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KVM: x86 emulator: Use opcode::execute for CMPXCHG
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CMPXCHG: 0F B0, 0F B1

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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Takuya Yoshikawa authored and Avi Kivity committed Dec 27, 2011
1 parent e1e210b commit e940b5c
Showing 1 changed file with 19 additions and 18 deletions.
37 changes: 19 additions & 18 deletions arch/x86/kvm/emulate.c
Original file line number Diff line number Diff line change
Expand Up @@ -1832,6 +1832,24 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
return rc;
}

static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
{
/* Save real source value, then compare EAX against destination. */
ctxt->src.orig_val = ctxt->src.val;
ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
emulate_2op_SrcV(ctxt, "cmp");

if (ctxt->eflags & EFLG_ZF) {
/* Success: write back to memory. */
ctxt->dst.val = ctxt->src.orig_val;
} else {
/* Failure: write the value we saw to EAX. */
ctxt->dst.type = OP_REG;
ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
}
return X86EMUL_CONTINUE;
}

static int em_lseg(struct x86_emulate_ctxt *ctxt)
{
int seg = ctxt->src2.val;
Expand Down Expand Up @@ -3400,7 +3418,7 @@ static struct opcode twobyte_table[256] = {
D(DstMem | SrcReg | Src2CL | ModRM),
D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
/* 0xB0 - 0xB7 */
D2bv(DstMem | SrcReg | ModRM | Lock | PageTable),
I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
Expand Down Expand Up @@ -4153,23 +4171,6 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
break;
case 0xae: /* clflush */
break;
case 0xb0 ... 0xb1: /* cmpxchg */
/*
* Save real source value, then compare EAX against
* destination.
*/
ctxt->src.orig_val = ctxt->src.val;
ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
emulate_2op_SrcV(ctxt, "cmp");
if (ctxt->eflags & EFLG_ZF) {
/* Success: write back to memory. */
ctxt->dst.val = ctxt->src.orig_val;
} else {
/* Failure: write the value we saw to EAX. */
ctxt->dst.type = OP_REG;
ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
}
break;
case 0xb6 ... 0xb7: /* movzx */
ctxt->dst.bytes = ctxt->op_bytes;
ctxt->dst.val = (ctxt->d & ByteOp) ? (u8) ctxt->src.val
Expand Down

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