On Thu, Apr 25, 2013 at 02:21:29PM +0800, Jason Wang wrote:
> Commit 14f9b664 (hw/virtio-net.c: set config size using host features) tries
> to
> calculate config size based on the host features. But it forgets the
> VIRTIO_NET_F_MAC were always set for qemu later. This will lead a zero config
> len for virtio-net device when both VIRTIO_NET_F_STATUS and VIRTIO_NET_F_MQ
> were
> disabled form command line. Then qemu will crash when user tries to read the
> config of virtio-net.
>
> Fix this by counting VIRTIO_NET_F_MAC and make sure the config at least
> contains
> the mac address.
>
> Cc: Jesse Larrew <jlar...@linux.vnet.ibm.com>
> Signed-off-by: Jason Wang <jasow...@redhat.com>
> ---
> hw/net/virtio-net.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 70c8fce..33a70ef 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -1264,7 +1264,8 @@ static void virtio_net_guest_notifier_mask(VirtIODevice
> *vdev, int idx,
>
> void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
> {
> - int i, config_size = 0;
> + /* VIRTIO_NET_F_MAC can't be disabled from qemu side */
> + int i, config_size = feature_sizes[0].end;
This would be cleaner:
host_features |= (1 << VIRTIO_NET_F_MAC);
no need for a comment then.
> for (i = 0; feature_sizes[i].flags != 0; i++) {
> if (host_features & feature_sizes[i].flags) {
> config_size = MAX(feature_sizes[i].end, config_size);
> --
> 1.7.1
