/****************************************************************************** * emulate.c * * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. * * Copyright (c) 2005 Keir Fraser * * Linux coding style, mod r/m decoder, segment base fixes, real-mode * privileged instructions: * * Copyright (C) 2006 Qumranet * * Avi Kivity <avi@qumranet.com> * Yaniv Kamay <yaniv@qumranet.com> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 */ #ifndef __KERNEL__ #include <stdio.h> #include <stdint.h> #include <public/xen.h> #define DPRINTF(_f, _a ...) printf(_f , ## _a) #else #include <linux/kvm_host.h> #include "kvm_cache_regs.h" #define DPRINTF(x...) do {} while (0) #endif #include <linux/module.h> #include <asm/kvm_emulate.h> #include "x86.h" #include "tss.h" /* * Opcode effective-address decode tables. * Note that we only emulate instructions that have at least one memory * operand (excluding implicit stack references). We assume that stack * references and instruction fetches will never occur in special memory * areas that require emulation. So, for example, 'mov <imm>,<reg>' need * not be handled. */ /* Operand sizes: 8-bit operands or specified/overridden size. */ #define ByteOp (1<<0) /* 8-bit operands. */ /* Destination operand type. */ #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */ #define DstReg (2<<1) /* Register operand. */ #define DstMem (3<<1) /* Memory operand. */ #define DstAcc (4<<1) /* Destination Accumulator */ #define DstDI (5<<1) /* Destination is in ES:(E)DI */ #define DstMem64 (6<<1) /* 64bit memory operand */ #define DstMask (7<<1) /* Source operand type. */ #define SrcNone (0<<4) /* No source operand. */ #define SrcImplicit (0<<4) /* Source operand is implicit in the opcode. */ #define SrcReg (1<<4) /* Register operand. */ #define SrcMem (2<<4) /* Memory operand. */ #define SrcMem16 (3<<4) /* Memory operand (16-bit). */ #define SrcMem32 (4<<4) /* Memory operand (32-bit). */ #define SrcImm (5<<4) /* Immediate operand. */ #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */ #define SrcOne (7<<4) /* Implied '1' */ #define SrcImmUByte (8<<4) /* 8-bit unsigned immediate operand. */ #define SrcImmU (9<<4) /* Immediate operand, unsigned */ #define SrcSI (0xa<<4) /* Source is in the DS:RSI */ #define SrcMask (0xf<<4) /* Generic ModRM decode. */ #define ModRM (1<<8) /* Destination is only written; never read. */ #define Mov (1<<9) #define BitOp (1<<10) #define MemAbs (1<<11) /* Memory operand is absolute displacement */ #define String (1<<12) /* String instruction (rep capable) */ #define Stack (1<<13) /* Stack instruction (push/pop) */ #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */ #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */ #define GroupMask 0xff /* Group number stored in bits 0:7 */ /* Misc flags */ #define Lock (1<<26) /* lock prefix is allowed for the instruction */ #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ #define No64 (1<<28) /* Source 2 operand type */ #define Src2None (0<<29) #define Src2CL (1<<29) #define Src2ImmByte (2<<29) #define Src2One (3<<29) #define Src2Imm16 (4<<29) #define Src2Mem16 (5<<29) /* Used for Ep encoding. First argument has to be in memory and second argument is located immediately after the first one in memory. */ #define Src2Mask (7<<29) enum { Group1_80, Group1_81, Group1_82, Group1_83, Group1A, Group3_Byte, Group3, Group4, Group5, Group7, Group8, Group9, }; static u32 opcode_table[256] = { /* 0x00 - 0x07 */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, ByteOp | DstAcc | SrcImm, DstAcc | SrcImm, ImplicitOps | Stack | No64, ImplicitOps | Stack | No64, /* 0x08 - 0x0F */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, ByteOp | DstAcc | SrcImm, DstAcc | SrcImm, ImplicitOps | Stack | No64, 0, /* 0x10 - 0x17 */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, ByteOp | DstAcc | SrcImm, DstAcc | SrcImm, ImplicitOps | Stack | No64, ImplicitOps | Stack | No64, /* 0x18 - 0x1F */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, ByteOp | DstAcc | SrcImm, DstAcc | SrcImm, ImplicitOps | Stack | No64, ImplicitOps | Stack | No64, /* 0x20 - 0x27 */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, DstAcc | SrcImmByte, DstAcc | SrcImm, 0, 0, /* 0x28 - 0x2F */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, 0, 0, 0, 0, /* 0x30 - 0x37 */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, 0, 0, 0, 0, /* 0x38 - 0x3F */ ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, ByteOp | DstAcc | SrcImm, DstAcc | SrcImm, 0, 0, /* 0x40 - 0x47 */ DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, /* 0x48 - 0x4F */ DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, /* 0x50 - 0x57 */ SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, /* 0x58 - 0x5F */ DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack, /* 0x60 - 0x67 */ ImplicitOps | Stack | No64, ImplicitOps | Stack | No64, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , 0, 0, 0, 0, /* 0x68 - 0x6F */ SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0, DstDI | ByteOp | Mov | String, DstDI | Mov | String, /* insb, insw/insd */ SrcSI | ByteOp | ImplicitOps | String, SrcSI | ImplicitOps | String, /* outsb, outsw/outsd */ /* 0x70 - 0x77 */ SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, /* 0x78 - 0x7F */ SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte, /* 0x80 - 0x87 */ Group | Group1_80, Group | Group1_81, Group | Group1_82, Group | Group1_83, ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, /* 0x88 - 0x8F */ ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov, ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstMem | SrcReg | ModRM | Mov, ModRM | DstReg, ImplicitOps | SrcMem | ModRM, Group | Group1A, /* 0x90 - 0x97 */ DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, /* 0x98 - 0x9F */ 0, 0, SrcImm | Src2Imm16 | No64, 0, ImplicitOps | Stack, ImplicitOps | Stack, 0, 0, /* 0xA0 - 0xA7 */ ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs, ByteOp | DstMem | SrcReg | Mov | MemAbs, DstMem | SrcReg | Mov | MemAbs, ByteOp | SrcSI | DstDI | Mov | String, SrcSI | DstDI | Mov | String, ByteOp | SrcSI | DstDI | String, SrcSI | DstDI | String, /* 0xA8 - 0xAF */ 0, 0, ByteOp | DstDI | Mov | String, DstDI | Mov | String, ByteOp | SrcSI | DstAcc | Mov | String, SrcSI | DstAcc | Mov | String, ByteOp | DstDI | String, DstDI | String, /* 0xB0 - 0xB7 */ ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov, /* 0xB8 - 0xBF */ DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, DstReg | SrcImm | Mov, /* 0xC0 - 0xC7 */ ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM, 0, ImplicitOps | Stack, 0, 0, ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov, /* 0xC8 - 0xCF */ 0, 0, 0, ImplicitOps | Stack, ImplicitOps, SrcImmByte, ImplicitOps | No64, ImplicitOps, /* 0xD0 - 0xD7 */ ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM, ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM, 0, 0, 0, 0, /* 0xD8 - 0xDF */ 0, 0, 0, 0, 0, 0, 0, 0, /* 0xE0 - 0xE7 */ 0, 0, 0, 0, ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc, ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc, /* 0xE8 - 0xEF */ SrcImm | Stack, SrcImm | ImplicitOps, SrcImmU | Src2Imm16 | No64, SrcImmByte | ImplicitOps, SrcNone | ByteOp | DstAcc, SrcNone | DstAcc, SrcNone | ByteOp | DstAcc, SrcNone | DstAcc, /* 0xF0 - 0xF7 */ 0, 0, 0, 0, ImplicitOps | Priv, ImplicitOps, Group | Group3_Byte, Group | Group3, /* 0xF8 - 0xFF */ ImplicitOps, 0, ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps, Group | Group4, Group | Group5, }; static u32 twobyte_table[256] = { /* 0x00 - 0x0F */ 0, Group | GroupDual | Group7, 0, 0, 0, ImplicitOps, ImplicitOps | Priv, 0, ImplicitOps | Priv, ImplicitOps | Priv, 0, 0, 0, ImplicitOps | ModRM, 0, 0, /* 0x10 - 0x1F */ 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0, /* 0x20 - 0x2F */ ModRM | ImplicitOps | Priv, ModRM | Priv, ModRM | ImplicitOps | Priv, ModRM | Priv, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x30 - 0x3F */ ImplicitOps | Priv, 0, ImplicitOps | Priv, 0, ImplicitOps, ImplicitOps | Priv, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x40 - 0x47 */ DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, /* 0x48 - 0x4F */ DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, /* 0x50 - 0x5F */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x60 - 0x6F */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x70 - 0x7F */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x80 - 0x8F */ SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, /* 0x90 - 0x9F */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xA0 - 0xA7 */ ImplicitOps | Stack, ImplicitOps | Stack, 0, DstMem | SrcReg | ModRM | BitOp, DstMem | SrcReg | Src2ImmByte | ModRM, DstMem | SrcReg | Src2CL | ModRM, 0, 0, /* 0xA8 - 0xAF */ ImplicitOps | Stack, ImplicitOps | Stack, 0, DstMem | SrcReg | ModRM | BitOp | Lock, DstMem | SrcReg | Src2ImmByte | ModRM, DstMem | SrcReg | Src2CL | ModRM, ModRM, 0, /* 0xB0 - 0xB7 */ ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, 0, DstMem | SrcReg | ModRM | BitOp | Lock, 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem16 | ModRM | Mov, /* 0xB8 - 0xBF */ 0, 0, Group | Group8, DstMem | SrcReg | ModRM | BitOp | Lock, 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem16 | ModRM | Mov, /* 0xC0 - 0xCF */ 0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, Group | GroupDual | Group9, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xD0 - 0xDF */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xE0 - 0xEF */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0xF0 - 0xFF */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; static u32 group_table[] = { [Group1_80*8] = ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM | Lock, ByteOp | DstMem | SrcImm | ModRM, [Group1_81*8] = DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM | Lock, DstMem | SrcImm | ModRM, [Group1_82*8] = ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64 | Lock, ByteOp | DstMem | SrcImm | ModRM | No64, [Group1_83*8] = DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM, [Group1A*8] = DstMem | SrcNone | ModRM | Mov | Stack, 0, 0, 0, 0, 0, 0, 0, [Group3_Byte*8] = ByteOp | SrcImm | DstMem | ModRM, 0, ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM, 0, 0, 0, 0, [Group3*8] = DstMem | SrcImm | ModRM, 0, DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, 0, 0, 0, 0, [Group4*8] = ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM, 0, 0, 0, 0, 0, 0, [Group5*8] = DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, SrcMem | ModRM | Stack, 0, SrcMem | ModRM | Stack, SrcMem | ModRM | Src2Mem16 | ImplicitOps, SrcMem | ModRM | Stack, 0, [Group7*8] = 0, 0, ModRM | SrcMem | Priv, ModRM | SrcMem | Priv, SrcNone | ModRM | DstMem | Mov, 0, SrcMem16 | ModRM | Mov | Priv, SrcMem | ModRM | ByteOp | Priv, [Group8*8] = 0, 0, 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock, [Group9*8] = 0, DstMem64 | ModRM | Lock, 0, 0, 0, 0, 0, 0, }; static u32 group2_table[] = { [Group7*8] = SrcNone | ModRM | Priv, 0, 0, SrcNone | ModRM | Priv, SrcNone | ModRM | DstMem | Mov, 0, SrcMem16 | ModRM | Mov | Priv, 0, [Group9*8] = 0, 0, 0, 0, 0, 0, 0, 0, }; /* EFLAGS bit definitions. */ #define EFLG_ID (1<<21) #define EFLG_VIP (1<<20) #define EFLG_VIF (1<<19) #define EFLG_AC (1<<18) #define EFLG_VM (1<<17) #define EFLG_RF (1<<16) #define EFLG_IOPL (3<<12) #define EFLG_NT (1<<14) #define EFLG_OF (1<<11) #define EFLG_DF (1<<10) #define EFLG_IF (1<<9) #define EFLG_TF (1<<8) #define EFLG_SF (1<<7) #define EFLG_ZF (1<<6) #define EFLG_AF (1<<4) #define EFLG_PF (1<<2) #define EFLG_CF (1<<0) /* * Instruction emulation: * Most instructions are emulated directly via a fragment of inline assembly * code. This allows us to save/restore EFLAGS and thus very easily pick up * any modified flags. */ #if defined(CONFIG_X86_64) #define _LO32 "k" /* force 32-bit operand */ #define _STK "%%rsp" /* stack pointer */ #elif defined(__i386__) #define _LO32 "" /* force 32-bit operand */ #define _STK "%%esp" /* stack pointer */ #endif /* * These EFLAGS bits are restored from saved value during emulation, and * any changes are written back to the saved value after emulation. */ #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF) /* Before executing instruction: restore necessary bits in EFLAGS. */ #define _PRE_EFLAGS(_sav, _msk, _tmp) \ /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \ "movl %"_sav",%"_LO32 _tmp"; " \ "push %"_tmp"; " \ "push %"_tmp"; " \ "movl %"_msk",%"_LO32 _tmp"; " \ "andl %"_LO32 _tmp",("_STK"); " \ "pushf; " \ "notl %"_LO32 _tmp"; " \ "andl %"_LO32 _tmp",("_STK"); " \ "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \ "pop %"_tmp"; " \ "orl %"_LO32 _tmp",("_STK"); " \ "popf; " \ "pop %"_sav"; " /* After executing instruction: write-back necessary bits in EFLAGS. */ #define _POST_EFLAGS(_sav, _msk, _tmp) \ /* _sav |= EFLAGS & _msk; */ \ "pushf; " \ "pop %"_tmp"; " \ "andl %"_msk",%"_LO32 _tmp"; " \ "orl %"_LO32 _tmp",%"_sav"; " #ifdef CONFIG_X86_64 #define ON64(x) x #else #define ON64(x) #endif #define ____emulate_2op(_op, _src, _dst, _eflags, _x, _y, _suffix) \ do { \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "4", "2") \ _op _suffix " %"_x"3,%1; " \ _POST_EFLAGS("0", "4", "2") \ : "=m" (_eflags), "=m" ((_dst).val), \ "=&r" (_tmp) \ : _y ((_src).val), "i" (EFLAGS_MASK)); \ } while (0) /* Raw emulation: instruction has two explicit operands. */ #define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \ do { \ unsigned long _tmp; \ \ switch ((_dst).bytes) { \ case 2: \ ____emulate_2op(_op,_src,_dst,_eflags,_wx,_wy,"w"); \ break; \ case 4: \ ____emulate_2op(_op,_src,_dst,_eflags,_lx,_ly,"l"); \ break; \ case 8: \ ON64(____emulate_2op(_op,_src,_dst,_eflags,_qx,_qy,"q")); \ break; \ } \ } while (0) #define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \ do { \ unsigned long _tmp; \ switch ((_dst).bytes) { \ case 1: \ ____emulate_2op(_op,_src,_dst,_eflags,_bx,_by,"b"); \ break; \ default: \ __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ _wx, _wy, _lx, _ly, _qx, _qy); \ break; \ } \ } while (0) /* Source operand is byte-sized and may be restricted to just %cl. */ #define emulate_2op_SrcB(_op, _src, _dst, _eflags) \ __emulate_2op(_op, _src, _dst, _eflags, \ "b", "c", "b", "c", "b", "c", "b", "c") /* Source operand is byte, word, long or quad sized. */ #define emulate_2op_SrcV(_op, _src, _dst, _eflags) \ __emulate_2op(_op, _src, _dst, _eflags, \ "b", "q", "w", "r", _LO32, "r", "", "r") /* Source operand is word, long or quad sized. */ #define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \ __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ "w", "r", _LO32, "r", "", "r") /* Instruction has three operands and one operand is stored in ECX register */ #define __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, _suffix, _type) \ do { \ unsigned long _tmp; \ _type _clv = (_cl).val; \ _type _srcv = (_src).val; \ _type _dstv = (_dst).val; \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "5", "2") \ _op _suffix " %4,%1 \n" \ _POST_EFLAGS("0", "5", "2") \ : "=m" (_eflags), "+r" (_dstv), "=&r" (_tmp) \ : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \ ); \ \ (_cl).val = (unsigned long) _clv; \ (_src).val = (unsigned long) _srcv; \ (_dst).val = (unsigned long) _dstv; \ } while (0) #define emulate_2op_cl(_op, _cl, _src, _dst, _eflags) \ do { \ switch ((_dst).bytes) { \ case 2: \ __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ "w", unsigned short); \ break; \ case 4: \ __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ "l", unsigned int); \ break; \ case 8: \ ON64(__emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ "q", unsigned long)); \ break; \ } \ } while (0) #define __emulate_1op(_op, _dst, _eflags, _suffix) \ do { \ unsigned long _tmp; \ \ __asm__ __volatile__ ( \ _PRE_EFLAGS("0", "3", "2") \ _op _suffix " %1; " \ _POST_EFLAGS("0", "3", "2") \ : "=m" (_eflags), "+m" ((_dst).val), \ "=&r" (_tmp) \ : "i" (EFLAGS_MASK)); \ } while (0) /* Instruction has only one explicit operand (no source operand). */ #define emulate_1op(_op, _dst, _eflags) \ do { \ switch ((_dst).bytes) { \ case 1: __emulate_1op(_op, _dst, _eflags, "b"); break; \ case 2: __emulate_1op(_op, _dst, _eflags, "w"); break; \ case 4: __emulate_1op(_op, _dst, _eflags, "l"); break; \ case 8: ON64(__emulate_1op(_op, _dst, _eflags, "q")); break; \ } \ } while (0) /* Fetch next part of the instruction being emulated. */ #define insn_fetch(_type, _size, _eip) \ ({ unsigned long _x; \ rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \ if (rc != X86EMUL_CONTINUE) \ goto done; \ (_eip) += (_size); \ (_type)_x; \ }) static inline unsigned long ad_mask(struct decode_cache *c) { return (1UL << (c->ad_bytes << 3)) - 1; } /* Access/update address held in a register, based on addressing mode. */ static inline unsigned long address_mask(struct decode_cache *c, unsigned long reg) { if (c->ad_bytes == sizeof(unsigned long)) return reg; else return reg & ad_mask(c); } static inline unsigned long register_address(struct decode_cache *c, unsigned long base, unsigned long reg) { return base + address_mask(c, reg); } static inline void register_address_increment(struct decode_cache *c, unsigned long *reg, int inc) { if (c->ad_bytes == sizeof(unsigned long)) *reg += inc; else *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c)); } static inline void jmp_rel(struct decode_cache *c, int rel) { register_address_increment(c, &c->eip, rel); } static void set_seg_override(struct decode_cache *c, int seg) { c->has_seg_override = true; c->seg_override = seg; } static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) { if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) return 0; return kvm_x86_ops->get_segment_base(ctxt->vcpu, seg); } static unsigned long seg_override_base(struct x86_emulate_ctxt *ctxt, struct decode_cache *c) { if (!c->has_seg_override) return 0; return seg_base(ctxt, c->seg_override); } static unsigned long es_base(struct x86_emulate_ctxt *ctxt) { return seg_base(ctxt, VCPU_SREG_ES); } static unsigned long ss_base(struct x86_emulate_ctxt *ctxt) { return seg_base(ctxt, VCPU_SREG_SS); } static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, unsigned long eip, u8 *dest) { struct fetch_cache *fc = &ctxt->decode.fetch; int rc; int size, cur_size; if (eip == fc->end) { cur_size = fc->end - fc->start; size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip)); rc = ops->fetch(ctxt->cs_base + eip, fc->data + cur_size, size, ctxt->vcpu, NULL); if (rc != X86EMUL_CONTINUE) return rc; fc->end += size; } *dest = fc->data[eip - fc->start]; return X86EMUL_CONTINUE; } static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, unsigned long eip, void *dest, unsigned size) { int rc; /* x86 instructions are limited to 15 bytes. */ if (eip + size - ctxt->eip > 15) return X86EMUL_UNHANDLEABLE; while (size--) { rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++); if (rc != X86EMUL_CONTINUE) return rc; } return X86EMUL_CONTINUE; } /* * Given the 'reg' portion of a ModRM byte, and a register block, return a * pointer into the block that addresses the relevant register. * @highbyte_regs specifies whether to decode AH,CH,DH,BH. */ static