Re: Possible regression with VGA and resolutions in Windows 10?

[Daniel P . Berrangé]

On Fri, Jul 24, 2020 at 04:10:32PM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > The behavior is similar when setting a custom resolution with the xres
> > and yres parameters. Setting it the first time works fine and it is
> > shown along with the short list. Setting it to something different on
> > the next boot will not be recognized unless the display adapter is
> > uninstalled and the VM rebooted.
> 
> Interesting.  Seems Windows caches the list of resolutions (or the edid
> blob) somewhere in the registry instead of loading it on every boot.
> I've seen simliar behavior with usb device info.
> 
> [ something for the 5.1 release notes I think, thanks for testing this ]

Do we need to be disabling edid in the old machine types to prevent this
change in guest ABI due to the changed BIOS ?

eg existing VMs using a versioned machine type shouldn't suddenly get edid
enabled where previously it was not present. Only VMs using the new 5.1 or
unversioned machine types should see the change in behaviour.

Regards,
Daniel
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