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authorPaolo Bonzini <pbonzini@redhat.com>2013-05-09 11:32:51 +0200
committerGleb Natapov <gleb@redhat.com>2013-05-09 13:15:08 +0300
commit326f578f7e1443bac2333712dd130a261ec15288 (patch)
tree7d1e6123f831b6789f68d4e9ea0f7f10a904230b /arch/x86/kvm/emulate.c
parent7fa57952d70f5737513d8319395e471d107e4e0d (diff)
KVM: emulator: emulate SALC
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> Cc: stable@vger.kernel.org # 3.9 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
-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 a06a550c2db8..8db0010ed150 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -535,6 +535,9 @@ 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; \
@@ -3961,7 +3964,8 @@ 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,

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