Re: [Qemu-devel] [Xen-devel] [v2][PATCH 4/8] xen, gfx passthrough: reserve 00:02.0 for INTEL IGD

[Fabio Fantoni <fabio.fantoni@m2r.biz>]

Il 19/05/2014 08:44, Gerd Hoffmann ha scritto:
>    Hi,
>
>> +    /*
>> +     * Some video bioses and gfx drivers will assume the bdf of IGD is 00:02.0.
>> +     * So user need to set it to 00:02.0 in Xen configure file explicitly,
>> +     * otherwise IGD will fail to work.
>> +     */
>> +    pci_reserve_pci_devfn(b, PCI_DEVFN(2, 0));
> That is asking for trouble.  Slot 2 is used by the qemu vga cards by
> default, and for quite a while (before memory api was merged) it even
> was impossible to change it.  libvirt still places the vga card at slot
> 2 for that reason -> boom.  I wouldn't be surprised if you find that
> assumption in other management libs / apps too.
>
> Why do you need that patch in the first place?  It should be possible to
> configure qemu to not occupy slot 2 if you need it that way.  Just pass
> '-vga none' to qemu.  Which you probably want anyway if you pass-through
> a vga to the guest.  And explicitly configure a slot (via addr=
> property) for all your pci devices.  Doing it only for the IGD works too
> if you list the device before any other pci device on the qemu command
> line.
>
> cheers,
>    Gerd

I already added vga none support on libxl, useful also for this cases:
http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=2e5738ff47b9d2e1948024100f87b1a25fcf004a

This patch is already tested and working, for now I not tested and I 
can't test with intel gpu passthrough, someone can test it with intel 
gpu passthrough?

Thanks for any reply and sorry for my bad english.

>
>
>
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