Re: [Qemu-devel] [PATCH] net: virtio-net: initialise local 'netcfg' variable

[Jason Wang]

On 2016年12月05日 17:10, P J P wrote:
>    Hello Jason,
>
> +-- On Mon, 5 Dec 2016, Jason Wang wrote --+
> | > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> | > index 01f1351..cb5b3dc 100644
> | > --- a/hw/net/virtio-net.c
> | > +++ b/hw/net/virtio-net.c
> | > @@ -72,7 +72,7 @@ static int vq2q(int queue_index)
> | >   static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
> | >   {
> | >       VirtIONet *n = VIRTIO_NET(vdev);
> | > -    struct virtio_net_config netcfg;
> | > +    struct virtio_net_config netcfg = {};
> | >
> | >       virtio_stw_p(vdev, &netcfg.status, n->status);
> | >       virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
> |
> | Good catch but since mtu patch wasn't accepted so mtu were in fact not exposed
> | to guest.
>
> 'mtu' appears to have been added by commit 'dbdfea9226c9d0bdd', could you
> pleae confirm?

Yes.

> | (FYI, you can have a look at Maxime patch, he did a stw_p here()).
>
>    +    virtio_stw_p(vdev, &netcfg.mtu, n->mtu);
>    +
>
>    Yes, but this isn't accepted yet, is it?
>
>
> Thank you.
> --
> Prasad J Pandit / Red Hat Product Security Team
> 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F

See feature_sizes[] in virtio-net.c, we won't expose mtu to guest until 
MTU feature were negotiated.

Thanks