linux-stable.git/drivers/net/ntb_netdev.c, branch v6.18.50 Linux kernel stable tree net: ntb_netdev: Count packets dropped on RX refill failure 2026-09-07T15:22:54+00:00 Koichiro Den den@valinux.co.jp 2026-08-19T17:25:39+00:00 b893152a886bb53f28dbe027d2d8e7fdeb23e1c6 commit 31ded341c375bb2faac1d77ab0012a732ba3e2a6 upstream. 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 <den@valinux.co.jp> Link: https://patch.msgid.link/20260819172539.1450821-3-den@valinux.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 31ded341c375bb2faac1d77ab0012a732ba3e2a6 upstream.

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 <den@valinux.co.jp>
Link: https://patch.msgid.link/20260819172539.1450821-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ntb_netdev: Avoid double-accounting netif_rx() drops 2026-09-07T15:22:54+00:00 Koichiro Den den@valinux.co.jp 2026-08-19T17:25:38+00:00 4fac86e97697545e21e9963ae417e8dabf95cb81 commit 82e15be2d8b9efa6fb1750528d9b6f40e6a8eea7 upstream. 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 <kuba@kernel.org> Signed-off-by: Koichiro Den <den@valinux.co.jp> Link: https://patch.msgid.link/20260819172539.1450821-2-den@valinux.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 82e15be2d8b9efa6fb1750528d9b6f40e6a8eea7 upstream.

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 <kuba@kernel.org>
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Link: https://patch.msgid.link/20260819172539.1450821-2-den@valinux.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ntb_netdev: Fix TX busy and drop handling 2026-09-07T15:22:54+00:00 Koichiro Den den@valinux.co.jp 2026-08-17T05:35:17+00:00 dfab7171cd3916e51561a2364a35b7186c40283f commit 8aaa47351db0f93a5c5297fbafdfa8bc75e8ae49 upstream. 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 <den@valinux.co.jp> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20260817053519.4135287-3-den@valinux.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8aaa47351db0f93a5c5297fbafdfa8bc75e8ae49 upstream.

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 <den@valinux.co.jp>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260817053519.4135287-3-den@valinux.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NTB: ntb_netdev: Preserve RX queue depth on allocation failure 2026-08-23T12:27:06+00:00 Koichiro Den den@valinux.co.jp 2026-08-06T03:25:37+00:00 a4e340971fe8ccd245d206db4d43b2a0eec240bd commit d2121faf133ac3bf9531b53a7e21273649a08517 upstream. 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 <den@valinux.co.jp> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20260806032537.3526498-1-den@valinux.co.jp Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d2121faf133ac3bf9531b53a7e21273649a08517 upstream.

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 <den@valinux.co.jp>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260806032537.3526498-1-den@valinux.co.jp
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ntb_netdev: Introduce per-queue context 2026-08-23T12:27:06+00:00 Koichiro Den den@valinux.co.jp 2026-03-05T15:56:36+00:00 08437c5156b0a0ec8d963af54d9f4a1398dd3415 commit ee970634c7773f248a0a27d8a645500371ae5249 upstream. Prepare ntb_netdev for multi-queue operation by moving queue-pair state out of struct ntb_netdev. Introduce struct ntb_netdev_queue to carry the ntb_transport_qp pointer, the per-QP TX timer and queue id. Pass this object as the callback context and convert the RX/TX handlers and link event path accordingly. The probe path allocates a fixed upper bound for netdev queues while instantiating only a single ntb_transport queue pair, preserving the previous behavior. Also store client_dev for future queue pair creation/removal via the ntb_transport API. Signed-off-by: Koichiro Den <den@valinux.co.jp> Link: https://patch.msgid.link/20260305155639.1885517-2-den@valinux.co.jp Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: d2121faf133a ("NTB: ntb_netdev: Preserve RX queue depth on allocation failure") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ee970634c7773f248a0a27d8a645500371ae5249 upstream.

