Re: [PATCH vhost v2 00/16] vdpa: Add support for vq descriptor mappings

[Michael S. Tsirkin]

On Thu, Sep 28, 2023 at 07:45:11PM +0300, Dragos Tatulea wrote:
> 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 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-next tree [1] first. Once this patch is applied
>   on mlx5-next, the change has to be pulled fom mlx5-next into the vhost
>   tree and only then the remaining patches can be applied.


I get it you plan v3?

> [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-next
> 
> 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        | 191 ++++++++++++++++-------------
>  drivers/vdpa/mlx5/core/resources.c |   6 +-
>  drivers/vdpa/mlx5/net/mlx5_vnet.c  | 100 ++++++++++-----
>  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, 264 insertions(+), 130 deletions(-)
> 
> -- 
> 2.41.0