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authorAvi Kivity <avi@redhat.com>2011-09-13 10:45:49 +0300
committerAvi Kivity <avi@redhat.com>2011-09-25 19:52:56 +0300
commitc191a7a0f4d3b17cc6cee1d3f721dfe23fc7d6c6 (patch)
tree7d71811d87b84250b3f205a12ab68fd59f00b803 /arch/x86
parent41ddf9784cb91c9e4d3a218eef3551bebe9c7362 (diff)
downloadop-kernel-dev-c191a7a0f4d3b17cc6cee1d3f721dfe23fc7d6c6.zip
op-kernel-dev-c191a7a0f4d3b17cc6cee1d3f721dfe23fc7d6c6.tar.gz
KVM: x86 emulator: streamline decode of segment registers
The opcodes push %seg pop %seg l%seg, %mem, %reg (e.g. lds/les/lss/lfs/lgs) all have an segment register encoded in the instruction. To allow reuse, decode the segment number into src2 during the decode stage instead of the execution stage. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/emulate.c99
1 files changed, 57 insertions, 42 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 1c95935..ab48611 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -51,6 +51,12 @@
#define OpImmFAddr 17ull /* Immediate far address */
#define OpMemFAddr 18ull /* Far address in memory */
#define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */
+#define OpES 20ull /* ES */
+#define OpCS 21ull /* CS */
+#define OpSS 22ull /* SS */
+#define OpDS 23ull /* DS */
+#define OpFS 24ull /* FS */
+#define OpGS 25ull /* GS */
#define OpBits 5 /* Width of operand field */
#define OpMask ((1ull << OpBits) - 1)
@@ -126,6 +132,12 @@
#define Src2ImmByte (OpImmByte << Src2Shift)
#define Src2One (OpOne << Src2Shift)
#define Src2Imm (OpImm << Src2Shift)
+#define Src2ES (OpES << Src2Shift)
+#define Src2CS (OpCS << Src2Shift)
+#define Src2SS (OpSS << Src2Shift)
+#define Src2DS (OpDS << Src2Shift)
+#define Src2FS (OpFS << Src2Shift)
+#define Src2GS (OpGS << Src2Shift)
#define Src2Mask (OpMask << Src2Shift)
#define X2(x...) x, x
@@ -3101,16 +3113,19 @@ static struct gprefix pfx_0f_6f_0f_7f = {
static struct opcode opcode_table[256] = {
/* 0x00 - 0x07 */
I6ALU(Lock, em_add),
- D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
+ D(ImplicitOps | Stack | No64 | Src2ES),
+ D(ImplicitOps | Stack | No64 | Src2ES),
/* 0x08 - 0x0F */
I6ALU(Lock, em_or),
- D(ImplicitOps | Stack | No64), N,
+ D(ImplicitOps | Stack | No64 | Src2CS), N,
/* 0x10 - 0x17 */
I6ALU(Lock, em_adc),
- D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
+ D(ImplicitOps | Stack | No64 | Src2SS),
+ D(ImplicitOps | Stack | No64 | Src2SS),
/* 0x18 - 0x1F */
I6ALU(Lock, em_sbb),
- D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
+ D(ImplicitOps | Stack | No64 | Src2DS),
+ D(ImplicitOps | Stack | No64 | Src2DS),
/* 0x20 - 0x27 */
I6ALU(Lock, em_and), N, N,
/* 0x28 - 0x2F */
@@ -3178,7 +3193,8 @@ static struct opcode opcode_table[256] = {
D2bv(DstMem | SrcImmByte | ModRM),
I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
I(ImplicitOps | Stack, em_ret),
- D(DstReg | SrcMemFAddr | ModRM | No64), D(DstReg | SrcMemFAddr | ModRM | No64),
+ D(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES),
+ D(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS),
G(ByteOp, group11), G(0, group11),
/* 0xC8 - 0xCF */
N, N, N, I(ImplicitOps | Stack, em_ret_far),
@@ -3253,20 +3269,22 @@ static struct opcode twobyte_table[256] = {
/* 0x90 - 0x9F */
X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
/* 0xA0 - 0xA7 */
- D(ImplicitOps | Stack), D(ImplicitOps | Stack),
+ D(Stack | Src2FS), D(Stack | Src2FS),
DI(ImplicitOps, cpuid), D(DstMem | SrcReg | ModRM | BitOp),
D(DstMem | SrcReg | Src2ImmByte | ModRM),
D(DstMem | SrcReg | Src2CL | ModRM), N, N,
/* 0xA8 - 0xAF */
- D(ImplicitOps | Stack), D(ImplicitOps | Stack),
+ D(Stack | Src2GS), D(Stack | Src2GS),
DI(ImplicitOps, rsm), D(DstMem | SrcReg | ModRM | BitOp | Lock),
