On 09/07/2015 04:44 PM, Eric Auger wrote:
> Hi,
> On 09/04/2015 04:24 PM, Christoffer Dall wrote:
>> We currently set the physical active state only when we *inject* a new
>> pending virtual interrupt, but this is actually not correct, because we
>> could have been preempted and run something else on the system that
>> resets the active state to clear. This causes us to run the VM with the
>> timer set to fire, but without setting the physical active state.
>>
>> The solution is to always check the LR configurations, and we if have a
>> mapped interrupt in the LR in either the pending or active state
>> (virtual), then set the physical active state.
>>
>> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
>> ---
>> virt/kvm/arm/vgic.c | 42 ++++++++++++++++++++++++++----------------
>> 1 file changed, 26 insertions(+), 16 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
>> index 9eb489a..6bd1c9b 100644
>> --- a/virt/kvm/arm/vgic.c
>> +++ b/virt/kvm/arm/vgic.c
>> @@ -1144,26 +1144,11 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu *vcpu, int irq,
>> struct irq_phys_map *map;
>> map = vgic_irq_map_search(vcpu, irq);
>>
>> - /*
>> - * If we have a mapping, and the virtual interrupt is
>> - * being injected, then we must set the state to
>> - * active in the physical world. Otherwise the
>> - * physical interrupt will fire and the guest will
>> - * exit before processing the virtual interrupt.
>> - */
>> if (map) {
>> - int ret;
>> -
>> - BUG_ON(!map->active);
> I have a question about this map->active. I did not find any user of
> kvm_vgic_set_phys_irq_active anymore. The flag is directly updated in
> vgic_sync_hwirq through the irq_get_irqchip_state query. In the same
> function, before there is a "BUG_ON(!map || !map->active);"
>
> Can't we have this BUG_ON firing?
hum ignore that comment. Didn't see the call to
kvm_vgic_set_phys_irq_active in arch_timer.c
Eric
>
>
>> vlr.hwirq = map->phys_irq;
>> vlr.state |= LR_HW;
>> vlr.state &= ~LR_EOI_INT;
>>
>> - ret = irq_set_irqchip_state(map->irq,
>> - IRQCHIP_STATE_ACTIVE,
>> - true);
>> - WARN_ON(ret);
>> -
>> /*
>> * Make sure we're not going to sample this
>> * again, as a HW-backed interrupt cannot be
>> @@ -1255,7 +1240,7 @@ static void __kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu)
>> struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>> struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
>> unsigned long *pa_percpu, *pa_shared;
>> - int i, vcpu_id;
>> + int i, vcpu_id, lr, ret;
>> int overflow = 0;
>> int nr_shared = vgic_nr_shared_irqs(dist);
>>
>> @@ -1310,6 +1295,31 @@ epilog:
>> */
>> clear_bit(vcpu_id, dist->irq_pending_on_cpu);
>> }
>> +
>> + for (lr = 0; lr < vgic->nr_lr; lr++) {
>> + struct vgic_lr vlr;
>> +
>> + if (!test_bit(lr, vgic_cpu->lr_used))
>> + continue;
>> +
>> + vlr = vgic_get_lr(vcpu, lr);
>> +
>> + /*
>> + * If we have a mapping, and the virtual interrupt is
>> + * presented to the guest (as pending or active), then we must
>> + * set the state to active in the physical world. See
>> + * Documentation/virtual/kvm/arm/vgic-mapped-irqs.txt.
> if upstreamed in 4.3 whereas the other series is not there,
> vgic-mapped-irqs.txt won't be available.
>> + */
>> + if (vlr.state & LR_HW) {
>> + struct irq_phys_map *map;
>> + map = vgic_irq_map_search(vcpu, vlr.irq);
>> +
>> + ret = irq_set_irqchip_state(map->irq,
>> + IRQCHIP_STATE_ACTIVE,
>> + true);
> I understand the need for manually setting the phys dist state in case
> of timer however for non shared IRQs, GIC does the job directly. But I
> guess it does not harm.
>
> Eric
>> + WARN_ON(ret);
>> + }
>> + }
>> }
>>
>> static bool vgic_process_maintenance(struct kvm_vcpu *vcpu)
>>
>
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