From 0bdbf3b071986ba80731203683cf623d5c0cacb1 Mon Sep 17 00:00:00 2001 From: Shanker Donthineni Date: Thu, 2 Feb 2017 20:30:03 -0600 Subject: KVM: arm/arm64: vgic: Stop injecting the MSI occurrence twice The IRQFD framework calls the architecture dependent function twice if the corresponding GSI type is edge triggered. For ARM, the function kvm_set_msi() is getting called twice whenever the IRQFD receives the event signal. The rest of the code path is trying to inject the MSI without any validation checks. No need to call the function vgic_its_inject_msi() second time to avoid an unnecessary overhead in IRQ queue logic. It also avoids the possibility of VM seeing the MSI twice. Simple fix, return -1 if the argument 'level' value is zero. Cc: stable@vger.kernel.org Reviewed-by: Eric Auger Reviewed-by: Christoffer Dall Signed-off-by: Shanker Donthineni Signed-off-by: Marc Zyngier --- virt/kvm/arm/vgic/vgic-irqfd.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'virt') diff --git a/virt/kvm/arm/vgic/vgic-irqfd.c b/virt/kvm/arm/vgic/vgic-irqfd.c index d918dcf26a5a..f138ed2e9c63 100644 --- a/virt/kvm/arm/vgic/vgic-irqfd.c +++ b/virt/kvm/arm/vgic/vgic-irqfd.c @@ -99,6 +99,9 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e, if (!vgic_has_its(kvm)) return -ENODEV; + if (!level) + return -1; + return vgic_its_inject_msi(kvm, &msi); } -- cgit