Rename the leftover ifq_idx parameter naming to rxq_idx to be
consistent with the rest of the file and the header declaration.
Back then this was taken out of the queue leasing series given
the cleanup is independent. No functional change.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/netdev/20260131160237.07789674@kernel.org
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260410130602.552600-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The netif_get_rx_queue_lease_locked() API hides the locking
and the descend onto the leased queue. Making the code
harder to follow (at least to me). Remove the API and open
code the descend a bit. Most of the code now looks like:
if (!leased)
return __helper(x);
hw_rxq = ..
netdev_lock(hw_rxq->dev);
ret = __helper(x);
netdev_unlock(hw_rxq->dev);
return ret;
Of course if we have more code paths that need the wrapping
we may need to revisit. For now, IMHO, having to know what
netif_get_rx_queue_lease_locked() does is not worth the 20LoC
it saves.
Link: https://patch.msgid.link/20260408151251.72bd2482@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Daniel Borkmann says:
====================
netkit: Support for io_uring zero-copy and AF_XDP
Containers use virtual netdevs to route traffic from a physical netdev
in the host namespace. They do not have access to the physical netdev
in the host and thus can't use memory providers or AF_XDP that require
reconfiguring/restarting queues in the physical netdev.
This patchset adds the concept of queue leasing to virtual netdevs that
allow containers to use memory providers and AF_XDP at native speed.
Leased queues are bound to a real queue in a physical netdev and act
as a proxy.
Memory providers and AF_XDP operations take an ifindex and queue id,
so containers would pass in an ifindex for a virtual netdev and a queue
id of a leased queue, which then gets proxied to the underlying real
queue.
We have implemented support for this concept in netkit and tested the
latter against Nvidia ConnectX-6 (mlx5) as well as Broadcom BCM957504
(bnxt_en) 100G NICs. For more details see the individual patches.
====================
Link: https://patch.msgid.link/20260402231031.447597-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a process in a container wants to setup a memory provider, it will
use the virtual netdev and a leased rxq, and call netif_mp_{open,close}_rxq
to try and restart the queue. At this point, proxy the queue restart on
the real rxq in the physical netdev.
For memory providers (io_uring zero-copy rx and devmem), it causes the
real rxq in the physical netdev to be filled from a memory provider that
has DMA mapped memory from a process within a container.
Signed-off-by: David Wei <dw@davidwei.uk>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-7-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net_mp_open_rxq is currently not used in the tree as all callers are
using __net_mp_open_rxq directly, and net_mp_close_rxq is only used
once while all other locations use __net_mp_close_rxq.
Consolidate into a single API, netif_mp_{open,close}_rxq, using the
netif_ prefix to indicate that the caller is responsible for locking.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-6-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Populate nested lease info to the queue-get response that returns the
ifindex, queue id with type and optionally netns id if the device
resides in a different netns.
Example with ynl client when using AF_XDP via queue leasing:
# ip a
[...]
4: enp10s0f0np0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp/id:24 qdisc mq state UP group default qlen 1000
link/ether e8:eb:d3:a3:43:f6 brd ff:ff:ff:ff:ff:ff
inet 10.0.0.2/24 scope global enp10s0f0np0
valid_lft forever preferred_lft forever
inet6 fe80::eaeb:d3ff:fea3:43f6/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
[...]
# ethtool -i enp10s0f0np0
driver: mlx5_core
[...]
# ynl --family netdev --output-json --do queue-get \
--json '{"ifindex": 4, "id": 15, "type": "rx"}'
{'id': 15,
'ifindex': 4,
'lease': {'ifindex': 8, 'netns-id': 0, 'queue': {'id': 1, 'type': 'rx'}},
'napi-id': 8227,
'type': 'rx',
'xsk': {}}
# ip netns list
foo (id: 0)
# ip netns exec foo ip a
[...]
8: nk@NONE: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
inet6 fe80::200:ff:fe00:0/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
[...]
# ip netns exec foo ethtool -i nk
driver: netkit
[...]
# ip netns exec foo ls /sys/class/net/nk/queues/
rx-0 rx-1 tx-0
# ip netns exec foo ynl --family netdev --output-json --do queue-get \
--json '{"ifindex": 8, "id": 1, "type": "rx"}'
{"id": 1, "type": "rx", "ifindex": 8, "xsk": {}}
Note that the caller of netdev_nl_queue_fill_one() holds the netdevice
lock. For the queue-get we do not lock both devices. When queues get
{un,}leased, both devices are locked, thus if __netif_get_rx_queue_lease()
returns a lease pointer, it points to a valid device. The netns-id is
fetched via peernet2id_alloc() similarly as done in OVS.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-4-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Implement netdev_nl_queue_create_doit which creates a new rx queue in a
virtual netdev and then leases it to a rx queue in a physical netdev.
