From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KhrJW-00070G-ST for qemu-devel@nongnu.org; Mon, 22 Sep 2008 15:43:18 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KhrJV-0006za-8N for qemu-devel@nongnu.org; Mon, 22 Sep 2008 15:43:18 -0400 Received: from [199.232.76.173] (port=52587 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KhrJV-0006zW-3s for qemu-devel@nongnu.org; Mon, 22 Sep 2008 15:43:17 -0400 Received: from mail-gx0-f19.google.com ([209.85.217.19]:54714) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KhrJU-0001rE-KK for qemu-devel@nongnu.org; Mon, 22 Sep 2008 15:43:16 -0400 Received: by gxk12 with SMTP id 12so3765780gxk.10 for ; Mon, 22 Sep 2008 12:43:15 -0700 (PDT) Message-ID: <48D7F519.1020808@codemonkey.ws> Date: Mon, 22 Sep 2008 14:42:17 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] jumbo frames: needing some help References: <20080919193742.vp0rkod868o0g84o@imap.uni-ulm.de> <48D3F66D.2080507@codemonkey.ws> <48D55D13.2050006@uni-ulm.de> In-Reply-To: <48D55D13.2050006@uni-ulm.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Martin Rauh wrote: > Anthony Liguori wrote: >> martin.rauh@uni-ulm.de wrote: >>> Hello, everyone! >>> >>> Sorry for the inconvenience, but as a part of my diploma thesis, I >>> am creating a virtual NIC for QEMU, in order to support a new >>> cluster OS of the university. (Saving the overhead caused by >>> emulating real hardware, it is not emulating an existing NIC.) >>> Anyway, now it seems to be working correctly, except for handling >>> jumbo frames, which I have to make available. >> >> You would have to post your patch. We seem to be able to handle >> jumbo frames nicely with virtio-net. >> >> BTW, are you aware of virtio-net? It has all of the properties that >> you are describing and it already exists for Linux and Windows. >> > No, I didn't know about virtio-net. Presumably it would be better to > support this virtio-net in our OS, but I think there's not enough time > left to develop a new driver now. I will recommend this for further > proceeding, thank you for this hint! > > http://home.vrweb.de/mrauh/testnic.c > Here is the source file of my virtual NIC, which I modelled on then > NE2000.c, but it is probably not very nice to read. I used > qemu_send_packet for sending and registered my testnic_receive > function via qemu_new_vlan_client. Do you agree in principle to this > approach, in terms of proceeding jumbo frames? Well if you don't have a patch to vl.c, that's probably your problem. There are a number of spots in the VLAN send functions that use buffers of 4096. You won't be able to receive a packet larger than that. Regards, Anthony Liguori > Thanks! > > Martin Rauh. > >