diff options
| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2011-04-13 00:24:55 +0900 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-05-11 07:57:08 -0400 |
| commit | 575e7c1417d41dd72ddf2a49965f833ce9352e92 (patch) | |
| tree | 0f7d85332966e89520dd00fcee03e66b47fdb15e /arch/x86 | |
| parent | be6d05cfdf1f2ddbdc367a6433d8eac49d6bfe6f (diff) | |
KVM: x86 emulator: Disable writeback for CMP emulation
This stops "CMP r/m, reg" to write back the data into memory.
Pointed out by Avi.
The writeback suppression now covers CMP, CMPS, SCAS.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 2ec69bc8584..1e0e3f8156f 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3671,6 +3671,7 @@ special_insn: break; case 0x38 ... 0x3d: cmp: /* cmp */ + c->dst.type = OP_NONE; /* Disable writeback. */ emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); break; case 0x40 ... 0x47: /* inc r16/r32 */ @@ -3797,7 +3798,6 @@ special_insn: rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes); break; case 0xa6 ... 0xa7: /* cmps */ - c->dst.type = OP_NONE; /* Disable writeback. */ goto cmp; case 0xa8 ... 0xa9: /* test ax, imm */ goto test; |