From 5c0aea0e8d98e38858fbb3a09870ed8487a01da2 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 28 Apr 2017 17:06:20 +0200 Subject: KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We needed the lock to avoid racing with creation of the irqchip on x86. As kvm_set_irq_routing() calls srcu_synchronize_expedited(), this lock might be held for a longer time. Let's introduce an arch specific callback to check if we can actually add irq routes. For x86, all we have to do is check if we have an irqchip in the kernel. We don't need kvm->lock at that point as the irqchip is marked as inititalized only when actually fully created. Reported-by: Steve Rutherford Reviewed-by: Radim Krčmář Fixes: 1df6ddede10a ("KVM: x86: race between KVM_SET_GSI_ROUTING and KVM_CREATE_IRQCHIP") Signed-off-by: David Hildenbrand Signed-off-by: Paolo Bonzini --- arch/x86/kvm/irq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/irq.h') diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h index 0edd22c3344c..d5005cc26521 100644 --- a/arch/x86/kvm/irq.h +++ b/arch/x86/kvm/irq.h @@ -111,7 +111,7 @@ static inline int irqchip_in_kernel(struct kvm *kvm) /* Matches smp_wmb() when setting irqchip_mode */ smp_rmb(); - return mode > KVM_IRQCHIP_INIT_IN_PROGRESS; + return mode != KVM_IRQCHIP_NONE; } void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu); -- cgit v1.2.3