Commit a035d5c6 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Gleb Natapov
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KVM: emulator: emulate AAM



This is used by SGABIOS, KVM breaks with emulate_invalid_guest_state=1.

AAM needs the source operand to be unsigned; do the same in AAD as well
for consistency, even though it does not affect the result.
Reported-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: stable@vger.kernel.org # 3.9
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGleb Natapov <gleb@redhat.com>
parent 8d76c49e
...@@ -2996,6 +2996,28 @@ static int em_das(struct x86_emulate_ctxt *ctxt) ...@@ -2996,6 +2996,28 @@ static int em_das(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE; return X86EMUL_CONTINUE;
} }
static int em_aam(struct x86_emulate_ctxt *ctxt)
{
u8 al, ah;
if (ctxt->src.val == 0)
return emulate_de(ctxt);
al = ctxt->dst.val & 0xff;
ah = al / ctxt->src.val;
al %= ctxt->src.val;
ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8);
/* Set PF, ZF, SF */
ctxt->src.type = OP_IMM;
ctxt->src.val = 0;
ctxt->src.bytes = 1;
fastop(ctxt, em_or);
return X86EMUL_CONTINUE;
}
static int em_aad(struct x86_emulate_ctxt *ctxt) static int em_aad(struct x86_emulate_ctxt *ctxt)
{ {
u8 al = ctxt->dst.val & 0xff; u8 al = ctxt->dst.val & 0xff;
...@@ -3936,7 +3958,8 @@ static const struct opcode opcode_table[256] = { ...@@ -3936,7 +3958,8 @@ static const struct opcode opcode_table[256] = {
/* 0xD0 - 0xD7 */ /* 0xD0 - 0xD7 */
G(Src2One | ByteOp, group2), G(Src2One, group2), G(Src2One | ByteOp, group2), G(Src2One, group2),
G(Src2CL | ByteOp, group2), G(Src2CL, group2), G(Src2CL | ByteOp, group2), G(Src2CL, group2),
N, I(DstAcc | SrcImmByte | No64, em_aad), N, N, I(DstAcc | SrcImmUByte | No64, em_aam),
I(DstAcc | SrcImmUByte | No64, em_aad), N, N,
/* 0xD8 - 0xDF */ /* 0xD8 - 0xDF */
N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
/* 0xE0 - 0xE7 */ /* 0xE0 - 0xE7 */
......
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