Prepare ntb_netdev for multi-queue operation by moving queue-pair state
out of struct ntb_netdev.

Introduce struct ntb_netdev_queue to carry the ntb_transport_qp pointer,
the per-QP TX timer and queue id. Pass this object as the callback
context and convert the RX/TX handlers and link event path accordingly.

The probe path allocates a fixed upper bound for netdev queues while
instantiating only a single ntb_transport queue pair, preserving the
previous behavior. Also store client_dev for future queue pair
creation/removal via the ntb_transport API.

Signed-off-by: Koichiro Den <den@valinux.co.jp>
Link: https://patch.msgid.link/20260305155639.1885517-2-den@valinux.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: d2121faf133a ("NTB: ntb_netdev: Preserve RX queue depth on allocation failure")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08T07:07:37+00:00 Ingo Molnar mingo@kernel.org 2025-05-09T05:51:14+00:00 41cb08555c4164996d67c78b3bf1c658075b75f1 Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com 
Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
treewide: Switch/rename to timer_delete[_sync]() 2025-04-05T08:30:12+00:00 Thomas Gleixner tglx@linutronix.de 2025-04-05T08:17:26+00:00 8fa7292fee5c5240402371ea89ab285ec856c916 timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> 
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx() 2024-07-03T01:56:46+00:00 Dave Jiang dave.jiang@intel.com 2024-07-01T18:15:38+00:00 e15a5d821e5192a3769d846079bc9aa380139baf The following is emitted when using idxd (DSA) dmanegine as the data mover for ntb_transport that ntb_netdev uses. [74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526 [74412.556784] caller is netif_rx_internal+0x42/0x130 [74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5 [74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024 [74412.581699] Call Trace: [74412.584514] <TASK> [74412.586933] dump_stack_lvl+0x55/0x70 [74412.591129] check_preemption_disabled+0xc8/0xf0 [74412.596374] netif_rx_internal+0x42/0x130 [74412.600957] __netif_rx+0x20/0xd0 [74412.604743] ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev] [74412.610985] ntb_complete_rxc+0xed/0x140 [ntb_transport] [74412.617010] ntb_rx_copy_callback+0x53/0x80 [ntb_transport] [74412.623332] idxd_dma_complete_txd+0xe3/0x160 [idxd] [74412.628963] idxd_wq_thread+0x1a6/0x2b0 [idxd] [74412.634046] irq_thread_fn+0x21/0x60 [74412.638134] ? irq_thread+0xa8/0x290 [74412.642218] irq_thread+0x1a0/0x290 [74412.646212] ? __pfx_irq_thread_fn+0x10/0x10 [74412.651071] ? __pfx_irq_thread_dtor+0x10/0x10 [74412.656117] ? __pfx_irq_thread+0x10/0x10 [74412.660686] kthread+0x100/0x130 [74412.664384] ? __pfx_kthread+0x10/0x10 [74412.668639] ret_from_fork+0x31/0x50 [74412.672716] ? __pfx_kthread+0x10/0x10 [74412.676978] ret_from_fork_asm+0x1a/0x30 [74412.681457] </TASK> The cause is due to the idxd driver interrupt completion handler uses threaded interrupt and the threaded handler is not hard or soft interrupt context. However __netif_rx() can only be called from interrupt context. Change the call to netif_rx() in order to allow completion via normal context for dmaengine drivers that utilize threaded irq handling. While the following commit changed from netif_rx() to __netif_rx(), baebdf48c360 ("net: dev: Makes sure netif_rx() can be invoked in any context."), the change should've been a noop instead. However, the code precedes this fix should've been using netif_rx_ni() or netif_rx_any_context(). Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device") Reported-by: Jerry Dai <jerry.dai@intel.com> Tested-by: Jerry Dai <jerry.dai@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Link: https://patch.msgid.link/20240701181538.3799546-1-dave.jiang@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
The following is emitted when using idxd (DSA) dmanegine as the data
mover for ntb_transport that ntb_netdev uses.

