[net-next,v5,0/4] virtio-net: Link queues to NAPIs

Message

Joe Damato Feb. 27, 2025, 6:50 p.m. UTC

Greetings:

Welcome to v5. Patches 1, 2, and 4 have no functional changes only
updated tags. Patch 3 was refactored as requested by Jason. See the
changelog below and the commit message for details.

Jakub recently commented [1] that I should not hold this series on
virtio-net linking queues to NAPIs behind other important work that is
on-going and suggested I re-spin, so here we are :)

As per the discussion on the v3 [2], now both RX and TX NAPIs use the
API to link queues to NAPIs. Since TX-only NAPIs don't have a NAPI ID,
commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present") now
correctly elides the TX-only NAPIs (instead of printing zero) when the
queues and NAPIs are linked.

As per the discussion on the v4 [3], patch 3 has been refactored to hold
RTNL only in the specific locations which need it as Jason requested.

See the commit message of patch 3 for an example of how to get the NAPI
to queue mapping information.

See the commit message of patch 4 for an example of how NAPI IDs are
persistent despite queue count changes.

Thanks,
Joe

[1]: https://lore.kernel.org/netdev/[e-mail]/
[2]: https://lore.kernel.org/netdev/[e-mail]/
[3]: https://lore.kernel.org/netdev/CACGkMEv=[e-mail]/

v5:
  - Patch 1 added Acked-by's from Michael and Jason. Added Tested-by
    from Lei. No functional changes.
  - Patch 2 added Acked-by's from Michael and Jason. Added Tested-by
    from Lei. No functional changes.
  - Patch 3:
    - Refactored as Jason requested, eliminating the
      virtnet_queue_set_napi helper entirely, and explicitly holding
      RTNL in the 3 locations where needed (refill_work, freeze, and
      restore).
    - Commit message updated to outline the known paths at the time the
      commit was written.
  - Patch 4 added Acked-by from Michael. Added Tested-by from Lei. No
    functional changes.

v4: https://lore.kernel.org/lkml/[e-mail]/
  - Dropped Jakub's patch (previously patch 1).
  - Significant refactor from v3 affecting patches 1-3.
  - Patch 4 added tags from Jason and Gerhard.

rfcv3: https://lore.kernel.org/netdev/[e-mail]/
  - patch 3:
    - Removed the xdp checks completely, as Gerhard Engleder pointed
      out, they are likely not necessary.

  - patch 4:
    - Added Xuan Zhuo's Reviewed-by.

v2: https://lore.kernel.org/netdev/[e-mail]/
  - patch 1:
    - New in the v2 from Jakub.

  - patch 2:
    - Previously patch 1, unchanged from v1.
    - Added Gerhard Engleder's Reviewed-by.
    - Added Lei Yang's Tested-by.

  - patch 3:
    - Introduced virtnet_napi_disable to eliminate duplicated code
      in virtnet_xdp_set, virtnet_rx_pause, virtnet_disable_queue_pair,
      refill_work as suggested by Jason Wang.
    - As a result of the above refactor, dropped Reviewed-by and
      Tested-by from patch 3.

  - patch 4:
    - New in v2. Adds persistent NAPI configuration. See commit message
      for more details.

v1: https://lore.kernel.org/netdev/[e-mail]/

Joe Damato (4):
  virtio-net: Refactor napi_enable paths
  virtio-net: Refactor napi_disable paths
  virtio-net: Map NAPIs to queues
  virtio_net: Use persistent NAPI config

 drivers/net/virtio_net.c | 95 ++++++++++++++++++++++++++++------------
 1 file changed, 67 insertions(+), 28 deletions(-)


base-commit: 7fe0353606d77a32c4c7f2814833dd1c043ebdd2

Comments

Lei Yang Feb. 28, 2025, 2:39 p.m. UTC | #1

I also tested this series of patches v5 with virtio-net regression
tests, everything works fine.

