kvm/ppc: IRQ disabling cleanup

Simplify the handling of lazy EE by going directly from fully-enabled
to hard-disabled.  This replaces the lazy_irq_pending() check
(including its misplaced kvm_guest_exit() call).

As suggested by Tiejun Chen, move the interrupt disabling into
kvmppc_prepare_to_enter() rather than have each caller do it.  Also
move the IRQ enabling on heavyweight exit into
kvmppc_prepare_to_enter().

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 9 insertions, 17 deletions

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 026dfaaa4772..3cf541a53e2a 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -68,14 +68,16 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
  */
 int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 {
-	int r = 1;
+	int r;
+
+	WARN_ON(irqs_disabled());
+	hard_irq_disable();
 
-	WARN_ON_ONCE(!irqs_disabled());
 	while (true) {
 		if (need_resched()) {
 			local_irq_enable();
 			cond_resched();
-			local_irq_disable();
+			hard_irq_disable();
 			continue;
 		}
 
@@ -101,7 +103,7 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 			local_irq_enable();
 			trace_kvm_check_requests(vcpu);
 			r = kvmppc_core_check_requests(vcpu);
-			local_irq_disable();
+			hard_irq_disable();
 			if (r > 0)
 				continue;
 			break;
@@ -113,22 +115,12 @@ int kvmppc_prepare_to_enter(struct kvm_vcpu *vcpu)
 			continue;
 		}
 
-#ifdef CONFIG_PPC64
-		/* lazy EE magic */
-		hard_irq_disable();
-		if (lazy_irq_pending()) {
-			/* Got an interrupt in between, try again */
-			local_irq_enable();
-			local_irq_disable();
-			kvm_guest_exit();
-			continue;
-		}
-#endif
-
 		kvm_guest_enter();
-		break;
+		return 1;
 	}
 
+	/* return to host */
+	local_irq_enable();
 	return r;
 }
 EXPORT_SYMBOL_GPL(kvmppc_prepare_to_enter);