KVM: PPC: Add return value in prepare_to_enter

Our prepare_to_enter helper wants to be able to return in more circumstances
to the host than only when an interrupt is pending. Broaden the interface a
bit and move even more generic code to the generic helper.
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/kvm/book3s_pr.c

@@ -589,6 +589,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                        unsigned int exit_nr)
 {
 	int r = RESUME_HOST;
+	int s;
 
 	vcpu->stat.sum_exits++;
 
@@ -862,10 +863,10 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		 * again due to a host external interrupt.
 		 */
 		local_irq_disable();
-		if (kvmppc_prepare_to_enter(vcpu)) {
+		s = kvmppc_prepare_to_enter(vcpu);
+		if (s <= 0) {
 			local_irq_enable();
-			run->exit_reason = KVM_EXIT_INTR;
-			r = -EINTR;
+			r = s;
 		} else {
 			kvmppc_lazy_ee_enable();
 		}
@@ -1074,10 +1075,9 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	 * a host external interrupt.
 	 */
 	local_irq_disable();
-	if (kvmppc_prepare_to_enter(vcpu)) {
+	ret = kvmppc_prepare_to_enter(vcpu);
+	if (ret <= 0) {
 		local_irq_enable();
-		kvm_run->exit_reason = KVM_EXIT_INTR;
-		ret = -EINTR;
 		goto out;
 	}
 

arch/powerpc/kvm/booke.c

@@ -467,7 +467,7 @@ void kvmppc_core_check_requests(struct kvm_vcpu *vcpu)
 
 int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 {
-	int ret;
+	int ret, s;
 #ifdef CONFIG_PPC_FPU
 	unsigned int fpscr;
 	int fpexc_mode;
@@ -480,10 +480,10 @@ int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	}
 
 	local_irq_disable();
-	if (kvmppc_prepare_to_enter(vcpu)) {
+	s = kvmppc_prepare_to_enter(vcpu);
+	if (s <= 0) {
 		local_irq_enable();
-		kvm_run->exit_reason = KVM_EXIT_INTR;
-		ret = -EINTR;
+		ret = s;
 		goto out;
 	}
 	kvmppc_lazy_ee_enable();
@@ -642,6 +642,7 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
                        unsigned int exit_nr)
 {
 	int r = RESUME_HOST;
+	int s;
 
 	/* update before a new last_exit_type is rewritten */
 	kvmppc_update_timing_stats(vcpu);
@@ -948,11 +949,10 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	 */
 	if (!(r & RESUME_HOST)) {
 		local_irq_disable();
-		if (kvmppc_prepare_to_enter(vcpu)) {
+		s = kvmppc_prepare_to_enter(vcpu);
+		if (s <= 0) {
 			local_irq_enable();
-			run->exit_reason = KVM_EXIT_INTR;
-			r = (-EINTR << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
-			kvmppc_account_exit(vcpu, SIGNAL_EXITS);
+			r = (s << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
 		} else {
 			kvmppc_lazy_ee_enable();
 		}

arch/powerpc/kvm/powerpc.c

@@ -53,11 +53,14 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
  * Common checks before entering the guest world.  Call with interrupts
  * disabled.
  *
- * returns !0 if a signal is pending and check_signal is true
+ * returns:
+ *
+ * == 1 if we're ready to go into guest state
+ * <= 0 if we need to go back to the host with return value
  */
 int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 {
-	int r = 0;
+	int r = 1;
 
 	WARN_ON_ONCE(!irqs_disabled());
 	while (true) {
@@ -69,7 +72,9 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 		}
 
 		if (signal_pending(current)) {
-			r = 1;
+			kvmppc_account_exit(vcpu, SIGNAL_EXITS);
+			vcpu->run->exit_reason = KVM_EXIT_INTR;
+			r = -EINTR;
 			break;
 		}