator Register. */
    {
        PPR_LOG_OVERFLOW_EARLY_T const PprLogBOverflowEarly = pThis->PprLogBOverflowEarly;
        pHlp->pfnPrintf(pHlp, "  PPR Log B overflow early warning        = %#RX64\n",    PprLogBOverflowEarly.u64);
        if (fVerbose)
        {
            pHlp->pfnPrintf(pHlp, "    Threshold                               = %#x\n",     PprLogBOverflowEarly.n.u15Threshold);
            pHlp->pfnPrintf(pHlp, "    Interrupt enable                        = %RTbool\n", PprLogBOverflowEarly.n.u1IntrEn);
            pHlp->pfnPrintf(pHlp, "    Enable                                  = %RTbool\n", PprLogBOverflowEarly.n.u1Enable);
        }
    }
}


/**
 * @callback_method_impl{FNSSMDEVSAVEEXEC}
 */
static DECLCALLBACK(int) iommuAmdR3SaveExec(PPDMDEVINS pDevIns, PSSMHANDLE pSSM)
{
    /** @todo IOMMU: Save state. */
    RT_NOREF2(pDevIns, pSSM);
    return VERR_NOT_IMPLEMENTED;
}


/**
 * @callback_method_impl{FNSSMDEVLOADEXEC}
 */
static DECLCALLBACK(int) iommuAmdR3LoadExec(PPDMDEVINS pDevIns, PSSMHANDLE pSSM, uint32_t uVersion, uint32_t uPass)
{
    /** @todo IOMMU: Load state. */
    RT_NOREF4(pDevIns, pSSM, uVersion, uPass);
    return VERR_NOT_IMPLEMENTED;
}


/**
 * @interface_method_impl{PDMDEVREG,pfnReset}
 */
static DECLCALLBACK(void) iommuAmdR3Reset(PPDMDEVINS pDevIns)
{
    /*
     * Resets read-write portion of the IOMMU state.
     *
     * State data not initialized here is expected to be initialized during
     * device construction and remain read-only through the lifetime of the VM.
     */
    PIOMMU     pThis   = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);

    pThis->DevTabBaseAddr.u64     = 0;

    pThis->CmdBufBaseAddr.u64     = 0;
    pThis->CmdBufBaseAddr.n.u4Len = 8;

    pThis->EvtLogBaseAddr.u64     = 0;
    pThis->EvtLogBaseAddr.n.u4Len = 8;

    pThis->Ctrl.u64               = 0;

    pThis->ExclRangeBaseAddr.u64  = 0;
    pThis->ExclRangeLimit.u64     = 0;

