source: vbox/trunk/src/VBox/VMM/VMMAll/DBGFAll.cpp@ 48749

/* $Id: DBGFAll.cpp 47683 2013-08-12 23:09:09Z vboxsync $ */
/** @file
 * DBGF - Debugger Facility, All Context Code.
 */

/*
 * Copyright (C) 2006-2013 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_DBGF
#include <VBox/vmm/dbgf.h>
#include "DBGFInternal.h"
#include <VBox/vmm/vm.h>
#include <VBox/err.h>
#include <iprt/assert.h>


/**
 * Gets the hardware breakpoint configuration as DR7.
 *
 * @returns DR7 from the DBGF point of view.
 * @param   pVM         Pointer to the VM.
 */
VMM_INT_DECL(RTGCUINTREG) DBGFBpGetDR7(PVM pVM)
{
    RTGCUINTREG uDr7 = X86_DR7_GD | X86_DR7_GE | X86_DR7_LE | X86_DR7_RA1_MASK;
    PDBGFBP     pBp = &pVM->dbgf.s.aHwBreakpoints[0];
    unsigned    cLeft = RT_ELEMENTS(pVM->dbgf.s.aHwBreakpoints);
    while (cLeft-- > 0)
    {
        if (    pBp->enmType == DBGFBPTYPE_REG
            &&  pBp->fEnabled)
        {
            static const uint8_t s_au8Sizes[8] =
            {
                X86_DR7_LEN_BYTE, X86_DR7_LEN_BYTE, X86_DR7_LEN_WORD, X86_DR7_LEN_BYTE,
                X86_DR7_LEN_DWORD,X86_DR7_LEN_BYTE, X86_DR7_LEN_BYTE, X86_DR7_LEN_QWORD
            };
            uDr7 |= X86_DR7_G(pBp->u.Reg.iReg)
                 |  X86_DR7_RW(pBp->u.Reg.iReg, pBp->u.Reg.fType)
                 |  X86_DR7_LEN(pBp->u.Reg.iReg, s_au8Sizes[pBp->u.Reg.cb]);
        }
        pBp++;
    }
    return uDr7;
}


/**
 * Gets the address of the hardware breakpoint number 0.
 *
 * @returns DR0 from the DBGF point of view.
 * @param   pVM         Pointer to the VM.
 */
VMM_INT_DECL(RTGCUINTREG) DBGFBpGetDR0(PVM pVM)
{
    PCDBGFBP    pBp = &pVM->dbgf.s.aHwBreakpoints[0];
    Assert(pBp->u.Reg.iReg == 0);
    return pBp->GCPtr;
}


/**
 * Gets the address of the hardware breakpoint number 1.
 *
 * @returns DR1 from the DBGF point of view.
 * @param   pVM         Pointer to the VM.
 */
VMM_INT_DECL(RTGCUINTREG) DBGFBpGetDR1(PVM pVM)
{
    PCDBGFBP    pBp = &pVM->dbgf.s.aHwBreakpoints[1];
    Assert(pBp->u.Reg.iReg == 1);
    return pBp->GCPtr;
}


/**
 * Gets the address of the hardware breakpoint number 2.
 *
 * @returns DR2 from the DBGF point of view.
 * @param   pVM         Pointer to the VM.
 */
VMM_INT_DECL(RTGCUINTREG) DBGFBpGetDR2(PVM pVM)
{
    PCDBGFBP    pBp = &pVM->dbgf.s.aHwBreakpoints[2];
    Assert(pBp->u.Reg.iReg == 2);
    return pBp->GCPtr;
}


/**
 * Gets the address of the hardware breakpoint number 3.
 *
 * @returns DR3 from the DBGF point of view.
 * @param   pVM         Pointer to the VM.
 */
VMM_INT_DECL(RTGCUINTREG) DBGFBpGetDR3(PVM pVM)
{
    PCDBGFBP    pBp = &pVM->dbgf.s.aHwBreakpoints[3];
    Assert(pBp->u.Reg.iReg == 3);
    return pBp->GCPtr;
}


