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

[Cole Robinson]

On 10/25/2018 09:37 PM, 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.

virt-manager/virt-install 2.0.0 will never explicitly set cirrus, but 
that release is quite new. The previous release's default for x86 was 
roughly:

if using spice graphics:
    use qxl
elif guest os is windows:
    use vga
else:
    use cirrus

It was definitely sub optimal. Maybe your virt-install commands were 
explicitly setting --graphics vnc which would trigger cirrus in that case.

> 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.