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References: <20230912130132.561193-1-dtatulea@nvidia.com>
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From:   Lei Yang <leiyang@redhat.com>
Date:   Wed, 13 Sep 2023 09:03:15 +0800
Message-ID: <CAPpAL=w6KeBG5Ur037GNQa=n_fdoUwrFo+ATsFtX9HbWPHZvsg@mail.gmail.com>
Subject: Re: [PATCH 00/16] vdpa: Add support for vq descriptor mappings
To:     Dragos Tatulea <dtatulea@nvidia.com>,
        =?UTF-8?Q?Eugenio_P=C3=A9rez?= <eperezma@redhat.com>,
        Si-Wei Liu <si-wei.liu@oracle.com>
Cc:     Jason Wang <jasowang@redhat.com>,
        "Michael S . Tsirkin" <mst@redhat.com>,
        Saeed Mahameed <saeedm@nvidia.com>,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, Parav Pandit <parav@nvidia.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>, kvm@vger.kernel.org
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Hi Dragos, Eugenio and Si-Wei

My name is Lei Yang, a software Quality Engineer from Red Hat.  And
always paying attention to improving the live migration downtime
issues because there are others QE asked about this problem when I
share live migration status  recently. Therefore I would like to test
it in my environment. Before the testing I want to know if there is an
expectation of downtime range based on this series of patches? In
addition, QE also can help do a regression test based on this series
of patches if there is a requirement.

Regards and thanks
Lei


On Tue, Sep 12, 2023 at 9:04=E2=80=AFPM Dragos Tatulea <dtatulea@nvidia.com=
> 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.
>
> [0] https://lore.kernel.org/virtualization/1694248959-13369-1-git-send-em=
ail-si-wei.liu@oracle.com
>
> Dragos Tatulea (13):
>   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
>   Cover letter: vdpa/mlx5: Add support for vq descriptor mappings
>
> 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
>