From: Carsten Otte <cotte@de.ibm.com>
Date: Wed, 21 May 2008 11:37:37 +0000 (+0200)
Subject: KVM: s390: fix interrupt delivery
X-Git-Tag: v2.6.26-rc6~11^2~13
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=0ff318674503ce3787ef62d84f4d948db204b268;p=linux-2.6-omap-h63xx.git

KVM: s390: fix interrupt delivery

The current code delivers pending interrupts before it checks for
need_resched. On a busy host, this can lead to a longer interrupt
latency if the interrupt is injected while the process is scheduled
away. This patch moves delivering the interrupt _after_ schedule(),
which makes more sense.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 40e4f2de732..ded27c7777c 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -435,6 +435,8 @@ static void __vcpu_run(struct kvm_vcpu *vcpu)
 	if (test_thread_flag(TIF_MCCK_PENDING))
 		s390_handle_mcck();
 
+	kvm_s390_deliver_pending_interrupts(vcpu);
+
 	vcpu->arch.sie_block->icptcode = 0;
 	local_irq_disable();
 	kvm_guest_enter();
@@ -480,7 +482,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	might_sleep();
 
 	do {
-		kvm_s390_deliver_pending_interrupts(vcpu);
 		__vcpu_run(vcpu);
 		rc = kvm_handle_sie_intercept(vcpu);
 	} while (!signal_pending(current) && !rc);