VMM/VMMAll/TRPMAll.cpp

	TRPMAll.cpp revision 677833bc953b6cb418c701facbdcf4aa18d6c44e
/** @file
 *
 * TRPM - Trap Monitor - Any Context.
 */

/*
 * Copyright (C) 2006 InnoTek Systemberatung GmbH
 *
 * 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 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.
 *
 * If you received this file as part of a commercial VirtualBox
 * distribution, then only the terms of your commercial VirtualBox
 * license agreement apply instead of the previous paragraph.
 */


/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#define LOG_GROUP LOG_GROUP_TRPM
#include <VBox/trpm.h>
#include <VBox/pgm.h>
#include <VBox/mm.h>
#include <VBox/patm.h>
#include <VBox/selm.h>
#include "TRPMInternal.h"
#include <VBox/vm.h>
#include <VBox/err.h>
#include <VBox/x86.h>

#include <VBox/log.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#include <iprt/param.h>


/**
 * Query info about the current active trap/interrupt.
 * If no trap is active active an error code is returned.
 *
 * @returns VBox status code.
 * @param   pVM                     The virtual machine.
 * @param   pu8TrapNo               Where to store the trap number.
 * @param   pfSoftwareInterrupt     Where to store the software interrupt indicator.
 */
TRPMDECL(int)  TRPMQueryTrap(PVM pVM, uint8_t *pu8TrapNo, bool *pfSoftwareInterrupt)
{
    /*
     * Check if we have a trap at present.
     */
    if (pVM->trpm.s.uActiveVector != ~0U)
    {
        if (pu8TrapNo)
            *pu8TrapNo = (uint8_t)pVM->trpm.s.uActiveVector;
        if (pfSoftwareInterrupt)
            *pfSoftwareInterrupt = !!pVM->trpm.s.fActiveSoftwareInterrupt;
        return VINF_SUCCESS;
    }

    return VERR_TRPM_NO_ACTIVE_TRAP;
}


/**
 * Gets the trap number for the current trap.
 *
 * The caller is responsible for making sure there is an active trap which
 * takes an error code when making this request.
 *
 * @returns The current trap number.
 * @param   pVM         VM handle.
 */
TRPMDECL(uint8_t)  TRPMGetTrapNo(PVM pVM)
{
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
    return (uint8_t)pVM->trpm.s.uActiveVector;
}


/**
 * Gets the error code for the current trap.
 *
 * The caller is responsible for making sure there is an active trap which
 * takes an error code when making this request.
 *
 * @returns Error code.
 * @param   pVM         VM handle.
 */
TRPMDECL(RTGCUINT)  TRPMGetErrorCode(PVM pVM)
{
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
#ifdef VBOX_STRICT
    switch (pVM->trpm.s.uActiveVector)
    {
        case 0x0a:
        case 0x0b:
        case 0x0c:
        case 0x0d:
        case 0x0e:
        case 0x11:
        case 0x08:
            break;
        default:
            AssertMsgFailed(("This trap (%#x) doesn't have any error code\n", pVM->trpm.s.uActiveVector));
            break;
    }
#endif
    return pVM->trpm.s.uActiveErrorCode;
}


/**
 * Gets the fault address for the current trap.
 *
 * The caller is responsible for making sure there is an active trap 0x0e when
 * making this request.
 *
 * @returns Fault address associated with the trap.
 * @param   pVM         VM handle.
 */
TRPMDECL(RTGCUINTPTR) TRPMGetFaultAddress(PVM pVM)
{
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
    AssertMsg(pVM->trpm.s.uActiveVector == 0xe, ("Not trap 0e!\n"));
    return pVM->trpm.s.uActiveCR2;
}


/**
 * Clears the current active trap/exception/interrupt.
 *
 * The caller is responsible for making sure there is an active trap
 * when making this request.
 *
 * @returns VBox status code.
 * @param   pVM         The virtual machine handle.
 */
TRPMDECL(int) TRPMResetTrap(PVM pVM)
{
    /*
     * Cannot reset non-existing trap!
     */
    if (pVM->trpm.s.uActiveVector == ~0U)
    {
        AssertMsgFailed(("No active trap!\n"));
        return VERR_TRPM_NO_ACTIVE_TRAP;
    }

    /*
     * Reset it.
     */
    pVM->trpm.s.uActiveVector = ~0U;
    return VINF_SUCCESS;
}


