From 0552f73b9a81d39d50b71a5c06cf36efff80b6fd Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Thu, 18 Oct 2007 15:19:01 +0200 Subject: [PATCH] KVM: Move kvm_guest_exit() after local_irq_enable() We need to make sure that the timer interrupt happens before we clear PF_VCPU, so the accounting code actually sees guest mode. http://lkml.org/lkml/2007/10/15/114 Signed-off-by: Laurent Vivier Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index af2d288c881d..8c458f262872 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -2054,12 +2054,21 @@ again: kvm_x86_ops->run(vcpu, kvm_run); - kvm_guest_exit(); vcpu->guest_mode = 0; local_irq_enable(); ++vcpu->stat.exits; + /* + * We must have an instruction between local_irq_enable() and + * kvm_guest_exit(), so the timer interrupt isn't delayed by + * the interrupt shadow. The stat.exits increment will do nicely. + * But we need to prevent reordering, hence this barrier(): + */ + barrier(); + + kvm_guest_exit(); + preempt_enable(); /* -- 2.20.1