Tested-by: Lei Yang <[e-mail]>

On Fri, Feb 28, 2025 at 2:50 AM Joe Damato <[e-mail]> wrote:
>
> Greetings:
>
> Welcome to v5. Patches 1, 2, and 4 have no functional changes only
> updated tags. Patch 3 was refactored as requested by Jason. See the
> changelog below and the commit message for details.
>
> Jakub recently commented [1] that I should not hold this series on
> virtio-net linking queues to NAPIs behind other important work that is
> on-going and suggested I re-spin, so here we are :)
>
> As per the discussion on the v3 [2], now both RX and TX NAPIs use the
> API to link queues to NAPIs. Since TX-only NAPIs don't have a NAPI ID,
> commit 6597e8d35851 ("netdev-genl: Elide napi_id when not present") now
> correctly elides the TX-only NAPIs (instead of printing zero) when the
> queues and NAPIs are linked.
>
> As per the discussion on the v4 [3], patch 3 has been refactored to hold
> RTNL only in the specific locations which need it as Jason requested.
>
> See the commit message of patch 3 for an example of how to get the NAPI
> to queue mapping information.
>
> See the commit message of patch 4 for an example of how NAPI IDs are
> persistent despite queue count changes.
>
> Thanks,
> Joe
>
> [1]: https://lore.kernel.org/netdev/[e-mail]/
> [2]: https://lore.kernel.org/netdev/[e-mail]/
> [3]: https://lore.kernel.org/netdev/CACGkMEv=[e-mail]/
>
> v5:
>   - Patch 1 added Acked-by's from Michael and Jason. Added Tested-by
>     from Lei. No functional changes.
>   - Patch 2 added Acked-by's from Michael and Jason. Added Tested-by
>     from Lei. No functional changes.
>   - Patch 3:
>     - Refactored as Jason requested, eliminating the
>       virtnet_queue_set_napi helper entirely, and explicitly holding
>       RTNL in the 3 locations where needed (refill_work, freeze, and
>       restore).
>     - Commit message updated to outline the known paths at the time the
>       commit was written.
>   - Patch 4 added Acked-by from Michael. Added Tested-by from Lei. No
>     functional changes.
>
> v4: https://lore.kernel.org/lkml/[e-mail]/
>   - Dropped Jakub's patch (previously patch 1).
>   - Significant refactor from v3 affecting patches 1-3.
>   - Patch 4 added tags from Jason and Gerhard.
>
> rfcv3: https://lore.kernel.org/netdev/[e-mail]/
>   - patch 3:
>     - Removed the xdp checks completely, as Gerhard Engleder pointed
>       out, they are likely not necessary.
>
>   - patch 4:
>     - Added Xuan Zhuo's Reviewed-by.
>
> v2: https://lore.kernel.org/netdev/[e-mail]/
>   - patch 1:
>     - New in the v2 from Jakub.
>
>   - patch 2:
>     - Previously patch 1, unchanged from v1.
>     - Added Gerhard Engleder's Reviewed-by.
>     - Added Lei Yang's Tested-by.
>
>   - patch 3:
>     - Introduced virtnet_napi_disable to eliminate duplicated code
>       in virtnet_xdp_set, virtnet_rx_pause, virtnet_disable_queue_pair,
>       refill_work as suggested by Jason Wang.
>     - As a result of the above refactor, dropped Reviewed-by and
>       Tested-by from patch 3.
>
>   - patch 4:
>     - New in v2. Adds persistent NAPI configuration. See commit message
>       for more details.
>
> v1: https://lore.kernel.org/netdev/[e-mail]/
>
> Joe Damato (4):
>   virtio-net: Refactor napi_enable paths
>   virtio-net: Refactor napi_disable paths
>   virtio-net: Map NAPIs to queues
>   virtio_net: Use persistent NAPI config
>
>  drivers/net/virtio_net.c | 95 ++++++++++++++++++++++++++++------------
>  1 file changed, 67 insertions(+), 28 deletions(-)
>
>
> base-commit: 7fe0353606d77a32c4c7f2814833dd1c043ebdd2
> --
> 2.45.2
>