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authorChristoffer Dall <christoffer.dall@linaro.org>2014-12-09 14:35:33 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2014-12-15 11:36:21 +0100
commitca7d9c829d419c06e450afa5f785d58198c37caa (patch)
tree04f7fd0e5f7e6469c93056534cf5142cfa80ef3b
parent716139df2517fbc3f2306dbe8eba0fa88dca0189 (diff)
downloadlinux-ca7d9c829d419c06e450afa5f785d58198c37caa.tar.gz
arm/arm64: KVM: Initialize the vgic on-demand when injecting IRQs
Userspace assumes that it can wire up IRQ injections after having created all VCPUs and after having created the VGIC, but potentially before starting the first VCPU. This can currently lead to lost IRQs because the state of that IRQ injection is not stored anywhere and we don't return an error to userspace. We haven't seen this problem manifest itself yet, presumably because guests reset the devices on boot, but this could cause issues with migration and other non-standard startup configurations. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
-rw-r--r--virt/kvm/arm/vgic.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index d862ea50216..e373b76c542 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1694,16 +1694,26 @@ out:
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
bool level)
{
+ int ret = 0;
int vcpu_id;
- if (likely(vgic_ready(kvm))) {
- vcpu_id = vgic_update_irq_pending(kvm, cpuid, irq_num, level);
- if (vcpu_id >= 0)
- /* kick the specified vcpu */
- kvm_vcpu_kick(kvm_get_vcpu(kvm, vcpu_id));
+ if (unlikely(!vgic_initialized(kvm))) {
+ mutex_lock(&kvm->lock);
+ ret = vgic_init(kvm);
+ mutex_unlock(&kvm->lock);
+
+ if (ret)
+ goto out;
}
- return 0;
+ vcpu_id = vgic_update_irq_pending(kvm, cpuid, irq_num, level);
+ if (vcpu_id >= 0) {
+ /* kick the specified vcpu */
+ kvm_vcpu_kick(kvm_get_vcpu(kvm, vcpu_id));
+ }
+
+out:
+ return ret;
}
static irqreturn_t vgic_maintenance_handler(int irq, void *data)