KVM: Fold kvm_run::exit_type into kvm_run::exit_reason

Currently, userspace is told about the nature of the last exit from the
guest using two fields, exit_type and exit_reason, where exit_type has
just two enumerations (and no need for more).  So fold exit_type into
exit_reason, reducing the complexity of determining what really happened.
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/kvm_main.c

@@ -1608,8 +1608,7 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
 	vcpu->mmio_needed = 0;
 
-	if (kvm_run->exit_type == KVM_EXIT_TYPE_VM_EXIT
-	    && kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {
+	if (kvm_run->exit_reason == KVM_EXIT_HYPERCALL) {
 		kvm_arch_ops->cache_regs(vcpu);
 		vcpu->regs[VCPU_REGS_RAX] = kvm_run->hypercall.ret;
 		kvm_arch_ops->decache_regs(vcpu);

drivers/kvm/svm.c

@@ -1298,8 +1298,6 @@ static int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
 	u32 exit_code = vcpu->svm->vmcb->control.exit_code;
 
-	kvm_run->exit_type = KVM_EXIT_TYPE_VM_EXIT;
-
 	if (is_external_interrupt(vcpu->svm->vmcb->control.exit_int_info) &&
 	    exit_code != SVM_EXIT_EXCP_BASE + PF_VECTOR)
 		printk(KERN_ERR "%s: unexpected exit_ini_info 0x%x "
@@ -1609,8 +1607,9 @@ again:
 	vcpu->svm->next_rip = 0;
 
 	if (vcpu->svm->vmcb->control.exit_code == SVM_EXIT_ERR) {
-		kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;
-		kvm_run->exit_reason = vcpu->svm->vmcb->control.exit_code;
+		kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+		kvm_run->fail_entry.hardware_entry_failure_reason
+			= vcpu->svm->vmcb->control.exit_code;
 		post_kvm_run_save(vcpu, kvm_run);
 		return 0;
 	}

drivers/kvm/vmx.c

@@ -1922,10 +1922,10 @@ again:
 
 	asm ("mov %0, %%ds; mov %0, %%es" : : "r"(__USER_DS));
 
-	kvm_run->exit_type = 0;
 	if (fail) {
-		kvm_run->exit_type = KVM_EXIT_TYPE_FAIL_ENTRY;
-		kvm_run->exit_reason = vmcs_read32(VM_INSTRUCTION_ERROR);
+		kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+		kvm_run->fail_entry.hardware_entry_failure_reason
+			= vmcs_read32(VM_INSTRUCTION_ERROR);
 		r = 0;
 	} else {
 		/*
@@ -1935,7 +1935,6 @@ again:
 			profile_hit(KVM_PROFILING, (void *)vmcs_readl(GUEST_RIP));
 
 		vcpu->launched = 1;
-		kvm_run->exit_type = KVM_EXIT_TYPE_VM_EXIT;
 		r = kvm_handle_exit(kvm_run, vcpu);
 		if (r > 0) {
 			/* Give scheduler a change to reschedule. */

include/linux/kvm.h

@@ -11,7 +11,7 @@
 #include <asm/types.h>
 #include <linux/ioctl.h>
 
-#define KVM_API_VERSION 7
+#define KVM_API_VERSION 8
 
 /*
  * Architectural interrupt line count, and the size of the bitmap needed
@@ -34,9 +34,6 @@ struct kvm_memory_region {
 #define KVM_MEM_LOG_DIRTY_PAGES  1UL
 
 
-#define KVM_EXIT_TYPE_FAIL_ENTRY 1
-#define KVM_EXIT_TYPE_VM_EXIT    2
-
 enum kvm_exit_reason {
 	KVM_EXIT_UNKNOWN          = 0,
 	KVM_EXIT_EXCEPTION        = 1,
@@ -47,6 +44,7 @@ enum kvm_exit_reason {
 	KVM_EXIT_MMIO             = 6,
 	KVM_EXIT_IRQ_WINDOW_OPEN  = 7,
 	KVM_EXIT_SHUTDOWN         = 8,
+	KVM_EXIT_FAIL_ENTRY       = 9,
 };
 
 /* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
@@ -57,12 +55,11 @@ struct kvm_run {
 	__u8 padding1[3];
 
 	/* out */
-	__u32 exit_type;
 	__u32 exit_reason;
 	__u32 instruction_length;
 	__u8 ready_for_interrupt_injection;
 	__u8 if_flag;
-	__u16 padding2;
+	__u8 padding2[6];
 
 	/* in (pre_kvm_run), out (post_kvm_run) */
 	__u64 cr8;
@@ -71,8 +68,12 @@ struct kvm_run {
 	union {
 		/* KVM_EXIT_UNKNOWN */
 		struct {
-			__u32 hardware_exit_reason;
+			__u64 hardware_exit_reason;
 		} hw;
+		/* KVM_EXIT_FAIL_ENTRY */
+		struct {
+			__u64 hardware_entry_failure_reason;
+		} fail_entry;
 		/* KVM_EXIT_EXCEPTION */
 		struct {
 			__u32 exception;