/**
 * Checks if any of the hardware breakpoints are armed.
 *
 * @returns true if armed, false if not.
 * @param   pVM         The cross context VM structure.
 */
VMM_INT_DECL(bool) DBGFBpIsHwArmed(PVM pVM)
{
    Assert(RT_ELEMENTS(pVM->dbgf.s.aHwBreakpoints) == 4);
    return (pVM->dbgf.s.aHwBreakpoints[0].fEnabled && pVM->dbgf.s.aHwBreakpoints[0].enmType == DBGFBPTYPE_REG)
        || (pVM->dbgf.s.aHwBreakpoints[1].fEnabled && pVM->dbgf.s.aHwBreakpoints[1].enmType == DBGFBPTYPE_REG)
        || (pVM->dbgf.s.aHwBreakpoints[2].fEnabled && pVM->dbgf.s.aHwBreakpoints[2].enmType == DBGFBPTYPE_REG)
        || (pVM->dbgf.s.aHwBreakpoints[3].fEnabled && pVM->dbgf.s.aHwBreakpoints[3].enmType == DBGFBPTYPE_REG);
}


/**
 * Checks if any of the hardware I/O breakpoints are armed.
 *
 * @returns true if armed, false if not.
 * @param   pVM         The cross context VM structure.
 */
VMM_INT_DECL(bool) DBGFBpIsHwIoArmed(PVM pVM)
{
    Assert(RT_ELEMENTS(pVM->dbgf.s.aHwBreakpoints) == 4);
    /** @todo cache this! */
    return (   pVM->dbgf.s.aHwBreakpoints[0].u.Reg.fType == X86_DR7_RW_IO
            && pVM->dbgf.s.aHwBreakpoints[0].fEnabled
            && pVM->dbgf.s.aHwBreakpoints[0].enmType     == DBGFBPTYPE_REG
           )
        || (   pVM->dbgf.s.aHwBreakpoints[1].u.Reg.fType == X86_DR7_RW_IO
            && pVM->dbgf.s.aHwBreakpoints[1].fEnabled
            && pVM->dbgf.s.aHwBreakpoints[1].enmType     == DBGFBPTYPE_REG
           )
        || (   pVM->dbgf.s.aHwBreakpoints[2].u.Reg.fType == X86_DR7_RW_IO
            && pVM->dbgf.s.aHwBreakpoints[2].fEnabled
            && pVM->dbgf.s.aHwBreakpoints[2].enmType     == DBGFBPTYPE_REG
           )
        || (   pVM->dbgf.s.aHwBreakpoints[3].u.Reg.fType == X86_DR7_RW_IO
            && pVM->dbgf.s.aHwBreakpoints[3].fEnabled
            && pVM->dbgf.s.aHwBreakpoints[3].enmType     == DBGFBPTYPE_REG
           );
}


/**
 * Checks I/O access for guest or hypervisor breakpoints.
 *
 * @returns Strict VBox status code
 * @retval  VINF_SUCCESS no breakpoint.
 * @retval  VINF_EM_DBG_BREAKPOINT hypervisor breakpoint triggered.
 * @retval  VINF_EM_RAW_GUEST_TRAP guest breakpoint triggered, DR6 and DR7 have
 *          been updated appropriately.
 *
 * @param   pVM         The cross context VM structure.
 * @param   pVCpu       The cross context CPU structure for the calling EMT.
 * @param   pCtx        The CPU context for the calling EMT.
 * @param   uIoPort     The I/O port being accessed.
 * @param   cbValue     The size/width of the access, in bytes.
 */
VMM_INT_DECL(VBOXSTRICTRC)  DBGFBpCheckIo(PVM pVM, PVMCPU pVCpu, PCPUMCTX pCtx, RTIOPORT uIoPort, uint8_t cbValue)
{
    uint32_t const uIoPortFirst = uIoPort;
    uint32_t const uIoPortLast  = uIoPortFirst + cbValue - 1;


