KVM: arm/arm64: vgic: Stop injecting the MSI occurrence twice
authorShanker Donthineni <shankerd@codeaurora.org>
Fri, 3 Feb 2017 02:30:03 +0000 (20:30 -0600)
committerMarc Zyngier <marc.zyngier@arm.com>
Wed, 8 Feb 2017 15:13:14 +0000 (15:13 +0000)
commit0bdbf3b071986ba80731203683cf623d5c0cacb1
tree7779937b27f194a5d9ad93fb713209e4dc28acfb
parent11710dec8a45084a3e0ad2f6da944c990fad23a4
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 <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
virt/kvm/arm/vgic/vgic-irqfd.c