; $Id: HWACCMR0Mixed.mac 20996 2009-06-26 22:20:02Z vboxsync $
;; @file
; HWACCMR0Mixed.mac - Stuff that darwin needs to build two versions of.
;
; Included by HWACCMR0A.asm with RT_ARCH_AMD64 defined or or undefined.
;

;
; Copyright (C) 2006-2007 Sun Microsystems, Inc.
;
; 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.
;
; Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
; Clara, CA 95054 USA or visit http://www.sun.com if you need
; additional information or have any questions.
;


;/**
; * Prepares for and executes VMLAUNCH/VMRESUME (32 bits guest mode)
; *
; * @returns VBox status code
; * @param   fResume    x86:[ebp+8], msc:rcx,gcc:rdi     vmlauch/vmresume
; * @param   pCtx       x86:[ebp+c], msc:rdx,gcc:rsi     Guest context
; * @param   pCache     x86:[esp+10],msc:r8, gcc:rdx     VMCS cache
; */
ALIGNCODE(16)
BEGINPROC MY_NAME(VMXR0StartVM32)
    push    xBP
    mov     xBP, xSP

    pushf
    cli

    ;/* Save all general purpose host registers. */
    MYPUSHAD

    ;/* First we have to save some final CPU context registers. */
    mov     eax, VMX_VMCS_HOST_RIP
%ifdef RT_ARCH_AMD64
    lea     r10, [.vmlaunch_done wrt rip]
    vmwrite rax, r10
%else
    mov     ecx, .vmlaunch_done
    vmwrite eax, ecx
%endif
    ;/* Note: assumes success... */

    ;/* Manual save and restore:
    ; * - General purpose registers except RIP, RSP
    ; *
    ; * Trashed:
    ; * - CR2 (we don't care)
    ; * - LDTR (reset to 0)
    ; * - DRx (presumably not changed at all)
    ; * - DR7 (reset to 0x400)
    ; * - EFLAGS (reset to RT_BIT(1); not relevant)
    ; *
    ; */

    ;/* Save the Guest CPU context pointer. */
%ifdef RT_ARCH_AMD64
 %ifdef ASM_CALL64_GCC
    ; fResume already in rdi
    ; pCtx    already in rsi
    mov     rbx, rdx        ; pCache
 %else
    mov     rdi, rcx        ; fResume
    mov     rsi, rdx        ; pCtx
    mov     rbx, r8         ; pCache
 %endif
%else
    mov     edi, [ebp + 8]  ; fResume
    mov     esi, [ebp + 12] ; pCtx
    mov     ebx, [ebp + 16] ; pCache
%endif

    ;/* Save segment registers */
    ; Note: MYPUSHSEGS trashes rdx & rcx, so we moved it here (msvc amd64 case)
    MYPUSHSEGS xAX, ax

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    mov     ecx, [xBX + VMCSCACHE.Write.cValidEntries]
    cmp     ecx, 0
    je      .no_cached_writes
    mov     edx, ecx
    mov     ecx, 0
    jmp     .cached_write

ALIGN(16)
.cached_write:
    mov     eax, [xBX + VMCSCACHE.Write.aField + xCX*4]
    vmwrite xAX, [xBX + VMCSCACHE.Write.aFieldVal + xCX*8]
    inc     xCX
    cmp     xCX, xDX
    jl     .cached_write

    mov     dword [xBX + VMCSCACHE.Write.cValidEntries], 0
.no_cached_writes:

    ; Save the pCache pointer
    push    xBX
%endif

    ; Save the pCtx pointer
    push    xSI

    ; Save LDTR
    xor     eax, eax
    sldt    ax
    push    xAX

    ; The TR limit is reset to 0x67; restore it manually
    str     eax
    push    xAX

    ; VMX only saves the base of the GDTR & IDTR and resets the limit to 0xffff; we must restore the limit correctly!
    sub     xSP, xS*2
    sgdt    [xSP]

    sub     xSP, xS*2
    sidt    [xSP]

%ifdef VBOX_WITH_DR6_EXPERIMENT
    ; Restore DR6 - experiment, not safe!
    mov     xBX, [xSI + CPUMCTX.dr6]
    mov     dr6, xBX
%endif