/**
 * Assert trap/exception/interrupt.
 *
 * The caller is responsible for making sure there is no active trap
 * when making this request.
 *
 * @returns VBox status code.
 * @param   pVM                 The virtual machine.
 * @param   u8TrapNo            The trap vector to assert.
 * @param   fSoftwareInterrupt  Indicate if it's a software interrupt or not.
 */
TRPMDECL(int)  TRPMAssertTrap(PVM pVM, uint8_t u8TrapNo, bool fSoftwareInterrupt)
{
    Log2(("TRPMAssertTrap: u8TrapNo=%02x fSoftwareInterrupt=%d\n", u8TrapNo, fSoftwareInterrupt));

    /*
     * Cannot assert a trap when one is already active.
     */
    if (pVM->trpm.s.uActiveVector != ~0U)
    {
        AssertMsgFailed(("Active trap %#x\n", pVM->trpm.s.uActiveVector));
        return VERR_TRPM_ACTIVE_TRAP;
    }

    pVM->trpm.s.uActiveVector               = u8TrapNo;
    pVM->trpm.s.fActiveSoftwareInterrupt    = fSoftwareInterrupt;
    pVM->trpm.s.uActiveErrorCode            = ~0;
    pVM->trpm.s.uActiveCR2                  = 0xdeadface;
    return VINF_SUCCESS;
}


/**
 * Sets the error code of the current trap.
 * (This function is for use in trap handlers and such.)
 *
 * The caller is responsible for making sure there is an active trap
 * which takes an errorcode when making this request.
 *
 * @param   pVM         The virtual machine.
 * @param   uErrorCode  The new error code.
 */
TRPMDECL(void)  TRPMSetErrorCode(PVM pVM, RTGCUINT uErrorCode)
{
    Log2(("TRPMSetErrorCode: uErrorCode=%VGv\n", uErrorCode));
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
    pVM->trpm.s.uActiveErrorCode = uErrorCode;
#ifdef VBOX_STRICT
    switch (pVM->trpm.s.uActiveVector)
    {
        case 0x0a: case 0x0b: case 0x0c: case 0x0d: case 0x0e:
            AssertMsg(uErrorCode != ~(RTGCUINT)0, ("Invalid uErrorCode=%#x u8TrapNo=%d\n", uErrorCode, pVM->trpm.s.uActiveVector));
            break;
        case 0x11: case 0x08:
            AssertMsg(uErrorCode == 0,              ("Invalid uErrorCode=%#x u8TrapNo=%d\n", uErrorCode, pVM->trpm.s.uActiveVector));
            break;
        default:
            AssertMsg(uErrorCode == ~(RTGCUINT)0, ("Invalid uErrorCode=%#x u8TrapNo=%d\n", uErrorCode, pVM->trpm.s.uActiveVector));
            break;
    }
#endif
}


/**
 * Sets the error code of the current trap.
 * (This function is for use in trap handlers and such.)
 *
 * The caller is responsible for making sure there is an active trap 0e
 * when making this request.
 *
 * @param   pVM         The virtual machine.
 * @param   uCR2        The new fault address (cr2 register).
 */
TRPMDECL(void)  TRPMSetFaultAddress(PVM pVM, RTGCUINTPTR uCR2)
{
    Log2(("TRPMSetFaultAddress: uCR2=%VGv\n", uCR2));
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
    AssertMsg(pVM->trpm.s.uActiveVector == 0xe, ("Not trap 0e!\n"));
    pVM->trpm.s.uActiveCR2 = uCR2;
}


/**
 * Checks if the current active trap/interrupt/exception/fault/whatever is a software
 * interrupt or not.
 *
 * The caller is responsible for making sure there is an active trap
 * when making this request.
 *
 * @returns true if software interrupt, false if not.
 *
 * @param   pVM         VM handle.
 */
TRPMDECL(bool) TRPMIsSoftwareInterrupt(PVM pVM)
{
    AssertMsg(pVM->trpm.s.uActiveVector != ~0U, ("No active trap!\n"));
    return !!pVM->trpm.s.fActiveSoftwareInterrupt;
}


/**
 * Check if there is an active trap.
 *
 * @returns true if trap active, false if not.
 * @param   pVM         The virtual machine.
 */
TRPMDECL(bool)  TRPMHasTrap(PVM pVM)
{
    return pVM->trpm.s.uActiveVector != ~0U;
}