void *decode_register(u8 modrm_reg, unsigned long *regs, int highbyte_regs) { void *p; p = ®s[modrm_reg]; if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) p = (unsigned char *)®s[modrm_reg & 3] + 1; return p; } static int read_descriptor(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, void *ptr, u16 *size, unsigned long *address, int op_bytes) { int rc; if (op_bytes == 2) op_bytes = 3; *address = 0; rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2, ctxt->vcpu, NULL); if (rc != X86EMUL_CONTINUE) return rc; rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes, ctxt->vcpu, NULL); return rc; } static int test_cc(unsigned int condition, unsigned int flags) { int rc = 0; switch ((condition & 15) >> 1) { case 0: /* o */ rc |= (flags & EFLG_OF); break; case 1: /* b/c/nae */ rc |= (flags & EFLG_CF); break; case 2: /* z/e */ rc |= (flags & EFLG_ZF); break; case 3: /* be/na */ rc |= (flags & (EFLG_CF|EFLG_ZF)); break; case 4: /* s */ rc |= (flags & EFLG_SF); break; case 5: /* p/pe */ rc |= (flags & EFLG_PF); break; case 7: /* le/ng */ rc |= (flags & EFLG_ZF); /* fall through */ case 6: /* l/nge */ rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF)); break; } /* Odd condition identifiers (lsb == 1) have inverted sense. */ return (!!rc ^ (condition & 1)); } static void decode_register_operand(struct operand *op, struct decode_cache *c, int inhibit_bytereg) { unsigned reg = c->modrm_reg; int highbyte_regs = c->rex_prefix == 0; if (!(c->d & ModRM)) reg = (c->b & 7) | ((c->rex_prefix & 1) << 3); op->type = OP_REG; if ((c->d & ByteOp) && !inhibit_bytereg) { op->ptr = decode_register(reg, c->regs, highbyte_regs); op->val = *(u8 *)op->ptr; op->bytes = 1; } else { op->ptr = decode_register(reg, c->regs, 0); op->bytes = c->op_bytes; switch (op->bytes) { case 2: op->val = *(u16 *)op->ptr; break; case 4: op->val = *(u32 *)op->ptr; break; case 8: op->val = *(u64 *) op->ptr; break; } } op->orig_val = op->val; } static int decode_modrm(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; u8 sib; int index_reg = 0, base_reg = 0, scale; int rc = X86EMUL_CONTINUE; if (c->rex_prefix) { c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */ index_reg = (c->rex_prefix & 2) << 2; /* REX.X */ c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */ } c->modrm = insn_fetch(u8, 1, c->eip); c->modrm_mod |= (c->modrm & 0xc0) >> 6; c->modrm_reg |= (c->modrm & 0x38) >> 3; c->modrm_rm |= (c->modrm & 0x07); c->modrm_ea = 0; c->use_modrm_ea = 1; if (c->modrm_mod == 3) { c->modrm_ptr = decode_register(c->modrm_rm, c->regs, c->d & ByteOp); c->modrm_val = *(unsigned long *)c->modrm_ptr; return rc; } if (c->ad_bytes == 2) { unsigned bx = c->regs[VCPU_REGS_RBX]; unsigned bp = c->regs[VCPU_REGS_RBP]; unsigned si = c->regs[VCPU_REGS_RSI]; unsigned di = c->regs[VCPU_REGS_RDI]; /* 16-bit ModR/M decode. */ switch (c->modrm_mod) { case 0: if (c->modrm_rm == 6) c->modrm_ea += insn_fetch(u16, 2, c->eip); break; case 1: c->modrm_ea += insn_fetch(s8, 1, c->eip); break; case 2: c->modrm_ea += insn_fetch(u16, 2, c->eip); break; } switch (c->modrm_rm) { case 0: c->modrm_ea += bx + si; break; case 1: c->modrm_ea += bx + di; break; case 2: c->modrm_ea += bp + si; break; case 3: c->modrm_ea += bp + di; break; case 4: c->modrm_ea += si; break; case 5: c->modrm_ea += di; break; case 6: if (c->modrm_mod != 0) c->modrm_ea += bp; break; case 7: c->modrm_ea += bx; break; } if (c->modrm_rm == 2 || c->modrm_rm == 3 || (c->modrm_rm == 6 && c->modrm_mod != 0)) if (!c->has_seg_override) set_seg_override(c, VCPU_SREG_SS); c->modrm_ea = (u16)c->modrm_ea; } else { /* 32/64-bit ModR/M decode. */ if ((c->modrm_rm & 7) == 4) { sib = insn_fetch(u8, 1, c->eip); index_reg |= (sib >> 3) & 7; base_reg |= sib & 7; scale = sib >> 6; if ((base_reg & 7) == 5 && c->modrm_mod == 0) c->modrm_ea += insn_fetch(s32, 4, c->eip); else c->modrm_ea += c->regs[base_reg]; if (index_reg != 4) c->modrm_ea += c->regs[index_reg] << scale; } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) { if (ctxt->mode == X86EMUL_MODE_PROT64) c->rip_relative = 1; } else c->modrm_ea += c->regs[c->modrm_rm]; switch (c->modrm_mod) { case 0: if (c->modrm_rm == 5) c->modrm_ea += insn_fetch(s32, 4, c->eip); break; case 1: c->modrm_ea += insn_fetch(s8, 1, c->eip); break; case 2: c->modrm_ea += insn_fetch(s32, 4, c->eip); break; } } done: return rc; } static int decode_abs(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; switch (c->ad_bytes) { case 2: c->modrm_ea = insn_fetch(u16, 2, c->eip); break; case 4: c->modrm_ea = insn_fetch(u32, 4, c->eip); break; case 8: c->modrm_ea = insn_fetch(u64, 8, c->eip); break; } done: return rc; } int x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; int mode = ctxt->mode; int def_op_bytes, def_ad_bytes, group; /* we cannot decode insn before we complete previous rep insn */ WARN_ON(ctxt->restart); /* Shadow copy of register state. Committed on successful emulation. */ memset(c, 0, sizeof(struct decode_cache)); c->eip = ctxt->eip; c->fetch.start = c->fetch.end = c->eip; ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS); memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); switch (mode) { case X86EMUL_MODE_REAL: case X86EMUL_MODE_VM86: case X86EMUL_MODE_PROT16: def_op_bytes = def_ad_bytes = 2; break; case X86EMUL_MODE_PROT32: def_op_bytes = def_ad_bytes = 4; break; #ifdef CONFIG_X86_64 case X86EMUL_MODE_PROT64: def_op_bytes = 4; def_ad_bytes = 8; break; #endif default: return -1; } c->op_bytes = def_op_bytes; c->ad_bytes = def_ad_bytes; /* Legacy prefixes. */ for (;;) { switch (c->b = insn_fetch(u8, 1, c->eip)) { case 0x66: /* operand-size override */ /* switch between 2/4 bytes */ c->op_bytes = def_op_bytes ^ 6; break; case 0x67: /* address-size override */ if (mode == X86EMUL_MODE_PROT64) /* switch between 4/8 bytes */ c->ad_bytes = def_ad_bytes ^ 12; else /* switch between 2/4 bytes */ c->ad_bytes = def_ad_bytes ^ 6; break; case 0x26: /* ES override */ case 0x2e: /* CS override */ case 0x36: /* SS override */ case 0x3e: /* DS override */ set_seg_override(c, (c->b >> 3) & 3); break; case 0x64: /* FS override */ case 0x65: /* GS override */ set_seg_override(c, c->b & 7); break; case 0x40 ... 0x4f: /* REX */ if (mode != X86EMUL_MODE_PROT64) goto done_prefixes; c->rex_prefix = c->b; continue; case 0xf0: /* LOCK */ c->lock_prefix = 1; break; case 0xf2: /* REPNE/REPNZ */ c->rep_prefix = REPNE_PREFIX; break; case 0xf3: /* REP/REPE/REPZ */ c->rep_prefix = REPE_PREFIX; break; default: goto done_prefixes; } /* Any legacy prefix after a REX prefix nullifies its effect. */ c->rex_prefix = 0; } done_prefixes: /* REX prefix. */ if (c->rex_prefix) if (c->rex_prefix & 8) c->op_bytes = 8; /* REX.W */ /* Opcode byte(s). */ c->d = opcode_table[c->b]; if (c->d == 0) { /* Two-byte opcode? */ if (c->b == 0x0f) { c->twobyte = 1; c->b = insn_fetch(u8, 1, c->eip); c->d = twobyte_table[c->b]; } } if (c->d & Group) { group = c->d & GroupMask; c->modrm = insn_fetch(u8, 1, c->eip); --c->eip; group = (group << 3) + ((c->modrm >> 3) & 7); if ((c->d & GroupDual) && (c->modrm >> 6) == 3) c->d = group2_table[group]; else c->d = group_table[group]; } /* Unrecognised? */ if (c->d == 0) { DPRINTF("Cannot emulate %02x\n", c->b); return -1; } if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack)) c->op_bytes = 8; /* ModRM and SIB bytes. */ if (c->d & ModRM) rc = decode_modrm(ctxt, ops); else if (c->d & MemAbs) rc = decode_abs(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; if (!c->has_seg_override) set_seg_override(c, VCPU_SREG_DS); if (!(!c->twobyte && c->b == 0x8d)) c->modrm_ea += seg_override_base(ctxt, c); if (c->ad_bytes != 8) c->modrm_ea = (u32)c->modrm_ea; if (c->rip_relative) c->modrm_ea += c->eip; /* * Decode and fetch the source operand: register, memory * or immediate. */ switch (c->d & SrcMask) { case SrcNone: break; case SrcReg: decode_register_operand(&c->src, c, 0); break; case SrcMem16: c->src.bytes = 2; goto srcmem_common; case SrcMem32: c->src.bytes = 4; goto srcmem_common; case SrcMem: c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; /* Don't fetch the address for invlpg: it could be unmapped. */ if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7) break; srcmem_common: /* * For instructions with a ModR/M byte, switch to register * access if Mod = 3. */ if ((c->d & ModRM) && c->modrm_mod == 3) { c->src.type = OP_REG; c->src.val = c->modrm_val; c->src.ptr = c->modrm_ptr; break; } c->src.type = OP_MEM; c->src.ptr = (unsigned long *)c->modrm_ea; c->src.val = 0; break; case SrcImm: case SrcImmU: c->src.type = OP_IMM; c->src.ptr = (unsigned long *)c->eip; c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; if (c->src.bytes == 8) c->src.bytes = 4; /* NB. Immediates are sign-extended as necessary. */ switch (c->src.bytes) { case 1: c->src.val = insn_fetch(s8, 1, c->eip); break; case 2: c->src.val = insn_fetch(s16, 2, c->eip); break; case 4: c->src.val = insn_fetch(s32, 4, c->eip); break; } if ((c->d & SrcMask) == SrcImmU) { switch (c->src.bytes) { case 1: c->src.val &= 0xff; break; case 2: c->src.val &= 0xffff; break; case 4: c->src.val &= 0xffffffff; break; } } break; case SrcImmByte: case SrcImmUByte: c->src.type = OP_IMM; c->src.ptr = (unsigned long *)c->eip; c->src.bytes = 1; if ((c->d & SrcMask) == SrcImmByte) c->src.val = insn_fetch(s8, 1, c->eip); else c->src.val = insn_fetch(u8, 1, c->eip); break; case SrcOne: c->src.bytes = 1; c->src.val = 1; break; case SrcSI: c->src.type = OP_MEM; c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->src.ptr = (unsigned long *) register_address(c, seg_override_base(ctxt, c), c->regs[VCPU_REGS_RSI]); c->src.val = 