From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53872) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bAXgF-0002Sa-On for qemu-devel@nongnu.org; Wed, 08 Jun 2016 03:13:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bAXg9-00041o-8t for qemu-devel@nongnu.org; Wed, 08 Jun 2016 03:13:34 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:47680 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bAXg8-00041Y-Vr for qemu-devel@nongnu.org; Wed, 08 Jun 2016 03:13:29 -0400 Message-ID: <5757C593.3060209@kamp.de> Date: Wed, 08 Jun 2016 09:13:23 +0200 From: Peter Lieven MIME-Version: 1.0 References: <1465304408-16545-1-git-send-email-pl@kamp.de> <5757BDA0.8090504@redhat.com> In-Reply-To: <5757BDA0.8090504@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [Qemu-stable] [PATCH V2] net: fix qemu_announce_self not emitting packets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jason Wang , qemu-devel@nongnu.org Cc: pbonzini@redhat.com, hongyang.yang@easystack.cn, qemu-stable@nongnu.org Am 08.06.2016 um 08:39 schrieb Jason Wang: > > > On 2016年06月07日 21:00, 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); >> + >> if (nc->link_down) { >> return iov_size(iov, iovcnt); >> } >> @@ -722,7 +727,10 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender, >> return 0; >> } >> - if (nc->info->receive_iov) { >> + if (flags & QEMU_NET_PACKET_FLAG_RAW && 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); >> + } else if (nc->info->receive_iov) { >> ret = nc->info->receive_iov(nc, iov, iovcnt); >> } else { >> ret = nc_sendv_compat(nc, iov, iovcnt, flags); > > We still have raw packet support in nv_sendv_compat, can we use it? (and then there's no need for the assert above). Okay, so Version 1 of the patch is more appropiate. I would either use V1 or revert fefe2a78. The issue is quite serious for live migration. Peter