From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44693) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCNYE-00032B-OR for qemu-devel@nongnu.org; Tue, 07 Jul 2015 03:44:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZCNYB-0004SY-IY for qemu-devel@nongnu.org; Tue, 07 Jul 2015 03:44:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41024) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZCNYB-0004SI-Cu for qemu-devel@nongnu.org; Tue, 07 Jul 2015 03:44:19 -0400 Message-ID: <559B834B.3010807@redhat.com> Date: Tue, 07 Jul 2015 15:44:11 +0800 From: Jason Wang MIME-Version: 1.0 References: <1436232067-29144-1-git-send-email-famz@redhat.com> In-Reply-To: <1436232067-29144-1-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] net: Flush queued packets when guest resumes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , qemu-devel@nongnu.org Cc: jcmvbkbc@gmail.com, Stefan Hajnoczi , mst@redhat.com On 07/07/2015 09:21 AM, Fam Zheng wrote: > Since commit 6e99c63 "net/socket: Drop net_socket_can_send" and friends, > net queues need to be explicitly flushed after qemu_can_send_packet() > returns false, because the netdev side will disable the polling of fd. > > This fixes the case of "cont" after "stop" (or migration). > > Signed-off-by: Fam Zheng > > --- > > v2: Unify with VM stop handler. (Stefan) > --- > net/net.c | 19 ++++++++++++------- > 1 file changed, 12 insertions(+), 7 deletions(-) > > diff --git a/net/net.c b/net/net.c > index 6ff7fec..28a5597 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -1257,14 +1257,19 @@ void qmp_set_link(const char *name, bool up, Error **errp) > static void net_vm_change_state_handler(void *opaque, int running, > RunState state) > { > - /* Complete all queued packets, to guarantee we don't modify > - * state later when VM is not running. > - */ > - if (!running) { > - NetClientState *nc; > - NetClientState *tmp; > + NetClientState *nc; > + NetClientState *tmp; > > - QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) { > + QTAILQ_FOREACH_SAFE(nc, &net_clients, next, tmp) { > + if (running) { > + /* Flush queued packets and wake up backends. */ > + if (nc->peer && qemu_can_send_packet(nc)) { > + qemu_flush_queued_packets(nc->peer); > + } > + } else { > + /* Complete all queued packets, to guarantee we don't modify > + * state later when VM is not running. > + */ > qemu_flush_or_purge_queued_packets(nc, true); > } Looks like qemu_can_send_packet() checks both nc->peer and runstate. So probably, we can simplify this to: if (qemu_can_send_packet(nc)) qemu_flush_queued_packets(nc->peer); else qemu_flush_or_purge_queued_packets(nc, true); > }