From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LXhgp-0005lS-Rm for qemu-devel@nongnu.org; Thu, 12 Feb 2009 14:57:39 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LXhgn-0005lA-5i for qemu-devel@nongnu.org; Thu, 12 Feb 2009 14:57:38 -0500 Received: from [199.232.76.173] (port=47885 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LXhgn-0005l7-1M for qemu-devel@nongnu.org; Thu, 12 Feb 2009 14:57:37 -0500 Received: from mail2.shareable.org ([80.68.89.115]:39269) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LXhgm-00021j-1g for qemu-devel@nongnu.org; Thu, 12 Feb 2009 14:57:36 -0500 Date: Thu, 12 Feb 2009 19:57:30 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: [PATCH 0/4] qemu: TAP filtering support Message-ID: <20090212195730.GA805@shareable.org> References: <20090210212841.9760.96780.stgit@kvm.aw> <1234380678.14052.238.camel@blaa> <1234381866.7026.1524.camel@lappy> <1234383541.14052.247.camel@blaa> <1234384639.7026.1533.camel@lappy> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234384639.7026.1533.camel@lappy> 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 Cc: Mark McLoughlin , kvm@vger.kernel.org Alex Williamson wrote: > TUNSETTXFITLER has only existed since 2.6.26, so the ioctl will fail on > anything older and it will be disabled anyway. The patch will fix .29 > and should get rolled into .28 stable, so we're looking at an exposure > of 2 kernel releases. Unfortunately a few community distros went out on > those kernels, so perhaps the prudent approach would be to make the > default disabled until we're a few releases beyond. I don't know any > way you could detect it outside of ugly parsing of uname -r. Thanks, I would parse uname -r - it's not hard, Linux versions have always matched %d.%d.%d, and map in a standard way to a 32-bit integer for easy comparisons. A few QEMU releases later, someone will run the new version on a 2.6.26 to 2.6.28 host. It's quite usual in my experience to run a QEMU that's much newer than the corresponding host kernel, because upgrading host is a big deal (if you only have one or two) due to being heavily used, whereas upgrading QEMU/KVM is much easier as you can do it one VM guest at a time. -- Jamie