Re: [Qemu-stable] [PATCH] net: fix qemu_announce_self not emitting packets

[Peter Lieven]

Am 07.06.2016 um 09:55 schrieb Paolo Bonzini:
> On 07/06/2016 09:37, Peter Lieven wrote:
> > commit fefe2a78 accidently dropped the code path for injecting
> > raw packets. This feature is needed for sending gratuitous ARPs
> > after an incoming migration has completed. The result is increased
> > network downtime for vservers where the network card is not virtio-net
> > with the VIRTIO_NET_F_GUEST_ANNOUNCE feature.
> >
> > Fixes: fefe2a78abde932e0f340b21bded2c86def1d242
> > Cc: address@hidden
> > Cc: address@hidden
> > Signed-off-by: Peter Lieven <address@hidden>
> > ---
> >   net/net.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/net.c b/net/net.c
> > index 5f3e5a9..d5834ea 100644
> > --- a/net/net.c
> > +++ b/net/net.c
> > @@ -722,7 +722,11 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,
> >           return 0;
> >       }
> >   
> > -    if (nc->info->receive_iov) {
> > +    if (flags & QEMU_NET_PACKET_FLAG_RAW && iovcnt == 1 &&
> > +        nc->info->receive_raw) {
> > +        /* this is required for qemu_announce_self() */
> > +        ret = nc->info->receive_raw(nc, iov[0].iov_base, iov[0].iov_len);
> Possibly move "iovcnt == 1" from the if condition to an assertion inside it?

I do not know if there is any other user that emits raw packets than 
qemu_announce_self.

The question is do you want to abort or just return -1 (which is the case 
without this patch).

Peter