0; break; } /* * Decode and fetch the second source operand: register, memory * or immediate. */ switch (c->d & Src2Mask) { case Src2None: break; case Src2CL: c->src2.bytes = 1; c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8; break; case Src2ImmByte: c->src2.type = OP_IMM; c->src2.ptr = (unsigned long *)c->eip; c->src2.bytes = 1; c->src2.val = insn_fetch(u8, 1, c->eip); break; case Src2Imm16: c->src2.type = OP_IMM; c->src2.ptr = (unsigned long *)c->eip; c->src2.bytes = 2; c->src2.val = insn_fetch(u16, 2, c->eip); break; case Src2One: c->src2.bytes = 1; c->src2.val = 1; break; case Src2Mem16: c->src2.type = OP_MEM; c->src2.bytes = 2; c->src2.ptr = (unsigned long *)(c->modrm_ea + c->src.bytes); c->src2.val = 0; break; } /* Decode and fetch the destination operand: register or memory. */ switch (c->d & DstMask) { case ImplicitOps: /* Special instructions do their own operand decoding. */ return 0; case DstReg: decode_register_operand(&c->dst, c, c->twobyte && (c->b == 0xb6 || c->b == 0xb7)); break; case DstMem: case DstMem64: if ((c->d & ModRM) && c->modrm_mod == 3) { c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.type = OP_REG; c->dst.val = c->dst.orig_val = c->modrm_val; c->dst.ptr = c->modrm_ptr; break; } c->dst.type = OP_MEM; c->dst.ptr = (unsigned long *)c->modrm_ea; if ((c->d & DstMask) == DstMem64) c->dst.bytes = 8; else c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.val = 0; if (c->d & BitOp) { unsigned long mask = ~(c->dst.bytes * 8 - 1); c->dst.ptr = (void *)c->dst.ptr + (c->src.val & mask) / 8; } break; case DstAcc: c->dst.type = OP_REG; c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = &c->regs[VCPU_REGS_RAX]; switch (c->dst.bytes) { case 1: c->dst.val = *(u8 *)c->dst.ptr; break; case 2: c->dst.val = *(u16 *)c->dst.ptr; break; case 4: c->dst.val = *(u32 *)c->dst.ptr; break; case 8: c->dst.val = *(u64 *)c->dst.ptr; break; } c->dst.orig_val = c->dst.val; break; case DstDI: c->dst.type = OP_MEM; c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = (unsigned long *) register_address(c, es_base(ctxt), c->regs[VCPU_REGS_RDI]); c->dst.val = 0; break; } done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; } static int read_emulated(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, unsigned long addr, void *dest, unsigned size) { int rc; struct read_cache *mc = &ctxt->decode.mem_read; while (size) { int n = min(size, 8u); size -= n; if (mc->pos < mc->end) goto read_cached; rc = ops->read_emulated(addr, mc->data + mc->end, n, ctxt->vcpu); if (rc != X86EMUL_CONTINUE) return rc; mc->end += n; read_cached: memcpy(dest, mc->data + mc->pos, n); mc->pos += n; dest += n; addr += n; } return X86EMUL_CONTINUE; } static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, unsigned int size, unsigned short port, void *dest) { struct read_cache *rc = &ctxt->decode.io_read; if (rc->pos == rc->end) { /* refill pio read ahead */ struct decode_cache *c = &ctxt->decode; unsigned int in_page, n; unsigned int count = c->rep_prefix ? address_mask(c, c->regs[VCPU_REGS_RCX]) : 1; in_page = (ctxt->eflags & EFLG_DF) ? offset_in_page(c->regs[VCPU_REGS_RDI]) : PAGE_SIZE - offset_in_page(c->regs[VCPU_REGS_RDI]); n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size, count); if (n == 0) n = 1; rc->pos = rc->end = 0; if (!ops->pio_in_emulated(size, port, rc->data, n, ctxt->vcpu)) return 0; rc->end = n * size; } memcpy(dest, rc->data + rc->pos, size); rc->pos += size; return 1; } static u32 desc_limit_scaled(struct desc_struct *desc) { u32 limit = get_desc_limit(desc); return desc->g ? (limit << 12) | 0xfff : limit; } static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 selector, struct desc_ptr *dt) { if (selector & 1 << 2) { struct desc_struct desc; memset (dt, 0, sizeof *dt); if (!ops->get_cached_descriptor(&desc, VCPU_SREG_LDTR, ctxt->vcpu)) return; dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ dt->address = get_desc_base(&desc); } else ops->get_gdt(dt, ctxt->vcpu); } /* allowed just for 8 bytes segments */ static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 selector, struct desc_struct *desc) { struct desc_ptr dt; u16 index = selector >> 3; int ret; u32 err; ulong addr; get_descriptor_table_ptr(ctxt, ops, selector, &dt); if (dt.size < index * 8 + 7) { kvm_inject_gp(ctxt->vcpu, selector & 0xfffc); return X86EMUL_PROPAGATE_FAULT; } addr = dt.address + index * 8; ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) kvm_inject_page_fault(ctxt->vcpu, addr, err); return ret; } /* allowed just for 8 bytes segments */ static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 selector, struct desc_struct *desc) { struct desc_ptr dt; u16 index = selector >> 3; u32 err; ulong addr; int ret; get_descriptor_table_ptr(ctxt, ops, selector, &dt); if (dt.size < index * 8 + 7) { kvm_inject_gp(ctxt->vcpu, selector & 0xfffc); return X86EMUL_PROPAGATE_FAULT; } addr = dt.address + index * 8; ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) kvm_inject_page_fault(ctxt->vcpu, addr, err); return ret; } static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 selector, int seg) { struct desc_struct seg_desc; u8 dpl, rpl, cpl; unsigned err_vec = GP_VECTOR; u32 err_code = 0; bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ int ret; memset(&seg_desc, 0, sizeof seg_desc); if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) || ctxt->mode == X86EMUL_MODE_REAL) { /* set real mode segment descriptor */ set_desc_base(&seg_desc, selector << 4); set_desc_limit(&seg_desc, 0xffff); seg_desc.type = 3; seg_desc.p = 1; seg_desc.s = 1; goto load; } /* NULL selector is not valid for TR, CS and SS */ if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR) && null_selector) goto exception; /* TR should be in GDT only */ if (seg == VCPU_SREG_TR && (selector & (1 << 2))) goto exception; if (null_selector) /* for NULL selector skip all following checks */ goto load; ret = read_segment_descriptor(ctxt, ops, selector, &seg_desc); if (ret != X86EMUL_CONTINUE) return ret; err_code = selector & 0xfffc; err_vec = GP_VECTOR; /* can't load system descriptor into segment selecor */ if (seg <= VCPU_SREG_GS && !seg_desc.s) goto exception; if (!seg_desc.p) { err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; goto exception; } rpl = selector & 3; dpl = seg_desc.dpl; cpl = ops->cpl(ctxt->vcpu); switch (seg) { case VCPU_SREG_SS: /* * segment is not a writable data segment or segment * selector's RPL != CPL or segment selector's RPL != CPL */ if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) goto exception; break; case VCPU_SREG_CS: if (!(seg_desc.type & 8)) goto exception; if (seg_desc.type & 4) { /* conforming */ if (dpl > cpl) goto exception; } else { /* nonconforming */ if (rpl > cpl || dpl != cpl) goto exception; } /* CS(RPL) <- CPL */ selector = (selector & 0xfffc) | cpl; break; case VCPU_SREG_TR: if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) goto exception; break; case VCPU_SREG_LDTR: if (seg_desc.s || seg_desc.type != 2) goto exception; break; default: /* DS, ES, FS, or GS */ /* * segment is not a data or readable code segment or * ((segment is a data or nonconforming code segment) * and (both RPL and CPL > DPL)) */ if ((seg_desc.type & 0xa) == 0x8 || (((seg_desc.type & 0xc) != 0xc) && (rpl > dpl && cpl > dpl))) goto exception; break; } if (seg_desc.s) { /* mark segment as accessed */ seg_desc.type |= 1; ret = write_segment_descriptor(ctxt, ops, selector, &seg_desc); if (ret != X86EMUL_CONTINUE) return ret; } load: ops->set_segment_selector(selector, seg, ctxt->vcpu); ops->set_cached_descriptor(&seg_desc, seg, ctxt->vcpu); return X86EMUL_CONTINUE; exception: kvm_queue_exception_e(ctxt->vcpu, err_vec, err_code); return X86EMUL_PROPAGATE_FAULT; } static inline void emulate_push(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; c->dst.type = OP_MEM; c->dst.bytes = c->op_bytes; c->dst.val = c->src.val; register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes); c->dst.ptr = (void *) register_address(c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]); } static int emulate_pop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, void *dest, int len) { struct decode_cache *c = &ctxt->decode; int rc; rc = read_emulated(ctxt, ops, register_address(c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]), dest, len); if (rc != X86EMUL_CONTINUE) return rc; register_address_increment(c, &c->regs[VCPU_REGS_RSP], len); return rc; } static int emulate_popf(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, void *dest, int len) { int rc; unsigned long val, change_mask; int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; int cpl = ops->cpl(ctxt->vcpu); rc = emulate_pop(ctxt, ops, &val, len); if (rc != X86EMUL_CONTINUE) return rc; change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID; switch(ctxt->mode) { case X86EMUL_MODE_PROT64: case X86EMUL_MODE_PROT32: case X86EMUL_MODE_PROT16: if (cpl == 0) change_mask |= EFLG_IOPL; if (cpl <= iopl) change_mask |= EFLG_IF; break; case X86EMUL_MODE_VM86: if (iopl < 3) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } change_mask |= EFLG_IF; break; default: /* real mode */ change_mask |= (EFLG_IOPL | EFLG_IF); break; } *(unsigned long *)dest = (ctxt->eflags & ~change_mask) | (val & change_mask); return rc; } static void emulate_push_sreg(struct x86_emulate_ctxt *ctxt, int seg) { struct decode_cache *c = &ctxt->decode; struct kvm_segment segment; kvm_x86_ops->get_segment(ctxt->vcpu, &segment, seg); c->src.val = segment.selector; emulate_push(ctxt); } static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, int seg) { struct decode_cache *c = &ctxt->decode; unsigned long selector; int rc; rc = emulate_pop(ctxt, ops, &selector, c->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, ops, (u16)selector, seg); return rc; } static void emulate_pusha(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; unsigned long old_esp = c->regs[VCPU_REGS_RSP]; int reg = VCPU_REGS_RAX; while (reg <= VCPU_REGS_RDI) { (reg == VCPU_REGS_RSP) ? (c->src.val = old_esp) : (c->src.val = c->regs[reg]); emulate_push(ctxt); ++reg; } } static int emulate_popa(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; int reg = VCPU_REGS_RDI; while (reg >= VCPU_REGS_RAX) { if (reg == VCPU_REGS_RSP) { register_address_increment(c, &c->regs[VCPU_REGS_RSP], c->op_bytes); --reg; } rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes); if (rc != X86EMUL_CONTINUE) break; --reg; } return rc; } static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; return emulate_pop(ctxt, ops, &c->dst.val, c->dst.bytes); } static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; switch (c->modrm_reg) { case 0: /* rol */ emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags); break; case 1: /* ror */ emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags); break; case 2: /* rcl */ emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags); break; case 3: /* rcr */ emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags); break; case 4: /* sal/shl */ case 6: /* sal/shl */ emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags); break; case 5: /* shr */ emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags); break; case 7: /* sar */ emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags); break; } } static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; switch (c->modrm_reg) { case 0 ... 1: /* test */ emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); break; case 2: /* not */ c->dst.val = ~c->dst.val; break; case 3: /* neg */ emulate_1op("neg", c->dst, ctxt->eflags); break; default: return 0; } return 1; } static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; switch (c->modrm_reg) { case 0: /* inc */ emulate_1op("inc", c->dst, ctxt->eflags); break; case 1: /* dec */ emulate_1op("dec", c->dst, ctxt->eflags); break; case 2: /* call near abs */ { long int old_eip; old_eip = c->eip; c->eip = c->src.val; c->src.val = old_eip; emulate_push(ctxt); break; } case 4: /* jmp abs */ c->eip = c->src.val; break; case 6: /* push */ emulate_push(ctxt); break; } return X86EMUL_CONTINUE; } static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; u64 old = c->dst.orig_val; if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) || ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) { c->regs[VCPU_REGS_RAX] = (u32) (old >> 0); c->regs[VCPU_REGS_RDX] = (u32) (old >> 32); ctxt->eflags &= ~EFLG_ZF; } else { c->dst.val = ((u64)c->regs[VCPU_REGS_RCX] << 32) | (u32) c->regs[VCPU_REGS_RBX]; ctxt->eflags |= EFLG_ZF; } return X86EMUL_CONTINUE; } static int emulate_ret_far(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { struct decode_cache *c = &ctxt->decode; int rc; unsigned long cs; rc = emulate_pop(ctxt, ops, &c->eip, c->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; if (c->op_bytes == 4) c->eip = (u32)c->eip; rc = emulate_pop(ctxt, ops, &cs, c->op_bytes); if (rc != X86EMUL_CONTINUE) return rc; rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS); return rc; } static inline int writeback(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { int rc; struct decode_cache *c = &ctxt->decode; switch (c->dst.type) { case OP_REG: /* The 4-byte case *is* correct: * in 64-bit mode we zero-extend. */ switch (c->dst.bytes) { case 1: *(u8 *)c->dst.ptr = (u8)c->dst.val; break; case 2: *(u16 *)c->dst.ptr = (u16)c->dst.val; break; case 4: *c->dst.ptr = (u32)c->dst.val; break; /* 64b: zero-ext */ case 8: *c->dst.ptr = c->dst.val; break; } break; case OP_MEM: if (c->lock_prefix) rc = ops->cmpxchg_emulated( (unsigned long)c->dst.ptr, &c->dst.orig_val, &c->dst.val, c->dst.bytes, ctxt->vcpu); else rc = ops->write_emulated( (unsigned long)c->dst.ptr, &c->dst.val, c->dst.bytes, ctxt->vcpu); if (rc != X86EMUL_CONTINUE) return rc; break; case OP_NONE: /* no writeback */ break; default: break; } return X86EMUL_CONTINUE; } static void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask) { u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(ctxt->vcpu, mask); /* * an sti; sti; sequence only disable interrupts for the first * instruction. So, if the last instruction, be it emulated or * not, left the system with the INT_STI flag enabled, it * means that the last instruction is an sti. We should not * leave the flag on in this case. The same goes for mov ss */ if (!(int_shadow & mask)) ctxt->interruptibility = mask; } static inline void setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, struct kvm_segment *cs, struct kvm_segment *ss) { memset(cs, 0, sizeof(struct kvm_segment)); kvm_x86_ops->get_segment(ctxt->vcpu, cs, VCPU_SREG_CS); memset(ss, 0, sizeof(struct kvm_segment)); cs->l = 0; /* will be adjusted later */ cs->base = 0; /* flat segment */ cs->g = 1; /* 4kb granularity */ cs->limit = 0xffffffff; /* 4GB limit */ cs->type = 0x0b; /* Read, Execute, Accessed */ cs->s = 1; cs->dpl = 0; /* will be adjusted later */ cs->present = 1; cs->db = 1; ss->unusable = 0; ss->base = 0; /* flat segment */ ss->limit = 0xffffffff; /* 4GB limit */ ss->g = 1; /* 4kb granularity */ ss->s = 1; ss->type = 0x03; /* Read/Write, Accessed */ ss->db = 1; /* 32bit stack segment */ ss->dpl = 0; ss->present = 1; } static int emulate_syscall(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; struct kvm_segment cs, ss; u64 msr_data; /* syscall is not available in real mode */ if (ctxt->mode == X86EMUL_MODE_REAL || ctxt->mode == X86EMUL_MODE_VM86) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); return X86EMUL_PROPAGATE_FAULT; } setup_syscalls_segments(ctxt, &cs, &ss); kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); msr_data >>= 32; cs.selector = (u16)(msr_data & 0xfffc); ss.selector = (u16)(msr_data + 8); if (is_long_mode(ctxt->vcpu)) { cs.db = 0; cs.l = 1; } kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS); kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS); c->regs[VCPU_REGS_RCX] = c->eip; if (is_long_mode(ctxt->vcpu)) { #ifdef CONFIG_X86_64 c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF; kvm_x86_ops->get_msr(ctxt->vcpu, ctxt->mode == X86EMUL_MODE_PROT64 ? MSR_LSTAR : MSR_CSTAR, &msr_data); c->eip = msr_data; kvm_x86_ops->get_msr(ctxt->vcpu, MSR_SYSCALL_MASK, &msr_data); ctxt->eflags &= ~(msr_data | EFLG_RF); #endif } else { /* legacy mode */ kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); c->eip = (u32)msr_data; ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); } return X86EMUL_CONTINUE; } static int emulate_sysenter(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; struct kvm_segment cs, ss; u64 msr_data; /* inject #GP if in real mode */ if (ctxt->mode == X86EMUL_MODE_REAL) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } /* XXX sysenter/sysexit have not been tested in 64bit mode. * Therefore, we inject an #UD. */ if (ctxt->mode == X86EMUL_MODE_PROT64) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); return X86EMUL_PROPAGATE_FAULT; } setup_syscalls_segments(ctxt, &cs, &ss); kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data); switch (ctxt->mode) { case X86EMUL_MODE_PROT32: if ((msr_data & 0xfffc) == 0x0) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } break; case X86EMUL_MODE_PROT64: if (msr_data == 0x0) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } break; } ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); cs.selector = (u16)msr_data; cs.selector &= ~SELECTOR_RPL_MASK; ss.selector = cs.selector + 8; ss.selector &= ~SELECTOR_RPL_MASK; if (ctxt->mode == X86EMUL_MODE_PROT64 || is_long_mode(ctxt->vcpu)) { cs.db = 0; cs.l = 1; } kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS); kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS); kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_EIP, &msr_data); c->eip = msr_data; kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_ESP, &msr_data); c->regs[VCPU_REGS_RSP] = msr_data; return X86EMUL_CONTINUE; } static int emulate_sysexit(struct x86_emulate_ctxt *ctxt) { struct decode_cache *c = &ctxt->decode; struct kvm_segment cs, ss; u64 msr_data; int usermode; /* inject #GP if in real mode or Virtual 8086 mode */ if (ctxt->mode == X86EMUL_MODE_REAL || ctxt->mode == X86EMUL_MODE_VM86) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } setup_syscalls_segments(ctxt, &cs, &ss); if ((c->rex_prefix & 0x8) != 0x0) usermode = X86EMUL_MODE_PROT64; else usermode = X86EMUL_MODE_PROT32; cs.dpl = 3; ss.dpl = 3; kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data); switch (usermode) { case X86EMUL_MODE_PROT32: cs.selector = (u16)(msr_data + 16); if ((msr_data & 0xfffc) == 0x0) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } ss.selector = (u16)(msr_data + 24); break; case X86EMUL_MODE_PROT64: cs.selector = (u16)(msr_data + 32); if (msr_data == 0x0) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } ss.selector = cs.selector + 8; cs.db = 0; cs.l = 1; break; } cs.selector |= SELECTOR_RPL_MASK; ss.selector |= SELECTOR_RPL_MASK; kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS); kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS); c->eip = ctxt->vcpu->arch.regs[VCPU_REGS_RDX]; c->regs[VCPU_REGS_RSP] = ctxt->vcpu->arch.regs[VCPU_REGS_RCX]; return X86EMUL_CONTINUE; } static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { int iopl; if (ctxt->mode == X86EMUL_MODE_REAL) return false; if (ctxt->mode == X86EMUL_MODE_VM86) return true; iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; return ops->cpl(ctxt->vcpu) > iopl; } static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 port, u16 len) { struct kvm_segment tr_seg; int r; u16 io_bitmap_ptr; u8 perm, bit_idx = port & 0x7; unsigned mask = (1 << len) - 1; kvm_get_segment(ctxt->vcpu, &tr_seg, VCPU_SREG_TR); if (tr_seg.unusable) return false; if (tr_seg.limit < 103) return false; r = ops->read_std(tr_seg.base + 102, &io_bitmap_ptr, 2, ctxt->vcpu, NULL); if (r != X86EMUL_CONTINUE) return false; if (io_bitmap_ptr + port/8 > tr_seg.limit) return false; r = ops->read_std(tr_seg.base + io_bitmap_ptr + port/8, &perm, 1, ctxt->vcpu, NULL); if (r != X86EMUL_CONTINUE) return false; if ((perm >> bit_idx) & mask) return false; return true; } static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 port, u16 len) { if (emulator_bad_iopl(ctxt, ops)) if (!emulator_io_port_access_allowed(ctxt, ops, port, len)) return false; return true; } static u32 get_cached_descriptor_base(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, int seg) { struct desc_struct desc; if (ops->get_cached_descriptor(&desc, seg, ctxt->vcpu)) return get_desc_base(&desc); else return ~0; } static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct tss_segment_16 *tss) { struct decode_cache *c = &ctxt->decode; tss->ip = c->eip; tss->flag = ctxt->eflags; tss->ax = c->regs[VCPU_REGS_RAX]; tss->cx = c->regs[VCPU_REGS_RCX]; tss->dx = c->regs[VCPU_REGS_RDX]; tss->bx = c->regs[VCPU_REGS_RBX]; tss->sp = c->regs[VCPU_REGS_RSP]; tss->bp = c->regs[VCPU_REGS_RBP]; tss->si = c->regs[VCPU_REGS_RSI]; tss->di = c->regs[VCPU_REGS_RDI]; tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu); tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu); tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu); tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu); tss->ldt = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu); } static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct tss_segment_16 *tss) { struct decode_cache *c = &ctxt->decode; int ret; c->eip = tss->ip; ctxt->eflags = tss->flag | 2; c->regs[VCPU_REGS_RAX] = tss->ax; c->regs[VCPU_REGS_RCX] = tss->cx; c->regs[VCPU_REGS_RDX] = tss->dx; c->regs[VCPU_REGS_RBX] = tss->bx; c->regs[VCPU_REGS_RSP] = tss->sp; c->regs[VCPU_REGS_RBP] = tss->bp; c->regs[VCPU_REGS_RSI] = tss->si; c->regs[VCPU_REGS_RDI] = tss->di; /* * SDM says that segment selectors are loaded before segment * descriptors */ ops->set_segment_selector(tss->ldt, VCPU_SREG_LDTR, ctxt->vcpu); ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu); ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu); ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu); ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu); /* * Now load segment descriptors. If fault happenes at this stage * it is handled in a context of new task */ ret = load_segment_descriptor(ctxt, ops, tss->ldt, VCPU_SREG_LDTR); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); if (ret != X86EMUL_CONTINUE) return ret; return X86EMUL_CONTINUE; } static int task_switch_16(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 tss_selector, u16 old_tss_sel, ulong old_tss_base, struct desc_struct *new_desc) { struct tss_segment_16 tss_seg; int ret; u32 err, new_tss_base = get_desc_base(new_desc); ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err); return ret; } save_state_to_tss16(ctxt, ops, &tss_seg); ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err); return ret; } ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err); return ret; } if (old_tss_sel != 0xffff) { tss_seg.prev_task_link = old_tss_sel; ret = ops->write_std(new_tss_base, &tss_seg.prev_task_link, sizeof tss_seg.prev_task_link, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err); return ret; } } return load_state_from_tss16(ctxt, ops, &tss_seg); } static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct tss_segment_32 *tss) { struct decode_cache *c = &ctxt->decode; tss->cr3 = ops->get_cr(3, ctxt->vcpu); tss->eip = c->eip; tss->eflags = ctxt->eflags; tss->eax = c->regs[VCPU_REGS_RAX]; tss->ecx = c->regs[VCPU_REGS_RCX]; tss->edx = c->regs[VCPU_REGS_RDX]; tss->ebx = c->regs[VCPU_REGS_RBX]; tss->esp = c->regs[VCPU_REGS_RSP]; tss->ebp = c->regs[VCPU_REGS_RBP]; tss->esi = c->regs[VCPU_REGS_RSI]; tss->edi = c->regs[VCPU_REGS_RDI]; tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu); tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu); tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu); tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu); tss->fs = ops->get_segment_selector(VCPU_SREG_FS, ctxt->vcpu); tss->gs = ops->get_segment_selector(VCPU_SREG_GS, ctxt->vcpu); tss->ldt_selector = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu); } static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, struct tss_segment_32 *tss) { struct decode_cache *c = &ctxt->decode; int ret; ops->set_cr(3, tss->cr3, ctxt->vcpu); c->eip = tss->eip; ctxt->eflags = tss->eflags | 2; c->regs[VCPU_REGS_RAX] = tss->eax; c->regs[VCPU_REGS_RCX] = tss->ecx; c->regs[VCPU_REGS_RDX] = tss->edx; c->regs[VCPU_REGS_RBX] = tss->ebx; c->regs[VCPU_REGS_RSP] = tss->esp; c->regs[VCPU_REGS_RBP] = tss->ebp; c->regs[VCPU_REGS_RSI] = tss->esi; c->regs[VCPU_REGS_RDI] = tss->edi; /* * SDM says that segment selectors are loaded before segment * descriptors */ ops->set_segment_selector(tss->ldt_selector, VCPU_SREG_LDTR, ctxt->vcpu); ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu); ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu); ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu); ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu); ops->set_segment_selector(tss->fs, VCPU_SREG_FS, ctxt->vcpu); ops->set_segment_selector(tss->gs, VCPU_SREG_GS, ctxt->vcpu); /* * Now load segment descriptors. If fault happenes at this stage * it is handled in a context of new task */ ret = load_segment_descriptor(ctxt, ops, tss->ldt_selector, VCPU_SREG_LDTR); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->fs, VCPU_SREG_FS); if (ret != X86EMUL_CONTINUE) return ret; ret = load_segment_descriptor(ctxt, ops, tss->gs, VCPU_SREG_GS); if (ret != X86EMUL_CONTINUE) return ret; return X86EMUL_CONTINUE; } static int task_switch_32(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 tss_selector, u16 old_tss_sel, ulong old_tss_base, struct desc_struct *new_desc) { struct tss_segment_32 tss_seg; int ret; u32 err, new_tss_base = get_desc_base(new_desc); ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err); return ret; } save_state_to_tss32(ctxt, ops, &tss_seg); ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err); return ret; } ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err); return ret; } if (old_tss_sel != 0xffff) { tss_seg.prev_task_link = old_tss_sel; ret = ops->write_std(new_tss_base, &tss_seg.prev_task_link, sizeof tss_seg.prev_task_link, ctxt->vcpu, &err); if (ret == X86EMUL_PROPAGATE_FAULT) { /* FIXME: need to provide precise fault address */ kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err); return ret; } } return load_state_from_tss32(ctxt, ops, &tss_seg); } static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 tss_selector, int reason, bool has_error_code, u32 error_code) { struct desc_struct curr_tss_desc, next_tss_desc; int ret; u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu); ulong old_tss_base = get_cached_descriptor_base(ctxt, ops, VCPU_SREG_TR); u32 desc_limit; /* FIXME: old_tss_base == ~0 ? */ ret = read_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc); if (ret != X86EMUL_CONTINUE) return ret; ret = read_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc); if (ret != X86EMUL_CONTINUE) return ret; /* FIXME: check that next_tss_desc is tss */ if (reason != TASK_SWITCH_IRET) { if ((tss_selector & 3) > next_tss_desc.dpl || ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) { kvm_inject_gp(ctxt->vcpu, 0); return X86EMUL_PROPAGATE_FAULT; } } desc_limit = desc_limit_scaled(&next_tss_desc); if (!next_tss_desc.p || ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || desc_limit < 0x2b)) { kvm_queue_exception_e(ctxt->vcpu, TS_VECTOR, tss_selector & 0xfffc); return X86EMUL_PROPAGATE_FAULT; } if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ write_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc); } if (reason == TASK_SWITCH_IRET) ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; /* set back link to prev task only if NT bit is set in eflags note that old_tss_sel is not used afetr this point */ if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) old_tss_sel = 0xffff; if (next_tss_desc.type & 8) ret = task_switch_32(ctxt, ops, tss_selector, old_tss_sel, old_tss_base, &next_tss_desc); else ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel, old_tss_base, &next_tss_desc); if (ret != X86EMUL_CONTINUE) return ret; if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; if (reason != TASK_SWITCH_IRET) { next_tss_desc.type |= (1 << 1); /* set busy flag */ write_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc); } ops->set_cr(0, ops->get_cr(0, ctxt->vcpu) | X86_CR0_TS, ctxt->vcpu); ops->set_cached_descriptor(&next_tss_desc, VCPU_SREG_TR, ctxt->vcpu); ops->set_segment_selector(tss_selector, VCPU_SREG_TR, ctxt->vcpu); if (has_error_code) { struct decode_cache *c = &ctxt->decode; c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; c->lock_prefix = 0; c->src.val = (unsigned long) error_code; emulate_push(ctxt); } return ret; } int