    ; Restore CR2
    mov     ebx, [xSI + CPUMCTX.cr2]
    mov     cr2, xBX

    mov     eax, VMX_VMCS_HOST_RSP
    vmwrite xAX, xSP
    ;/* Note: assumes success... */
    ;/* Don't mess with ESP anymore!! */

    ;/* Restore Guest's general purpose registers. */
    mov     eax, [xSI + CPUMCTX.eax]
    mov     ebx, [xSI + CPUMCTX.ebx]
    mov     ecx, [xSI + CPUMCTX.ecx]
    mov     edx, [xSI + CPUMCTX.edx]
    mov     ebp, [xSI + CPUMCTX.ebp]

    ; resume or start?
    cmp     xDI, 0                  ; fResume
    je      .vmlauch_lauch

    ;/* Restore edi & esi. */
    mov     edi, [xSI + CPUMCTX.edi]
    mov     esi, [xSI + CPUMCTX.esi]

    vmresume
    jmp     .vmlaunch_done;      ;/* here if vmresume detected a failure. */

.vmlauch_lauch:
    ;/* Restore edi & esi. */
    mov     edi, [xSI + CPUMCTX.edi]
    mov     esi, [xSI + CPUMCTX.esi]

    vmlaunch
    jmp     .vmlaunch_done;      ;/* here if vmlaunch detected a failure. */

ALIGNCODE(16) ;; @todo YASM BUG - this alignment is wrong on darwin, it's 1 byte off.
.vmlaunch_done:
    jc      near .vmxstart_invalid_vmxon_ptr
    jz      near .vmxstart_start_failed

    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    push    xDI
    mov     xDI, [xSP + xS * 3]         ; pCtx (*3 to skip the saved LDTR + TR)

    mov     [ss:xDI + CPUMCTX.eax], eax
    mov     [ss:xDI + CPUMCTX.ebx], ebx
    mov     [ss:xDI + CPUMCTX.ecx], ecx
    mov     [ss:xDI + CPUMCTX.edx], edx
    mov     [ss:xDI + CPUMCTX.esi], esi
    mov     [ss:xDI + CPUMCTX.ebp], ebp
%ifdef RT_ARCH_AMD64
    pop     xAX                                 ; the guest edi we pushed above
    mov     dword [ss:xDI + CPUMCTX.edi], eax
%else
    pop     dword [ss:xDI + CPUMCTX.edi]        ; the guest edi we pushed above
%endif

%ifdef VBOX_WITH_DR6_EXPERIMENT
    ; Save DR6 - experiment, not safe!
    mov     xAX, dr6
    mov     [ss:xDI + CPUMCTX.dr6], xAX
%endif

    ; Restore TSS selector; must mark it as not busy before using ltr (!)
    ; ASSUME that this is supposed to be 'BUSY'. (saves 20-30 ticks on the T42p)
    ; @todo get rid of sgdt
    pop     xBX         ; saved TR
%ifndef RT_ARCH_AMD64
    sub     xSP, xS*2
    sgdt    [xSP]
    mov     eax, ebx
    and     al, 0F8h                                ; mask away TI and RPL bits, get descriptor offset.
    add     xAX, [xSP + 2]                          ; eax <- GDTR.address + descriptor offset.
    and     dword [ss:xAX + 4], ~0200h                 ; clear busy flag (2nd type2 bit)
    ltr     bx
    add     xSP, xS*2
%endif

    pop     xAX         ; saved LDTR
    lldt    ax

    add     xSP, xS      ; pCtx

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    pop     xDX         ; saved pCache

    mov     ecx, [ss:xDX + VMCSCACHE.Read.cValidEntries]
    cmp     ecx, 0  ; can't happen
    je      .no_cached_reads
    jmp     .cached_read

ALIGN(16)
.cached_read:
    dec     xCX
    mov     eax, [ss:xDX + VMCSCACHE.Read.aField + xCX*4]
    vmread  [ss:xDX + VMCSCACHE.Read.aFieldVal + xCX*8], xAX
    cmp     xCX, 0
    jnz     .cached_read
.no_cached_reads:

    ; Save CR2 for EPT
    mov     xAX, cr2
    mov     [ss:xDX + VMCSCACHE.cr2], xAX
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore general purpose registers
    MYPOPAD

    mov     eax, VINF_SUCCESS

.vmstart_end:
    popf
    pop     xBP
    ret


.vmxstart_invalid_vmxon_ptr:
    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    ; Restore TSS selector; must mark it as not busy before using ltr (!)
    ; ASSUME that this is supposed to be 'BUSY'. (saves 20-30 ticks on the T42p)
    ; @todo get rid of sgdt
    pop     xBX         ; saved TR
%ifndef RT_ARCH_AMD64
    sub     xSP, xS*2
    sgdt    [xSP]
    mov     eax, ebx
    and     al, 0F8h                                ; mask away TI and RPL bits, get descriptor offset.
    add     eax, [xSP + 2]                          ; eax <- GDTR.address + descriptor offset.
    and     dword [ss:eax + 4], ~0200h                 ; clear busy flag (2nd type2 bit)
    ltr     bx
    add     xSP, xS*2
%endif

    pop     xAX         ; saved LDTR
    lldt    ax

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    add     xSP, xS*2   ; pCtx + pCache
%else
    add     xSP, xS     ; pCtx
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore all general purpose host registers.
    MYPOPAD
    mov     eax, VERR_VMX_INVALID_VMXON_PTR
    jmp     .vmstart_end

.vmxstart_start_failed:
    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    ; Restore TSS selector; must mark it as not busy before using ltr (!)
    ; ASSUME that this is supposed to be 'BUSY'. (saves 20-30 ticks on the T42p)
    ; @todo get rid of sgdt
    pop     xBX         ; saved TR
%ifndef RT_ARCH_AMD64
    sub     xSP, xS*2
    sgdt    [xSP]
    mov     eax, ebx
    and     al, 0F8h                                ; mask away TI and RPL bits, get descriptor offset.
    add     eax, [xSP + 2]                          ; eax <- GDTR.address + descriptor offset.
    and     dword [ss:eax + 4], ~0200h                 ; clear busy flag (2nd type2 bit)
    ltr     bx
    add     xSP, xS*2
%endif

    pop     xAX         ; saved LDTR
    lldt    ax

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    add     xSP, xS*2   ; pCtx + pCache
%else
    add     xSP, xS     ; pCtx
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore all general purpose host registers.
    MYPOPAD
    mov     eax, VERR_VMX_UNABLE_TO_START_VM
    jmp     .vmstart_end

ENDPROC MY_NAME(VMXR0StartVM32)

%ifdef RT_ARCH_AMD64
;/**
; * Prepares for and executes VMLAUNCH/VMRESUME (64 bits guest mode)
; *
; * @returns VBox status code
; * @param   fResume    msc:rcx, gcc:rdi     vmlauch/vmresume
; * @param   pCtx       msc:rdx, gcc:rsi     Guest context
; * @param   pCache     msc:r8,  gcc:rdx     VMCS cache
; */
ALIGNCODE(16)
BEGINPROC MY_NAME(VMXR0StartVM64)
    push    xBP
    mov     xBP, xSP

    pushf
    cli

    ;/* Save all general purpose host registers. */
    MYPUSHAD

    ;/* First we have to save some final CPU context registers. */
    lea     r10, [.vmlaunch64_done wrt rip]
    mov     rax, VMX_VMCS_HOST_RIP  ;/* return address (too difficult to continue after VMLAUNCH?) */
    vmwrite rax, r10
    ;/* Note: assumes success... */

    ;/* Manual save and restore:
    ; * - General purpose registers except RIP, RSP
    ; *
    ; * Trashed:
    ; * - CR2 (we don't care)
    ; * - LDTR (reset to 0)
    ; * - DRx (presumably not changed at all)
    ; * - DR7 (reset to 0x400)
    ; * - EFLAGS (reset to RT_BIT(1); not relevant)
    ; *
    ; */

    ;/* Save the Guest CPU context pointer. */
%ifdef ASM_CALL64_GCC
    ; fResume already in rdi
    ; pCtx    already in rsi
    mov     rbx, rdx        ; pCache
%else
    mov     rdi, rcx        ; fResume
    mov     rsi, rdx        ; pCtx
    mov     rbx, r8         ; pCache
%endif

    ;/* Save segment registers */
    ; Note: MYPUSHSEGS trashes rdx & rcx, so we moved it here (msvc amd64 case)
    MYPUSHSEGS xAX, ax

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    mov     ecx, [xBX + VMCSCACHE.Write.cValidEntries]
    cmp     ecx, 0
    je      .no_cached_writes
    mov     edx, ecx
    mov     ecx, 0
    jmp     .cached_write