    pThis->ExtFeat.n.u1PrefetchSup           = 0;
    pThis->ExtFeat.n.u1PprSup                = 0;
    pThis->ExtFeat.n.u1X2ApicSup             = 0;
    pThis->ExtFeat.n.u1NoExecuteSup          = 0;
    pThis->ExtFeat.n.u1GstTranslateSup       = 0;
    pThis->ExtFeat.n.u1InvAllSup             = 0;
    pThis->ExtFeat.n.u1GstVirtApicSup        = 0;
    pThis->ExtFeat.n.u1HwErrorSup            = 1;
    pThis->ExtFeat.n.u1PerfCounterSup        = 0;
    pThis->ExtFeat.n.u2HostAddrTranslateSize = 0;   /* Requires GstTranslateSup. */
    pThis->ExtFeat.n.u2GstAddrTranslateSize  = 0;   /* Requires GstTranslateSup. */
    pThis->ExtFeat.n.u2GstCr3RootTblLevel    = 0;   /* Requires GstTranslateSup. */
    pThis->ExtFeat.n.u2SmiFilterSup          = 0;
    pThis->ExtFeat.n.u3SmiFilterCount        = 0;
    pThis->ExtFeat.n.u3GstVirtApicModeSup    = 0;   /* Requires GstVirtApicSup */
    pThis->ExtFeat.n.u2DualPprLogSup         = 0;
    pThis->ExtFeat.n.u2DualEvtLogSup         = 0;
    pThis->ExtFeat.n.u5MaxPasidSup           = 0;   /* Requires GstTranslateSup. */
    pThis->ExtFeat.n.u1UserSupervisorSup     = 0;
    AssertCompile(IOMMU_MAX_DEV_TAB_SEGMENTS < RT_ELEMENTS(g_acDevTabSegs));
    pThis->ExtFeat.n.u2DevTabSegSup          = IOMMU_MAX_DEV_TAB_SEGMENTS;
    pThis->ExtFeat.n.u1PprLogOverflowWarn    = 0;
    pThis->ExtFeat.n.u1PprAutoRespSup        = 0;
    pThis->ExtFeat.n.u2MarcSup               = 0;
    pThis->ExtFeat.n.u1BlockStopMarkSup      = 0;
    pThis->ExtFeat.n.u1PerfOptSup            = 0;
    pThis->ExtFeat.n.u1MsiCapMmioSup         = 1;
    pThis->ExtFeat.n.u1GstIoSup              = 0;
    pThis->ExtFeat.n.u1HostAccessSup         = 0;
    pThis->ExtFeat.n.u1EnhancedPprSup        = 0;
    pThis->ExtFeat.n.u1AttrForwardSup        = 0;
    pThis->ExtFeat.n.u1HostDirtySup          = 0;
    pThis->ExtFeat.n.u1InvIoTlbTypeSup       = 0;
    pThis->ExtFeat.n.u1GstUpdateDisSup       = 0;
    pThis->ExtFeat.n.u1ForcePhysDstSup       = 0;

    pThis->PprLogBaseAddr.u64        = 0;
    pThis->PprLogBaseAddr.n.u4Len    = 8;

    pThis->HwEvtHi.u64               = 0;
    pThis->HwEvtLo                   = 0;
    pThis->HwEvtStatus.u64           = 0;

    pThis->GALogBaseAddr.n.u40Base   = 0;
    pThis->GALogBaseAddr.n.u4Len     = 8;
    pThis->GALogTailAddr.u64         = 0;

    pThis->PprLogBBaseAddr.n.u40Base = 0;
    pThis->PprLogBBaseAddr.n.u4Len   = 8;
    pThis->EvtLogBBaseAddr.n.u40Base = 0;
    pThis->EvtLogBBaseAddr.n.u4Len   = 8;

    memset(&pThis->DevTabSeg[0], 0, sizeof(pThis->DevTabSeg));

    pThis->DevSpecificFeat.u64       = 0;
    pThis->DevSpecificCtrl.u64       = 0;
    pThis->DevSpecificStatus.u64     = 0;

    pThis->MsiMiscInfo.u64           = 0;
    pThis->PerfOptCtrl.u32           = 0;

    pThis->XtGenIntrCtrl.u64         = 0;
    pThis->XtPprIntrCtrl.u64         = 0;
    pThis->XtGALogIntrCtrl.u64       = 0;

    memset(&pThis->aMarcApers[0], 0, sizeof(pThis->aMarcApers));

    pThis->RsvdReg                   = 0;

    pThis->CmdBufHeadPtr.u64         = 0;
    pThis->CmdBufTailPtr.u64         = 0;
    pThis->EvtLogHeadPtr.u64         = 0;
    pThis->EvtLogTailPtr.u64         = 0;

    pThis->Status.u64                = 0;

    pThis->PprLogHeadPtr.u64         = 0;
    pThis->PprLogTailPtr.u64         = 0;

    pThis->GALogHeadPtr.u64          = 0;
    pThis->GALogTailPtr.u64          = 0;

    pThis->PprLogBHeadPtr.u64        = 0;
    pThis->PprLogBTailPtr.u64        = 0;

    pThis->EvtLogBHeadPtr.u64        = 0;
    pThis->EvtLogBTailPtr.u64        = 0;

    pThis->PprLogAutoResp.u64        = 0;
    pThis->PprLogOverflowEarly.u64   = 0;
    pThis->PprLogBOverflowEarly.u64  = 0;

