On Sat, Dec 13 2014 at 11:17:28 AM, Christoffer Dall <christoffer.dall@xxxxxxxxxx> wrote:
> 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.
>
> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
> ---
> virt/kvm/arm/vgic.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index e1bef68..330445c 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -1693,11 +1693,22 @@ out:
> int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
> bool level)
> {
> - if (likely(vgic_ready(kvm)) &&
> - vgic_update_irq_pending(kvm, cpuid, irq_num, level))
> + int ret = 0;
> +
> + if (unlikely(!vgic_initialized(kvm))) {
> + mutex_lock(&kvm->lock);
> + ret = vgic_init(kvm);
> + mutex_unlock(&kvm->lock);
> +
> + if (ret)
> + goto out;
> + }
> +
> + if (vgic_update_irq_pending(kvm, cpuid, irq_num, level))
> vgic_kick_vcpus(kvm);
>
> - return 0;
> +out:
> + return ret;
> }
>
> static irqreturn_t vgic_maintenance_handler(int irq, void *data)
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
M.
--
Jazz is not dead. It just smells funny.
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