| 1 | /* $Id: TRPMRC.cpp 69111 2017-10-17 14:26:02Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * TRPM - The Trap Monitor, Guest Context
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2006-2017 Oracle Corporation
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 10 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 11 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 12 | * General Public License (GPL) as published by the Free Software
|
|---|
| 13 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 14 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 15 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 16 | */
|
|---|
| 17 |
|
|---|
| 18 |
|
|---|
| 19 | /*********************************************************************************************************************************
|
|---|
| 20 | * Header Files *
|
|---|
| 21 | *********************************************************************************************************************************/
|
|---|
| 22 | #define LOG_GROUP LOG_GROUP_TRPM
|
|---|
| 23 | #include <VBox/vmm/trpm.h>
|
|---|
| 24 | #include <VBox/vmm/cpum.h>
|
|---|
| 25 | #include <VBox/vmm/em.h>
|
|---|
| 26 | #include <VBox/vmm/vmm.h>
|
|---|
| 27 | #include "TRPMInternal.h"
|
|---|
| 28 | #include <VBox/vmm/vm.h>
|
|---|
| 29 |
|
|---|
| 30 | #include <VBox/err.h>
|
|---|
| 31 | #include <iprt/assert.h>
|
|---|
| 32 | #include <iprt/asm.h>
|
|---|
| 33 | #include <iprt/x86.h>
|
|---|
| 34 | #include <VBox/log.h>
|
|---|
| 35 | #include <VBox/vmm/selm.h>
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 |
|
|---|
| 39 | /**
|
|---|
| 40 | * Arms a temporary trap handler for traps in Hypervisor code.
|
|---|
| 41 | *
|
|---|
| 42 | * The operation is similar to a System V signal handler. I.e. when the handler
|
|---|
| 43 | * is called it is first set to default action. So, if you need to handler more
|
|---|
| 44 | * than one trap, you must reinstall the handler.
|
|---|
| 45 | *
|
|---|
| 46 | * To uninstall the temporary handler, call this function with pfnHandler set to NULL.
|
|---|
| 47 | *
|
|---|
| 48 | * @returns VBox status code.
|
|---|
| 49 | * @param pVM The cross context VM structure.
|
|---|
| 50 | * @param iTrap Trap number to install handler [0..255].
|
|---|
| 51 | * @param pfnHandler Pointer to the handler. Use NULL for uninstalling the handler.
|
|---|
| 52 | */
|
|---|
| 53 | VMMRCDECL(int) TRPMGCSetTempHandler(PVM pVM, unsigned iTrap, PFNTRPMGCTRAPHANDLER pfnHandler)
|
|---|
| 54 | {
|
|---|
| 55 | /*
|
|---|
| 56 | * Validate input.
|
|---|
| 57 | */
|
|---|
| 58 | if (iTrap >= RT_ELEMENTS(pVM->trpm.s.aTmpTrapHandlers))
|
|---|
| 59 | {
|
|---|
| 60 | AssertMsgFailed(("Trap handler iTrap=%u is out of range!\n", iTrap));
|
|---|
| 61 | return VERR_INVALID_PARAMETER;
|
|---|
| 62 | }
|
|---|
| 63 |
|
|---|
| 64 | /*
|
|---|
| 65 | * Install handler.
|
|---|
| 66 | */
|
|---|
| 67 | pVM->trpm.s.aTmpTrapHandlers[iTrap] = (RTRCPTR)(uintptr_t)pfnHandler;
|
|---|
| 68 | return VINF_SUCCESS;
|
|---|
| 69 | }
|
|---|
| 70 |
|
|---|
| 71 |
|
|---|
| 72 | /**
|
|---|
| 73 | * Return to host context from a hypervisor trap handler.
|
|---|
| 74 | *
|
|---|
| 75 | * This function will *never* return.
|
|---|
| 76 | * It will also reset any traps that are pending.
|
|---|
| 77 | *
|
|---|
| 78 | * @param pVM The cross context VM structure.
|
|---|
| 79 | * @param rc The return code for host context.