    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_BASE_ADDR_REG_LO, 0);
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_BASE_ADDR_REG_HI, 0);
}


/**
 * @interface_method_impl{PDMDEVREG,pfnDestruct}
 */
static DECLCALLBACK(int) iommuAmdR3Destruct(PPDMDEVINS pDevIns)
{
    PDMDEV_CHECK_VERSIONS_RETURN_QUIET(pDevIns);
    PIOMMU   pThis   = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    LogFlowFunc(("\n"));

    /* Close the command thread semaphore. */
    if (pThis->hEvtCmdThread != NIL_SUPSEMEVENT)
    {
        PDMDevHlpSUPSemEventClose(pDevIns, pThis->hEvtCmdThread);
        pThis->hEvtCmdThread = NIL_SUPSEMEVENT;
    }
    return VINF_SUCCESS;
}


/**
 * @interface_method_impl{PDMDEVREG,pfnConstruct}
 */
static DECLCALLBACK(int) iommuAmdR3Construct(PPDMDEVINS pDevIns, int iInstance, PCFGMNODE pCfg)
{
    NOREF(iInstance);

    PDMDEV_CHECK_VERSIONS_RETURN(pDevIns);
    PIOMMU          pThis   = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    PIOMMUCC        pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PIOMMUCC);
    PCPDMDEVHLPR3   pHlp    = pDevIns->pHlpR3;
    int             rc;
    LogFlowFunc(("\n"));

    pThisCC->pDevInsR3 = pDevIns;

    /*
     * Validate and read the configuration.
     */
    PDMDEV_VALIDATE_CONFIG_RETURN(pDevIns, "Device|Function", "");

    uint8_t uPciDevice;
    rc = pHlp->pfnCFGMQueryU8Def(pCfg, "Device", &uPciDevice, 0);
    if (RT_FAILURE(rc))
        return PDMDEV_SET_ERROR(pDevIns, rc, N_("IOMMU: Failed to query \"Device\""));

    uint8_t uPciFunction;
    rc = pHlp->pfnCFGMQueryU8Def(pCfg, "Function", &uPciFunction, 2);
    if (RT_FAILURE(rc))
        return PDMDEV_SET_ERROR(pDevIns, rc, N_("IOMMU: Failed to query \"Function\""));

    /*
     * Register the IOMMU with PDM.
     */
    PDMIOMMUREGR3 IommuReg;
    RT_ZERO(IommuReg);
    IommuReg.u32Version  = PDM_IOMMUREGCC_VERSION;
    IommuReg.pfnMemRead  = iommuAmdDeviceMemRead;
    IommuReg.pfnMemWrite = iommuAmdDeviceMemWrite;
    IommuReg.u32TheEnd   = PDM_IOMMUREGCC_VERSION;
    rc = PDMDevHlpIommuRegister(pDevIns, &IommuReg, &pThisCC->CTX_SUFF(pIommuHlp), &pThis->idxIommu);
    if (RT_FAILURE(rc))
        return PDMDEV_SET_ERROR(pDevIns, rc, N_("Failed to register ourselves as an IOMMU device"));
    if (pThisCC->CTX_SUFF(pIommuHlp)->u32Version != PDM_IOMMUHLPR3_VERSION)
        return PDMDevHlpVMSetError(pDevIns, VERR_VERSION_MISMATCH, RT_SRC_POS,
                                   N_("IOMMU helper version mismatch; got %#x expected %#x"),
                                   pThisCC->CTX_SUFF(pIommuHlp)->u32Version, PDM_IOMMUHLPR3_VERSION);
    if (pThisCC->CTX_SUFF(pIommuHlp)->u32TheEnd != PDM_IOMMUHLPR3_VERSION)
        return PDMDevHlpVMSetError(pDevIns, VERR_VERSION_MISMATCH, RT_SRC_POS,
                                   N_("IOMMU helper end-version mismatch; got %#x expected %#x"),
                                   pThisCC->CTX_SUFF(pIommuHlp)->u32TheEnd, PDM_IOMMUHLPR3_VERSION);