/**
 * Query all info about the current active trap/interrupt.
 * If no trap is active active an error code is returned.
 *
 * @returns VBox status code.
 * @param   pVM                     The virtual machine.
 * @param   pu8TrapNo               Where to store the trap number.
 * @param   pfSoftwareInterrupt   Where to store the software interrupt indicator.
 * @param   puErrorCode             Where to store the error code associated with some traps.
 *                                  ~0U is stored if the trap have no error code.
 * @param   puCR2                   Where to store the CR2 associated with a trap 0E.
 */
TRPMDECL(int)  TRPMQueryTrapAll(PVM pVM, uint8_t *pu8TrapNo, bool *pfSoftwareInterrupt, PRTGCUINT puErrorCode, PRTGCUINTPTR puCR2)
{
    /*
     * Check if we have a trap at present.
     */
    if (pVM->trpm.s.uActiveVector == ~0U)
        return VERR_TRPM_NO_ACTIVE_TRAP;

    if (pu8TrapNo)
        *pu8TrapNo              = (uint8_t)pVM->trpm.s.uActiveVector;
    if (pfSoftwareInterrupt)
        *pfSoftwareInterrupt    = !!pVM->trpm.s.fActiveSoftwareInterrupt;
    if (puErrorCode)
        *puErrorCode            = pVM->trpm.s.uActiveErrorCode;
    if (puCR2)
        *puCR2                  = pVM->trpm.s.uActiveCR2;

    return VINF_SUCCESS;
}


/**
 * Save the active trap.
 *
 * This routine useful when doing try/catch in the hypervisor.
 * Any function which uses temporary trap handlers should
 * probably also use this facility to save the original trap.
 *
 * @param   pVM     VM handle.
 */
TRPMDECL(void) TRPMSaveTrap(PVM pVM)
{
    pVM->trpm.s.uSavedVector            = pVM->trpm.s.uActiveVector;
    pVM->trpm.s.fSavedSoftwareInterrupt = pVM->trpm.s.fActiveSoftwareInterrupt;
    pVM->trpm.s.uSavedErrorCode         = pVM->trpm.s.uActiveErrorCode;
    pVM->trpm.s.uSavedCR2               = pVM->trpm.s.uActiveCR2;
}


/**
 * Restore a saved trap.
 *
 * Multiple restores of a saved trap is possible.
 *
 * @param   pVM     VM handle.
 */
TRPMDECL(void) TRPMRestoreTrap(PVM pVM)
{
    pVM->trpm.s.uActiveVector            = pVM->trpm.s.uSavedVector;
    pVM->trpm.s.fActiveSoftwareInterrupt = pVM->trpm.s.fSavedSoftwareInterrupt;
    pVM->trpm.s.uActiveErrorCode         = pVM->trpm.s.uSavedErrorCode;
    pVM->trpm.s.uActiveCR2               = pVM->trpm.s.uSavedCR2;
}


/**
 * Forward trap or interrupt to the guest's handler
 *
 *
 * @returns VBox status code.
 *  or does not return at all (when the trap is actually forwarded)
 *
 * @param   pVM         The VM to operate on.
 * @param   pRegFrame   Pointer to the register frame for the trap.
 * @param   iGate       Trap or interrupt gate number
 * @param   opsize      Instruction size (only relevant for software interrupts)
 * @param   enmError    TRPM_TRAP_HAS_ERRORCODE or TRPM_TRAP_NO_ERRORCODE.
 * @param   enmType     TRPM event type
 * @internal
 */
TRPMDECL(int) TRPMForwardTrap(PVM pVM, PCPUMCTXCORE pRegFrame, uint32_t iGate, uint32_t opsize, TRPMERRORCODE enmError, TRPMEVENT enmType)
{
    X86EFLAGS eflags;

#ifdef TRPM_FORWARD_TRAPS_IN_GC
    Log(("TRPMForwardTrap: eip=%VGv iGate=%d\n", pRegFrame->eip, iGate));

#ifdef DEBUG
    switch (iGate) {
    case 14:
        if (pRegFrame->eip == pVM->trpm.s.uActiveCR2)
        {
            int rc;
            RTGCPTR pCallerGC;
#ifdef IN_GC
            rc = MMGCRamRead(pVM, &pCallerGC, (RTGCPTR)pRegFrame->esp, sizeof(pCallerGC));
#else
            rc = PGMPhysReadGCPtr(pVM, &pCallerGC, (RTGCPTR)pRegFrame->esp, sizeof(pCallerGC));
#endif
            if (VBOX_SUCCESS(rc))
            {
                Log(("TRPMForwardTrap: caller=%VGv\n", pCallerGC));
            }
        }
        /* no break */
    case 8:
    case 10:
    case 11:
    case 12:
    case 13:
    case 17:
        Assert(enmError == TRPM_TRAP_HAS_ERRORCODE);
        break;
    default:
        Assert(enmError == TRPM_TRAP_NO_ERRORCODE);
        break;
    }
#endif /* DEBUG */

