linux.git/net/core/netdev_rx_queue.c, branch v6.18.21 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git net: add helper to pre-check if PP for an Rx queue will be unreadable 2025-09-04T08:19:17+00:00 Jakub Kicinski kuba@kernel.org 2025-09-01T21:12:10+00:00 3ceb08838b576b20108d7facf6baa3dbf792afe9 mlx5 pokes into the rxq state to check if the queue has a memory provider, and therefore whether it may produce unreadable mem. Add a helper for doing this in the page pool API. fbnic will want a similar thing (tho, for a slightly different reason). Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20250901211214.1027927-11-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> 
mlx5 pokes into the rxq state to check if the queue has a memory
provider, and therefore whether it may produce unreadable mem.
Add a helper for doing this in the page pool API. fbnic will want
a similar thing (tho, for a slightly different reason).

Reviewed-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20250901211214.1027927-11-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
net: Reoder rxq_idx check in __net_mp_open_rxq() 2025-06-25T23:53:51+00:00 Yue Haibing yuehaibing@huawei.com 2025-06-24T14:01:59+00:00 f6fa45d67e0546c114063c8b0acff48a0924738d array_index_nospec() clamp the rxq_idx within the range of [0, dev->real_num_rx_queues), move the check before it. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250624140159.3929503-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
array_index_nospec() clamp the rxq_idx within the range of
[0, dev->real_num_rx_queues), move the check before it.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250624140159.3929503-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: avoid false positive warnings in __net_mp_close_rxq() 2025-04-04T14:35:38+00:00 Jakub Kicinski kuba@kernel.org 2025-04-03T01:34:05+00:00 34f71de3f548eba0604c9cbabc1eb68b2f81fa0f Commit under Fixes solved the problem of spurious warnings when we uninstall an MP from a device while its down. The __net_mp_close_rxq() which is used by io_uring was not fixed. Move the fix over and reuse __net_mp_close_rxq() in the devmem path. Acked-by: Stanislav Fomichev <sdf@fomichev.me> Fixes: a70f891e0fa0 ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()") Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250403013405.2827250-3-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Commit under Fixes solved the problem of spurious warnings when we
uninstall an MP from a device while its down. The __net_mp_close_rxq()
which is used by io_uring was not fixed. Move the fix over and reuse
__net_mp_close_rxq() in the devmem path.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Fixes: a70f891e0fa0 ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()")
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250403013405.2827250-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: move mp dev config validation to __net_mp_open_rxq() 2025-04-04T14:35:38+00:00 Jakub Kicinski kuba@kernel.org 2025-04-03T01:34:04+00:00 ec304b70d46bd2ed66541c5b57b63276529e05b1 devmem code performs a number of safety checks to avoid having to reimplement all of them in the drivers. Move those to __net_mp_open_rxq() and reuse that function for binding to make sure that io_uring ZC also benefits from them. While at it rename the queue ID variable to rxq_idx in __net_mp_open_rxq(), we touch most of the relevant lines. The XArray insertion is reordered after the netdev_rx_queue_restart() call, otherwise we'd need to duplicate the queue index check or risk inserting an invalid pointer. The XArray allocation failures should be extremely rare. Reviewed-by: Mina Almasry <almasrymina@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Fixes: 6e18ed929d3b ("net: add helpers for setting a memory provider on an rx queue") Link: https://patch.msgid.link/20250403013405.2827250-2-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
devmem code performs a number of safety checks to avoid having
to reimplement all of them in the drivers. Move those to
__net_mp_open_rxq() and reuse that function for binding to make
sure that io_uring ZC also benefits from them.

While at it rename the queue ID variable to rxq_idx in
__net_mp_open_rxq(), we touch most of the relevant lines.

The XArray insertion is reordered after the netdev_rx_queue_restart()
call, otherwise we'd need to duplicate the queue index check
or risk inserting an invalid pointer. The XArray allocation
failures should be extremely rare.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Fixes: 6e18ed929d3b ("net: add helpers for setting a memory provider on an rx queue")
Link: https://patch.msgid.link/20250403013405.2827250-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: designate queue counts as "double ops protected" by instance lock 2025-03-25T17:06:49+00:00 Jakub Kicinski kuba@kernel.org 2025-03-24T22:45:31+00:00 0a65dcf6249b75c841b4218426b0d246a805c7e0 Drivers which opt into instance lock protection of ops should only call set_real_num_*_queues() under the instance lock. This means that queue counts are double protected (writes are under both rtnl_lock and instance lock, readers under either). Some readers may still be under the rtnl_lock, however, so for now we need double protection of writers. OTOH queue API paths are only under the protection of the instance lock, so we need to validate that the instance is actually locking ops, otherwise the input checks we do against queue count are racy. Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250324224537.248800-6-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Drivers which opt into instance lock protection of ops should
only call set_real_num_*_queues() under the instance lock.
This means that queue counts are double protected (writes
are under both rtnl_lock and instance lock, readers under
either).