|
|---|
| 80 | */
|
|---|
| 81 | VMMRCDECL(void) TRPMGCHyperReturnToHost(PVM pVM, int rc)
|
|---|
| 82 | {
|
|---|
| 83 | PVMCPU pVCpu = VMMGetCpu0(pVM);
|
|---|
| 84 |
|
|---|
| 85 | LogFlow(("TRPMGCHyperReturnToHost: rc=%Rrc\n", rc));
|
|---|
| 86 | TRPMResetTrap(pVCpu);
|
|---|
| 87 | VMMRCGuestToHost(pVM, rc);
|
|---|
| 88 | AssertReleaseFailed();
|
|---|
| 89 | }
|
|---|
| 90 |
|
|---|
| 91 |
|
|---|
| 92 | /**
|
|---|
| 93 | * @callback_method_impl{FNPGMRCVIRTPFHANDLER,
|
|---|
| 94 | * \#PF Virtual Handler callback for Guest write access to the Guest's own current IDT.}
|
|---|
| 95 | */
|
|---|
| 96 | DECLEXPORT(VBOXSTRICTRC) trpmRCGuestIDTWritePfHandler(PVM pVM, PVMCPU pVCpu, RTGCUINT uErrorCode, PCPUMCTXCORE pRegFrame,
|
|---|
| 97 | RTGCPTR pvFault, RTGCPTR pvRange, uintptr_t offRange, void *pvUser)
|
|---|
| 98 | {
|
|---|
| 99 | uint16_t cbIDT;
|
|---|
| 100 | RTGCPTR GCPtrIDT = (RTGCPTR)CPUMGetGuestIDTR(pVCpu, &cbIDT);
|
|---|
| 101 | #ifdef VBOX_STRICT
|
|---|
| 102 | RTGCPTR GCPtrIDTEnd = (RTGCPTR)((RTGCUINTPTR)GCPtrIDT + cbIDT + 1);
|
|---|
| 103 | #endif
|
|---|
| 104 | uint32_t iGate = ((RTGCUINTPTR)pvFault - (RTGCUINTPTR)GCPtrIDT)/sizeof(VBOXIDTE);
|
|---|
| 105 | RT_NOREF_PV(offRange); RT_NOREF_PV(pvRange); RT_NOREF_PV(pRegFrame); RT_NOREF_PV(pVM);
|
|---|
| 106 |
|
|---|
| 107 | AssertMsg(offRange < (uint32_t)cbIDT+1, ("pvFault=%RGv GCPtrIDT=%RGv-%RGv pvRange=%RGv\n", pvFault, GCPtrIDT, GCPtrIDTEnd, pvRange));
|
|---|
| 108 | Assert((RTGCPTR)(RTRCUINTPTR)pvRange == GCPtrIDT);
|
|---|
| 109 | NOREF(uErrorCode); NOREF(pvUser);
|
|---|
| 110 |
|
|---|
| 111 | #if 0
|
|---|
| 112 | /* Note! this causes problems in Windows XP as instructions following the update can be dangerous (str eax has been seen) */
|
|---|
| 113 | /* Note! not going back to ring 3 could make the code scanner miss them. */
|
|---|
| 114 | /* Check if we can handle the write here. */
|
|---|
| 115 | if ( iGate != 3 /* Gate 3 is handled differently; could do it here as well, but let ring 3 handle this case for now. */
|
|---|
| 116 | && !ASMBitTest(&pVM->trpm.s.au32IdtPatched[0], iGate)) /* Passthru gates need special attention too. */
|
|---|
| 117 | {
|
|---|
| 118 | uint32_t cb;
|
|---|
| 119 | int rc = EMInterpretInstructionEx(pVM, pVCpu, pRegFrame, pvFault, &cb);
|
|---|
| 120 | if (RT_SUCCESS(rc) && cb)
|
|---|
| 121 | {
|
|---|
| 122 | uint32_t iGate1 = (offRange + cb - 1)/sizeof(VBOXIDTE);
|
|---|
| 123 |
|
|---|
| 124 | Log(("trpmRCGuestIDTWriteHandler: write to gate %x (%x) offset %x cb=%d\n", iGate, iGate1, offRange, cb));
|
|---|
| 125 |
|
|---|
| 126 | trpmClearGuestTrapHandler(pVM, iGate);
|
|---|