emulator_task_switch(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops, u16 tss_selector, int reason, bool has_error_code, u32 error_code) { struct decode_cache *c = &ctxt->decode; int rc; memset(c, 0, sizeof(struct decode_cache)); c->eip = ctxt->eip; memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); c->dst.type = OP_NONE; rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason, has_error_code, error_code); if (rc == X86EMUL_CONTINUE) { memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs); kvm_rip_write(ctxt->vcpu, c->eip); rc = writeback(ctxt, ops); } return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; } static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base, int reg, struct operand *op) { struct decode_cache *c = &ctxt->decode; int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; register_address_increment(c, &c->regs[reg], df * op->bytes); op->ptr = (unsigned long *)register_address(c, base, c->regs[reg]); } int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { u64 msr_data; struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; int saved_dst_type = c->dst.type; ctxt->interruptibility = 0; ctxt->decode.mem_read.pos = 0; /* Shadow copy of register state. Committed on successful emulation. * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't * modify them. */ memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } /* LOCK prefix is allowed only with some instructions */ if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } /* Privileged instruction can be executed only in CPL=0 */ if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } if (c->rep_prefix && (c->d & String)) { ctxt->restart = true; /* All REP prefixes have the same first termination condition */ if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { string_done: ctxt->restart = false; kvm_rip_write(ctxt->vcpu, c->eip); goto done; } /* The second termination condition only applies for REPE * and REPNE. Test if the repeat string operation prefix is * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the * corresponding termination condition according to: * - if REPE/REPZ and ZF = 0 then done * - if REPNE/REPNZ and ZF = 1 then done */ if ((c->b == 0xa6) || (c->b == 0xa7) || (c->b == 0xae) || (c->b == 0xaf)) { if ((c->rep_prefix == REPE_PREFIX) && ((ctxt->eflags & EFLG_ZF) == 0)) goto string_done; if ((c->rep_prefix == REPNE_PREFIX) && ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) goto string_done; } c->eip = ctxt->eip; } if (c->src.type == OP_MEM) { rc = read_emulated(ctxt, ops, (unsigned long)c->src.ptr, &c->src.val, c->src.bytes); if (rc != X86EMUL_CONTINUE) goto done; c->src.orig_val = c->src.val; } if (c->src2.type == OP_MEM) { rc = read_emulated(ctxt, ops, (unsigned long)c->src2.ptr, &c->src2.val, c->src2.bytes); if (rc != X86EMUL_CONTINUE) goto done; } if ((c->d & DstMask) == ImplicitOps) goto special_insn; if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { /* optimisation - avoid slow emulated read if Mov */ rc = read_emulated(ctxt, ops, (unsigned long)c->dst.ptr, &c->dst.val, c->dst.bytes); if (rc != X86EMUL_CONTINUE) goto done; } c->dst.orig_val = c->dst.val; special_insn: if (c->twobyte) goto twobyte_insn; switch (c->b) { case 0x00 ... 0x05: add: /* add */ emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags); break; case 0x06: /* push es */ emulate_push_sreg(ctxt, VCPU_SREG_ES); break; case 0x07: /* pop es */ rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_ES); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x08 ... 0x0d: or: /* or */ emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); break; case 0x0e: /* push cs */ emulate_push_sreg(ctxt, VCPU_SREG_CS); break; case 0x10 ... 0x15: adc: /* adc */ emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags); break; case 0x16: /* push ss */ emulate_push_sreg(ctxt, VCPU_SREG_SS); break; case 0x17: /* pop ss */ rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_SS); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x18 ... 0x1d: sbb: /* sbb */ emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags); break; case 0x1e: /* push ds */ emulate_push_sreg(ctxt, VCPU_SREG_DS); break; case 0x1f: /* pop ds */ rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_DS); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x20 ... 0x25: and: /* and */ emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags); break; case 0x28 ... 0x2d: sub: /* sub */ emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags); break; case 0x30 ... 0x35: xor: /* xor */ emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags); break; case 0x38 ... 0x3d: cmp: /* cmp */ emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); break; case 0x40 ... 0x47: /* inc r16/r32 */ emulate_1op("inc", c->dst, ctxt->eflags); break; case 0x48 ... 0x4f: /* dec r16/r32 */ emulate_1op("dec", c->dst, ctxt->eflags); break; case 0x50 ... 0x57: /* push reg */ emulate_push(ctxt); break; case 0x58 ... 0x5f: /* pop reg */ pop_instruction: rc = emulate_pop(ctxt, ops, &c->dst.val, c->op_bytes); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x60: /* pusha */ emulate_pusha(ctxt); break; case 0x61: /* popa */ rc = emulate_popa(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x63: /* movsxd */ if (ctxt->mode != X86EMUL_MODE_PROT64) goto cannot_emulate; c->dst.val = (s32) c->src.val; break; case 0x68: /* push imm */ case 0x6a: /* push imm8 */ emulate_push(ctxt); break; case 0x6c: /* insb */ case 0x6d: /* insw/insd */ c->dst.bytes = min(c->dst.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX], c->dst.bytes)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->regs[VCPU_REGS_RDX], &c->dst.val)) goto done; /* IO is needed, skip writeback */ break; case 0x6e: /* outsb */ case 0x6f: /* outsw/outsd */ c->src.bytes = min(c->src.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX], c->src.bytes)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } ops->pio_out_emulated(c->src.bytes, c->regs[VCPU_REGS_RDX], &c->src.val, 1, ctxt->vcpu); c->dst.type = OP_NONE; /* nothing to writeback */ break; case 0x70 ... 0x7f: /* jcc (short) */ if (test_cc(c->b, ctxt->eflags)) jmp_rel(c, c->src.val); break; case 0x80 ... 0x83: /* Grp1 */ switch (c->modrm_reg) { case 0: goto add; case 1: goto or; case 2: goto adc; case 3: goto sbb; case 4: goto and; case 5: goto sub; case 6: goto xor; case 7: goto cmp; } break; case 0x84 ... 0x85: emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); break; case 0x86 ... 0x87: /* xchg */ xchg: /* Write back the register source. */ switch (c->dst.bytes) { case 1: *(u8 *) c->src.ptr = (u8) c->dst.val; break; case 2: *(u16 *) c->src.ptr = (u16) c->dst.val; break; case 4: *c->src.ptr = (u32) c->dst.val; break; /* 64b reg: zero-extend */ case 8: *c->src.ptr = c->dst.val; break; } /* * Write back the memory destination with implicit LOCK * prefix. */ c->dst.val = c->src.val; c->lock_prefix = 1; break; case 0x88 ... 0x8b: /* mov */ goto mov; case 0x8c: { /* mov r/m, sreg */ struct kvm_segment segreg; if (c->modrm_reg <= VCPU_SREG_GS) kvm_get_segment(ctxt->vcpu, &segreg, c->modrm_reg); else { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } c->dst.val = segreg.selector; break; } case 0x8d: /* lea r16/r32, m */ c->dst.val = c->modrm_ea; break; case 0x8e: { /* mov seg, r/m16 */ uint16_t sel; sel = c->src.val; if (c->modrm_reg == VCPU_SREG_CS || c->modrm_reg > VCPU_SREG_GS) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } if (c->modrm_reg == VCPU_SREG_SS) toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_MOV_SS); rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg); c->dst.type = OP_NONE; /* Disable writeback. */ break; } case 0x8f: /* pop (sole member of Grp1a) */ rc = emulate_grp1a(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; break; case 0x90: /* nop / xchg r8,rax */ if (!(c->rex_prefix & 1)) { /* nop */ c->dst.type = OP_NONE; break; } case 0x91 ... 0x97: /* xchg reg,rax */ c->src.type = c->dst.type = OP_REG; c->src.bytes = c->dst.bytes = c->op_bytes; c->src.ptr = (unsigned long *) &c->regs[VCPU_REGS_RAX]; c->src.val = *(c->src.ptr); goto xchg; case 0x9c: /* pushf */ c->src.val = (unsigned long) ctxt->eflags; emulate_push(ctxt); break; case 0x9d: /* popf */ c->dst.type = OP_REG; c->dst.ptr = (unsigned long *) &ctxt->eflags; c->dst.bytes = c->op_bytes; rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes); if (rc != X86EMUL_CONTINUE) goto done; break; case 0xa0 ... 0xa1: /* mov */ c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; c->dst.val = c->src.val; break; case 0xa2 ... 0xa3: /* mov */ c->dst.val = (unsigned long)c->regs[VCPU_REGS_RAX]; break; case 0xa4 ... 0xa5: /* movs */ goto mov; case 0xa6 ... 0xa7: /* cmps */ c->dst.type = OP_NONE; /* Disable writeback. */ DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr); goto cmp; case 0xaa ... 0xab: /* stos */ c->dst.val = c->regs[VCPU_REGS_RAX]; break; case 0xac ... 0xad: /* lods */ goto mov; case 0xae ... 0xaf: /* scas */ DPRINTF("Urk! I don't handle SCAS.\n"); goto cannot_emulate; case 0xb0 ... 0xbf: /* mov r, imm */ goto mov; case 0xc0 ... 0xc1: emulate_grp2(ctxt); break; case 0xc3: /* ret */ c->dst.type = OP_REG; c->dst.ptr = &c->eip; c->dst.bytes = c->op_bytes; goto pop_instruction; case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */ mov: c->dst.val = c->src.val; break; case 0xcb: /* ret far */ rc = emulate_ret_far(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; break; case 0xd0 ... 0xd1: /* Grp2 */ c->src.val = 1; emulate_grp2(ctxt); break; case 0xd2 ... 