    /*
     * Initialize read-only PCI configuration space.
     */
    PPDMPCIDEV pPciDev = pDevIns->apPciDevs[0];
    PDMPCIDEV_ASSERT_VALID(pDevIns, pPciDev);

    /* Header. */
    PDMPciDevSetVendorId(pPciDev,           IOMMU_PCI_VENDOR_ID);     /* AMD */
    PDMPciDevSetDeviceId(pPciDev,           IOMMU_PCI_DEVICE_ID);     /* VirtualBox IOMMU device */
    PDMPciDevSetCommand(pPciDev,            0);                       /* Command */
    PDMPciDevSetStatus(pPciDev,             0x5);                     /* Status - CapList supported */
    PDMPciDevSetRevisionId(pPciDev,         IOMMU_PCI_REVISION_ID);   /* VirtualBox specific device implementation revision */
    PDMPciDevSetClassBase(pPciDev,          0x08);                    /* System Base Peripheral */
    PDMPciDevSetClassSub(pPciDev,           0x06);                    /* IOMMU */
    PDMPciDevSetClassProg(pPciDev,          0x00);                    /* IOMMU Programming interface */
    PDMPciDevSetHeaderType(pPciDev,         0x00);                    /* Single function, type 0. */
    PDMPciDevSetSubSystemId(pPciDev,        IOMMU_PCI_DEVICE_ID);     /* AMD */
    PDMPciDevSetSubSystemVendorId(pPciDev,  IOMMU_PCI_VENDOR_ID);     /* VirtualBox IOMMU device */
    PDMPciDevSetCapabilityList(pPciDev,     IOMMU_PCI_OFF_CAP_HDR);   /* Offset into capability registers. */
    PDMPciDevSetInterruptPin(pPciDev,       0x01);                    /* INTA#. */
    PDMPciDevSetInterruptLine(pPciDev,      0x00);                    /* For software compatibility; no effect on hardware. */
    /* Capability Header. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_CAP_HDR,
                        RT_BF_MAKE(IOMMU_BF_CAPHDR_CAP_ID,    0xf)    /* RO - Secure Device capability block */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_CAP_PTR,   IOMMU_PCI_OFF_MSI_CAP_HDR)  /* RO - Offset to next capability block */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_CAP_TYPE,  0x3)    /* RO - IOMMU capability block */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_CAP_REV,   0x1)    /* RO - IOMMU interface revision */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_IOTLB_SUP, 0x0)    /* RO - Remote IOTLB support */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_HT_TUNNEL, 0x0)    /* RO - HyperTransport Tunnel support */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_NP_CACHE,  0x0)    /* RO - Cache NP page table entries */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_EFR_SUP,   0x1)    /* RO - Extended Feature Register support */
                      | RT_BF_MAKE(IOMMU_BF_CAPHDR_CAP_EXT,   0x1));  /* RO - Misc. Information Register support */
    /* Base Address Low Register. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_BASE_ADDR_REG_LO, 0x0);  /* RW - Base address (Lo) and enable bit. */
    /* Base Address High Register. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_BASE_ADDR_REG_HI, 0x0);  /* RW - Base address (Hi) */
    /* IOMMU Range Register. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_RANGE_REG, 0x0);         /* RW - Range register (implemented as RO by us). */
    /* Misc. Information Register 0. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MISCINFO_REG_0,
                        RT_BF_MAKE(IOMMU_BF_MISCINFO_0_MSI_NUM,     0x0)    /* RO - MSI number */
                      | RT_BF_MAKE(IOMMU_BF_MISCINFO_0_GVA_SIZE,    0x2)    /* RO - Guest Virt. Addr size (2=48 bits) */
                      | RT_BF_MAKE(IOMMU_BF_MISCINFO_0_PA_SIZE,     0x30)   /* RO - Physical Addr size (48 bits) */
                      | RT_BF_MAKE(IOMMU_BF_MISCINFO_0_VA_SIZE,     0x40)   /* RO - Virt. Addr size (64 bits) */
                      | RT_BF_MAKE(IOMMU_BF_MISCINFO_0_HT_ATS_RESV, 0x0)    /* RW - HT ATS reserved */
                      | RT_BF_MAKE(IOMMU_BF_MISCINFO_0_MSI_NUM_PPR, 0x0));  /* RW - PPR interrupt number */
    /* Misc. Information Register 1. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MISCINFO_REG_0, 0);
    /* MSI Capability Header register. */
    PDMMSIREG MsiReg;
    RT_ZERO(MsiReg);
    MsiReg.cMsiVectors    = 1;
    MsiReg.iMsiCapOffset  = IOMMU_PCI_OFF_MSI_CAP_HDR;
    MsiReg.iMsiNextOffset = 0; /* IOMMU_PCI_OFF_MSI_MAP_CAP_HDR */
    MsiReg.fMsi64bit      = 1; /* 64-bit addressing support is mandatory; See AMD spec. 2.8 "IOMMU Interrupt Support". */
    rc = PDMDevHlpPCIRegisterMsi(pDevIns, &MsiReg);
    AssertRCReturn(rc, rc);

