On 12/09/2014 04:44 PM, Christoffer Dall 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, Actually we did with VFIO signaling setup before VGIC init! 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 <[email protected]> > --- > virt/kvm/arm/vgic.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > index c98cc6b..feef015 100644 > --- a/virt/kvm/arm/vgic.c > +++ b/virt/kvm/arm/vgic.c > @@ -1693,8 +1693,13 @@ 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)) > + if (unlikely(!vgic_initialized(kvm))) { > + mutex_lock(&kvm->lock); > + vgic_init(kvm); > + mutex_unlock(&kvm->lock); > + } I was previously encouraged to test the virtual interrupt controller readiness when setting irqfd up(proposal made in https://lkml.org/lkml/2014/12/3/601). I guess this becomes useless now, correct? Reviewed-by on the whole series.
Eric > + > + if (vgic_update_irq_pending(kvm, cpuid, irq_num, level)) > vgic_kick_vcpus(kvm); > > return 0; > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
