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authorPaolo Bonzini <pbonzini@redhat.com>2013-05-09 11:32:51 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-19 11:38:09 -0700
commitc2b4972016dcc9d883ce5333d97d9454d9ae24e1 (patch)
tree892482b3d9713936d225822c2619c9c7757da22c /arch/x86/kvm
parente3ed61f1dcb250148b14c37d62918d6fe9e01070 (diff)
KVM: emulator: emulate SALC
commit 326f578f7e1443bac2333712dd130a261ec15288 upstream. This is an almost-undocumented instruction available in 32-bit mode. I say "almost" undocumented because AMD documents it in their opcode maps just to say that it is unavailable in 64-bit mode (sections "A.2.1 One-Byte Opcodes" and "B.3 Invalid and Reassigned Instructions in 64-Bit Mode"). It is roughly equivalent to "sbb %al, %al" except it does not set the flags. Use fastop to emulate it, but do not use the opcode directly because it would fail if the host is 64-bit! Reported-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/emulate.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 56c10f128d9..59622c9cc63 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -534,6 +534,9 @@ FOP_SETCC(setle)
FOP_SETCC(setnle)
FOP_END;
+FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET
+FOP_END;
+
#define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \
do { \
unsigned long _tmp; \
@@ -3951,7 +3954,8 @@ static const struct opcode opcode_table[256] = {
G(Src2One | ByteOp, group2), G(Src2One, group2),
G(Src2CL | ByteOp, group2), G(Src2CL, group2),
I(DstAcc | SrcImmUByte | No64, em_aam),
- I(DstAcc | SrcImmUByte | No64, em_aad), N,
+ I(DstAcc | SrcImmUByte | No64, em_aad),
+ F(DstAcc | ByteOp | No64, em_salc),
I(DstAcc | SrcXLat | ByteOp, em_mov),
/* 0xD8 - 0xDF */
N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,