    /* MSI Address (Lo, Hi) and MSI data are read-write PCI config registers handled by our generic PCI config space code. */
#if 0
    /* MSI Address Lo. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_LO, 0);         /* RW - MSI message address (Lo). */
    /* MSI Address Hi. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_ADDR_HI, 0);         /* RW - MSI message address (Hi). */
    /* MSI Data. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_DATA, 0);            /* RW - MSI data. */
#endif

#if 0
    /** @todo IOMMU: I don't know if we need to support this, enable later if
     *        required. */
    /* MSI Mapping Capability Header register. */
    PDMPciDevSetDWord(pPciDev, IOMMU_PCI_OFF_MSI_MAP_CAP_HDR,
                        RT_BF_MAKE(IOMMU_BF_MSI_MAP_CAPHDR_CAP_ID,   0x8)       /* RO - Capability ID */
                      | RT_BF_MAKE(IOMMU_BF_MSI_MAP_CAPHDR_CAP_PTR,  0x0)       /* RO - Offset to next capability (NULL) */
                      | RT_BF_MAKE(IOMMU_BF_MSI_MAP_CAPHDR_EN,       0x1)       /* RO - MSI mapping capability enable */
                      | RT_BF_MAKE(IOMMU_BF_MSI_MAP_CAPHDR_FIXED,    0x1)       /* RO - MSI mapping range is fixed */
                      | RT_BF_MAKE(IOMMU_BF_MSI_MAP_CAPHDR_CAP_TYPE, 0x15));    /* RO - MSI mapping capability */
    /* When implementing don't forget to copy this to its MMIO shadow register (MsiMapCapHdr) in iommuAmdR3Init. */
#endif

    /*
     * Register the PCI function with PDM.
     */
    rc = PDMDevHlpPCIRegisterEx(pDevIns, pPciDev, 0 /* fFlags */, uPciDevice, uPciFunction, "amd-iommu");
    AssertLogRelRCReturn(rc, rc);

    /*
     * Intercept PCI config. space accesses.
     */
    rc = PDMDevHlpPCIInterceptConfigAccesses(pDevIns, pPciDev, iommuAmdR3PciConfigRead, iommuAmdR3PciConfigWrite);
    AssertLogRelRCReturn(rc, rc);

