From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932797Ab1KHO5e (ORCPT ); Tue, 8 Nov 2011 09:57:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:65108 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755730Ab1KHO53 (ORCPT ); Tue, 8 Nov 2011 09:57:29 -0500 Message-ID: <4EB94340.5040205@redhat.com> Date: Tue, 08 Nov 2011 16:57:04 +0200 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20110927 Thunderbird/7.0 MIME-Version: 1.0 To: Christoph Hellwig CC: Alexander Graf , Linus Torvalds , Ingo Molnar , "linux-kernel@vger.kernel.org List" , "kvm@vger.kernel.org list" , qemu-devel Developers , Pekka Enberg , Am?rico Wang , Blue Swirl Subject: Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels References: <1320543320-32728-1-git-send-email-agraf@suse.de> <4EB93FA4.8020800@redhat.com> <20111108145257.GA10846@infradead.org> In-Reply-To: <20111108145257.GA10846@infradead.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/08/2011 04:52 PM, Christoph Hellwig wrote: > On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote: > > On 11/06/2011 03:35 AM, Alexander Graf wrote: > > > To quickly get going, just execute the following as user: > > > > > > $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash > > > > > > This will drop you into a shell on your rootfs. > > > > > > > Doesn't work on Fedora 15. F15's qemu-kvm doesn't have -machine or > > -virtfs. Even qemu.git on F15 won't build virtfs since xattr.h > > detection is broken (patch posted). > > Nevermind that running virtfs as a rootfs is a really dumb idea. You > do now want to run a VM that has a rootfs that gets changed all the > time behind your back. True. > Running qemu -snapshot on the actual root block device is the only > safe way to reuse the host installation, although it gets a bit > complicated if people have multiple devices mounted into the namespace. How is -snapshot any different? If the host writes a block after the guest has been launched, but before that block was cowed, then the guest will see the new block. It could work with a btrfs snapshot, but not everyone uses that. -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] KVM: Add wrapper script around QEMU to test kernels Date: Tue, 08 Nov 2011 16:57:04 +0200 Message-ID: <4EB94340.5040205@redhat.com> References: <1320543320-32728-1-git-send-email-agraf@suse.de> <4EB93FA4.8020800@redhat.com> <20111108145257.GA10846@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Blue Swirl , "kvm@vger.kernel.org list" , "linux-kernel@vger.kernel.org List" , qemu-devel Developers , Alexander Graf , Pekka Enberg , Am?rico Wang , Ingo Molnar , Linus Torvalds To: Christoph Hellwig Return-path: In-Reply-To: <20111108145257.GA10846@infradead.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On 11/08/2011 04:52 PM, Christoph Hellwig wrote: > On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote: > > On 11/06/2011 03:35 AM, Alexander Graf wrote: > > > To quickly get going, just execute the following as user: > > > > > > $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash > > > > > > This will drop you into a shell on your rootfs. > > > > > > > Doesn't work on Fedora 15. F15's qemu-kvm doesn't have -machine or > > -virtfs. Even qemu.git on F15 won't build virtfs since xattr.h > > detection is broken (patch posted). > > Nevermind that running virtfs as a rootfs is a really dumb idea. You > do now want to run a VM that has a rootfs that gets changed all the > time behind your back. True. > Running qemu -snapshot on the actual root block device is the only > safe way to reuse the host installation, although it gets a bit > complicated if people have multiple devices mounted into the namespace. How is -snapshot any different? If the host writes a block after the guest has been launched, but before that block was cowed, then the guest will see the new block. It could work with a btrfs snapshot, but not everyone uses that. -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNn7C-0000Hv-Te for qemu-devel@nongnu.org; Tue, 08 Nov 2011 09:57:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RNn79-0003KY-0Z for qemu-devel@nongnu.org; Tue, 08 Nov 2011 09:57:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2740) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RNn78-0003KM-O3 for qemu-devel@nongnu.org; Tue, 08 Nov 2011 09:57:26 -0500 Message-ID: <4EB94340.5040205@redhat.com> Date: Tue, 08 Nov 2011 16:57:04 +0200 From: Avi Kivity MIME-Version: 1.0 References: <1320543320-32728-1-git-send-email-agraf@suse.de> <4EB93FA4.8020800@redhat.com> <20111108145257.GA10846@infradead.org> In-Reply-To: <20111108145257.GA10846@infradead.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] KVM: Add wrapper script around QEMU to test kernels List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Christoph Hellwig Cc: Blue Swirl , "kvm@vger.kernel.org list" , "linux-kernel@vger.kernel.org List" , qemu-devel Developers , Alexander Graf , Pekka Enberg , Am?rico Wang , Ingo Molnar , Linus Torvalds On 11/08/2011 04:52 PM, Christoph Hellwig wrote: > On Tue, Nov 08, 2011 at 04:41:40PM +0200, Avi Kivity wrote: > > On 11/06/2011 03:35 AM, Alexander Graf wrote: > > > To quickly get going, just execute the following as user: > > > > > > $ ./Documentation/run-qemu.sh -r / -a init=/bin/bash > > > > > > This will drop you into a shell on your rootfs. > > > > > > > Doesn't work on Fedora 15. F15's qemu-kvm doesn't have -machine or > > -virtfs. Even qemu.git on F15 won't build virtfs since xattr.h > > detection is broken (patch posted). > > Nevermind that running virtfs as a rootfs is a really dumb idea. You > do now want to run a VM that has a rootfs that gets changed all the > time behind your back. True. > Running qemu -snapshot on the actual root block device is the only > safe way to reuse the host installation, although it gets a bit > complicated if people have multiple devices mounted into the namespace. How is -snapshot any different? If the host writes a block after the guest has been launched, but before that block was cowed, then the guest will see the new block. It could work with a btrfs snapshot, but not everyone uses that. -- error compiling committee.c: too many arguments to function