Re: RFC: Making QEMU honour 'readonly' flag for disks

["Daniel P. Berrange" <berrange@redhat.com>]

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
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