[Libguestfs] [virt-v2v RFC wave 2 02/10] convert_linux: use "modesetting" X.org driver for Standard_VGA

[Laszlo Ersek]

On 11/02/21 10:25, Gerd Hoffmann wrote:
>   Hi,
> 
>>> (II) LoadModule: "modesetting"
>>> (II) LoadModule: "fbdev"
>>> (II) LoadModule: "vesa"
>>> (II) UnloadModule: "fbdev"
>>> (II) UnloadModule: "vesa"
> 
>> This tells us that the standard VGA device model is driven by the
>> "modesetting" driver. Update the "configure_display_driver" function (for
>> Linux guests) accordingly.
> 
> Correct.
> 
> Acked-by: Gerd Hoffmann <kraxel at redhat.com>
> 
>>    and configure_display_driver video =
>>      let video_driver =
>>        match video with
>> -      | Standard_VGA -> assert false
>> +      | Standard_VGA -> "modesetting"
>>        | QXL -> "qxl"
>>        | Cirrus -> "cirrus" in
> 
> Oh.  More updates needed.
> 
> cirrus is modesetting too, unless you use a *really* old distro.
> 
>    kraxel at sirius ~/distgit/xorg-x11-drv-cirrus (rawhide)# cat dead.package 
>    2014-07-06: retired driver, because it does not support KMS: https://lists.fedoraproject.org/pipermail/devel/2013-August/188429.html
> 
> qxl is on a similar path.  In case xorg-x11-drv-qxl.rpm is installed
> xorg will prefer the qxl driver.  In case the driver is not present xorg
> will use the modesetting driver instead and it'll work equally fine.
> I think RHEL-9 doesn't ship xorg-x11-drv-qxl.rpm any more.
> 
> virtio-gpu will also be handled by the modesetting driver.
> 
> So possibly you can just do 'let video_driver = "modesetting"'

That might require a bunch of testing, plus I'd rather not mix in
unrelated changes... If we really want to drive Cirrus with a different
x.org driver, we should (perhaps, if at all) have a separate RHBZ about
that.

I will pick up your A-b for the "surgical" stdvga-related change though,
if that's OK with you.

Thanks!
Laszlo

> 
> take care & HTH,
>   Gerd
>