diff options
| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2012-04-30 17:48:25 +0900 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-05-06 16:15:58 +0300 |
| commit | 9f4260e73ac43aaa91eb5de95950e1de7002f467 (patch) | |
| tree | 9984a53a3ec8ba905cf209d02686f415ada5a425 | |
| parent | 1c2545be05f436523cabc54087c6a60ea10110d3 (diff) | |
| download | linux-9f4260e73ac43aaa91eb5de95950e1de7002f467.tar.gz linux-9f4260e73ac43aaa91eb5de95950e1de7002f467.tar.xz linux-9f4260e73ac43aaa91eb5de95950e1de7002f467.zip | |
KVM: x86 emulator: Avoid pushing back ModRM byte fetched for group decoding
Although ModRM byte is fetched for group decoding, it is soon pushed
back to make decode_modrm() fetch it later again.
Now that ModRM flag can be found in the top level opcode tables, fetch
ModRM byte before group decoding to make the code simpler.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | arch/x86/kvm/emulate.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8d2c3d04cfec..7fd25763b0e0 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -972,7 +972,6 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */ } - ctxt->modrm = insn_fetch(u8, ctxt); ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6; ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; ctxt->modrm_rm |= (ctxt->modrm & 0x07); @@ -3976,17 +3975,16 @@ done_prefixes: } ctxt->d = opcode.flags; + if (ctxt->d & ModRM) + ctxt->modrm = insn_fetch(u8, ctxt); + while (ctxt->d & GroupMask) { switch (ctxt->d & GroupMask) { case Group: - ctxt->modrm = insn_fetch(u8, ctxt); - --ctxt->_eip; goffset = (ctxt->modrm >> 3) & 7; opcode = opcode.u.group[goffset]; break; case GroupDual: - ctxt->modrm = insn_fetch(u8, ctxt); - --ctxt->_eip; goffset = (ctxt->modrm >> 3) & 7; if ((ctxt->modrm >> 6) == 3) opcode = opcode.u.gdual->mod3[goffset]; |