diff options
Diffstat (limited to 'arch/x86/kvm/x86_emulate.c')
-rw-r--r-- | arch/x86/kvm/x86_emulate.c | 257 |
1 files changed, 162 insertions, 95 deletions
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index 932f216d890c..f2f90468f8b1 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -121,7 +121,7 @@ static u16 opcode_table[256] = { 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ , 0, 0, 0, 0, /* 0x68 - 0x6F */ - 0, 0, ImplicitOps | Mov | Stack, 0, + SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0, SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* insb, insw/insd */ SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* outsb, outsw/outsd */ /* 0x70 - 0x77 */ @@ -138,9 +138,11 @@ static u16 opcode_table[256] = { /* 0x88 - 0x8F */ ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov, ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov, - 0, ModRM | DstReg, 0, Group | Group1A, - /* 0x90 - 0x9F */ - 0, 0, 0, 0, 0, 0, 0, 0, + DstMem | SrcReg | ModRM | Mov, ModRM | DstReg, + DstReg | SrcMem | ModRM | Mov, Group | Group1A, + /* 0x90 - 0x97 */ + DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, + /* 0x98 - 0x9F */ 0, 0, 0, 0, ImplicitOps | Stack, ImplicitOps | Stack, 0, 0, /* 0xA0 - 0xA7 */ ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs, @@ -152,7 +154,8 @@ static u16 opcode_table[256] = { ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String, ByteOp | ImplicitOps | String, ImplicitOps | String, /* 0xB0 - 0xBF */ - 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + DstReg | SrcImm | Mov, 0, 0, 0, 0, 0, 0, 0, /* 0xC0 - 0xC7 */ ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM, 0, ImplicitOps | Stack, 0, 0, @@ -168,7 +171,8 @@ static u16 opcode_table[256] = { /* 0xE0 - 0xE7 */ 0, 0, 0, 0, 0, 0, 0, 0, /* 0xE8 - 0xEF */ - ImplicitOps | Stack, SrcImm|ImplicitOps, 0, SrcImmByte|ImplicitOps, + ImplicitOps | Stack, SrcImm | ImplicitOps, + ImplicitOps, SrcImmByte | ImplicitOps, 0, 0, 0, 0, /* 0xF0 - 0xF7 */ 0, 0, 0, 0, @@ -215,7 +219,7 @@ static u16 twobyte_table[256] = { /* 0xA0 - 0xA7 */ 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0, /* 0xA8 - 0xAF */ - 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0, + 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, ModRM, 0, /* 0xB0 - 0xB7 */ ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0, DstMem | SrcReg | ModRM | BitOp, @@ -518,6 +522,39 @@ 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 linear, u8 *dest) @@ -660,7 +697,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, { struct decode_cache *c = &ctxt->decode; u8 sib; - int index_reg = 0, base_reg = 0, scale, rip_relative = 0; + int index_reg = 0, base_reg = 0, scale; int rc = 0; if (c->rex_prefix) { @@ -731,47 +768,28 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, } if (c->modrm_rm == 2 || c->modrm_rm == 3 || (c->modrm_rm == 6 && c->modrm_mod != 0)) - if (!c->override_base) - c->override_base = &ctxt->ss_base; + 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. */ - switch (c->modrm_rm) { - case 4: - case 12: + 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; - switch (base_reg) { - case 5: - if (c->modrm_mod != 0) - c->modrm_ea += c->regs[base_reg]; - else - c->modrm_ea += - insn_fetch(s32, 4, c->eip); - break; - default: + 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]; - } - switch (index_reg) { - case 4: - break; - default: + if (index_reg != 4) c->modrm_ea += c->regs[index_reg] << scale; - } - break; - case 5: - if (c->modrm_mod != 0) - c->modrm_ea += c->regs[c->modrm_rm]; - else if (ctxt->mode == X86EMUL_MODE_PROT64) - rip_relative = 1; - break; - default: + } 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]; - break; - } switch (c->modrm_mod) { case 0: if (c->modrm_rm == 5) @@ -785,22 +803,6 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, break; } } - if (rip_relative) { - c->modrm_ea += c->eip; - switch (c->d & SrcMask) { - case SrcImmByte: - c->modrm_ea += 1; - break; - case SrcImm: - if (c->d & ByteOp) - c->modrm_ea += 1; - else - if (c->op_bytes == 8) - c->modrm_ea += 4; - else - c->modrm_ea += c->op_bytes; - } - } done: return rc; } @@ -838,6 +840,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) memset(c, 0, sizeof(struct decode_cache)); c->eip = ctxt->vcpu->arch.rip; + ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS); memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs); switch (mode) { @@ -876,23 +879,15 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) /* switch between 2/4 bytes */ c->ad_bytes = def_ad_bytes ^ 6; break; + case 0x26: /* ES override */ case 0x2e: /* CS override */ - c->override_base = &ctxt->cs_base; - break; + case 0x36: /* SS override */ case 0x3e: /* DS override */ - c->override_base = &ctxt->ds_base; - break; - case 0x26: /* ES override */ - c->override_base = &ctxt->es_base; + set_seg_override(c, (c->b >> 3) & 3); break; case 0x64: /* FS override */ - c->override_base = &ctxt->fs_base; - break; case 0x65: /* GS override */ - c->override_base = &ctxt->gs_base; - break; - case 0x36: /* SS override */ - c->override_base = &ctxt->ss_base; + set_seg_override(c, c->b & 7); break; case 0x40 ... 0x4f: /* REX */ if (mode != X86EMUL_MODE_PROT64) @@ -964,15 +959,11 @@ done_prefixes: if (rc) goto done; - if (!c->override_base) - c->override_base = &ctxt->ds_base; - if (mode == X86EMUL_MODE_PROT64 && - c->override_base != &ctxt->fs_base && - c->override_base != &ctxt->gs_base) - c->override_base = NULL; + if (!c->has_seg_override) + set_seg_override(c, VCPU_SREG_DS); - if (c->override_base) - c->modrm_ea += *c->override_base; + 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; @@ -1049,6 +1040,7 @@ done_prefixes: break; case DstMem: 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; @@ -1058,6 +1050,9 @@ done_prefixes: break; } + if (c->rip_relative) + c->modrm_ea += c->eip; + done: return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; } @@ -1070,7 +1065,7 @@ static inline void emulate_push(struct x86_emulate_ctxt *ctxt) 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, ctxt->ss_base, + c->dst.ptr = (void *) register_address(c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]); } @@ -1080,7 +1075,7 @@ static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, struct decode_cache *c = &ctxt->decode; int rc; - rc = ops->read_std(register_address(c, ctxt->ss_base, + rc = ops->read_std(register_address(c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]), &c->dst.val, c->dst.bytes, ctxt->vcpu); if (rc != 0) @@ -1402,11 +1397,11 @@ special_insn: register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes); c->dst.ptr = (void *) register_address( - c, ctxt->ss_base, c->regs[VCPU_REGS_RSP]); + c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]); break; case 0x58 ... 0x5f: /* pop reg */ pop_instruction: - if ((rc = ops->read_std(register_address(c, ctxt->ss_base, + if ((rc = ops->read_std(register_address(c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]), c->dst.ptr, c->op_bytes, ctxt->vcpu)) != 0) goto done; @@ -1420,9 +1415,8 @@ special_insn: goto cannot_emulate; c->dst.val = (s32) c->src.val; break; + case 0x68: /* push imm */ case 0x6a: /* push imm8 */ - c->src.val = 0L; - c->src.val = insn_fetch(s8, 1, c->eip); emulate_push(ctxt); break; case 0x6c: /* insb */ @@ -1433,7 +1427,7 @@ special_insn: c->rep_prefix ? address_mask(c, c->regs[VCPU_REGS_RCX]) : 1, (ctxt->eflags & EFLG_DF), - register_address(c, ctxt->es_base, + register_address(c, es_base(ctxt), c->regs[VCPU_REGS_RDI]), c->rep_prefix, c->regs[VCPU_REGS_RDX]) == 0) { @@ -1449,9 +1443,8 @@ special_insn: c->rep_prefix ? address_mask(c, c->regs[VCPU_REGS_RCX]) : 1, (ctxt->eflags & EFLG_DF), - register_address(c, c->override_base ? - *c->override_base : - ctxt->ds_base, + register_address(c, + seg_override_base(ctxt, c), c->regs[VCPU_REGS_RSI]), c->rep_prefix, c->regs[VCPU_REGS_RDX]) == 0) { @@ -1490,6 +1483,7 @@ special_insn: 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: @@ -1514,14 +1508,60 @@ special_insn: break; case 0x88 ... 