[libvirt] [PATCH v2] qemu: handle multicast overflow on macvtap NIC_RX_FILTER_CHANGED

Michal Privoznik mprivozn at redhat.com
Mon Dec 3 12:52:45 UTC 2018

On 11/30/18 6:50 PM, Jason Baron wrote:
> Guest network devices can set 'overflow' when there are a number of multicast
> ips configured. For virtio_net, the limit is only 64. In this case, the list
> of mac addresses is empty and the 'overflow' condition is set. Thus, the guest
> will currently receive no multicast traffic in this state.
> When 'overflow' is set in the guest, let's turn this into ALLMULTI on the host.
> Signed-off-by: Jason Baron <jbaron at akamai.com>
> ---
> v1->v2:
>  1. check for < 0 in virNetDevSetRcvAllMulti() (Michal Privoznik)
>  2. restrict overflow check to VIR_NETDEV_RX_FILTER_MODE_NORMAL mode as to
>     avoid unnecessarily calling rx filter updates for other modes 
>  3. update virNetDevSetRcvAllMulti() call to use guestFilter->multicast.overflow
>     directly (Michal Privoznik)
>  src/qemu/qemu_driver.c | 22 +++++++++++++++-------
>  1 file changed, 15 insertions(+), 7 deletions(-)


We're currently in a freeze. While this is a bug fix I'm not sure it's
that critical. The freeze should be over any minute now, so do you mind
if I merge it after that?


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