    /* Retrieve the eflags including the virtualized bits. */
    /** @note hackish as the cpumctxcore structure doesn't contain the right value */
    eflags.u32 = CPUMRawGetEFlags(pVM, pRegFrame);

    /* VM_FF_INHIBIT_INTERRUPTS should be cleared upfront or don't call this function at all for dispatching hardware interrupts. */
    Assert(enmType != TRPM_HARDWARE_INT || !VM_FF_ISSET(pVM, VM_FF_INHIBIT_INTERRUPTS));

    /*
     * If it's a real guest trap and the guest's page fault handler is marked as safe for GC execution, then we call it directly.
     * Well, only if the IF flag is set.
     */
    /*
     * @todo if the trap handler was modified and marked invalid, then we should *now* go back to the host context and install a new patch.
     *
     */
    if (    pVM->trpm.s.aGuestTrapHandler[iGate]
        && (eflags.Bits.u1IF)
        && !(eflags.Bits.u1VM) /* @todo implement when needed (illegal for same privilege level transfers). */
        && !PATMIsPatchGCAddr(pVM, (RTGCPTR)pRegFrame->eip)
       )
    {
        uint16_t    cbIDT;
        RTGCPTR     GCPtrIDT = (RTGCPTR)CPUMGetGuestIDTR(pVM, &cbIDT);
        uint32_t    cpl;
        VBOXIDTE    GuestIdte;
        RTGCPTR     pIDTEntry;
        int         rc;

        Assert(PATMAreInterruptsEnabledByCtxCore(pVM, pRegFrame));

        /* Must get the CPL from the SS selector (CS might be conforming) */
        if ((pRegFrame->ss & X86_SEL_RPL) == 1)
            cpl = 0;
        else
            cpl = (pRegFrame->ss & X86_SEL_RPL);

        if (GCPtrIDT && iGate * sizeof(VBOXIDTE) >= cbIDT)
            goto failure;

        /*
         * BIG TODO: The checks are not complete. see trap and interrupt dispatching section in Intel docs for details
         *           All very obscure, but still necessary.
         *           Currently only some CS & TSS selector checks are missing.
         *
         */
        pIDTEntry = (RTGCPTR)((RTGCUINTPTR)GCPtrIDT + sizeof(VBOXIDTE) * iGate);
#ifdef IN_GC
        rc = MMGCRamRead(pVM, &GuestIdte, pIDTEntry, sizeof(GuestIdte));
#else
        rc = PGMPhysReadGCPtr(pVM, &GuestIdte, pIDTEntry, sizeof(GuestIdte));
#endif
        if (VBOX_FAILURE(rc))
        {
            /* The page might be out of sync. (@todo might cross a page boundary) */
            Log(("Page %VGv out of sync -> prefetch and try again\n", pIDTEntry));
            rc = PGMPrefetchPage(pVM, pIDTEntry); /** @todo r=bird: rainy day: this isn't entirely safe because of access bit virtualiziation and CSAM. */
            if (rc != VINF_SUCCESS)
            {
                Log(("TRPMForwardTrap: PGMPrefetchPage failed with rc=%Vrc\n", rc));
                goto failure;
            }
#ifdef IN_GC
            rc = MMGCRamRead(pVM, &GuestIdte, pIDTEntry, sizeof(GuestIdte));
#else
            rc = PGMPhysReadGCPtr(pVM, &GuestIdte, pIDTEntry, sizeof(GuestIdte));
#endif
        }
        if (    VBOX_SUCCESS(rc)
            &&  GuestIdte.Gen.u1Present
            &&  (GuestIdte.Gen.u5Type2 == VBOX_IDTE_TYPE2_TRAP_32 || GuestIdte.Gen.u5Type2 == VBOX_IDTE_TYPE2_INT_32)
            &&  (GuestIdte.Gen.u2DPL == 3 || GuestIdte.Gen.u2DPL == 0)
            &&  (GuestIdte.Gen.u16SegSel & 0xfffc)  /* must not be zero */
            &&  (enmType == TRPM_TRAP || enmType == TRPM_HARDWARE_INT || cpl <= GuestIdte.Gen.u2DPL)  /* CPL <= DPL if software int */
           )
        {
            RTGCPTR   pHandler, dummy;
            GCPTRTYPE(uint32_t *)pTrapStackGC;
#ifndef IN_GC
            HCPTRTYPE(uint32_t *)pTrapStackHC;
#endif

            pHandler = (RTGCPTR)((GuestIdte.Gen.u16OffsetHigh << 16) | GuestIdte.Gen.u16OffsetLow);