0x8b: /* mov */ goto mov; + case 0x8c: { /* mov r/m, sreg */ + struct kvm_segment segreg; + + if (c->modrm_reg <= 5) + kvm_get_segment(ctxt->vcpu, &segreg, c->modrm_reg); + else { + printk(KERN_INFO "0x8c: Invalid segreg in modrm byte 0x%02x\n", + c->modrm); + goto cannot_emulate; + } + 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; + int type_bits; + int err; + + sel = c->src.val; + if (c->modrm_reg <= 5) { + type_bits = (c->modrm_reg == 1) ? 9 : 1; + err = kvm_load_segment_descriptor(ctxt->vcpu, sel, + type_bits, c->modrm_reg); + } else { + printk(KERN_INFO "Invalid segreg in modrm byte 0x%02x\n", + c->modrm); + goto cannot_emulate; + } + + if (err < 0) + goto cannot_emulate; + + c->dst.type = OP_NONE; /* Disable writeback. */ + break; + } case 0x8f: /* pop (sole member of Grp1a) */ rc = emulate_grp1a(ctxt, ops); if (rc != 0) 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); @@ -1540,11 +1580,10 @@ special_insn: c->dst.type = OP_MEM; c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = (unsigned long *)register_address(c, - ctxt->es_base, + es_base(ctxt), c->regs[VCPU_REGS_RDI]); if ((rc = ops->read_emulated(register_address(c, - c->override_base ? *c->override_base : - ctxt->ds_base, + seg_override_base(ctxt, c), c->regs[VCPU_REGS_RSI]), &c->dst.val, c->dst.bytes, ctxt->vcpu)) != 0) @@ -1560,8 +1599,7 @@ special_insn: c->src.type = OP_NONE; /* Disable writeback. */ c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->src.ptr = (unsigned long *)register_address(c, - c->override_base ? *c->override_base : - ctxt->ds_base, + seg_override_base(ctxt, c), c->regs[VCPU_REGS_RSI]); if ((rc = ops->read_emulated((unsigned long)c->src.ptr, &c->src.val, @@ -1572,7 +1610,7 @@ special_insn: c->dst.type = OP_NONE; /* Disable writeback. */ c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = (unsigned long *)register_address(c, - ctxt->es_base, + es_base(ctxt), c->regs[VCPU_REGS_RDI]); if ((rc = ops->read_emulated((unsigned long)c->dst.ptr, &c->dst.val, @@ -1596,7 +1634,7 @@ special_insn: c->dst.type = OP_MEM; c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = (unsigned long *)register_address(c, - ctxt->es_base, + es_base(ctxt), c->regs[VCPU_REGS_RDI]); c->dst.val = c->regs[VCPU_REGS_RAX]; register_address_increment(c, &c->regs[VCPU_REGS_RDI], @@ -1608,8 +1646,7 @@ special_insn: c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; if ((rc = ops->read_emulated(register_address(c, - c->override_base ? *c->override_base : - ctxt->ds_base, + seg_override_base(ctxt, c), c->regs[VCPU_REGS_RSI]), &c->dst.val, c->dst.bytes, @@ -1622,6 +1659,8 @@ special_insn: case 0xae ... 0xaf: /* scas */ DPRINTF("Urk! I don't handle SCAS.\n"); goto cannot_emulate; + case 0xb8: /* mov r, imm */ + goto mov; case 0xc0 ... 0xc1: emulate_grp2(ctxt); break; @@ -1660,13 +1699,39 @@ special_insn: break; } case 0xe9: /* jmp rel */ - case 0xeb: /* jmp rel short */ + goto jmp; + case 0xea: /* jmp far */ { + uint32_t eip; + uint16_t sel; + + switch (c->op_bytes) { + case 2: + eip = insn_fetch(u16, 2, c->eip); + break; + case 4: + eip = insn_fetch(u32, 4, c->eip); + break; + default: + DPRINTF("jmp far: Invalid op_bytes\n"); + goto cannot_emulate; + } + sel = insn_fetch(u16, 2, c->eip); + if (kvm_load_segment_descriptor(ctxt->vcpu, sel, 9, VCPU_SREG_CS) < 0) { + DPRINTF("jmp far: Failed to load CS descriptor\n"); + goto cannot_emulate; + } + + c->eip = eip; + break; + } + case 0xeb: + jmp: /* jmp rel short */ jmp_rel(c, c->src.val); c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xf4: /* hlt */ ctxt->vcpu->arch.halt_request = 1; - goto done; + break; case 0xf5: /* cmc */ /* complement carry flag from eflags reg */ ctxt->eflags ^= EFLG_CF; @@ -1882,6 +1947,8 @@ twobyte_insn: c->src.val &= (c->dst.bytes << 3) - 1; emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags); break; + case 0xae: /* clflush */ + break; case 0xb0 ... 0xb1: /* cmpxchg */ /* * Save real source value, then compare EAX against |