From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46287) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bAJ5y-00013Z-5n for qemu-devel@nongnu.org; Tue, 07 Jun 2016 11:39:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bAJ5r-0002Ry-Rh for qemu-devel@nongnu.org; Tue, 07 Jun 2016 11:39:10 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:47907 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bAJ5r-0002R8-ID for qemu-devel@nongnu.org; Tue, 07 Jun 2016 11:39:03 -0400 References: <1465304408-16545-1-git-send-email-pl@kamp.de> From: Peter Lieven Message-ID: <5756EA90.8010103@kamp.de> Date: Tue, 7 Jun 2016 17:38:56 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V2] net: fix qemu_announce_self not emitting packets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yang Hongyang Cc: qemu devel , s.priebe@profihost.ag, Jason Wang , qemu-stable@nongnu.org, Paolo Bonzini Am 07.06.2016 um 17:28 schrieb Yang Hongyang: > > > On Tue, Jun 7, 2016 at 9:00 PM, 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: hongyang.yang@easystack.cn > Signed-off-by: Peter Lieven > > --- > v1->v2: assert that only raw packets with a plain buffer come in. [Paolo] > > net/net.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/net/net.c b/net/net.c > index 5f3e5a9..5e1b5fa 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -714,6 +714,11 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender, > NetClientState *nc = opaque; > int ret; > > + /* we currently only support sending raw packets via qemu_send_packet_raw. > + * If we want generic raw iov support we need to implement something like > + * .receive_raw_iov in NetClientInfo first. */ > + assert(!(flags & QEMU_NET_PACKET_FLAG_RAW) || iovcnt == 1); > + > > > This assert is hard to understand IMO...I think move assert(iovcnt==1) as well as the > comment to if condition below as Paolo said previously is better... This assert would only trigger if the NetClient implements .receive_raw. This way it could happen that someone injects RAW packets via an other way than qemu_send_packet_raw. But he might not see that its not allowed if he uses a backend that does not implement sending raw packets. If then someone uses a tap backend things break again. Peter