[PATCH vhost v3 00/16] vdpa: Add support for vq descriptor mappings

From: Dragos Tatulea
Date: Mon Oct 09 2023 - 07:24:26 EST


This patch series adds support for vq descriptor table mappings which
are used to improve vdpa live migration downtime. The improvement comes
from using smaller mappings which take less time to create and destroy
in hw.

The first part adds the vdpa core changes from Si-Wei [0].

The second part adds support in mlx5_vdpa:
- Refactor the mr code to be able to cleanly add descriptor mappings.
- Add hardware descriptor mr support.
- Properly update iotlb for cvq during ASID switch.

Changes in v3:

- dup_iotlb now checks for src == dst case and returns an error.
- Renamed iotlb parameter in dup_iotlb to dst.
- Removed a redundant check of the asid value.
- Fixed a commit message.
- mx5_ifc.h patch has been applied to mlx5-vhost tree. When applying
this series please pull from that tree first.

Changes in v2:

- The "vdpa/mlx5: Enable hw support for vq descriptor mapping" change
was split off into two patches to avoid merge conflicts into the tree
of Linus.

The first patch contains only changes for mlx5_ifc.h. This must be
applied into the mlx5-vdpa tree [1] first. Once this patch is applied
on mlx5-vdpa, the change has to be pulled fom mlx5-vdpa into the vhost
tree and only then the remaining patches can be applied.

[0] https://lore.kernel.org/virtualization/1694248959-13369-1-git-send-email-si-wei.liu@xxxxxxxxxx
[1] https://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux.git/log/?h=mlx5-vhost

Dragos Tatulea (13):
vdpa/mlx5: Expose descriptor group mkey hw capability
vdpa/mlx5: Create helper function for dma mappings
vdpa/mlx5: Decouple cvq iotlb handling from hw mapping code
vdpa/mlx5: Take cvq iotlb lock during refresh
vdpa/mlx5: Collapse "dvq" mr add/delete functions
vdpa/mlx5: Rename mr destroy functions
vdpa/mlx5: Allow creation/deletion of any given mr struct
vdpa/mlx5: Move mr mutex out of mr struct
vdpa/mlx5: Improve mr update flow
vdpa/mlx5: Introduce mr for vq descriptor
vdpa/mlx5: Enable hw support for vq descriptor mapping
vdpa/mlx5: Make iotlb helper functions more generic
vdpa/mlx5: Update cvq iotlb mapping on ASID change

Si-Wei Liu (3):
vdpa: introduce dedicated descriptor group for virtqueue
vhost-vdpa: introduce descriptor group backend feature
vhost-vdpa: uAPI to get dedicated descriptor group id

drivers/vdpa/mlx5/core/mlx5_vdpa.h | 31 +++--
drivers/vdpa/mlx5/core/mr.c | 194 ++++++++++++++++-------------
drivers/vdpa/mlx5/core/resources.c | 6 +-
drivers/vdpa/mlx5/net/mlx5_vnet.c | 98 ++++++++++-----
drivers/vhost/vdpa.c | 27 ++++
include/linux/mlx5/mlx5_ifc.h | 8 +-
include/linux/mlx5/mlx5_ifc_vdpa.h | 7 +-
include/linux/vdpa.h | 11 ++
include/uapi/linux/vhost.h | 8 ++
include/uapi/linux/vhost_types.h | 5 +
10 files changed, 266 insertions(+), 129 deletions(-)

--
2.41.0