ALIGN(16)
.cached_write:
    mov     eax, [xBX + VMCSCACHE.Write.aField + xCX*4]
    vmwrite xAX, [xBX + VMCSCACHE.Write.aFieldVal + xCX*8]
    inc     xCX
    cmp     xCX, xDX
    jl     .cached_write

    mov     dword [xBX + VMCSCACHE.Write.cValidEntries], 0
.no_cached_writes:

    ; Save the pCache pointer
    push    xBX
%endif

    ; Save the host LSTAR, CSTAR, SFMASK & KERNEL_GSBASE MSRs and restore the guest MSRs
    ;; @todo use the automatic load feature for MSRs
    LOADGUESTMSR MSR_K8_LSTAR, CPUMCTX.msrLSTAR
%if 0  ; not supported on Intel CPUs
    LOADGUESTMSR MSR_K8_CSTAR, CPUMCTX.msrCSTAR
%endif
    LOADGUESTMSR MSR_K6_STAR, CPUMCTX.msrSTAR
    LOADGUESTMSR MSR_K8_SF_MASK, CPUMCTX.msrSFMASK
    LOADGUESTMSR MSR_K8_KERNEL_GS_BASE, CPUMCTX.msrKERNELGSBASE

    ; Save the pCtx pointer
    push    xSI

    ; Save LDTR
    xor     eax, eax
    sldt    ax
    push    xAX

    ; VMX only saves the base of the GDTR & IDTR and resets the limit to 0xffff; we must restore the limit correctly!
    sub     xSP, xS*2
    sgdt    [xSP]

    sub     xSP, xS*2
    sidt    [xSP]

%ifdef VBOX_WITH_DR6_EXPERIMENT
    ; Restore DR6 - experiment, not safe!
    mov     xBX, [xSI + CPUMCTX.dr6]
    mov     dr6, xBX
%endif

    ; Restore CR2
    mov     rbx, qword [xSI + CPUMCTX.cr2]
    mov     cr2, rbx

    mov     eax, VMX_VMCS_HOST_RSP
    vmwrite xAX, xSP
    ;/* Note: assumes success... */
    ;/* Don't mess with ESP anymore!! */

    ;/* Restore Guest's general purpose registers. */
    mov     rax, qword [xSI + CPUMCTX.eax]
    mov     rbx, qword [xSI + CPUMCTX.ebx]
    mov     rcx, qword [xSI + CPUMCTX.ecx]
    mov     rdx, qword [xSI + CPUMCTX.edx]
    mov     rbp, qword [xSI + CPUMCTX.ebp]
    mov     r8,  qword [xSI + CPUMCTX.r8]
    mov     r9,  qword [xSI + CPUMCTX.r9]
    mov     r10, qword [xSI + CPUMCTX.r10]
    mov     r11, qword [xSI + CPUMCTX.r11]
    mov     r12, qword [xSI + CPUMCTX.r12]
    mov     r13, qword [xSI + CPUMCTX.r13]
    mov     r14, qword [xSI + CPUMCTX.r14]
    mov     r15, qword [xSI + CPUMCTX.r15]

    ; resume or start?
    cmp     xDI, 0                  ; fResume
    je      .vmlauch64_lauch

    ;/* Restore edi & esi. */
    mov     rdi, qword [xSI + CPUMCTX.edi]
    mov     rsi, qword [xSI + CPUMCTX.esi]

    vmresume
    jmp     .vmlaunch64_done;      ;/* here if vmresume detected a failure. */

.vmlauch64_lauch:
    ;/* Restore rdi & rsi. */
    mov     rdi, qword [xSI + CPUMCTX.edi]
    mov     rsi, qword [xSI + CPUMCTX.esi]

    vmlaunch
    jmp     .vmlaunch64_done;      ;/* here if vmlaunch detected a failure. */

ALIGNCODE(16)
.vmlaunch64_done:
    jc      near .vmxstart64_invalid_vmxon_ptr
    jz      near .vmxstart64_start_failed

