From 6c14280125a374d4c279a68276f97245e03e3f68 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 15 Jan 2008 18:27:32 +0200 Subject: [PATCH] KVM: Fix unbounded preemption latency When preparing to enter the guest, if an interrupt comes in while preemption is disabled but interrupts are still enabled, we miss a preemption point. Fix by explicitly checking whether we need to reschedule. Signed-off-by: Thomas Gleixner Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 77d57ff3d74e..f0493e7dcf0c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2535,6 +2535,13 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) local_irq_disable(); + if (need_resched()) { + local_irq_enable(); + preempt_enable(); + r = 1; + goto out; + } + if (signal_pending(current)) { local_irq_enable(); preempt_enable(); -- GitLab