[PATCH] Support x-vga=on for PCI host passthrough devices

[Steven Newbury]

On Wed, 2020-10-07 at 15:56 +0100, Steven Newbury wrote:
> 
> As I see it there are two distinct validation requirements:
> 
> 1) It should only apply to hostdev PCI vfio devices
> 
I think I've come up with a solution:  Add a new enum to extFlags to
allow vga, and set the flag for vfio pci devices in domain_conf.c.
 Then throw an error if vga is set when the flag is not.  Doesn't help
with below though, unless there's some way to know the device class.

> 2) It is only relevant to PCI Class 3 (Display Controller), but
> libvirt
> doesn't know about the PCI device class, does it?
> 
> 
> 1 is the most important probably.  Should it just be hard error if
> it's
> defined for each devices type except for hostdev in domain_conf.c or
> check for device type hostdev before setting the parameter and ignore
> it otherwise?
> 
> 
>