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

[Paolo Bonzini <pbonzini@redhat.com>]

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: qemu-stable@nongnu.org
> Cc: yanghy@cn.fujitsu.com
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  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?

Thanks,

Paolo

> +    } else  if (nc->info->receive_iov) {
>          ret = nc->info->receive_iov(nc, iov, iovcnt);
>      } else {
>          ret = nc_sendv_compat(nc, iov, iovcnt, flags);
>