KVM: Add a special exit reason when exiting due to an interrupt

This is redundant, as we also return -EINTR from the ioctl, but it
allows us to examine the exit_reason field on resume without seeing
old data.
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/svm.c

@@ -1619,12 +1619,14 @@ again:
 		if (signal_pending(current)) {
 			++kvm_stat.signal_exits;
 			post_kvm_run_save(vcpu, kvm_run);
+			kvm_run->exit_reason = KVM_EXIT_INTR;
 			return -EINTR;
 		}
 
 		if (dm_request_for_irq_injection(vcpu, kvm_run)) {
 			++kvm_stat.request_irq_exits;
 			post_kvm_run_save(vcpu, kvm_run);
+			kvm_run->exit_reason = KVM_EXIT_INTR;
 			return -EINTR;
 		}
 		kvm_resched(vcpu);

drivers/kvm/vmx.c

@@ -1941,12 +1941,14 @@ again:
 			if (signal_pending(current)) {
 				++kvm_stat.signal_exits;
 				post_kvm_run_save(vcpu, kvm_run);
+				kvm_run->exit_reason = KVM_EXIT_INTR;
 				return -EINTR;
 			}
 
 			if (dm_request_for_irq_injection(vcpu, kvm_run)) {
 				++kvm_stat.request_irq_exits;
 				post_kvm_run_save(vcpu, kvm_run);
+				kvm_run->exit_reason = KVM_EXIT_INTR;
 				return -EINTR;
 			}
 

include/linux/kvm.h

@@ -11,7 +11,7 @@
 #include <asm/types.h>
 #include <linux/ioctl.h>
 
-#define KVM_API_VERSION 8
+#define KVM_API_VERSION 9
 
 /*
  * Architectural interrupt line count, and the size of the bitmap needed
@@ -45,6 +45,7 @@ enum kvm_exit_reason {
 	KVM_EXIT_IRQ_WINDOW_OPEN  = 7,
 	KVM_EXIT_SHUTDOWN         = 8,
 	KVM_EXIT_FAIL_ENTRY       = 9,
+	KVM_EXIT_INTR             = 10,
 };
 
 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */