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authorPaolo Bonzini <pbonzini@redhat.com>2013-05-09 11:32:49 +0200
committerGleb Natapov <gleb@redhat.com>2013-05-09 13:12:58 +0300
commita035d5c64d08a8ac12d81b596e7fa6d95a73c347 (patch)
treed294150c9d50c711d48e9d2e1827b4dde7c316ec /arch/x86/kvm/emulate.c
parent8d76c49e9ffeee839bc0b7a3278a23f99101263e (diff)
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: 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.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8e517bba6a7c..55322a7c113d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2996,6 +2996,28 @@ static int em_das(struct x86_emulate_ctxt *ctxt)
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)
{
u8 al = ctxt->dst.val & 0xff;
@@ -3936,7 +3958,8 @@ static const struct opcode opcode_table[256] = {
/* 0xD0 - 0xD7 */
G(Src2One | ByteOp, group2), G(Src2One, 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 */
N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
/* 0xE0 - 0xE7 */

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