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>
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 6a8c32e..07b89c7 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -643,7 +643,7 @@
 		local_irq_enable();
 		kvm_vcpu_block(vcpu);
 		clear_bit(KVM_REQ_UNHALT, &vcpu->requests);
-		local_irq_disable();
+		hard_irq_disable();
 
 		kvmppc_set_exit_type(vcpu, EMULATED_MTMSRWE_EXITS);
 		r = 1;
@@ -688,13 +688,12 @@
 		return -EINVAL;
 	}
 
-	local_irq_disable();
 	s = kvmppc_prepare_to_enter(vcpu);
 	if (s <= 0) {
-		local_irq_enable();
 		ret = s;
 		goto out;
 	}
+	/* interrupts now hard-disabled */
 
 #ifdef CONFIG_PPC_FPU
 	/* Save userspace FPU state in stack */
@@ -1187,12 +1186,11 @@
 	 * aren't already exiting to userspace for some other reason.
 	 */
 	if (!(r & RESUME_HOST)) {
-		local_irq_disable();
 		s = kvmppc_prepare_to_enter(vcpu);
-		if (s <= 0) {
-			local_irq_enable();
+		if (s <= 0)
 			r = (s << 2) | RESUME_HOST | (r & RESUME_FLAG_NV);
-		} else {
+		else {
+			/* interrupts now hard-disabled */
 			kvmppc_fix_ee_before_entry();
 		}
 	}