On Tue, Mar 25, 2014 at 05:39:12PM +0800, Amos Kong wrote: > On Wed, Mar 19, 2014 at 11:38:57PM +0100, Stefan Fritsch wrote: > > Hi, > > > > Am Dienstag, 25. Februar 2014, 11:06:33 schrieb Amos Kong: > > > > > On Wed, Feb 12, 2014 at 10:46:28PM +0100, Stefan Fritsch wrote: > > > > > > If VIRTIO_NET_F_CTRL_VLAN is not negotiated, do not filter out > > > > > > all > > > > > > VLAN-tagged packets but send them to the guest. > > > > > > AFAICS, no fix has been committed, yet. Is there anything I need to do > > to get this fixed? > > Michael asked in IRC to continually add a RxState for vlan in > RxFilter notification through QMP events. > > (sorry I didn't talk too much becaused I'm in meeting) > > I mentioned in [1] [2], we don't need to add this new state > if we apply patch Stefan's patch[3] > > Michael said Stefan's fix is wrong, but the problem exists. > The problem is the bug fixed by [3], not the problem that was > mentioned in [4] > > > Michael, what's wrong with Stefan's patch? > > > Thanks, Amos > > [1] http://lists.gnu.org/archive/html/qemu-devel/2014-02/msg03835.html > [2] https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg04434.html > [3] virtio-net: Do not filter VLANs without F_CTRL_VLAN > [4] https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg02604.html >
Mainly what's wrong is the effect this has on the output of query-rx-filter. the patch is incomplete: management should be able to see that vlan filtering is disabled. Besides, looking at guest features at reset time is also not a good idea, it works by luck. A better place would be virtio_net_set_features. > > > > > Can we just update receive_filter() to filter out VLAN-tagged > > > > > packets only when VIRTIO_NET_F_CTRL_VLAN is negotiated? > > > > > > If we change receive_filter(), we also need a flag to indicate > > > management this feature isn't negotiated, management will do some > > > additional operation to host device to get same effect. > > > > > > > > > > We could. But this adds a (very small) per-packet overhead while > > > > my patch only adds overhead during reset. Therefore I didn't > > > > take that approach. But if changing receive_filter() makes > > > > management much easier, that could be acceptable. > > > > > > Actually your solution is better, QEMU will return a long list > > > [0,1,2,...4095] to management, host device will filter all the vlan > > > packets and send to QEMU. > > > > > > So the problem raised by mst doesn't exist. > > > > Cheers, > > Stefan > > > > -- > Amos.