            /* Note: SELMValidateAndConvertCSAddr checks for code type, memory type, selector validity. */
            /** @todo dpl <= cpl else GPF */
            rc = SELMValidateAndConvertCSAddr(pVM, 0, GuestIdte.Gen.u16SegSel, NULL, pHandler, &dummy);
            if (rc == VINF_SUCCESS)
            {
                VBOXGDTR gdtr = {0};
                bool     fConforming = false;
                int      idx = 0;
                uint32_t dpl;
                uint32_t ss_r0;
                uint32_t esp_r0;
                VBOXDESC Desc;
                RTGCPTR  pGdtEntry;

                CPUMGetGuestGDTR(pVM, &gdtr);
                Assert(gdtr.pGdt && gdtr.cbGdt > GuestIdte.Gen.u16SegSel);

                if (!gdtr.pGdt)
                    goto failure;

                pGdtEntry = (RTGCPTR)&((VBOXDESC *)gdtr.pGdt)[GuestIdte.Gen.u16SegSel >> X86_SEL_SHIFT];
#ifdef IN_GC
                rc = MMGCRamRead(pVM, &Desc, pGdtEntry, sizeof(Desc));
#else
                rc = PGMPhysReadGCPtr(pVM, &Desc, pGdtEntry, sizeof(Desc));
#endif
                if (VBOX_FAILURE(rc))
                {
                    /* The page might be out of sync. (@todo might cross a page boundary) */
                    Log(("Page %VGv out of sync -> prefetch and try again\n", pGdtEntry));
                    rc = PGMPrefetchPage(pVM, pGdtEntry);  /** @todo r=bird: rainy day: this isn't entirely safe because of access bit virtualiziation and CSAM. */
                    if (rc != VINF_SUCCESS)
                    {
                        Log(("PGMPrefetchPage failed with rc=%Vrc\n", rc));
                        return rc;
                    }
#ifdef IN_GC
                    rc = MMGCRamRead(pVM, &Desc, pGdtEntry, sizeof(Desc));
#else
                    rc = PGMPhysReadGCPtr(pVM, &Desc, pGdtEntry, sizeof(Desc));
#endif
                    if (VBOX_FAILURE(rc))
                    {
                        Log(("MMGCRamRead failed with %Vrc\n", rc));
                        goto failure;
                    }
                }

                if (Desc.Gen.u4Type & X86_SEL_TYPE_CONF)
                {
                    Log(("Conforming code selector\n"));
                    fConforming = true;
                }
                /** @todo check descriptor type!! */

                dpl = Desc.Gen.u2Dpl;

                if (!fConforming && dpl < cpl)  /* to inner privilege level */
                {
                    SELMGetRing1Stack(pVM, &ss_r0, &esp_r0);
                    Assert((ss_r0 & X86_SEL_RPL) == 1);

                    if (   !esp_r0
                        || !ss_r0
                        || (ss_r0 & X86_SEL_RPL) != ((dpl == 0) ? 1 : dpl)
                        || SELMToFlatEx(pVM, ss_r0, (RTGCPTR)esp_r0, SELMTOFLAT_FLAGS_CPL1, (PRTGCPTR)&pTrapStackGC, NULL) != VINF_SUCCESS
                       )
                    {
                        Log(("Invalid ring 0 stack %04X:%VGv\n", ss_r0, esp_r0));
                        goto failure;
                    }
                }
                else
                if (fConforming || dpl == cpl)  /* to the same privilege level */
                {
                    ss_r0  = pRegFrame->ss;
                    esp_r0 = pRegFrame->esp;

