/* $Id: CPUMRC.cpp 69111 2017-10-17 14:26:02Z vboxsync $ */ /** @file * CPUM - Raw-mode Context Code. */ /* * Copyright (C) 2006-2017 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_CPUM #include #include #include #include #include #include "CPUMInternal.h" #include #include #include #include #include /********************************************************************************************************************************* * Internal Functions * *********************************************************************************************************************************/ RT_C_DECLS_BEGIN /* addressed from asm (not called so no DECLASM). */ DECLCALLBACK(int) cpumRCHandleNPAndGP(PVM pVM, PCPUMCTXCORE pRegFrame, uintptr_t uUser); RT_C_DECLS_END /** * Deal with traps occurring during segment loading and IRET when resuming guest * context execution. * * @returns VBox status code. * @param pVM The cross context VM structure. * @param pRegFrame The register frame. * @param uUser User argument. In this case a combination of the * CPUM_HANDLER_* \#defines. */ DECLCALLBACK(int) cpumRCHandleNPAndGP(PVM pVM, PCPUMCTXCORE pRegFrame, uintptr_t uUser) { Log(("********************************************************\n")); Log(("cpumRCHandleNPAndGP: eip=%RX32 uUser=%#x\n", pRegFrame->eip, uUser)); Log(("********************************************************\n")); /* * Take action based on what's happened. */ switch (uUser & CPUM_HANDLER_TYPEMASK) { case CPUM_HANDLER_GS: case CPUM_HANDLER_DS: case CPUM_HANDLER_ES: case CPUM_HANDLER_FS: TRPMGCHyperReturnToHost(pVM, VINF_EM_RAW_STALE_SELECTOR); break; case CPUM_HANDLER_IRET: TRPMGCHyperReturnToHost(pVM, VINF_EM_RAW_IRET_TRAP); break; } AssertMsgFailed(("uUser=%#x eip=%#x\n", uUser, pRegFrame->eip)); RT_NOREF_PV(pRegFrame); return VERR_TRPM_DONT_PANIC; } /** * Called by TRPM and CPUM assembly code to make sure the guest state is * ready for execution. * * @param pVM The cross context VM structure. */ DECLASM(void) CPUMRCAssertPreExecutionSanity(PVM pVM) { #ifdef VBOX_STRICT /* * Check some important assumptions before resuming guest execution. */ PVMCPU pVCpu = VMMGetCpu0(pVM); PCCPUMCTX pCtx = &pVCpu->cpum.s.Guest; uint8_t const uRawCpl = CPUMGetGuestCPL(pVCpu); uint32_t const u32EFlags = CPUMRawGetEFlags(pVCpu); bool const fPatch = PATMIsPatchGCAddr(pVM, pCtx->eip); AssertMsg(pCtx->eflags.Bits.u1IF, ("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); AssertMsg(pCtx->eflags.Bits.u2IOPL < RT_MAX(uRawCpl, 1U), ("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); if (!(u32EFlags & X86_EFL_VM)) { AssertMsg((u32EFlags & X86_EFL_IF) || fPatch,("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); AssertMsg((pCtx->cs.Sel & X86_SEL_RPL) > 0, ("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); AssertMsg((pCtx->ss.Sel & X86_SEL_RPL) > 0, ("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); } AssertMsg(CPUMIsGuestInRawMode(pVCpu), ("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); //Log2(("cs:eip=%04x:%08x ss:esp=%04x:%08x cpl=%u raw/efl=%#x/%#x%s\n", pCtx->cs.Sel, pCtx->eip, pCtx->ss.Sel, pCtx->esp, uRawCpl, u32EFlags, pCtx->eflags.u, fPatch ? " patch" : "")); #else RT_NOREF_PV(pVM); #endif } /** * Get the current privilege level of the guest. * * @returns CPL * @param pVCpu The cross context virtual CPU structure of the calling EMT. * @param pRegFrame Pointer to the register frame. * * @todo r=bird: This is very similar to CPUMGetGuestCPL and I cannot quite * see why this variant of the code is necessary. */ VMMDECL(uint32_t) CPUMRCGetGuestCPL(PVMCPU pVCpu, PCPUMCTXCORE pRegFrame) { /* * CPL can