Re: [PATCH vhost v4 00/15] vdpa/mlx5: Add support for resumable vqs

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Dec 19, 2023 at 08:08:43PM +0200, Dragos Tatulea wrote:
> Add support for resumable vqs in the mlx5_vdpa driver. This is a
> firmware feature that can be used for the following benefits:
> - Full device .suspend/.resume.
> - .set_map doesn't need to destroy and create new vqs anymore just to
>   update the map. When resumable vqs are supported it is enough to
>   suspend the vqs, set the new maps, and then resume the vqs.
> 
> The first patch exposes relevant bits for the feature in mlx5_ifc.h.
> That means it needs to be applied to the mlx5-vhost tree [0] first. Once
> applied there, the change has to be pulled from mlx5-vhost into the
> vhost tree and only then the remaining patches can be applied. Same flow
> as the vq descriptor mappings patchset [1].
> 
> The second part implements the vdpa backend feature support to allow
> vq state and address changes when the device is in DRIVER_OK state and
> suspended.
> 
> The third part adds support for seletively modifying vq parameters. This
> is needed to be able to use resumable vqs.
> 
> Then the actual support for resumable vqs is added.
> 
> The last part of the series introduces reference counting for mrs which
> is necessary to avoid freeing mkeys too early or leaking them.


I lost track. Are you going to send v5 or not?

> * Changes in v4:
> - Added vdpa backend feature support for changing vq properties in
>   DRIVER_OK when device is suspended. Added support in the driver as
>   well.
> - Dropped Acked-by for the patches that had the tag mistakenly
>   added.
> 
> * Changes in v3:
> - Faulty version. Please ignore.
> 
> * Changes in v2:
> - Added mr refcounting patches.
> - Deleted unnecessary patch: "vdpa/mlx5: Split function into locked and
>   unlocked variants"
> - Small print improvement in "Introduce per vq and device resume"
>   patch.
> - Patch 1/7 has been applied to mlx5-vhost branch.
> 
> 
> Dragos Tatulea (15):
>   vdpa: Add VHOST_BACKEND_F_CHANGEABLE_VQ_ADDR_IN_SUSPEND flag
>   vdpa: Add VHOST_BACKEND_F_CHANGEABLE_VQ_STATE_IN_SUSPEND flag
>   vdpa: Accept VHOST_BACKEND_F_CHANGEABLE_VQ_ADDR_IN_SUSPEND backend
>     feature
>   vdpa: Accept VHOST_BACKEND_F_CHANGEABLE_VQ_STATE_IN_SUSPEND backend
>     feature
>   vdpa: Track device suspended state
>   vdpa: Block vq address change in DRIVER_OK unless device supports it
>   vdpa: Block vq state change in DRIVER_OK unless device supports it
>   vdpa/mlx5: Expose resumable vq capability
>   vdpa/mlx5: Allow modifying multiple vq fields in one modify command
>   vdpa/mlx5: Introduce per vq and device resume
>   vdpa/mlx5: Mark vq addrs for modification in hw vq
>   vdpa/mlx5: Mark vq state for modification in hw vq
>   vdpa/mlx5: Use vq suspend/resume during .set_map
>   vdpa/mlx5: Introduce reference counting to mrs
>   vdpa/mlx5: Add mkey leak detection
> 
>  drivers/vdpa/mlx5/core/mlx5_vdpa.h |  10 +-
>  drivers/vdpa/mlx5/core/mr.c        |  69 +++++++--
>  drivers/vdpa/mlx5/net/mlx5_vnet.c  | 218 ++++++++++++++++++++++++++---
>  drivers/vhost/vdpa.c               |  51 ++++++-
>  include/linux/mlx5/mlx5_ifc.h      |   3 +-
>  include/linux/mlx5/mlx5_ifc_vdpa.h |   4 +
>  include/uapi/linux/vhost_types.h   |   8 ++
>  7 files changed, 322 insertions(+), 41 deletions(-)
> 
> -- 
> 2.43.0