From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark McLoughlin Subject: Re: [PATCH] kvm: qemu: Handle tap fds with IFF_VNET_HDR Date: Thu, 21 Aug 2008 10:30:31 +0100 Message-ID: <1219311031.4008.13.camel@muff> References: <1218485535-877-1-git-send-email-markmc@redhat.com> <48A1957C.4070007@qumranet.com> <1218638393.29159.38.camel@muff> <48A30ABE.3040903@qumranet.com> <1219251898.5068.33.camel@muff> <48AC5923.3040901@codemonkey.ws> <48AC59BD.9080407@qumranet.com> Reply-To: Mark McLoughlin Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from mx1.redhat.com ([66.187.233.31]:45306 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751263AbYHUJbA (ORCPT ); Thu, 21 Aug 2008 05:31:00 -0400 In-Reply-To: <48AC59BD.9080407@qumranet.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, 2008-08-20 at 20:51 +0300, Avi Kivity wrote: > Anthony Liguori wrote: > > Mark McLoughlin wrote: > >> Allow users to pass an IFF_VNET_HDR tap fd via "-net tap,fd=X" > >> by querying the fd with the recently added TUNGETIFF ioctl() to > >> see if IFF_VNET_HDR has been enabled. > >> > >> Note: users wishing to pass an IFF_VNET_HDR tap fd to qemu > >> should check both that a) this version of qemu can handle > >> such an fd and b) that the TUNGETIFF ioctl() is available in > >> the running kernel. > >> > >> We add a comment to the "qemu -help" output to indicate to > >> users that this version of qemu supports IFF_VNET_HDR. > >> > > > > The -help output is not a supported interface. An info command in the > > monitor would be a better way to detect this. > > > > You need to know this before you create a virtual machine. I suggested > a 'qemu -capabilities' thing to describe what this qemu can do. I'll take a stab at "-capabilities" later. In the mean time, it may make sense to commit the patch minus the -help string. Cheers, Mark.