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(a)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@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"'
take care & HTH,
  Gerd