Re: [Qemu-devel] QEMU -netdev vhost=on + -device virtio-net-pci bug

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 05/03/13 23:56, Michael S. Tsirkin wrote:
>> The patch f56a12475ff1b8aa61210d08522c3c8aaf0e2648 "vhost: backend
>> masking support" breaks virtio-net + vhost=on on PPC64 platform.
>>
>> The problem command line is:
>> 1) -netdev tap,id=tapnet,ifname=tap0,script=qemu-ifup.sh,vhost=on \
>> -device virtio-net-pci,netdev=tapnet,addr=0.0 \
>
> I think the issue is irqfd in not supported on kvm ppc.

How can I make sure this is the case? Some work has been done there
recently but midnight is quite late to figure this out :)


> Could you please check this:
>
> +        /* If guest supports masking, set up irqfd now.
> +         * Otherwise, delay until unmasked in the frontend.
> +         */
> +        if (proxy->vdev->guest_notifier_mask) {
> +            ret = kvm_virtio_pci_irqfd_use(proxy, queue_no, vector);
> +            if (ret < 0) {
> +                kvm_virtio_pci_vq_vector_release(proxy, vector);
> +                goto undo;
> +            }
> +        }
>
>
> Could you please add a printf before "undo" and check whether the
> error path above is triggered?


Checked, it is not triggered.


-- 
Alexey