    /*
     * Create the MMIO region.
     * Mapping of the region is done when software configures it via PCI config space.
     */
    rc = PDMDevHlpMmioCreate(pDevIns, IOMMU_MMIO_REGION_SIZE, pPciDev, 0 /* iPciRegion */, iommuAmdMmioWrite, iommuAmdMmioRead,
                             NULL /* pvUser */, IOMMMIO_FLAGS_READ_DWORD_QWORD | IOMMMIO_FLAGS_WRITE_DWORD_QWORD_ZEROED,
                             "AMD-IOMMU", &pThis->hMmio);
    AssertLogRelRCReturn(rc, rc);

    /*
     * Register saved state.
     */
    rc = PDMDevHlpSSMRegisterEx(pDevIns, IOMMU_SAVED_STATE_VERSION, sizeof(IOMMU), NULL,
                                NULL, NULL, NULL,
                                NULL, iommuAmdR3SaveExec, NULL,
                                NULL, iommuAmdR3LoadExec, NULL);
    AssertLogRelRCReturn(rc, rc);

    /*
     * Register debugger info item.
     */
    rc = PDMDevHlpDBGFInfoRegister(pDevIns, "iommu", "Display IOMMU state.", iommuAmdR3DbgInfo);
    AssertLogRelRCReturn(rc, rc);

    /*
     * Create the command thread and its event semaphore.
     */
    rc = PDMDevHlpThreadCreate(pDevIns, &pThisCC->pCmdThread, pThis, iommuAmdR3CmdThread, iommuAmdR3CmdThreadWakeUp,
                               0 /* cbStack */, RTTHREADTYPE_IO, "AMD-IOMMU");
    AssertLogRelRCReturn(rc, rc);

    rc = PDMDevHlpSUPSemEventCreate(pDevIns, &pThis->hEvtCmdThread);
    AssertLogRelRCReturn(rc, rc);

    /*
     * Initialize parts of the IOMMU state as it would during reset.
     * Must be called -after- initializing PCI config. space registers.
     */
    iommuAmdR3Reset(pDevIns);

    return VINF_SUCCESS;
}

# else  /* !IN_RING3 */

/**
 * @callback_method_impl{PDMDEVREGR0,pfnConstruct}
 */
static DECLCALLBACK(int) iommuAmdRZConstruct(PPDMDEVINS pDevIns)
{
    PDMDEV_CHECK_VERSIONS_RETURN(pDevIns);
    PIOMMU   pThis   = PDMDEVINS_2_DATA(pDevIns, PIOMMU);
    PIOMMUCC pThisCC = PDMDEVINS_2_DATA_CC(pDevIns, PIOMMUCC);

    pThisCC->CTX_SUFF(pDevIns) = pDevIns;

    /* Set up the MMIO RZ handlers. */
    int rc = PDMDevHlpMmioSetUpContext(pDevIns, pThis->hMmio, iommuAmdMmioWrite, iommuAmdMmioRead, NULL /* pvUser */);
    AssertRCReturn(rc, rc);

    /* Set up the IOMMU RZ callbacks. */
    PDMIOMMUREGCC IommuReg;
    RT_ZERO(IommuReg);
    IommuReg.u32Version  = PDM_IOMMUREGCC_VERSION;
    IommuReg.idxIommu    = pThis->idxIommu;
    IommuReg.pfnMemRead  = iommuAmdDeviceMemRead;
    IommuReg.pfnMemWrite = iommuAmdDeviceMemWrite;
    IommuReg.u32TheEnd   = PDM_IOMMUREGCC_VERSION;
    rc = PDMDevHlpIommuSetUpContext(pDevIns, &IommuReg, &pThisCC->CTX_SUFF(pIommuHlp));
    AssertRCReturn(rc, rc);

