This patchset introduces a migration_version attribute under sysfs of VFIO Mediated devices. This migration_version attribute is used to check migration compatibility between two mdev devices of the same mdev type. Patch 1 defines migration_version attribute in Documentation/vfio-mediated-device.txt Patch 2 uses GVT as an example to show how to expose migration_version attribute and check migration compatibility in vendor driver. v4: 1. fixed indentation/spell errors, reworded several error messages 2. added a missing memory free for error handling in patch 2 v3: 1. renamed version to migration_version 2. let errno to be freely defined by vendor driver 3. let checking mdev_type be prerequisite of migration compatibility check 4. reworded most part of patch 1 5. print detailed error log in patch 2 and generate migration_version string at init time v2: 1. renamed patched 1 2. made definition of device version string completely private to vendor driver 3. reverted changes to sample mdev drivers 4. described intent and usage of version attribute more clearly. Yan Zhao (2): vfio/mdev: add migration_version attribute for mdev device drm/i915/gvt: export migration_version to mdev sysfs for Intel vGPU Documentation/vfio-mediated-device.txt | 113 +++++++++++++ drivers/gpu/drm/i915/gvt/Makefile | 2 +- drivers/gpu/drm/i915/gvt/gvt.c | 39 +++++ drivers/gpu/drm/i915/gvt/gvt.h | 5 + drivers/gpu/drm/i915/gvt/migration_version.c | 168 +++++++++++++++++++ drivers/gpu/drm/i915/gvt/vgpu.c | 13 +- 6 files changed, 337 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/drm/i915/gvt/migration_version.c -- 2.17.1