                    if (    eflags.Bits.u1VM    /* illegal */
                        ||  SELMToFlatEx(pVM, ss_r0, (RTGCPTR)esp_r0, SELMTOFLAT_FLAGS_CPL1, (PRTGCPTR)&pTrapStackGC, NULL) != VINF_SUCCESS)
                    {
                        AssertMsgFailed(("Invalid stack %04X:%VGv???\n", ss_r0, esp_r0));
                        goto failure;
                    }
                }
                else
                {
                    Log(("Invalid cpl-dpl combo %d vs %d\n", cpl, dpl));
                    goto failure;
                }
                /*
                 * Build trap stack frame on guest handler's stack
                 */
#ifdef IN_GC
                Assert((pRegFrame->ss & X86_SEL_RPL) != 0);
                rc = PGMVerifyAccess(pVM, (RTGCUINTPTR)pTrapStackGC - 6*sizeof(uint32_t), 6 * sizeof(uint32_t), X86_PTE_RW);
#else
                Assert((pRegFrame->ss & X86_SEL_RPL) == 0 || (pRegFrame->ss & X86_SEL_RPL) == 3);
                if (    PAGE_ADDRESS(pTrapStackGC) != PAGE_ADDRESS(pTrapStackGC - 6*sizeof(uint32_t)) /* fail if we cross a page boundary */
                    ||  VBOX_FAILURE((rc = PGMPhysGCPtr2HCPtr(pVM, pTrapStackGC, (PRTHCPTR)&pTrapStackHC)))
                   )
                {
                    AssertRC(rc);
                    goto failure;
                }
#endif
                if (rc == VINF_SUCCESS)
                {
                    Log(("TRAP%02X: Handler %04X:%08X Stack %04X:%08X RPL=%d CR2=%08X\n", iGate, GuestIdte.Gen.u16SegSel, pHandler, ss_r0, esp_r0, (pRegFrame->ss & X86_SEL_RPL), pVM->trpm.s.uActiveCR2));

                    if (fConforming == false && dpl < cpl)
                    {
                        if ((pRegFrame->ss & X86_SEL_RPL) == 1)
                            CTXSUFF(pTrapStack)[--idx] = pRegFrame->ss & ~1;    /* Mask away traces of raw ring execution (ring 1). */
                        else
                            CTXSUFF(pTrapStack)[--idx] = pRegFrame->ss;

                        CTXSUFF(pTrapStack)[--idx] = pRegFrame->esp;
                    }

                    /* @note we use the original eflags, not the copy that includes the virtualized bits! */
                    CTXSUFF(pTrapStack)[--idx] = pRegFrame->eflags.u32;

                    if ((pRegFrame->cs & X86_SEL_RPL) == 1)
                        CTXSUFF(pTrapStack)[--idx] = pRegFrame->cs & ~1;    /* Mask away traces of raw ring execution (ring 1). */
                    else
                        CTXSUFF(pTrapStack)[--idx] = pRegFrame->cs;

                    if (enmType == TRPM_SOFTWARE_INT)
                    {
                        Assert(opsize);
                        CTXSUFF(pTrapStack)[--idx] = pRegFrame->eip + opsize;    /* return address = next instruction */
                    }
                    else
                        CTXSUFF(pTrapStack)[--idx] = pRegFrame->eip;

                    if (enmError == TRPM_TRAP_HAS_ERRORCODE)
                    {
                        CTXSUFF(pTrapStack)[--idx] = pVM->trpm.s.uActiveErrorCode;
                    }

                    Assert(esp_r0 > -idx*sizeof(uint32_t));
                    /* Adjust ESP accordingly */
                    esp_r0 +=  idx*sizeof(uint32_t);

                    /* Mask away dangerous flags for the trap/interrupt handler. */
                    eflags.u32 &= ~(X86_EFL_TF | X86_EFL_VM | X86_EFL_RF | X86_EFL_NT);
#ifdef DEBUG
                    for (int j=idx;j<0;j++)
                    {
                        LogFlow(("Stack %VGv pos %02d: %08x\n", &CTXSUFF(pTrapStack)[j], j, CTXSUFF(pTrapStack)[j]));
                    }
                    char *pszPrefix = "";
                    char *szEFlags = "";

                    LogFlow((   "%seax=%08x %sebx=%08x %secx=%08x %sedx=%08x %sesi=%08x %sedi=%08x\n"
                            "%seip=%08x %sesp=%08x %sebp=%08x %siopl=%d %*s\n"
                            "%scs=%04x %sds=%04x %ses=%04x %sfs=%04x %sgs=%04x                       %seflags=%08x\n",
                            pszPrefix, pRegFrame->eax, pszPrefix, pRegFrame->ebx, pszPrefix, pRegFrame->ecx, pszPrefix, pRegFrame->edx, pszPrefix, pRegFrame->esi, pszPrefix, pRegFrame->edi,
                            pszPrefix, pRegFrame->eip, pszPrefix, pRegFrame->esp, pszPrefix, pRegFrame->ebp, pszPrefix, eflags.Bits.u2IOPL, *pszPrefix ? 33 : 31, szEFlags,
                            pszPrefix, (RTSEL)pRegFrame->cs, pszPrefix, (RTSEL)pRegFrame->ds, pszPrefix, (RTSEL)pRegFrame->es,
                            pszPrefix, (RTSEL)pRegFrame->fs, pszPrefix, (RTSEL)pRegFrame->gs, pszPrefix, eflags.u32));
#endif