    return VINF_SUCCESS;
}

# endif /* !IN_RING3 */

/**
 * The device registration structure.
 */
const PDMDEVREG g_DeviceIommuAmd =
{
    /* .u32Version = */             PDM_DEVREG_VERSION,
    /* .uReserved0 = */             0,
    /* .szName = */                 "iommu-amd",
    /* .fFlags = */                 PDM_DEVREG_FLAGS_DEFAULT_BITS | PDM_DEVREG_FLAGS_RZ | PDM_DEVREG_FLAGS_NEW_STYLE,
    /* .fClass = */                 PDM_DEVREG_CLASS_BUS_ISA,   /* Instantiate after PDM_DEVREG_CLASS_BUS_PCI */
    /* .cMaxInstances = */          ~0U,
    /* .uSharedVersion = */         42,
    /* .cbInstanceShared = */       sizeof(IOMMU),
    /* .cbInstanceCC = */           sizeof(IOMMUCC),
    /* .cbInstanceRC = */           sizeof(IOMMURC),
    /* .cMaxPciDevices = */         1,
    /* .cMaxMsixVectors = */        0,
    /* .pszDescription = */         "IOMMU (AMD)",
#if defined(IN_RING3)
    /* .pszRCMod = */               "VBoxDDRC.rc",
    /* .pszR0Mod = */               "VBoxDDR0.r0",
    /* .pfnConstruct = */           iommuAmdR3Construct,
    /* .pfnDestruct = */            iommuAmdR3Destruct,
    /* .pfnRelocate = */            NULL,
    /* .pfnMemSetup = */            NULL,
    /* .pfnPowerOn = */             NULL,
    /* .pfnReset = */               iommuAmdR3Reset,
    /* .pfnSuspend = */             NULL,
    /* .pfnResume = */              NULL,
    /* .pfnAttach = */              NULL,
    /* .pfnDetach = */              NULL,
    /* .pfnQueryInterface = */      NULL,
    /* .pfnInitComplete = */        NULL,
    /* .pfnPowerOff = */            NULL,
    /* .pfnSoftReset = */           NULL,
    /* .pfnReserved0 = */           NULL,
    /* .pfnReserved1 = */           NULL,
    /* .pfnReserved2 = */           NULL,
    /* .pfnReserved3 = */           NULL,
    /* .pfnReserved4 = */           NULL,
    /* .pfnReserved5 = */           NULL,
    /* .pfnReserved6 = */           NULL,
    /* .pfnReserved7 = */           NULL,
#elif defined(IN_RING0)
    /* .pfnEarlyConstruct = */      NULL,
    /* .pfnConstruct = */           iommuAmdRZConstruct,
    /* .pfnDestruct = */            NULL,
    /* .pfnFinalDestruct = */       NULL,
    /* .pfnRequest = */             NULL,
    /* .pfnReserved0 = */           NULL,
    /* .pfnReserved1 = */           NULL,
    /* .pfnReserved2 = */           NULL,
    /* .pfnReserved3 = */           NULL,
    /* .pfnReserved4 = */           NULL,
    /* .pfnReserved5 = */           NULL,
    /* .pfnReserved6 = */           NULL,
    /* .pfnReserved7 = */           NULL,
#elif defined(IN_RC)
    /* .pfnConstruct = */           iommuAmdRZConstruct,
    /* .pfnReserved0 = */           NULL,
    /* .pfnReserved1 = */           NULL,
    /* .pfnReserved2 = */           NULL,
    /* .pfnReserved3 = */           NULL,
    /* .pfnReserved4 = */           NULL,
    /* .pfnReserved5 = */           NULL,
    /* .pfnReserved6 = */           NULL,
    /* .pfnReserved7 = */           NULL,
#else
# error "Not in IN_RING3, IN_RING0 or IN_RC!"
#endif
    /* .u32VersionEnd = */          PDM_DEVREG_VERSION
};

#endif /* !VBOX_DEVICE_STRUCT_TESTCASE */