    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    push    xDI
    mov     xDI, [xSP + xS * 2]         ; pCtx (*2 to skip the saved LDTR)

    mov     qword [xDI + CPUMCTX.eax], rax
    mov     qword [xDI + CPUMCTX.ebx], rbx
    mov     qword [xDI + CPUMCTX.ecx], rcx
    mov     qword [xDI + CPUMCTX.edx], rdx
    mov     qword [xDI + CPUMCTX.esi], rsi
    mov     qword [xDI + CPUMCTX.ebp], rbp
    mov     qword [xDI + CPUMCTX.r8],  r8
    mov     qword [xDI + CPUMCTX.r9],  r9
    mov     qword [xDI + CPUMCTX.r10], r10
    mov     qword [xDI + CPUMCTX.r11], r11
    mov     qword [xDI + CPUMCTX.r12], r12
    mov     qword [xDI + CPUMCTX.r13], r13
    mov     qword [xDI + CPUMCTX.r14], r14
    mov     qword [xDI + CPUMCTX.r15], r15

    pop     xAX                                 ; the guest edi we pushed above
    mov     qword [xDI + CPUMCTX.edi], rax

%ifdef VBOX_WITH_DR6_EXPERIMENT
    ; Save DR6 - experiment, not safe!
    mov     xAX, dr6
    mov     [xDI + CPUMCTX.dr6], xAX
%endif

    pop     xAX         ; saved LDTR
    lldt    ax

    pop     xSI         ; pCtx (needed in rsi by the macros below)

    ; Restore the host LSTAR, CSTAR, SFMASK & KERNEL_GSBASE MSRs
    ;; @todo use the automatic load feature for MSRs
    LOADHOSTMSREX MSR_K8_KERNEL_GS_BASE, CPUMCTX.msrKERNELGSBASE
    LOADHOSTMSR MSR_K8_SF_MASK
    LOADHOSTMSR MSR_K6_STAR
%if 0  ; not supported on Intel CPUs
    LOADHOSTMSR MSR_K8_CSTAR
%endif
    LOADHOSTMSR MSR_K8_LSTAR

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    pop     xDX         ; saved pCache

    mov     ecx, [xDX + VMCSCACHE.Read.cValidEntries]
    cmp     ecx, 0  ; can't happen
    je      .no_cached_reads
    jmp     .cached_read

ALIGN(16)
.cached_read:
    dec     xCX
    mov     eax, [xDX + VMCSCACHE.Read.aField + xCX*4]
    vmread  [xDX + VMCSCACHE.Read.aFieldVal + xCX*8], xAX
    cmp      xCX, 0
    jnz     .cached_read
.no_cached_reads:

    ; Save CR2 for EPT
    mov     xAX, cr2
    mov     [xDX + VMCSCACHE.cr2], xAX
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore general purpose registers
    MYPOPAD

    mov     eax, VINF_SUCCESS

.vmstart64_end:
    popf
    pop     xBP
    ret


.vmxstart64_invalid_vmxon_ptr:
    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    pop     xAX         ; saved LDTR
    lldt    ax

    pop     xSI         ; pCtx (needed in rsi by the macros below)

    ; Restore the host LSTAR, CSTAR, SFMASK & KERNEL_GSBASE MSRs
    ;; @todo use the automatic load feature for MSRs
    LOADHOSTMSREX MSR_K8_KERNEL_GS_BASE, CPUMCTX.msrKERNELGSBASE
    LOADHOSTMSR MSR_K8_SF_MASK
    LOADHOSTMSR MSR_K6_STAR
%if 0  ; not supported on Intel CPUs
    LOADHOSTMSR MSR_K8_CSTAR
%endif
    LOADHOSTMSR MSR_K8_LSTAR

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    add     xSP, xS     ; pCache
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore all general purpose host registers.
    MYPOPAD
    mov     eax, VERR_VMX_INVALID_VMXON_PTR
    jmp     .vmstart64_end

.vmxstart64_start_failed:
    ; Restore base and limit of the IDTR & GDTR
    lidt    [xSP]
    add     xSP, xS*2
    lgdt    [xSP]
    add     xSP, xS*2

    pop     xAX         ; saved LDTR
    lldt    ax

    pop     xSI         ; pCtx (needed in rsi by the macros below)

    ; Restore the host LSTAR, CSTAR, SFMASK & KERNEL_GSBASE MSRs
    ;; @todo use the automatic load feature for MSRs
    LOADHOSTMSREX MSR_K8_KERNEL_GS_BASE, CPUMCTX.msrKERNELGSBASE
    LOADHOSTMSR MSR_K8_SF_MASK
    LOADHOSTMSR MSR_K6_STAR
%if 0  ; not supported on Intel CPUs
    LOADHOSTMSR MSR_K8_CSTAR
%endif
    LOADHOSTMSR MSR_K8_LSTAR

