KVM: Clear exception queue before emulating an instruction

If we're emulating an instruction, either it will succeed, in which case
any previously queued exception will be spurious, or we will requeue the
same exception.

Signed-off-by: Avi Kivity <avi@qumranet.com>

arch/x86/kvm/x86.c

@@ -20,6 +20,7 @@
 #include "i8254.h"
 #include "tss.h"
 #include "kvm_cache_regs.h"
+#include "x86.h"
 
 #include <linux/clocksource.h>
 #include <linux/kvm.h>
@@ -2121,6 +2122,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
 	int r;
 	struct decode_cache *c;
 
+	kvm_clear_exception_queue(vcpu);
 	vcpu->arch.mmio_fault_cr2 = cr2;
 	/*
 	 * TODO: fix x86_emulate.c to use guest_read/write_register