D(DstMem | SrcReg | Src2ImmByte | ModRM),
D(DstMem | SrcReg | Src2CL | ModRM),
D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
/* 0xB0 - 0xB7 */
D2bv(DstMem | SrcReg | ModRM | Lock),
- D(DstReg | SrcMemFAddr | ModRM), D(DstMem | SrcReg | ModRM | BitOp | Lock),
- D(DstReg | SrcMemFAddr | ModRM), D(DstReg | SrcMemFAddr | ModRM),
+ D(DstReg | SrcMemFAddr | ModRM | Src2SS),
+ D(DstMem | SrcReg | ModRM | BitOp | Lock),
+ D(DstReg | SrcMemFAddr | ModRM | Src2FS),
+ D(DstReg | SrcMemFAddr | ModRM | Src2GS),
D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xB8 - 0xBF */
N, N,
@@ -3436,6 +3454,24 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
case OpMemFAddr:
ctxt->memop.bytes = ctxt->op_bytes + 2;
goto mem_common;
+ case OpES:
+ op->val = VCPU_SREG_ES;
+ break;
+ case OpCS:
+ op->val = VCPU_SREG_CS;
+ break;
+ case OpSS:
+ op->val = VCPU_SREG_SS;
+ break;
+ case OpDS:
+ op->val = VCPU_SREG_DS;
+ break;
+ case OpFS:
+ op->val = VCPU_SREG_FS;
+ break;
+ case OpGS:
+ op->val = VCPU_SREG_GS;
+ break;
case OpImplicit:
/* Special instructions do their own operand decoding. */
default:
@@ -3803,26 +3839,15 @@ special_insn:
switch (ctxt->b) {
case 0x06: /* push es */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_ES);
- break;
- case 0x07: /* pop es */
- rc = emulate_pop_sreg(ctxt, VCPU_SREG_ES);
- break;
case 0x0e: /* push cs */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_CS);
- break;
case 0x16: /* push ss */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_SS);
- break;
- case 0x17: /* pop ss */
- rc = emulate_pop_sreg(ctxt, VCPU_SREG_SS);
- break;
case 0x1e: /* push ds */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_DS);
+ rc = emulate_push_sreg(ctxt, ctxt->src2.val);
break;
+ case 0x07: /* pop es */
+ case 0x17: /* pop ss */
case 0x1f: /* pop ds */
- rc = emulate_pop_sreg(ctxt, VCPU_SREG_DS);
- break;
+ rc = emulate_pop_sreg(ctxt, ctxt->src2.val);
case 0x40 ... 0x47: /* inc r16/r32 */
emulate_1op(ctxt, "inc");
break;
@@ -3869,10 +3894,8 @@ special_insn:
rc = em_grp2(ctxt);
break;
case 0xc4: /* les */
- rc = emulate_load_segment(ctxt, VCPU_SREG_ES);
- break;
case 0xc5: /* lds */
- rc = emulate_load_segment(ctxt, VCPU_SREG_DS);
+ rc = emulate_load_segment(ctxt, ctxt->src2.val);
break;
case 0xcc: /* int3 */
rc = emulate_int(ctxt, 3);
@@ -4078,10 +4101,12 @@ twobyte_insn:
ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
break;
case 0xa0: /* push fs */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_FS);
+ case 0xa8: /* push gs */
+ rc = emulate_push_sreg(ctxt, ctxt->src2.val);
break;
case 0xa1: /* pop fs */
- rc = emulate_pop_sreg(ctxt, VCPU_SREG_FS);
+ case 0xa9: /* pop gs */
+ rc = emulate_pop_sreg(ctxt, ctxt->src2.val);
break;
case 0xa3:
bt: /* bt */
@@ -4094,12 +4119,6 @@ twobyte_insn:
case 0xa5: /* shld cl, r, r/m */
emulate_2op_cl(ctxt, "shld");
break;
- case 0xa8: /* push gs */
- rc = emulate_push_sreg(ctxt, VCPU_SREG_GS);
- break;
- case 0xa9: /* pop gs */
- rc = emulate_pop_sreg(ctxt, VCPU_SREG_GS);
- break;
case 0xab:
bts: /* bts */
emulate_2op_SrcV_nobyte(ctxt, "bts");
@@ -4128,18 +4147,14 @@ twobyte_insn:
}
break;
case 0xb2: /* lss */
- rc = emulate_load_segment(ctxt, VCPU_SREG_SS);
+ case 0xb4: /* lfs */
+ case 0xb5: /* lgs */
+ rc = emulate_load_segment(ctxt, ctxt->src2.val);
break;
case 0xb3:
btr: /* btr */
emulate_2op_SrcV_nobyte(ctxt, "btr");
break;
- case 0xb4: /* lfs */
- rc = emulate_load_segment(ctxt, VCPU_SREG_FS);
- break;
- case 0xb5: /* lgs */
- rc = emulate_load_segment(ctxt, VCPU_SREG_GS);
- break;
case 0xb6 ... 0xb7: /* movzx */
ctxt->dst.bytes = ctxt->op_bytes;
ctxt->dst.val = (ctxt->d & ByteOp) ? (u8) ctxt->src.val
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