%ifdef VMX_USE_CACHED_VMCS_ACCESSES
    add     xSP, xS     ; pCache
%endif

    ; Restore segment registers
    MYPOPSEGS xAX, ax

    ; Restore all general purpose host registers.
    MYPOPAD
    mov     eax, VERR_VMX_UNABLE_TO_START_VM
    jmp     .vmstart64_end
ENDPROC MY_NAME(VMXR0StartVM64)
%endif ; RT_ARCH_AMD64


;/**
; * Prepares for and executes VMRUN (32 bits guests)
; *
; * @returns VBox status code
; * @param   HCPhysVMCB     Physical address of host VMCB
; * @param   HCPhysVMCB     Physical address of guest VMCB
; * @param   pCtx           Guest context
; */
ALIGNCODE(16)
BEGINPROC MY_NAME(SVMR0VMRun)
%ifdef RT_ARCH_AMD64 ; fake a cdecl stack frame
 %ifdef ASM_CALL64_GCC
    push    rdx
    push    rsi
    push    rdi
 %else
    push    r8
    push    rdx
    push    rcx
 %endif
    push    0
%endif
    push    xBP
    mov     xBP, xSP
    pushf

    ;/* Manual save and restore:
    ; * - General purpose registers except RIP, RSP, RAX
    ; *
    ; * Trashed:
    ; * - CR2 (we don't care)
    ; * - LDTR (reset to 0)
    ; * - DRx (presumably not changed at all)
    ; * - DR7 (reset to 0x400)
    ; */

    ;/* Save all general purpose host registers. */
    MYPUSHAD

    ;/* Save the Guest CPU context pointer. */
    mov     xSI, [xBP + xS*2 + RTHCPHYS_CB*2]   ; pCtx
    push    xSI                     ; push for saving the state at the end

    ; save host fs, gs, sysenter msr etc
    mov     xAX, [xBP + xS*2]       ; pVMCBHostPhys (64 bits physical address; x86: take low dword only)
    push    xAX                     ; save for the vmload after vmrun
    vmsave

    ; setup eax for VMLOAD
    mov     xAX, [xBP + xS*2 + RTHCPHYS_CB]     ; pVMCBPhys (64 bits physical address; take low dword only)

    ;/* Restore Guest's general purpose registers. */
    ;/* EAX is loaded from the VMCB by VMRUN */
    mov     ebx, [xSI + CPUMCTX.ebx]
    mov     ecx, [xSI + CPUMCTX.ecx]
    mov     edx, [xSI + CPUMCTX.edx]
    mov     edi, [xSI + CPUMCTX.edi]
    mov     ebp, [xSI + CPUMCTX.ebp]
    mov     esi, [xSI + CPUMCTX.esi]

    ; Clear the global interrupt flag & execute sti to make sure external interrupts cause a world switch
    clgi
    sti

    ; load guest fs, gs, sysenter msr etc
    vmload
    ; run the VM
    vmrun

    ;/* EAX is in the VMCB already; we can use it here. */

    ; save guest fs, gs, sysenter msr etc
    vmsave

    ; load host fs, gs, sysenter msr etc
    pop     xAX                     ; pushed above
    vmload

    ; Set the global interrupt flag again, but execute cli to make sure IF=0.
    cli
    stgi

    pop     xAX                     ; pCtx

    mov     [ss:xAX + CPUMCTX.ebx], ebx
    mov     [ss:xAX + CPUMCTX.ecx], ecx
    mov     [ss:xAX + CPUMCTX.edx], edx
    mov     [ss:xAX + CPUMCTX.esi], esi
    mov     [ss:xAX + CPUMCTX.edi], edi
    mov     [ss:xAX + CPUMCTX.ebp], ebp

    ; Restore general purpose registers
    MYPOPAD

    mov     eax, VINF_SUCCESS

    popf
    pop     xBP
%ifdef RT_ARCH_AMD64
    add     xSP, 4*xS
%endif
    ret
ENDPROC MY_NAME(SVMR0VMRun)

