From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Daniel P. Berrange" Subject: Re: RFC: Making QEMU honour 'readonly' flag for disks Date: Thu, 24 Jul 2008 14:41:47 +0100 Message-ID: <20080724134147.GC1138@redhat.com> References: <20080724113627.GU1138@redhat.com> <18568.34189.57005.491667@mariner.uk.xensource.com> Reply-To: "Daniel P. Berrange" Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <18568.34189.57005.491667@mariner.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ian Jackson Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On Thu, Jul 24, 2008 at 02:37:17PM +0100, Ian Jackson wrote: > Daniel P. Berrange writes ("[Xen-devel] RFC: Making QEMU honour 'readonly' flag for disks"): > > This proof of concept patch I've done against the RHEL-5 Xen tree introduces > > a new 'drv_read_only' flag to QEMU's BlockDriverState struct, and if set to > > non-zero, will cause the individual block backend drivers inside QEMU to > > always open with O_RDONLY, and never try O_RDWR. Ultimately this would be > > hooked up to the '-drive' parameter via a extra flag ',ro' in its args. > > It then makes xenstore.c set this flag based on the 'mode' parameter for > > the disk in xenstore. > > I think this is a good idea but you should discuss it with upstream to > try to minimise the difference between the patch that goes into our > tree and the one that goes into upstream. Ok, I'll do a generic patch for upstream QEMU and then a xenstore integration add on. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|