From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N3urd-0001io-41 for qemu-devel@nongnu.org; Fri, 30 Oct 2009 13:02:13 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N3urX-0001dJ-2u for qemu-devel@nongnu.org; Fri, 30 Oct 2009 13:02:11 -0400 Received: from [199.232.76.173] (port=36496 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N3urW-0001d3-Ul for qemu-devel@nongnu.org; Fri, 30 Oct 2009 13:02:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60536) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N3urU-0002ZM-Fc for qemu-devel@nongnu.org; Fri, 30 Oct 2009 13:02:05 -0400 Subject: Re: [Qemu-devel] [PATCH 00/19 v2] Add virtio-net/tap support for partial csums and GSO From: Mark McLoughlin In-Reply-To: <8715C76D-1E93-43E6-9D52-22D61FB856B2@nokia.com> References: <1256229830-28066-1-git-send-email-markmc@redhat.com> <8715C76D-1E93-43E6-9D52-22D61FB856B2@nokia.com> Content-Type: text/plain Date: Fri, 30 Oct 2009 16:59:53 +0000 Message-Id: <1256921993.6899.150.camel@blaa> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Reply-To: Mark McLoughlin List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Juha.Riihimaki@nokia.com Cc: qemu-devel@nongnu.org Hi, On Fri, 2009-10-30 at 11:04 +0100, Juha.Riihimaki@nokia.com wrote: > On Oct 22, 2009, at 19:43, ext Mark McLoughlin wrote: > > > Hey, > > Over a year ago we added some code to qemu-kvm.git which takes > > advantage of the recent tun/tap IFF_VNET_HDR feature in order to allow > > virtio-net to send and receive packets with partial checksums and > > segmentation offloaded: > > > > http://article.gmane.org/gmane.comp.emulators.kvm.devel/20440 > > > > "This allows us to pass larger packets and packets with > > partial checkums between the guest and the host, greatly > > increasing the achievable bandwidth." > > > > Unfortunately, that implementation was quite hacky as it > > made some assumptions that would break if e.g. you added another > > network client to a vlan where the feature had enabled. > > > > Now that we have the -netdev parameter, we can more safely > > pair the NIC and backend, allowing us to negatiate features like > > this. > > > > What follows is a somewhat cleaned up version of the code > > from qemu-kvm.git. Further cleanups are probably possible, but I > > think this much is mergeable. Some points of discussion: > > I think this patch set has broken the QEMU build on OS X. The reason > is that there are some definitions in tap-linux.h which only gets > included in net.c if __linux__ is defined but the other parts of net.c > which utilize definitions from tap-linux.h get compiled in > nevertheless. It compiles if all definitions (except for the extra > includes) from tap-linux.h are included for OS X as well. I've > attached below a sample of the compiler output. It doesn't look like this is still a problem anymore with latest git? Could you try again? There are probably other problems now :-) Thanks, Mark.