Example with ynl client:
# ynl --family netdev --output-json --do queue-create \
--json '{"ifindex": 8, "type": "rx", "lease": {"ifindex": 4, "queue": {"type": "rx", "id": 15}}}'
{'id': 1}
Note that the netdevice locking order is always from the virtual to
the physical device.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Co-developed-by: David Wei <dw@davidwei.uk>
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260402231031.447597-3-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Sashiko points out that we use qops in __net_mp_open_rxq()
but never validate they are null. This was introduced when
check was moved from netdev_rx_queue_restart().
Look at ops directly instead of the locking config.
qops imply netdev_need_ops_lock(). We used netdev_need_ops_lock()
initially to signify that the real_num_rx_queues check below
is safe without rtnl_lock, but I'm not sure if this is actually
clear to most people, anyway.
Fixes: da7772a2b4 ("net: move mp->rx_page_size validation to __net_mp_open_rxq()")
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20260404001938.2425670-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
I imagine (tm) that as the number of per-queue configuration
options grows some of them may conflict for certain drivers.
While the drivers can obviously do all the validation locally
doing so is fairly inconvenient as the config is fed to drivers
piecemeal via different ops (for different params and NIC-wide
vs per-queue).
Add a centralized callback for validating the queue config
in queue ops. The callback gets invoked before memory provider
is installed, and in the future should also be called when ring
params are modified.
The validation is done after each layer of configuration.
Since we can't fail MP un-binding we must make sure that
the config is valid both before and after MP overrides are
applied. This is moot for now since the set of MP and device
configs are disjoint. It will matter significantly in the future,
so adding it now so that we don't forget..
Link: https://patch.msgid.link/20260122005113.2476634-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We should follow the prepare/commit approach for queue configuration.
The qcfg struct should be added to dev->cfg rather than directly to
queue objects so that we can clone and discard the pending config
easily.
Remove the qcfg in struct netdev_rx_queue, and switch remaining callers
to netdev_queue_config(). netdev_queue_config() will construct the qcfg
on the fly based on device defaults and state of the queue.
ndo_default_qcfg becomes optional because having the callback itself
does not have any meaningful semantics to us.
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://patch.msgid.link/20260122005113.2476634-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Move mp->rx_page_size validation where the rest of MP input
validation lives. No other caller is modifying mp params so
validation logic in queue restarts is out of place.
Link: https://patch.msgid.link/20260122005113.2476634-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Allow memory providers to configure rx queues with a custom receive
page size. It's passed in struct pp_memory_provider_params, which is
copied into the queue, so it's preserved across queue restarts. Then,
it's propagated to the driver in a new queue config parameter.
Drivers should explicitly opt into using it by setting
QCFG_RX_PAGE_SIZE, in which case they should implement ndo_default_qcfg,
validate the size on queue restart and honour the current config in case
of a reset.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
We'll need to pass extra parameters when allocating a queue for memory
providers. Define a new structure for queue configurations, and pass it
to qapi callbacks. It's empty for now, actual parameters will be added
in following patches.
Configurations should persist across resets, and for that they're
default-initialised on device registration and stored in struct
netdev_rx_queue. We also add a new qapi callback for defaulting a given
config. It must be implemented if a driver wants to use queue configs
and is optional otherwise.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Instead of resetting memory provider parameters one by one in
__net_mp_{open,close}_rxq, memzero the entire structure. It'll be used
to extend the structure.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.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>
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>
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: a70f891e0f ("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>
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: 6e18ed929d ("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>
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>
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>
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>
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>
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>
Linus suggested during one of past maintainer summits (in context of
a DMA_BUF discussion) that symbol namespaces can be used to prevent
unwelcome but in-tree code from using all exported functions.
Create a namespace for netdev.
Export netdev_rx_queue_restart(), drivers may want to use it since
it gives them a simple and safe way to restart a queue to apply
config changes. But it's both too low level and too actively developed
to be used outside netdev.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Implement a memory provider that allocates dmabuf devmem in the form of
net_iov.
The provider receives a reference to the struct netdev_dmabuf_binding
via the pool->mp_priv pointer. The driver needs to set this pointer for
the provider in the net_iov.
The provider obtains a reference on the netdev_dmabuf_binding which
guarantees the binding and the underlying mapping remains alive until
the provider is destroyed.
Usage of PP_FLAG_DMA_MAP is required for this memory provide such that
the page_pool can provide the driver with the dma-addrs of the devmem.
Support for PP_FLAG_DMA_SYNC_DEV is omitted for simplicity & p.order !=
0.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Kaiyuan Zhang <kaiyuanz@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-7-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add netdev_rx_queue_restart(), which resets an rx queue using the
queue API recently merged[1].
The queue API was merged to enable the core net stack to reset individual
rx queues to actuate changes in the rx queue's configuration. In later
patches in this series, we will use netdev_rx_queue_restart() to reset
rx queues after binding or unbinding dmabuf configuration, which will
cause reallocation of the page_pool to repopulate its memory using the
new configuration.
[1] https://lore.kernel.org/netdev/20240430231420.699177-1-shailend@google.com/T/
Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20240910171458.219195-2-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
