Thread (32 messages) 32 messages, 3 authors, 2018-01-31

[PULL 28/28] KVM: arm/arm64: Fixup userspace irqchip static key optimization

From: Christoffer Dall <hidden>
Date: 2018-01-31 09:35:07
Also in: kvm, kvmarm
Subsystem: kernel virtual machine (kvm), the rest · Maintainers: Paolo Bonzini, Linus Torvalds

When I introduced a static key to avoid work in the critical path for
userspace irqchips which is very rarely used, I accidentally messed up
my logic and used && where I should have used ||, because the point was
to short-circuit the evaluation in case userspace irqchips weren't even
in use.

This fixes an issue when running in-kernel irqchip VMs alongside
userspace irqchip VMs.

Acked-by: Marc Zyngier <redacted>
Fixes: c44c232ee2d3 ("KVM: arm/arm64: Avoid work when userspace iqchips are not used")
Signed-off-by: Christoffer Dall <redacted>
---
 virt/kvm/arm/arch_timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 63cf828f3c4f..fb6bd9b9845e 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -286,7 +286,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level,
 	trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq,
 				   timer_ctx->irq.level);
 
-	if (!static_branch_unlikely(&userspace_irqchip_in_use) &&
+	if (!static_branch_unlikely(&userspace_irqchip_in_use) ||
 	    likely(irqchip_in_kernel(vcpu->kvm))) {
 		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
 					  timer_ctx->irq.irq,
-- 
2.14.2
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