From patchwork Fri Aug 24 13:39:53 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 179840 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id CFACA2C00E7 for ; Fri, 24 Aug 2012 23:50:33 +1000 (EST) Received: from localhost ([::1]:55552 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4uHP-0000Yv-W6 for incoming@patchwork.ozlabs.org; Fri, 24 Aug 2012 09:50:31 -0400 Received: from eggs.gnu.org ([208.118.235.92]:54450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4uHG-0000Xq-KY for qemu-devel@nongnu.org; Fri, 24 Aug 2012 09:50:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T4uHB-0006Ac-Vd for qemu-devel@nongnu.org; Fri, 24 Aug 2012 09:50:22 -0400 Received: from e06smtp12.uk.ibm.com ([195.75.94.108]:48543) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4uHB-00065M-Mv for qemu-devel@nongnu.org; Fri, 24 Aug 2012 09:50:17 -0400 Received: from /spool/local by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 24 Aug 2012 14:40:03 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp12.uk.ibm.com (192.168.101.142) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Fri, 24 Aug 2012 14:40:00 +0100 Received: from d06av01.portsmouth.uk.ibm.com (d06av01.portsmouth.uk.ibm.com [9.149.37.212]) by b06cxnps4076.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q7ODds5F24772814 for ; Fri, 24 Aug 2012 13:39:54 GMT Received: from d06av01.portsmouth.uk.ibm.com (loopback [127.0.0.1]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q7ODe0eW013063 for ; Fri, 24 Aug 2012 07:40:00 -0600 Received: from localhost (stefanha-thinkpad.manchester-maybrook.uk.ibm.com [9.174.219.145]) by d06av01.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q7ODdxmK013056; Fri, 24 Aug 2012 07:39:59 -0600 From: Stefan Hajnoczi To: Date: Fri, 24 Aug 2012 14:39:53 +0100 Message-Id: <1345815593-5555-4-git-send-email-stefanha@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1345815593-5555-1-git-send-email-stefanha@linux.vnet.ibm.com> References: <1345815593-5555-1-git-send-email-stefanha@linux.vnet.ibm.com> x-cbid: 12082413-8372-0000-0000-0000038EF7F0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 195.75.94.108 Cc: Paolo Bonzini , Vincent Palatin , Stefan Hajnoczi , "Roy.Li" Subject: [Qemu-devel] [PATCH 3/3] net: broadcast hub packets if at least one port can receive X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org In commit 60c07d933c66c4b30a83b7ccbc8a0cb3df1b2d0e ("net: fix qemu_can_send_packet logic") the "VLAN" broadcast behavior was changed to queue packets if any net client cannot receive. It turns out that this was not actually the right fix and just hides the real bug that hw/usb/dev-network.c:usbnet_receive() clobbers its receive buffer when called multiple times in a row. The commit also introduced a new bug that "VLAN" packets would not be sent if one of multiple net clients was down. The hw/usb/dev-network.c bug has since been fixed, so this patch reverts broadcast behavior to send packets as long as one net client can receive. Packets simply get queued for the net clients that are temporarily unable to receive. Reported-by: Roy.Li Signed-off-by: Stefan Hajnoczi --- net/hub.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/hub.c b/net/hub.c index ac157e3..650a8b4 100644 --- a/net/hub.c +++ b/net/hub.c @@ -97,12 +97,12 @@ static int net_hub_port_can_receive(NetClientState *nc) continue; } - if (!qemu_can_send_packet(&port->nc)) { - return 0; + if (qemu_can_send_packet(&port->nc)) { + return 1; } } - return 1; + return 0; } static ssize_t net_hub_port_receive(NetClientState *nc,