reliably be found in SS.DPL (hidden regs valid) or SS if not. * * Note! We used to check CS.DPL here, assuming it was always equal to * CPL even if a conforming segment was loaded. But this truned out to * only apply to older AMD-V. With VT-x we had an ACP2 regression * during install after a far call to ring 2 with VT-x. Then on newer * AMD-V CPUs we have to move the VMCB.guest.u8CPL into cs.Attr.n.u2Dpl * as well as ss.Attr.n.u2Dpl to make this (and other) code work right. * * So, forget CS.DPL, always use SS.DPL. * * Note! The SS RPL is always equal to the CPL, while the CS RPL * isn't necessarily equal if the segment is conforming. * See section 4.11.1 in the AMD manual. */ uint32_t uCpl; if (!pRegFrame->eflags.Bits.u1VM) { uCpl = (pRegFrame->ss.Sel & X86_SEL_RPL); #ifdef VBOX_WITH_RAW_MODE_NOT_R0 # ifdef VBOX_WITH_RAW_RING1 if (pVCpu->cpum.s.fRawEntered) { if ( uCpl == 2 && EMIsRawRing1Enabled(pVCpu->CTX_SUFF(pVM)) ) uCpl = 1; else if (uCpl == 1) uCpl = 0; } Assert(uCpl != 2); /* ring 2 support not allowed anymore. */ # else if (uCpl == 1) uCpl = 0; # endif #endif } else uCpl = 3; /* V86 has CPL=3; REM doesn't set DPL=3 in V8086 mode. See @bugref{5130}. */ return uCpl; } #ifdef VBOX_WITH_RAW_RING1 /** * Transforms the guest CPU state to raw-ring mode. * * This function will change the any of the cs and ss register with DPL=0 to DPL=1. * * Used by emInterpretIret() after the new state has been loaded. * * @param pVCpu The cross context virtual CPU structure. * @param pCtxCore The context core (for trap usage). * @see @ref pg_raw * @remarks Will be probably obsoleted by #5653 (it will leave and reenter raw * mode instead, I think). */ VMMDECL(void) CPUMRCRecheckRawState(PVMCPU pVCpu, PCPUMCTXCORE pCtxCore) { /* * Are we in Ring-0? */ if ( pCtxCore->ss.Sel && (pCtxCore->ss.Sel & X86_SEL_RPL) == 0 && !pCtxCore->eflags.Bits.u1VM) { /* * Set CPL to Ring-1. */ pCtxCore->ss.Sel |= 1; if ( pCtxCore->cs.Sel && (pCtxCore->cs.Sel & X86_SEL_RPL) == 0) pCtxCore->cs.Sel |= 1; } else { if ( EMIsRawRing1Enabled(pVCpu->CTX_SUFF(pVM)) && !pCtxCore->eflags.Bits.u1VM && (pCtxCore->ss.Sel & X86_SEL_RPL) == 1) { /* Set CPL to Ring-2. */ pCtxCore->ss.Sel = (pCtxCore->ss.Sel & ~X86_SEL_RPL) | 2; if (pCtxCore->cs.Sel && (pCtxCore->cs.Sel & X86_SEL_RPL) == 1) pCtxCore->cs.Sel = (pCtxCore->cs.Sel & ~X86_SEL_RPL) | 2; } } /* * Assert sanity. */ AssertMsg((pCtxCore->eflags.u32 & X86_EFL_IF), ("X86_EFL_IF is clear\n")); AssertReleaseMsg(pCtxCore->eflags.Bits.u2IOPL == 0, ("X86_EFL_IOPL=%d CPL=%d\n", pCtxCore->eflags.Bits.u2IOPL, pCtxCore->ss.Sel & X86_SEL_RPL)); pCtxCore->eflags.u32 |= X86_EFL_IF; /* paranoia */ } #endif /* VBOX_WITH_RAW_RING1 */ /** * Called by trpmGCExitTrap when VMCPU_FF_CPUM is set (by CPUMRZ.cpp). * * We can be called unecessarily here if we returned to ring-3 for some other * reason before we tried to resume executed guest code. This is detected and * ignored. * * @param pVCpu The cross context CPU structure for the calling EMT. */ VMMRCDECL(void) CPUMRCProcessForceFlag(PVMCPU pVCpu) { /* Only modify CR0 if we're in the post IEM state (host state saved, guest no longer active). */ if ((pVCpu->cpum.s.fUseFlags & (CPUM_USED_FPU_GUEST | CPUM_USED_FPU_HOST)) == CPUM_USED_FPU_HOST) { /* * Doing the same CR0 calculation as in AMD64andLegacy.mac so that we'll * catch guest FPU accesses and load the FPU/SSE/AVX register state as needed. */ uint32_t cr0 = ASMGetCR0(); cr0 |= pVCpu->cpum.s.Guest.cr0 & X86_CR0_EM; cr0 |= X86_CR0_TS | X86_CR0_MP; ASMSetCR0(cr0); Log6(("CPUMRCProcessForceFlag: cr0=%#x\n", cr0)); } else Log6(("CPUMRCProcessForceFlag: no change - cr0=%#x\n", ASMGetCR0())); }