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

[Steven Newbury]

On Wed, 2020-10-07 at 13:17 -0600, Alex Williamson wrote:
> Are you aware that you can add arbitrary options to devices using the
> <qemu:commandline> support in libvirt?  For example:
> 
> <domain type='kvm' xmlns:qemu='
> http://libvirt.org/schemas/domain/qemu/1.0'>
>   ...
>   <devices>
>     ...
>     <hostdev mode='subsystem' type='pci' managed='yes'>
>       <source>
>         <address domain='0x0000' bus='0x01' slot='0x00'
> function='0x0'/>
>       </source>
>       <address type='pci' domain='0x0000' bus='0x01' slot='0x00'
> function='0x0'/>
>       <alias name='ua-geforce8800'/>
>     </hostdev>
>     ...
>   </devices>
>   <qemu:commandline>
>     <qemu:arg value='-set'/>
>     <qemu:arg value='device.ua-geforce8800.x-vga=on'/>
>   </qemu:commandline>
> </domain>
> 
> This is generally how users make use of unsupportable or
> not-yet-supported QEMU features while still using libvirt to manage
> the
> VM.
I am aware of it, but I never managed to get virt-manager to accept
arbitary command line arguments, but never persisted in trying to get
it to work since it felt hackier than patching libvirt to accept the
parameter.