From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 4/4] lguest: Use GSO/IFF_VNET_HDR extensions on tun/tap Date: Wed, 25 Jun 2008 14:07:18 -0500 Message-ID: <48629766.4040905@codemonkey.ws> References: <200806260028.07883.rusty@rustcorp.com.au> <200806260029.40267.rusty@rustcorp.com.au> <200806260030.38293.rusty@rustcorp.com.au> <200806260032.12359.rusty__46755.7742762894$1214404667$gmane$org@rustcorp.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Max Krasnyansky , markmc@redhat.com, netdev@vger.kernel.org, Herbert Xu , virtualization@lists.linux-foundation.org To: Rusty Russell Return-path: Received: from yx-out-2324.google.com ([74.125.44.30]:8142 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752401AbYFYTHk (ORCPT ); Wed, 25 Jun 2008 15:07:40 -0400 Received: by yx-out-2324.google.com with SMTP id 31so701312yxl.1 for ; Wed, 25 Jun 2008 12:07:39 -0700 (PDT) In-Reply-To: <200806260032.12359.rusty__46755.7742762894$1214404667$gmane$org@rustcorp.com.au> Sender: netdev-owner@vger.kernel.org List-ID: Rusty Russell wrote: > @@ -1563,6 +1561,16 @@ static void setup_tun_net(char *arg) > /* Tell Guest what MAC address to use. */ > add_feature(dev, VIRTIO_NET_F_MAC); > add_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY); > + /* Expect Guest to handle everything except UFO */ > + add_feature(dev, VIRTIO_NET_F_CSUM); You're setting this feature twice. > + add_feature(dev, VIRTIO_NET_F_GUEST_CSUM); You set this feature, but I never see the virtio-net driver acknowledge the feature. Curiously, my implementation with KVM is struggling because UDP packet checksums are not correct so the DHCP client is ignoring them. If I disable CSUM offload, things it works fine (using the virtio-net header). The problem is only host=>guest, guest=>host is fine. Regards, Anthony Liguori