0xd3: /* Grp2 */ c->src.val = c->regs[VCPU_REGS_RCX]; emulate_grp2(ctxt); break; case 0xe4: /* inb */ case 0xe5: /* in */ goto do_io_in; case 0xe6: /* outb */ case 0xe7: /* out */ goto do_io_out; case 0xe8: /* call (near) */ { long int rel = c->src.val; c->src.val = (unsigned long) c->eip; jmp_rel(c, rel); emulate_push(ctxt); break; } case 0xe9: /* jmp rel */ goto jmp; case 0xea: /* jmp far */ jump_far: if (load_segment_descriptor(ctxt, ops, c->src2.val, VCPU_SREG_CS)) goto done; c->eip = c->src.val; break; case 0xeb: jmp: /* jmp rel short */ jmp_rel(c, c->src.val); c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xec: /* in al,dx */ case 0xed: /* in (e/r)ax,dx */ c->src.val = c->regs[VCPU_REGS_RDX]; do_io_in: c->dst.bytes = min(c->dst.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val, &c->dst.val)) goto done; /* IO is needed */ break; case 0xee: /* out al,dx */ case 0xef: /* out (e/r)ax,dx */ c->src.val = c->regs[VCPU_REGS_RDX]; do_io_out: c->dst.bytes = min(c->dst.bytes, 4u); if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } ops->pio_out_emulated(c->dst.bytes, c->src.val, &c->dst.val, 1, ctxt->vcpu); c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xf4: /* hlt */ ctxt->vcpu->arch.halt_request = 1; break; case 0xf5: /* cmc */ /* complement carry flag from eflags reg */ ctxt->eflags ^= EFLG_CF; c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xf6 ... 0xf7: /* Grp3 */ if (!emulate_grp3(ctxt, ops)) goto cannot_emulate; break; case 0xf8: /* clc */ ctxt->eflags &= ~EFLG_CF; c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfa: /* cli */ if (emulator_bad_iopl(ctxt, ops)) kvm_inject_gp(ctxt->vcpu, 0); else { ctxt->eflags &= ~X86_EFLAGS_IF; c->dst.type = OP_NONE; /* Disable writeback. */ } break; case 0xfb: /* sti */ if (emulator_bad_iopl(ctxt, ops)) kvm_inject_gp(ctxt->vcpu, 0); else { toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_STI); ctxt->eflags |= X86_EFLAGS_IF; c->dst.type = OP_NONE; /* Disable writeback. */ } break; case 0xfc: /* cld */ ctxt->eflags &= ~EFLG_DF; c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfd: /* std */ ctxt->eflags |= EFLG_DF; c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfe: /* Grp4 */ grp45: rc = emulate_grp45(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; break; case 0xff: /* Grp5 */ if (c->modrm_reg == 5) goto jump_far; goto grp45; } writeback: rc = writeback(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; /* * restore dst type in case the decoding will be reused * (happens for string instruction ) */ c->dst.type = saved_dst_type; if ((c->d & SrcMask) == SrcSI) string_addr_inc(ctxt, seg_override_base(ctxt, c), VCPU_REGS_RSI, &c->src); if ((c->d & DstMask) == DstDI) string_addr_inc(ctxt, es_base(ctxt), VCPU_REGS_RDI, &c->dst); if (c->rep_prefix && (c->d & String)) { struct read_cache *rc = &ctxt->decode.io_read; register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); /* * Re-enter guest when pio read ahead buffer is empty or, * if it is not used, after each 1024 iteration. */ if ((rc->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) || (rc->end != 0 && rc->end == rc->pos)) ctxt->restart = false; } /* * reset read cache here in case string instruction is restared * without decoding */ ctxt->decode.mem_read.end = 0; /* Commit shadow register state. */ memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs); kvm_rip_write(ctxt->vcpu, c->eip); ops->set_rflags(ctxt->vcpu, ctxt->eflags); done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; twobyte_insn: switch (c->b) { case 0x01: /* lgdt, lidt, lmsw */ switch (c->modrm_reg) { u16 size; unsigned long address; case 0: /* vmcall */ if (c->modrm_mod != 3 || c->modrm_rm != 1) goto cannot_emulate; rc = kvm_fix_hypercall(ctxt->vcpu); if (rc != X86EMUL_CONTINUE) goto done; /* Let the processor re-execute the fixed hypercall */ c->eip = ctxt->eip; /* Disable writeback. */ c->dst.type = OP_NONE; break; case 2: /* lgdt */ rc = read_descriptor(ctxt, ops, c->src.ptr, &size, &address, c->op_bytes); if (rc != X86EMUL_CONTINUE) goto done; realmode_lgdt(ctxt->vcpu, size, address); /* Disable writeback. */ c->dst.type = OP_NONE; break; case 3: /* lidt/vmmcall */ if (c->modrm_mod == 3) { switch (c->modrm_rm) { case 1: rc = kvm_fix_hypercall(ctxt->vcpu); if (rc != X86EMUL_CONTINUE) goto done; break; default: goto cannot_emulate; } } else { rc = read_descriptor(ctxt, ops, c->src.ptr, &size, &address, c->op_bytes); if (rc != X86EMUL_CONTINUE) goto done; realmode_lidt(ctxt->vcpu, size, address); } /* Disable writeback. */ c->dst.type = OP_NONE; break; case 4: /* smsw */ c->dst.bytes = 2; c->dst.val = ops->get_cr(0, ctxt->vcpu); break; case 6: /* lmsw */ ops->set_cr(0, (ops->get_cr(0, ctxt->vcpu) & ~0x0ful) | (c->src.val & 0x0f), ctxt->vcpu); c->dst.type = OP_NONE; break; case 5: /* not defined */ kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; case 7: /* invlpg*/ emulate_invlpg(ctxt->vcpu, c->modrm_ea); /* Disable writeback. */ c->dst.type = OP_NONE; break; default: goto cannot_emulate; } break; case 0x05: /* syscall */ rc = emulate_syscall(ctxt); if (rc != X86EMUL_CONTINUE) goto done; else goto writeback; break; case 0x06: emulate_clts(ctxt->vcpu); c->dst.type = OP_NONE; break; case 0x08: /* invd */ case 0x09: /* wbinvd */ case 0x0d: /* GrpP (prefetch) */ case 0x18: /* Grp16 (prefetch/nop) */ c->dst.type = OP_NONE; break; case 0x20: /* mov cr, reg */ switch (c->modrm_reg) { case 1: case 5 ... 7: case 9 ... 15: kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu); c->dst.type = OP_NONE; /* no writeback */ break; case 0x21: /* mov from dr to reg */ if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && (c->modrm_reg == 4 || c->modrm_reg == 5)) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]); c->dst.type = OP_NONE; /* no writeback */ break; case 0x22: /* mov reg, cr */ ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu); c->dst.type = OP_NONE; break; case 0x23: /* mov from reg to dr */ if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && (c->modrm_reg == 4 || c->modrm_reg == 5)) { kvm_queue_exception(ctxt->vcpu, UD_VECTOR); goto done; } emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]); c->dst.type = OP_NONE; /* no writeback */ break; case 0x30: /* wrmsr */ msr_data = (u32)c->regs[VCPU_REGS_RAX] | ((u64)c->regs[VCPU_REGS_RDX] << 32); if (kvm_set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } rc = X86EMUL_CONTINUE; c->dst.type = OP_NONE; break; case 0x32: /* rdmsr */ if (kvm_get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) { kvm_inject_gp(ctxt->vcpu, 0); goto done; } else { c->regs[VCPU_REGS_RAX] = (u32)msr_data; c->regs[VCPU_REGS_RDX] = msr_data >> 32; } rc = X86EMUL_CONTINUE; c->dst.type = OP_NONE; break; case 0x34: /* sysenter */ rc = emulate_sysenter(ctxt); if (rc != X86EMUL_CONTINUE) goto done; else goto writeback; break; case 0x35: /* sysexit */ rc = emulate_sysexit(ctxt); if (rc != X86EMUL_CONTINUE) goto done; else goto writeback; break; case 0x40 ... 0x4f: /* cmov */ c->dst.val = c->dst.orig_val = c->src.val; if (!test_cc(c->b, ctxt->eflags)) c->dst.type = OP_NONE; /* no writeback */ break; case 0x80 ... 0x8f: /* jnz rel, etc*/ if (test_cc(c->b, ctxt->eflags)) jmp_rel(c, c->src.val); c->dst.type = OP_NONE; break; case 0xa0: /* push fs */ emulate_push_sreg(ctxt, VCPU_SREG_FS); break; case 0xa1: /* pop fs */ rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_FS); if (rc != X86EMUL_CONTINUE) goto done; break; case 0xa3: bt: /* bt */ c->dst.type = OP_NONE; /* only subword offset */ c->src.val &= (c->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags); break; case 0xa4: /* shld imm8, r, r/m */ case 0xa5: /* shld cl, r, r/m */ emulate_2op_cl("shld", c->src2, c->src, c->dst, ctxt->eflags); break; case 0xa8: /* push gs */ emulate_push_sreg(ctxt, VCPU_SREG_GS); break; case 0xa9: /* pop gs */ rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_GS); if (rc != X86EMUL_CONTINUE) goto done; break; case 0xab: bts: /* bts */ /* only subword offset */ c->src.val &= (c->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags); break; case 0xac: /* shrd imm8, r, r/m */ case 0xad: /* shrd cl, r, r/m */ emulate_2op_cl("shrd", c->src2, c->src, c->dst, ctxt->eflags); break; case 0xae: /* clflush */ break; case 0xb0 ... 0xb1: /* cmpxchg */ /* * Save real source value, then compare EAX against * destination. */ c->src.orig_val = c->src.val; c->src.val = c->regs[VCPU_REGS_RAX]; emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); if (ctxt->eflags & EFLG_ZF) { /* Success: write back to memory. */ c->dst.val = c->src.orig_val; } else { /* Failure: write the value we saw to EAX. */ c->dst.type = OP_REG; c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; } break; case 0xb3: btr: /* btr */ /* only subword offset */ c->src.val &= (c->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags); break; case 0xb6 ... 0xb7: /* movzx */ c->dst.bytes = c->op_bytes; c->dst.val = (c->d & ByteOp) ? (u8) c->src.val : (u16) c->src.val; break; case 0xba: /* Grp8 */ switch (c->modrm_reg & 3) { case 0: goto bt; case 1: goto bts; case 2: goto btr; case 3: goto btc; } break; case 0xbb: btc: /* btc */ /* only subword offset */ c->src.val &= (c->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags); break; case 0xbe ... 0xbf: /* movsx */ c->dst.bytes = c->op_bytes; c->dst.val = (c->d & ByteOp) ? (s8) c->src.val : (s16) c->src.val; break; case 0xc3: /* movnti */ c->dst.bytes = c->op_bytes; c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val : (u64) c->src.val; break; case 0xc7: /* Grp9 (cmpxchg8b) */ rc = emulate_grp9(ctxt, ops); if (rc != X86EMUL_CONTINUE) goto done; break; } goto writeback; cannot_emulate: DPRINTF("Cannot emulate %02x\n", c->b); return -1; }