Some readers may still be under the rtnl_lock, however, so for
now we need double protection of writers.

OTOH queue API paths are only under the protection of the instance
lock, so we need to validate that the instance is actually locking
ops, otherwise the input checks we do against queue count are racy.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250324224537.248800-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: drop rtnl_lock for queue_mgmt operations 2025-03-12T20:32:35+00:00 Stanislav Fomichev sdf@fomichev.me 2025-03-11T14:40:26+00:00 1d22d3060b9b1f33da617045480c59c4c0511196 All drivers that use queue API are already converted to use netdev instance lock. Move netdev instance lock management to the netlink layer and drop rtnl_lock. Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Mina Almasry. <almasrymina@google.com> Link: https://patch.msgid.link/20250311144026.4154277-4-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
All drivers that use queue API are already converted to use
netdev instance lock. Move netdev instance lock management to
the netlink layer and drop rtnl_lock.

Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Mina Almasry. <almasrymina@google.com>
Link: https://patch.msgid.link/20250311144026.4154277-4-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: hold netdev instance lock during queue operations 2025-03-06T20:59:43+00:00 Stanislav Fomichev sdf@fomichev.me 2025-03-05T16:37:23+00:00 cae03e5bdd9e0c8570506c50f1f234da40201732 For the drivers that use queue management API, switch to the mode where core stack holds the netdev instance lock. This affects the following drivers: - bnxt - gve - netdevsim Originally I locked only start/stop, but switched to holding the lock over all iterations to make them look atomic to the device (feels like it should be easier to reason about). Reviewed-by: Eric Dumazet <edumazet@google.com> Cc: Saeed Mahameed <saeed@kernel.org> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250305163732.2766420-6-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
For the drivers that use queue management API, switch to the mode where
core stack holds the netdev instance lock. This affects the following
drivers:
- bnxt
- gve
- netdevsim

Originally I locked only start/stop, but switched to holding the
lock over all iterations to make them look atomic to the device
(feels like it should be easier to reason about).

Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-6-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: devmem: don't call queue stop / start when the interface is down 2025-02-08T01:21:02+00:00 Jakub Kicinski kuba@kernel.org 2025-02-06T22:56:36+00:00 3e7efc3f4f03bca0ea630c302e7c79cf807476bb We seem to be missing a netif_running() check from the devmem installation path. Starting a queue on a stopped device makes no sense. We still want to be able to allocate the memory, just to test that the device is indeed setting up the page pools in a memory provider compatible way. This is not a bug fix, because existing drivers check if the interface is down as part of the ops. But new drivers shouldn't have to do this, as long as they can correctly alloc/free while down. Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250206225638.1387810-3-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
We seem to be missing a netif_running() check from the devmem
installation path. Starting a queue on a stopped device makes
no sense. We still want to be able to allocate the memory, just
to test that the device is indeed setting up the page pools
in a memory provider compatible way.

This is not a bug fix, because existing drivers check if
the interface is down as part of the ops. But new drivers
shouldn't have to do this, as long as they can correctly
alloc/free while down.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250206225638.1387810-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: refactor netdev_rx_queue_restart() to use local qops 2025-02-08T01:21:02+00:00 Jakub Kicinski kuba@kernel.org 2025-02-06T22:56:35+00:00 1eb824d69f8d88405e4e80c568e8f07080309fb0 Shorten the lines by storing dev->queue_mgmt_ops in a temp variable. Reviewed-by: Mina Almasry <almasrymina@google.com> Link: https://patch.msgid.link/20250206225638.1387810-2-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Shorten the lines by storing dev->queue_mgmt_ops in a temp variable.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250206225638.1387810-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: add helpers for setting a memory provider on an rx queue 2025-02-07T00:27:31+00:00 David Wei dw@davidwei.uk 2025-02-04T21:56:21+00:00 6e18ed929d3ba9b3b92ba5894f9233686b3e3ec1 Add helpers that properly prep or remove a memory provider for an rx queue then restart the queue. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: David Wei <dw@davidwei.uk> Link: https://patch.msgid.link/20250204215622.695511-11-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Add helpers that properly prep or remove a memory provider for an rx
queue then restart the queue.

Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://patch.msgid.link/20250204215622.695511-11-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>