[RFC net-next v3 0/4] virtio_net: Link queues to NAPIs
From: Joe Damato
Date: Tue Jan 21 2025 - 14:11:20 EST
Greetings:
Welcome to RFC v3, since net-next is closed. See changelog below.
Recently [1], Jakub mentioned that there were a few drivers that are not
yet mapping queues to NAPIs.
While I don't have any of the other hardware mentioned, I do happen to
have a virtio_net laying around ;)
I've attempted to link queues to NAPIs, using the new locking Jakub
introduced avoiding RTNL.
Note: It seems virtio_net uses TX-only NAPIs which do not have NAPI IDs.
As such, I've left the TX NAPIs unset (as opposed to setting them to 0).
As per the discussion on the v2 [2], all RX queues now have their NAPIs
linked.
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/20250109084301.2445a3e3@xxxxxxxxxx/
[2]: https://lore.kernel.org/netdev/f8fe5618-af94-4f5b-8dbc-e8cae744aedf@xxxxxxxxxxxxxxxxxxxxx/
v3:
- 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:
- 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.
Jakub Kicinski (1):
net: protect queue -> napi linking with netdev_lock()
Joe Damato (3):
virtio_net: Prepare for NAPI to queue mapping
virtio_net: Map NAPIs to queues
virtio_net: Use persistent NAPI config
drivers/net/virtio_net.c | 38 +++++++++++++++++++++++++++--------
include/linux/netdevice.h | 9 +++++++--
include/net/netdev_rx_queue.h | 2 +-
net/core/dev.c | 16 ++++++++++++---
4 files changed, 51 insertions(+), 14 deletions(-)
base-commit: cf33d96f50903214226b379b3f10d1f262dae018
--
2.25.1