linux.git/drivers/net/ntb_netdev.c, branch v7.3-rc2

treewide: refresh kmalloc_obj() conversions

2026-09-05T04:37:00+00:00

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook

net: ntb_netdev: Fix statistics races

2026-09-01T03:09:35+00:00

ntb_netdev updates shared net_device stats from per-QP RX and TX
callbacks. Once multiple queues are enabled, concurrent updates can be
lost.

Use per-CPU tstats for packet and byte counters and DEV_STATS_INC() for
less frequent drop and error counters. Callbacks can run synchronously
in the xmit path or asynchronously from a tasklet or the memcpy kthread.
Pin TX updates against migration in the kthread path. Use the IRQ-safe
u64_stats helpers because netpoll can invoke the synchronous path with
IRQs disabled.

Let the core manage tstats while keeping transport teardown after
unregister_netdev(), outside RTNL. RCU lets unregister wait for TX
completions already updating stats, while later completions only consume
the skb and skip accounting and queue wake.

Fixes: 24d9e73c7e00 ("net: ntb_netdev: Support ethtool channels for multi-queue")
Cc: stable@vger.kernel.org
Suggested-by: Jakub Kicinski 
Signed-off-by: Koichiro Den 
Reviewed-by: Eric Dumazet 
Link: https://patch.msgid.link/20260830151617.3546585-1-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Count packets dropped on RX refill failure

2026-08-22T20:06:08+00:00

When replacement skb allocation fails, ntb_netdev drops a packet that
was received successfully and requeues the original buffer. The drop is
counted, but rx_packets and rx_bytes are not.

Count every good packet before allocating its replacement.

Fixes: d2121faf133a ("NTB: ntb_netdev: Preserve RX queue depth on allocation failure")
Cc: stable@vger.kernel.org
Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260819172539.1450821-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Avoid double-accounting netif_rx() drops

2026-08-22T20:06:08+00:00

netif_rx() already accounts packets it drops in the core rx_dropped
counter. ntb_netdev counts them again as both errors and drops.

Leave netif_rx() drops to the core. Count the packet and bytes
unconditionally since it was received successfully by the driver.

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Cc: stable@vger.kernel.org
Suggested-by: Jakub Kicinski 
Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260819172539.1450821-2-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Fix TX busy and drop handling

2026-08-20T20:43:24+00:00

Currently, ntb_netdev returns NETDEV_TX_BUSY for every enqueue error. It
also increments the drop and error counters while leaving the skb owned
by the qdisc, and may return BUSY with the subqueue still awake.
Retrying a permanent error cannot succeed either.

The unconditional BUSY return and premature accounting date back to the
initial driver. The error-path queue stop was later removed without
changing that return value. The current flow-control code includes a
resource check, but ntb_netdev does not honor its result before enqueue.

Honor the resource check before enqueue. For -EAGAIN and -EBUSY, stop
the subqueue, arm the existing reaper timer, and return BUSY without
touching the skb. For other errors, free the skb, increment tx_dropped,
and return NETDEV_TX_OK.

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Fixes: d723485cb4ca ("ntb_netdev: remove tx timeout")
Fixes: e74bfeedad08 ("NTB: Add flow control to the ntb_netdev")
Cc: stable@vger.kernel.org
Signed-off-by: Koichiro Den 
Reviewed-by: Dave Jiang 
Link: https://patch.msgid.link/20260817053519.4135287-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

NTB: ntb_netdev: Preserve RX queue depth on allocation failure

2026-08-11T09:04:55+00:00

ntb_netdev_rx_handler() hands the received skb to the network stack
before allocating its replacement. If the allocation fails, nothing is
reposted. Every failure therefore takes one buffer out of the RX queue
while the interface remains up, and enough failures eventually stall
reception.

A retry path could refill the queue later, but ntb_netdev has none.
Allocate the replacement first instead. If that fails, drop the packet
and repost the same skb. This keeps the queue full and lets packet
delivery resume as soon as memory is available again.

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Cc: stable@vger.kernel.org
Signed-off-by: Koichiro Den 
Reviewed-by: Dave Jiang 
Link: https://patch.msgid.link/20260806032537.3526498-1-den@valinux.co.jp
Signed-off-by: Paolo Abeni

net: ntb_netdev: add SPDX tag and remove boilerplate license text

2026-03-20T00:17:32+00:00

Add SPDX-License-Identifier tag to reflect the dual
GPL-2.0-only/BSD-3-Clause license, remove the redundant
boilerplate license text and contact information, keeping
only the driver description.

Signed-off-by: Oskar Ray-Frayssinet 
Acked-by: Dave Jiang 
Link: https://patch.msgid.link/20260318211153.9460-1-rayfraytech@gmail.com
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Support ethtool channels for multi-queue

2026-03-07T03:15:20+00:00

Support dynamic queue pair addition/removal via ethtool channels.
Use the combined channel count to control the number of netdev TX/RX
queues, each corresponding to a ntb_transport queue pair.

When the number of queues is reduced, tear down and free the removed
ntb_transport queue pairs (not just deactivate them) so other
ntb_transport clients can reuse the freed resources.

When the number of queues is increased, create additional queue pairs up
to NTB_NETDEV_MAX_QUEUES (=64). The effective limit is determined by the
underlying ntb_transport implementation and NTB hardware resources (the
number of MWs), so set_channels may return -ENOSPC if no more QPs can be
allocated.

Keep the default at one queue pair to preserve the previous behavior.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-5-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Factor out multi-queue helpers

2026-03-07T03:15:20+00:00

Implementing .set_channels will otherwise duplicate the same multi-queue
operations at multiple call sites. Factor out the following helpers:

  - ntb_netdev_update_carrier(): carrier is switched on when at least
                                 one QP link is up
  - ntb_netdev_queue_rx_drain(): drain and free all queued RX packets
                                 for one QP
  - ntb_netdev_queue_rx_fill():  prefill RX ring for one QP

No functional change.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-4-den@valinux.co.jp
Signed-off-by: Jakub Kicinski

net: ntb_netdev: Gate subqueue stop/wake by transport link

2026-03-07T03:15:20+00:00

When ntb_netdev is extended to multiple ntb_transport queue pairs, the
netdev carrier can be up as long as at least one QP link is up. In that
setup, a given QP may be link-down while the carrier remains on.

Make the link event handler start/stop the corresponding netdev TX
subqueue and drive carrier state based on whether any QP link is up.
Also guard subqueue wake/start points in the TX completion and timer
paths so a subqueue is not restarted while its QP link is down.

Stop all queues in ndo_open() and let the link event handler wake each
subqueue once ntb_transport link negotiation succeeds.

Signed-off-by: Koichiro Den 
Link: https://patch.msgid.link/20260305155639.1885517-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski