[libvirt] [Qemu-devel] [PATCH 3/3] cirrus: mark as deprecated

[Daniel P. Berrangé]

On Mon, Oct 29, 2018 at 10:12:44AM +0100, Gerd Hoffmann wrote:
> On Thu, Oct 25, 2018 at 09:37:58PM +0100, Daniel P. Berrangé wrote:
> > On Thu, Oct 25, 2018 at 10:52:56AM +0200, Gerd Hoffmann wrote:
> > > While being at it deprecate cirrus too.
> > > 
> > > Reason (short version): use stdvga instead.
> > > Verbose version:
> > >     https://www.kraxel.org/blog/2014/10/qemu-using-cirrus-considered-harmful
> > 
> > Every single one of my guests is using cirrus. This wasn't an explicit
> > choice on my part, so I believe it is being used as the default in
> > virt-install.
> > 
> > I don't debate the points in the blog post above that stdvga is a
> > better choice, but I don't think that's enough to justify deprecating
> > cirrus at this point in time, because when it then gets deleted it
> > will break way too many existing deployments.
> > 
> > We need to socialize info in that blog post above more widely and
> > especially ensure that apps are not using that by default. I don't
> > see it being viable to formally deprecate it in QEMU any time soon
> > though given existing usage.
> 
> Well, getting that message to the users is the point of deprecating it.
> I think in this specific case we'll need a longer (maybe much longer)
> deprecation period than only two releases.  But I think it still makes
> sense to deprecate it now.

As mentioned elsewhere in this thread, I think it is important that
QEMU distinction between devices that are best practice / recommended
for use with KVM virt, vs devices that exist solely for sake of
emulating hardware for use with old platforms.

I agree that cirrus doesn't have a place in a KVM guest for future,
but I don't thjink that means it should be deprecated & removed from
QEMU entirely, as its still relevant from POV of QEMU's goal to
emulate old hardware platforms.


Regards,
Daniel
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