From: Christoffer Dall <christoffer.dall@linaro.org>
To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org, Marc Zyngier <marc.zyngier@arm.com>,
Christoffer Dall <christoffer.dall@linaro.org>
Subject: [PATCH 3/3] KVM: arm/arm64: Fixup userspace irqchip static key optimization
Date: Tue, 30 Jan 2018 13:42:06 +0100 [thread overview]
Message-ID: <20180130124206.12262-4-christoffer.dall@linaro.org> (raw)
In-Reply-To: <20180130124206.12262-1-christoffer.dall@linaro.org>
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.
Fixes: c44c232ee2d3 ("KVM: arm/arm64: Avoid work when userspace iqchips are not used")
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
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
next prev parent reply other threads:[~2018-01-30 12:42 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-30 12:42 [PATCH 0/3] Additional fixes for kvmarm/next Christoffer Dall
2018-01-30 12:42 ` [PATCH 1/3] KVM: arm/arm64: Fix incorrect timer_is_pending logic Christoffer Dall
2018-01-31 8:26 ` Tomasz Nowicki
2018-01-31 8:59 ` Marc Zyngier
2018-01-30 12:42 ` [PATCH 2/3] KVM: arm/arm64: Fix userspace_irqchip_in_use counting Christoffer Dall
2018-01-31 9:00 ` Marc Zyngier
2018-01-30 12:42 ` Christoffer Dall [this message]
2018-01-31 9:00 ` [PATCH 3/3] KVM: arm/arm64: Fixup userspace irqchip static key optimization Marc Zyngier
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