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Diffstat (limited to 'arch/x86/kvm/x86_emulate.c')
-rw-r--r--arch/x86/kvm/x86_emulate.c257
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
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