    /*
     * Check hyper breakpoints first as the VMM debugger has priority over
     * the guest.
     */
    for (unsigned iBp = 0; iBp < RT_ELEMENTS(pVM->dbgf.s.aHwBreakpoints); iBp++)
    {
        if (   pVM->dbgf.s.aHwBreakpoints[iBp].u.Reg.fType == X86_DR7_RW_IO
            && pVM->dbgf.s.aHwBreakpoints[iBp].fEnabled
            && pVM->dbgf.s.aHwBreakpoints[iBp].enmType     == DBGFBPTYPE_REG )
        {
            uint8_t  cbReg      = pVM->dbgf.s.aHwBreakpoints[iBp].u.Reg.cb; Assert(RT_IS_POWER_OF_TWO(cbReg));
            uint64_t uDrXFirst  = pVM->dbgf.s.aHwBreakpoints[iBp].GCPtr & ~(uint64_t)(cbReg - 1);
            uint64_t uDrXLast   = uDrXFirst + cbReg - 1;
            if (uDrXFirst <= uIoPortLast && uDrXLast >= uIoPortFirst)
            {
                /* (See also DBGFRZTrap01Handler.) */
                pVCpu->dbgf.s.iActiveBp = pVM->dbgf.s.aHwBreakpoints[iBp].iBp;
                pVCpu->dbgf.s.fSingleSteppingRaw = false;

                LogFlow(("DBGFBpCheckIo: hit hw breakpoint %d at %04x:%RGv (iop %#x)\n",
                         pVM->dbgf.s.aHwBreakpoints[iBp].iBp, pCtx->cs.Sel, pCtx->rip, uIoPort));
                return VINF_EM_DBG_BREAKPOINT;
            }
        }
    }

    /*
     * Check the guest.
     */
    uint32_t const uDr7 = pCtx->dr[7];
    if (   (uDr7 & X86_DR7_ENABLED_MASK)
        && X86_DR7_ANY_RW_IO(uDr7)
        && (pCtx->cr4 & X86_CR4_DE) )
    {
        for (unsigned iBp = 0; iBp < 4; iBp++)
        {
            if (   (uDr7 & X86_DR7_L_G(iBp))
                && X86_DR7_GET_RW(uDr7, iBp) == X86_DR7_RW_IO)
            {
                /* ASSUME the breakpoint and the I/O width qualifier uses the same encoding (1 2 x 4). */
                static uint8_t const s_abInvAlign[4] = { 0, 1, 7, 3 };
                uint8_t  cbInvAlign = s_abInvAlign[X86_DR7_GET_LEN(uDr7, iBp)];
                uint64_t uDrXFirst  = pCtx->dr[iBp] & ~(uint64_t)cbInvAlign;
                uint64_t uDrXLast   = uDrXFirst + cbInvAlign;

                if (uDrXFirst <= uIoPortLast && uDrXLast >= uIoPortFirst)
                {
                    /*
                     * Update DR6 and DR7.
                     *
                     * See "AMD64 Architecture Programmer's Manual Volume 2",
                     * chapter 13.1.1.3 for details on DR6 bits.  The basics is
                     * that the B0..B3 bits are always cleared while the others
                     * must be cleared by software.
                     *
                     * The following sub chapters says the GD bit is always
                     * cleared when generating a #DB so the handler can safely
                     * access the debug registers.
                     */
                    pCtx->dr[6] &= ~X86_DR6_B_MASK;
                    pCtx->dr[6] |= X86_DR6_B(iBp);
                    pCtx->dr[7] &= ~X86_DR7_GD;
                    LogFlow(("DBGFBpCheckIo: hit hw breakpoint %d at %04x:%RGv (iop %#x)\n",
                             pVM->dbgf.s.aHwBreakpoints[iBp].iBp, pCtx->cs.Sel, pCtx->rip, uIoPort));
                    return VINF_EM_RAW_GUEST_TRAP;
                }
            }
        }
    }
    return VINF_SUCCESS;
}


/**
 * Returns the single stepping state for a virtual CPU.
 *
 * @returns stepping (true) or not (false).
 *
 * @param   pVCpu       Pointer to the VMCPU.
 */
VMM_INT_DECL(bool) DBGFIsStepping(PVMCPU pVCpu)
{
    return pVCpu->dbgf.s.fSingleSteppingRaw;
}