From: Dongwon Kim <dongwon....@intel.com> This patch series implements functions for .freeze and .restore hooks for virtio-gpu driver as well as pm-notifier to handle object restoration in S4(hiberation) case.
First patch adds `virtgpu_freeze` and `virtgpu_restore` functions. These functions handle the deletion of virtio queues before suspension and their recreation during the restoration process. Second patch implements a mechanism for restoring `virtio_gpu_object` instances. This is necessary because the host (QEMU) deletes all associated resources during the virtio-gpu reset, which occurs as part of hiberation/resume process. Third patch adds pm-notifier to the driver that handles resubmission of virtio-gpu objects to the QEMU once the guest resumes from hibenation. These changes ensure that the virtio-gpu driver can properly handle hibernation scenarios without resource loss. v2: 10ms sleep is added in virtgpu_freeze to avoid the situation the driver is locked up during resumption. v3: Plain 10ms delay (v2) is replaced with wait calls which wait until the virtio queue is empty. (Dmitry Osipenko) v4: New version of patchset only covers S4 case because loss of resources in S3 case can be avoided by skipping virtio-gpu-reset in QEMU (hw/display/virtio-gpu.c). To skip virtio-gpu-reset (soft-reset), virtio-gpu-pci device should be attached to PCIE bus AND a PCIE option, 'x-pcie-pm-no-soft-reset' should added and set to 'true'. (e.g. -device virtio-gpu-pci,bus=port,x-pcie-pm-no-soft-reset=true) v5: Remove virtio_gpu_object from the restore list before freeing the object to prevent an use-after-free situation. (Nirmoy Das) Protect restore list operations with a spinlock (Nirmoy Das) Move restore list node into virtio_gpu_bo struct to reduce memory usage (Dmitry Osipenko) Remove unused header - drm_atomic_helper.h (Dmitry Osipenko) Dongwon Kim (3): drm/virtio: Freeze and restore hooks to support suspend and resume drm/virtio: Add support for saving and restoring virtio_gpu_objects drm/virtio: Add PM notifier to restore objects after hibernation drivers/gpu/drm/virtio/virtgpu_drv.c | 60 +++++++++++++++++++++++- drivers/gpu/drm/virtio/virtgpu_drv.h | 12 +++++ drivers/gpu/drm/virtio/virtgpu_kms.c | 51 ++++++++++++++++++--- drivers/gpu/drm/virtio/virtgpu_object.c | 61 +++++++++++++++++++++++++ 4 files changed, 177 insertions(+), 7 deletions(-) -- 2.34.1