Re: [PATCH v5 11/26] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI

[Auger Eric]

Hi Marc,

On 27/10/2017 16:28, Marc Zyngier wrote:
> If the guest issues an INT command targetting a VLPI, let's
> call into the irq_set_irqchip_state() helper to make it pending
> on the physical side.
> 
> This works just as well if userspace decides to inject an interrupt
> using the normal userspace API...
There is also another path:
KVM_SIGNAL_MSI ioctl / kvm_send_userspace_msi / kvm_set_msi /
vgic_its_inject_msi / vgic_its_trigger_msi

I wonder whether we shouldn't prevent the userspace from messing up with
the host irq pending state?

Thanks

Eric
> 
> Acked-by: Christoffer Dall <cdall@xxxxxxxxxx>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
>  virt/kvm/arm/vgic/vgic-its.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 89768d2b6a91..b2a678d131d0 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -578,6 +578,10 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
>  	if (err)
>  		return err;
>  
> +	if (irq->hw)
> +		return irq_set_irqchip_state(irq->host_irq,
> +					     IRQCHIP_STATE_PENDING, true);
> +
>  	spin_lock(&irq->irq_lock);
>  	irq->pending_latch = true;
>  	vgic_queue_irq_unlock(kvm, irq);
>