[V1,mlx5-next,0/4] Improve mlx5 live migration driver

Message

Yishai Hadas May 8, 2022, 1:10 p.m. UTC

This series improves mlx5 live migration driver in few aspects as of
below.

Refactor to enable running migration commands in parallel over the PF
command interface.

To achieve that we exposed from mlx5_core an API to let the VF be
notified before that the PF command interface goes down/up. (e.g. PF
reload upon health recovery).

Once having the above functionality in place mlx5 vfio doesn't need any
more to obtain the global PF lock upon using the command interface but
can rely on the above mechanism to be in sync with the PF.

This can enable parallel VFs migration over the PF command interface
from kernel driver point of view.

In addition,
Moved to use the PF async command mode for the SAVE state command.
This enables returning earlier to user space upon issuing successfully
the command and improve latency by let things run in parallel.

Alex, as this series touches mlx5_core we may need to send this in a
pull request format to VFIO to avoid conflicts before acceptance.

V1:
- Put the net/mlx5 patch as the first patch based on Jason's note.
- Refactor and combine the previous first patch with the third patch to
  have a cleaner readable code, this follows Alex's notes on V0.

V0: https://lore.kernel.org/netdev/[e-mail]/T/

Yishai
Yishai Hadas (4):
  net/mlx5: Expose mlx5_sriov_blocking_notifier_register /  unregister
    APIs
  vfio/mlx5: Manage the VF attach/detach callback from the PF
  vfio/mlx5: Refactor to enable VFs migration in parallel
  vfio/mlx5: Run the SAVE state command in an async mode

 .../net/ethernet/mellanox/mlx5/core/sriov.c   |  65 ++++-
 drivers/vfio/pci/mlx5/cmd.c                   | 226 +++++++++++++-----
 drivers/vfio/pci/mlx5/cmd.h                   |  50 +++-
 drivers/vfio/pci/mlx5/main.c                  | 132 +++++-----
 include/linux/mlx5/driver.h                   |  12 +
 5 files changed, 352 insertions(+), 133 deletions(-)