From: Dongwon Kim <[email protected]>
This patch series implements the .freeze and .restore hooks for the virtio-gpu
driver, alongside a PM notifier to properly handle object tracking and
restoration for S4 (hibernation) scenarios.
The first patch adds the `virtgpu_freeze` and `virtgpu_restore` functions.
These functions orchestrate flushing pending work, safely deleting virtio
queues before suspension once they are empty, and recreating them during
the restoration process.
The second patch implements a tracking and recreation mechanism for active
`virtio_gpu_object` instances. This is necessary because the host hypervisor
(e.g., QEMU) terminates or resets the backend during a full hibernation cycle,
wiping out all previously established graphics resources and causing
post-resume
errors in the guest.
The third patch integrates a PM notifier block into the driver. It captures
the PM_HIBERNATION_PREPARE phase to check compatibility (blocking S4 if Virgl
3D is active) and sets a state flag. This flag instructs `virtgpu_restore` to
fully re-submit and restore active GPU objects immediately after the fresh
virtqueues are reconfigured.
These changes ensure that the virtio-gpu driver can cleanly survive guest
hibernation without experiencing host-side 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)
v6: Include object backed by imported dmabuf
(Dmitry Osipenko)
Not storing virgl objects in the restore_list as virgl 3D objects are not
recoverable.
(Dmitry Osipenko)
Change the name 'list',a node in restore_list to 'restore_node'
(Nirmoy Das)
Use mutex instead of spinlock when updating restore_list
(Nirmoy Das)
Initialize restore_node when virtio_gpu_object is created - this is to
check if the node is in the list with 'list_empty' before removing it.
Restoring objects in the PM notifier is too late, as virtio-gpu
message communication begins in virtgpu_restore once virtqueues
are re-established. To address this, a 'hibernation' flag is set
during the PM_HIBERNATION_PREPARE phase in the notifier. This flag
is then used in virtgpu_restore to detect if the system is resuming
from S4, allowing objects to be recovered immediately after virtqueues
are reconfigured.
v7: Add a helper, virtio_gpu_add_object_to_restore_list
(Dmitry Osipenko)
Unreference all objects before hibernation so they can be removed
on the host side, since they will be fully restored anyway. This
prevents the situation where host-side hibernation fails (leaving
all associated resources still alive) while the virtio-gpu driver
still attempts to restore those objects.
(Dmitry Osipenko)
v8: Add drm_print.h to virtgpu_prime.c
v9: Move duplicate wait_event_timeout blocks into a single
virtio_gpu_wait_queue helper function.
(Dmitry Osipenko)
Handle timeouts gracefully by returning -ETIMEDOUT to abort
the freeze operation if the host hangs.
(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 | 80 ++++++++++++++++++++++-
drivers/gpu/drm/virtio/virtgpu_drv.h | 25 ++++++-
drivers/gpu/drm/virtio/virtgpu_kms.c | 54 +++++++++++++--
drivers/gpu/drm/virtio/virtgpu_object.c | 87 ++++++++++++++++++++++++-
drivers/gpu/drm/virtio/virtgpu_prime.c | 45 ++++++++++++-
drivers/gpu/drm/virtio/virtgpu_vq.c | 30 ++++++++-
drivers/gpu/drm/virtio/virtgpu_vram.c | 5 +-
7 files changed, 312 insertions(+), 14 deletions(-)
--
2.34.1