                    Log(("PATM Handler %VGv Adjusted stack %08X new EFLAGS=%08X idx=%d dpl=%d cpl=%d\n", pVM->trpm.s.aGuestTrapHandler[iGate], esp_r0, eflags.u32, idx, dpl, cpl));

////                            AssertMsg(ASMGetCR2() == pTrpm->uActiveCR2, ("current cr2=%08x trpm cr2=%08x\n", ASMGetCR2(), pTrpm->uActiveCR2));

                    /* Make sure the internal guest context structure is up-to-date. */
                    CPUMSetGuestCR2(pVM, pVM->trpm.s.uActiveCR2);

#ifdef IN_GC
                    /** @note shouldn't be necessary */
                    ASMSetCR2(pVM->trpm.s.uActiveCR2);

                    /* Turn off interrupts for interrupt gates. */
                    if (GuestIdte.Gen.u5Type2 == VBOX_IDTE_TYPE2_INT_32)
                        CPUMRawSetEFlags(pVM, pRegFrame, eflags.u32 & ~X86_EFL_IF);

                    /* The virtualized bits must be removed again!! */
                    eflags.Bits.u1IF   = 1;
                    eflags.Bits.u2IOPL = 0;

                    STAM_COUNTER_INC(&pVM->trpm.s.CTXALLSUFF(paStatForwardedIRQ)[iGate]);
                    Assert(eflags.Bits.u1IF);
                    Assert(eflags.Bits.u2IOPL == 0);
                    CPUMGCCallGuestTrapHandler(pRegFrame, GuestIdte.Gen.u16SegSel | 1, pVM->trpm.s.aGuestTrapHandler[iGate], eflags.u32, ss_r0, (RTGCPTR)esp_r0);
                    /* does not return */
#else
                    /* Turn off interrupts for interrupt gates. */
                    if (GuestIdte.Gen.u5Type2 == VBOX_IDTE_TYPE2_INT_32)
                        eflags.Bits.u1IF = 0;

                    pRegFrame->eflags.u32 = eflags.u32;

                    pRegFrame->eip        = pVM->trpm.s.aGuestTrapHandler[iGate];
                    pRegFrame->cs         = GuestIdte.Gen.u16SegSel;
                    pRegFrame->esp        = esp_r0;
                    pRegFrame->ss         = ss_r0 & ~X86_SEL_RPL;     /* set rpl to ring 0 */
                    return VINF_SUCCESS;
#endif
                }
                else
                    Log(("TRAP%02X: PGMVerifyAccess %VGv failed with %Vrc -> forward to REM\n", iGate, pTrapStackGC, rc));
            }
            else
                Log(("SELMValidateAndConvertCSAddr failed with %Vrc\n", rc));
        }
        else
            Log(("MMRamRead %VGv size %d failed with %Vrc\n", (RTGCUINTPTR)GCPtrIDT + sizeof(VBOXIDTE) * iGate, sizeof(GuestIdte), rc));
    }
    else
    {
        Log(("Refused to forward trap: eflags=%08x IF=%d\n", eflags.u32, eflags.Bits.u1IF));
#ifdef VBOX_WITH_STATISTICS
        if (pVM->trpm.s.aGuestTrapHandler[iGate] == TRPM_INVALID_HANDLER)
            STAM_COUNTER_INC(&pVM->trpm.s.StatForwardFailNoHandler);
        else
        if (PATMIsPatchGCAddr(pVM, (RTGCPTR)pRegFrame->eip))
            STAM_COUNTER_INC(&pVM->trpm.s.StatForwardFailPatchAddr);
#endif
    }
failure:
    STAM_COUNTER_INC(&CTXSUFF(pVM->trpm.s.StatForwardFail));

    Log(("TRAP%02X: forwarding to REM (ss rpl=%d eflags=%08X VMIF=%d handler=%08X\n", iGate, pRegFrame->ss & X86_SEL_RPL, pRegFrame->eflags.u32, PATMAreInterruptsEnabledByCtxCore(pVM, pRegFrame), pVM->trpm.s.aGuestTrapHandler[iGate]));
#endif
    return VINF_EM_RAW_GUEST_TRAP;
}


