On 5/5/25 19:02, Tomita Moeko wrote:
As proposed in a previous discussion [1], detect IGD devices based on
whether it has VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION exposed by kernel
and enables OpRegion access by default. This enables out-of-the-box
display output support for IGD passthrough without having to manually
set x-igd-opregion=on, which probably saves effort for libvirt users.
This patchset also limits legacy mode to Gen6-9 devices, as Intel no
longer provides CSM support and VBIOS on newer IGD, and Seabios does not
support setting up the 64 bit BDSM register on Gen 11+ devices. Exposing
VGA ranges to guests by default on platforms without VGA mode support is
undesirable.
Additionally, as we enables OpRegion on IGD devices by default, and
Intel removes the BDSM register from Meteor Lake [2]. There seems to be
no extra register quirks rather than OpRegion required on newer devices.
To support them (and probably future devices), the generation limit is
removed, with BDSM quirk only applied to known Gen 6-12 devices.
Note: I have not been able to test this on Meteor Lake or newer
platforms due to lack of hardware.
[1]
https://lore.kernel.org/qemu-devel/20250325172239.27926-1-tomitamo...@gmail.com
[2]
https://edc.intel.com/content/www/us/en/design/publications/14th-generation-core-processors-cfg-and-mem-registers/d2-f0-processor-graphics-registers/
Changelog:
v3:
* Addressed a nit in patch #8
Link:
https://lore.kernel.org/qemu-devel/20250428161004.35613-1-tomitamo...@gmail.com
v2:
* Removed "Allow hotplugging with OpRegion enabled", hotplugging is
always forbidden.
* Test device is not hotplugged and get opregion in a single function.
* Update documentation along with code changes.
* Minor code style fixes.
Link:
https://lore.kernel.org/qemu-devel/20250421163112.21316-1-tomitamo...@gmail.com
Tomita Moeko (9):
vfio/igd: Restrict legacy mode to Gen6-9 devices
vfio/igd: Always emulate ASLS (OpRegion) register
vfio/igd: Detect IGD device by OpRegion
vfio/igd: Check vendor and device ID on GVT-g mdev
vfio/igd: Check OpRegion support on GVT-g mdev
vfio/igd: Enable OpRegion by default
vfio/igd: Allow overriding GMS with 0xf0 to 0xfe on Gen9+
vfio/igd: Only emulate GGC register when x-igd-gms is set
vfio/igd: Remove generation limitation for IGD passthrough
docs/igd-assign.txt | 11 ++-
hw/vfio/igd.c | 220 ++++++++++++++++++++++++++------------------
hw/vfio/pci.c | 2 +-
3 files changed, 138 insertions(+), 95 deletions(-)
.
Since Corvin and Alex had reviewed and tested the previous spin :
https://lore.kernel.org/qemu-devel/20250428161004.35613-1-tomitamo...@gmail.com/
let's add the trailers to v3 :
Reviewed-by: Corvin Köhne <c.koe...@beckhoff.com>
Reviewed-by: Alex Williamson <alex.william...@redhat.com>
Tested-by: Alex Williamson <alex.william...@redhat.com>
Moeko,
Please use b4 or equivalent to collect the trailers.
Thanks,
C.
