On 04/25/2013 02:59 PM, Michael S. Tsirkin wrote: > 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.
Sure, will send V2. >> 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