Re: [Qemu-devel] [PATCH v3 11/11] igd: move igd-passthrough-isa-bridge creation to machine init

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

> One thing I don't like about this is that it is going to skip the checks
> done in xen_pt_initfn.

Hmm?  Those checks are still done when you assign a igd ...

> For example it is going to create the isa bridge,
> even if there is going to be an error loading the vga bios or if the
> device specified is not even an Intel graphic card.

Creating the special igd-isa-bridge is no longer tied to actually
assigning a igd, but to the igd-passthru=on machine option being present
(and machine type being 'pc').

xen_pt_initfn checks that igd-passthru=on is set in case it finds a igd
device is assigned, that will make sure the igd-isa-bridge is present.

But, yes, you can create a igd-isa-bridge now even when not assigning a
igd device, either by specifying igd-passthru=on or using -device.  I
fail to see why this is a problem though, care to explain?

Also note that moving this to machine init nicely handles the fact that
the igd-isa-bridge is needed on 'pc' only, not on 'q35'.  If you don't
want create the igd-isa-bridge in machine init, what is your alternative
suggestion to handle this?

cheers,
  Gerd