%ifdef RT_ARCH_AMD64
;/**
; * Prepares for and executes VMRUN (64 bits guests)
; *
; * @returns VBox status code
; * @param   HCPhysVMCB     Physical address of host VMCB
; * @param   HCPhysVMCB     Physical address of guest VMCB
; * @param   pCtx           Guest context
; */
ALIGNCODE(16)
BEGINPROC MY_NAME(SVMR0VMRun64)
    ; fake a cdecl stack frame
 %ifdef ASM_CALL64_GCC
    push    rdx
    push    rsi
    push    rdi
 %else
    push    r8
    push    rdx
    push    rcx
 %endif
    push    0
    push    rbp
    mov     rbp, rsp
    pushf

    ;/* Manual save and restore:
    ; * - General purpose registers except RIP, RSP, RAX
    ; *
    ; * Trashed:
    ; * - CR2 (we don't care)
    ; * - LDTR (reset to 0)
    ; * - DRx (presumably not changed at all)
    ; * - DR7 (reset to 0x400)
    ; */

    ;/* Save all general purpose host registers. */
    MYPUSHAD

    ;/* Save the Guest CPU context pointer. */
    mov     rsi, [rbp + xS*2 + RTHCPHYS_CB*2]   ; pCtx
    push    rsi                     ; push for saving the state at the end

    ; save host fs, gs, sysenter msr etc
    mov     rax, [rbp + xS*2]       ; pVMCBHostPhys (64 bits physical address; x86: take low dword only)
    push    rax                     ; save for the vmload after vmrun
    vmsave

    ; setup eax for VMLOAD
    mov     rax, [rbp + xS*2 + RTHCPHYS_CB]     ; pVMCBPhys (64 bits physical address; take low dword only)

    ;/* Restore Guest's general purpose registers. */
    ;/* RAX is loaded from the VMCB by VMRUN */
    mov     rbx, qword [xSI + CPUMCTX.ebx]
    mov     rcx, qword [xSI + CPUMCTX.ecx]
    mov     rdx, qword [xSI + CPUMCTX.edx]
    mov     rdi, qword [xSI + CPUMCTX.edi]
    mov     rbp, qword [xSI + CPUMCTX.ebp]
    mov     r8,  qword [xSI + CPUMCTX.r8]
    mov     r9,  qword [xSI + CPUMCTX.r9]
    mov     r10, qword [xSI + CPUMCTX.r10]
    mov     r11, qword [xSI + CPUMCTX.r11]
    mov     r12, qword [xSI + CPUMCTX.r12]
    mov     r13, qword [xSI + CPUMCTX.r13]
    mov     r14, qword [xSI + CPUMCTX.r14]
    mov     r15, qword [xSI + CPUMCTX.r15]
    mov     rsi, qword [xSI + CPUMCTX.esi]

    ; Clear the global interrupt flag & execute sti to make sure external interrupts cause a world switch
    clgi
    sti

    ; load guest fs, gs, sysenter msr etc
    vmload
    ; run the VM
    vmrun

    ;/* RAX is in the VMCB already; we can use it here. */

    ; save guest fs, gs, sysenter msr etc
    vmsave

    ; load host fs, gs, sysenter msr etc
    pop     rax                     ; pushed above
    vmload

    ; Set the global interrupt flag again, but execute cli to make sure IF=0.
    cli
    stgi

    pop     rax                     ; pCtx

    mov     qword [rax + CPUMCTX.ebx], rbx
    mov     qword [rax + CPUMCTX.ecx], rcx
    mov     qword [rax + CPUMCTX.edx], rdx
    mov     qword [rax + CPUMCTX.esi], rsi
    mov     qword [rax + CPUMCTX.edi], rdi
    mov     qword [rax + CPUMCTX.ebp], rbp
    mov     qword [rax + CPUMCTX.r8],  r8
    mov     qword [rax + CPUMCTX.r9],  r9
    mov     qword [rax + CPUMCTX.r10], r10
    mov     qword [rax + CPUMCTX.r11], r11
    mov     qword [rax + CPUMCTX.r12], r12
    mov     qword [rax + CPUMCTX.r13], r13
    mov     qword [rax + CPUMCTX.r14], r14
    mov     qword [rax + CPUMCTX.r15], r15

    ; Restore general purpose registers
    MYPOPAD

    mov     eax, VINF_SUCCESS

    popf
    pop     rbp
    add     rsp, 4*xS
    ret
ENDPROC MY_NAME(SVMR0VMRun64)
%endif ; RT_ARCH_AMD64