| 127 | if (iGate != iGate1)
|
|---|
| 128 | trpmClearGuestTrapHandler(pVM, iGate1);
|
|---|
| 129 |
|
|---|
| 130 | STAM_COUNTER_INC(&pVM->trpm.s.StatRCWriteGuestIDTHandled);
|
|---|
| 131 | return VINF_SUCCESS;
|
|---|
| 132 | }
|
|---|
| 133 | }
|
|---|
| 134 | #else
|
|---|
| 135 | NOREF(iGate);
|
|---|
| 136 | #endif
|
|---|
| 137 |
|
|---|
| 138 | Log(("trpmRCGuestIDTWritePfHandler: eip=%RGv write to gate %x offset %x\n", pRegFrame->eip, iGate, offRange));
|
|---|
| 139 |
|
|---|
| 140 | /** @todo Check which IDT entry and keep the update cost low in TRPMR3SyncIDT() and CSAMCheckGates(). */
|
|---|
| 141 | VMCPU_FF_SET(pVCpu, VMCPU_FF_TRPM_SYNC_IDT);
|
|---|
| 142 |
|
|---|
| 143 | STAM_COUNTER_INC(&pVM->trpm.s.StatRCWriteGuestIDTFault);
|
|---|
| 144 | return VINF_EM_RAW_EMULATE_INSTR_IDT_FAULT;
|
|---|
| 145 | }
|
|---|
| 146 |
|
|---|
| 147 |
|
|---|
| 148 | /**
|
|---|
| 149 | * @callback_method_impl{FNPGMRCVIRTPFHANDLER,
|
|---|
| 150 | * \#PF Virtual Handler callback for Guest write access to the VBox shadow IDT.}
|
|---|
| 151 | */
|
|---|
| 152 | DECLEXPORT(VBOXSTRICTRC) trpmRCShadowIDTWritePfHandler(PVM pVM, PVMCPU pVCpu, RTGCUINT uErrorCode, PCPUMCTXCORE pRegFrame,
|
|---|
| 153 | RTGCPTR pvFault, RTGCPTR pvRange, uintptr_t offRange, void *pvUser)
|
|---|
| 154 | {
|
|---|
| 155 | LogRel(("FATAL ERROR: trpmRCShadowIDTWritePfHandler: eip=%08X pvFault=%RGv pvRange=%08RGv\r\n", pRegFrame->eip, pvFault, pvRange));
|
|---|
| 156 | NOREF(uErrorCode); NOREF(offRange); NOREF(pvUser);
|
|---|
| 157 |
|
|---|
| 158 | /*
|
|---|
| 159 | * If we ever get here, then the guest has *probably* executed an SIDT
|
|---|
| 160 | * instruction that we failed to patch. In theory this could be very bad,
|
|---|
| 161 | * but there are nasty applications out there that install device drivers
|
|---|
| 162 | * that mess with the guest's IDT. In those cases, it's quite ok to simply
|
|---|
| 163 | * ignore the writes and pretend success.
|
|---|
| 164 | *
|
|---|
| 165 | * Another posibility is that the guest is touching some page memory and
|
|---|
| 166 | * it having nothing to do with our IDT or anything like that, just a
|
|---|
| 167 | * potential conflict that we didn't discover in time.
|
|---|
| 168 | */
|
|---|
| 169 | DISSTATE Dis;
|
|---|
| 170 | int rc = EMInterpretDisasCurrent(pVM, pVCpu, &Dis, NULL);
|
|---|
| 171 | if (rc == VINF_SUCCESS)
|
|---|
| 172 | {
|
|---|
| 173 | /* Just ignore the write. */
|
|---|
| 174 | pRegFrame->eip += Dis.cbInstr;
|
|---|
| 175 | return VINF_SUCCESS;
|
|---|
| 176 | }
|
|---|
| 177 |
|
|---|
| 178 | return VERR_TRPM_SHADOW_IDT_WRITE;
|
|---|
| 179 | }
|
|---|
| 180 |
|
|---|
