Re: [PATCH] KVM: arm64: ITS: return 1 on successful MSI injection

Christoffer Dall
2016-08-02T12:23:09Z

On Tue, Aug 02, 2016 at 12:10:58PM +0100, Andre Przywara wrote:
> According to the KVM API documentation a successful MSI injection
> should return a value > 0 on success.
> Since we pass the return value of vgic_its_inject_msi() directly on
> to upper layers and userland, we need to use the same semantics here.
> Briefly tested with QEMU and kvmtool on GICv3 hardware and the model.
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> Applies on top of next-20160728. Let me know if I should use a
> different base.
>
> Cheers,
> Andre.
>
> virt/kvm/arm/vgic/vgic-its.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 07411cf..3268250 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -468,6 +468,7 @@ static void vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
> * Queries the KVM IO bus framework to get the ITS pointer from the given
> * doorbell address.
> * We then call vgic_its_trigger_msi() with the decoded data.
> + * According to the KVM_SIGNAL_MSI API description returns > 0 on success.
> */
> int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
> {
> @@ -493,7 +494,7 @@ int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
> vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
> mutex_unlock(&iodev->its->its_lock);
>
> - return 0;
> + return 1;
> }
>
> /* Requires the its_lock to be held. */

Do we have a clear understanding of what 'guest blocked the MSI'
constitutes in the ARM world?

Thanks,
-Christoffer