x86 emulator: fix parity calculation for AAD instruction

Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2b11318151a4..a335cc6cde72 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2995,14 +2995,11 @@ static int em_aad(struct x86_emulate_ctxt *ctxt)
 
         ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al;
 
-        ctxt->eflags &= ~(X86_EFLAGS_PF | X86_EFLAGS_SF | X86_EFLAGS_ZF);
-
-        if (!al)
-                ctxt->eflags |= X86_EFLAGS_ZF;
-        if (!(al & 1))
-                ctxt->eflags |= X86_EFLAGS_PF;
-        if (al & 0x80)
-                ctxt->eflags |= X86_EFLAGS_SF;
+        /* Set PF, ZF, SF */
+        ctxt->src.type = OP_IMM;
+        ctxt->src.val = 0;
+        ctxt->src.bytes = 1;
+        fastop(ctxt, em_or);
 
         return X86EMUL_CONTINUE;
 }