Re: [XEN PATCH] tools/libs/light/libxl_pci.c: explicitly grant access to Intel IGD opregion

[Chuck Zmudzinski <brchuckz@xxxxxxxxxxxx>]

On 3/31/22 10:19 AM, Jason Andryuk wrote:
> On Thu, Mar 31, 2022 at 10:05 AM Chuck Zmudzinski <brchuckz@xxxxxxxxxxxx> wrote:
> > That still doesn't answer my question - will the Qemu upstream
> > accept the patches that move the hypercalls to the toolstack? If
> > not, we have to live with what we have now, which is that the
> > hypercalls are done in Qemu.
> Xen-associated people maintain hw/xen code in QEMU, so yes it could be accepted.
>
> Maybe it would need to be backwards compatible to have libxl check the
> QEMU version to decide who makes the hypercall?  Unless it is broken
> today, in which case just make it work.
>
> Regards,
> Jason
I know of another reason to check the Qemu upstream version,
and that is dealing with deprecated / removed device model
options that xl.cfg still uses. I looked at that a few years ago
with regard to the deprecated 'usbdevice tablet' Qemu option,
but I did not see anything in libxl to distinguish Qemu versions
except for upstream vs. traditional. AFAICT, detecting traditional
vs. upstream Qemu depends solely on the device_model_version
xl.cfg setting. So it might be useful for libxl to add the capability
to detect the upstream Qemu version or at least create an xl.cfg
setting to inform libxl about the Qemu version.

Regards,

Chuck