/**
 * Raises a cpu exception which doesn't take an error code.
 *
 * This function may or may not dispatch the exception before returning.
 *
 * @returns VBox status code fit for scheduling.
 * @retval  VINF_EM_RAW_GUEST_TRAP if the exception was left pending.
 * @retval  VINF_TRPM_XCPT_DISPATCHED if the exception was raised and dispatched for raw-mode execution.
 * @retval  VINF_EM_RESCHEDULE_REM if the exception was dispatched and cannot be executed in raw-mode.
 *
 * @param   pVM         The VM handle.
 * @param   pCtxCore    The CPU context core.
 * @param   enmXcpt     The exception.
 */
TRPMDECL(int) TRPMRaiseXcpt(PVM pVM, PCPUMCTXCORE pCtxCore, X86XCPT enmXcpt)
{
    LogFlow(("TRPMRaiseXcptErr: cs:eip=%RTsel:%RX32 enmXcpt=%#x\n", pCtxCore->cs, pCtxCore->eip, enmXcpt));
/** @todo dispatch the trap. */
    pVM->trpm.s.uActiveVector            = enmXcpt;
    pVM->trpm.s.fActiveSoftwareInterrupt = false;
    pVM->trpm.s.uActiveErrorCode         = 0xdeadbeef;
    pVM->trpm.s.uActiveCR2               = 0xdeadface;
    return VINF_EM_RAW_GUEST_TRAP;
}


/**
 * Raises a cpu exception with an errorcode.
 *
 * This function may or may not dispatch the exception before returning.
 *
 * @returns VBox status code fit for scheduling.
 * @retval  VINF_EM_RAW_GUEST_TRAP if the exception was left pending.
 * @retval  VINF_TRPM_XCPT_DISPATCHED if the exception was raised and dispatched for raw-mode execution.
 * @retval  VINF_EM_RESCHEDULE_REM if the exception was dispatched and cannot be executed in raw-mode.
 *
 * @param   pVM         The VM handle.
 * @param   pCtxCore    The CPU context core.
 * @param   enmXcpt     The exception.
 * @param   uErr        The error code.
 */
TRPMDECL(int) TRPMRaiseXcptErr(PVM pVM, PCPUMCTXCORE pCtxCore, X86XCPT enmXcpt, uint32_t uErr)
{
    LogFlow(("TRPMRaiseXcptErr: cs:eip=%RTsel:%RX32 enmXcpt=%#x uErr=%RX32\n", pCtxCore->cs, pCtxCore->eip, enmXcpt, uErr));
/** @todo dispatch the trap. */
    pVM->trpm.s.uActiveVector            = enmXcpt;
    pVM->trpm.s.fActiveSoftwareInterrupt = false;
    pVM->trpm.s.uActiveErrorCode         = uErr;
    pVM->trpm.s.uActiveCR2               = 0xdeadface;
    return VINF_EM_RAW_GUEST_TRAP;
}


/**
 * Raises a cpu exception with an errorcode and CR2.
 *
 * This function may or may not dispatch the exception before returning.
 *
 * @returns VBox status code fit for scheduling.
 * @retval  VINF_EM_RAW_GUEST_TRAP if the exception was left pending.
 * @retval  VINF_TRPM_XCPT_DISPATCHED if the exception was raised and dispatched for raw-mode execution.
 * @retval  VINF_EM_RESCHEDULE_REM if the exception was dispatched and cannot be executed in raw-mode.
 *
 * @param   pVM         The VM handle.
 * @param   pCtxCore    The CPU context core.
 * @param   enmXcpt     The exception.
 * @param   uErr        The error code.
 * @param   uCR2        The CR2 value.
 */
TRPMDECL(int) TRPMRaiseXcptErrCR2(PVM pVM, PCPUMCTXCORE pCtxCore, X86XCPT enmXcpt, uint32_t uErr, RTGCUINTPTR uCR2)
{
    LogFlow(("TRPMRaiseXcptErr: cs:eip=%RTsel:%RX32 enmXcpt=%#x uErr=%RX32 uCR2=%RGv\n", pCtxCore->cs, pCtxCore->eip, enmXcpt, uErr, uCR2));
/** @todo dispatch the trap. */
    pVM->trpm.s.uActiveVector            = enmXcpt;
    pVM->trpm.s.fActiveSoftwareInterrupt = false;
    pVM->trpm.s.uActiveErrorCode         = uErr;
    pVM->trpm.s.uActiveCR2               = uCR2;
    return VINF_EM_RAW_GUEST_TRAP;
}