[v2,0/2] VFIO mdev aggregated resources handling

Message

Zhenyu Wang March 26, 2020, 5:41 a.m. UTC

Hi,

This is a refresh on previous series: https://patchwork.kernel.org/cover/11208279/
and https://patchwork.freedesktop.org/series/70425/

Current mdev device create interface depends on fixed mdev type, which
get uuid from user to create instance of mdev device. If user wants to
use customized number of resource for mdev device, then only can
create new mdev type for that which may not be flexible. This
requirement comes not only from to be able to allocate flexible
resources for KVMGT, but also from Intel scalable IO virtualization
which would use vfio/mdev to be able to allocate arbitrary resources
on mdev instance. More info on [1] [2] [3].

As we agreed that for current opaque mdev device type, we'd still
explore management interface based on mdev sysfs definition. And this
one tries to follow Alex's previous suggestion to create generic
parameters under 'mdev' directory for each device, so vendor driver
could provide support like as other defined mdev sysfs entries.

For mdev type with aggregation support, files as "aggregated_instances"
and "max_aggregation" should be created under 'mdev' directory. E.g

/sys/devices/pci0000:00/0000:00:02.0/<UUID>/mdev/
   |-- aggregated_instances
   |-- max_aggregation

"aggregated_instances" is used to set or return current number of
instances for aggregation, which can not be larger than "max_aggregation".

The first patch is to update the document for new mdev parameter directory.
The second one is to add aggregation support in GVT driver.

References:
[1] https://software.intel.com/en-us/download/intel-virtualization-technology-for-directed-io-architecture-specification
[2] https://software.intel.com/en-us/download/intel-scalable-io-virtualization-technical-specification
[3] https://schd.ws/hosted_files/lc32018/00/LC3-SIOV-final.pdf

Zhenyu Wang (2):
  Documentation/driver-api/vfio-mediated-device.rst: update for
    aggregation support
  drm/i915/gvt: mdev aggregation type

 .../driver-api/vfio-mediated-device.rst       |  19 ++
 drivers/gpu/drm/i915/gvt/aperture_gm.c        |  44 +++--
 drivers/gpu/drm/i915/gvt/gtt.c                |   9 +-
 drivers/gpu/drm/i915/gvt/gvt.c                |   7 +-
 drivers/gpu/drm/i915/gvt/gvt.h                |  42 +++--
 drivers/gpu/drm/i915/gvt/kvmgt.c              | 115 +++++++++++-
 drivers/gpu/drm/i915/gvt/vgpu.c               | 172 ++++++++++++------
 7 files changed, 314 insertions(+), 94 deletions(-)