[74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526
[74412.556784] caller is netif_rx_internal+0x42/0x130
[74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5
[74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024
[74412.581699] Call Trace:
[74412.584514]  <TASK>
[74412.586933]  dump_stack_lvl+0x55/0x70
[74412.591129]  check_preemption_disabled+0xc8/0xf0
[74412.596374]  netif_rx_internal+0x42/0x130
[74412.600957]  __netif_rx+0x20/0xd0
[74412.604743]  ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev]
[74412.610985]  ntb_complete_rxc+0xed/0x140 [ntb_transport]
[74412.617010]  ntb_rx_copy_callback+0x53/0x80 [ntb_transport]
[74412.623332]  idxd_dma_complete_txd+0xe3/0x160 [idxd]
[74412.628963]  idxd_wq_thread+0x1a6/0x2b0 [idxd]
[74412.634046]  irq_thread_fn+0x21/0x60
[74412.638134]  ? irq_thread+0xa8/0x290
[74412.642218]  irq_thread+0x1a0/0x290
[74412.646212]  ? __pfx_irq_thread_fn+0x10/0x10
[74412.651071]  ? __pfx_irq_thread_dtor+0x10/0x10
[74412.656117]  ? __pfx_irq_thread+0x10/0x10
[74412.660686]  kthread+0x100/0x130
[74412.664384]  ? __pfx_kthread+0x10/0x10
[74412.668639]  ret_from_fork+0x31/0x50
[74412.672716]  ? __pfx_kthread+0x10/0x10
[74412.676978]  ret_from_fork_asm+0x1a/0x30
[74412.681457]  </TASK>

The cause is due to the idxd driver interrupt completion handler uses
threaded interrupt and the threaded handler is not hard or soft interrupt
context. However __netif_rx() can only be called from interrupt context.
Change the call to netif_rx() in order to allow completion via normal
context for dmaengine drivers that utilize threaded irq handling.

While the following commit changed from netif_rx() to __netif_rx(),
baebdf48c360 ("net: dev: Makes sure netif_rx() can be invoked in any context."),
the change should've been a noop instead. However, the code precedes this
fix should've been using netif_rx_ni() or netif_rx_any_context().

Fixes: 548c237c0a99 ("net: Add support for NTB virtual ethernet device")
Reported-by: Jerry Dai <jerry.dai@intel.com>
Tested-by: Jerry Dai <jerry.dai@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20240701181538.3799546-1-dave.jiang@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07T23:19:14+00:00 Eric Dumazet edumazet@google.com 2024-05-06T10:28:12+00:00 1eb2cded45b35816085c1f962933c187d970f9dc Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Simon Horman <horms@kernel.org> Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Shannon Nelson <shannon.nelson@amd.com> Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Simon Horman <horms@kernel.org>
Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ntb_netdev: Fix module_init problem 2023-07-08T15:03:53+00:00 Geoff Levand geoff@infradead.org 2023-06-30T21:58:46+00:00 ce946519f95fe8f74ee1dba25512a33895520f41 With both the ntb_transport_init and the ntb_netdev_init_module routines in the module_init init group, the ntb_netdev_init_module routine can be called before the ntb_transport_init routine that it depends on is called. To assure the proper initialization order put ntb_netdev_init_module in the late_initcall group. Fixes runtime errors where the ntb_netdev_init_module call fails with ENODEV. Signed-off-by: Geoff Levand <geoff@infradead.org> Reviewed-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us> 
With both the ntb_transport_init and the ntb_netdev_init_module routines in the
module_init init group, the ntb_netdev_init_module routine can be called before
the ntb_transport_init routine that it depends on is called.  To assure the
proper initialization order put ntb_netdev_init_module in the late_initcall
group.

Fixes runtime errors where the ntb_netdev_init_module call fails with ENODEV.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>