Add flow control mechanism between paired netdevsim devices to stop the
TX queue during high traffic scenarios. When a receive queue becomes
congested (approaching NSIM_RING_SIZE limit), the corresponding transmit
queue on the peer device is stopped using netif_subqueue_try_stop().
Once the receive queue has sufficient capacity again, the peer's
transmit queue is resumed with netif_tx_wake_queue().
Key changes:
* Add nsim_stop_peer_tx_queue() to pause peer TX when RX queue is full
* Add nsim_start_peer_tx_queue() to resume peer TX when RX queue drains
* Implement queue mapping validation to ensure TX/RX queue count match
* Wake all queues during device unlinking to prevent stuck queues
* Use RCU protection when accessing peer device references
* wake the queues when changing the queue numbers
* Remove IFF_NO_QUEUE given it will enqueue packets now
The flow control only activates when devices have matching TX/RX queue
counts to ensure proper queue mapping.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250711-netdev_flow_control-v3-1-aa1d5a155762@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Protect all ethtool callbacks and PHY related state with the netdev
instance lock, for drivers which want / need to have their ops
instance-locked. Basically take the lock everywhere we take rtnl_lock.
It was tempting to take the lock in ethnl_ops_begin(), but turns
out we actually nest those calls (when generating notifications).
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Cc: Saeed Mahameed <saeed@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250305163732.2766420-11-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Test XDP and HDS interaction. While at it add a test for using the IOCTL,
as that turned out to be the real culprit.
Testing bnxt:
# NETIF=eth0 ./ksft-net-drv/drivers/net/hds.py
KTAP version 1
1..12
ok 1 hds.get_hds
ok 2 hds.get_hds_thresh
ok 3 hds.set_hds_disable # SKIP disabling of HDS not supported by the device
ok 4 hds.set_hds_enable
ok 5 hds.set_hds_thresh_zero
ok 6 hds.set_hds_thresh_max
ok 7 hds.set_hds_thresh_gt
ok 8 hds.set_xdp
ok 9 hds.enabled_set_xdp
ok 10 hds.ioctl
ok 11 hds.ioctl_set_xdp
ok 12 hds.ioctl_enabled_set_xdp
# Totals: pass:11 fail:0 xfail:0 xpass:0 skip:1 error:0
and netdevsim:
# ./ksft-net-drv/drivers/net/hds.py
KTAP version 1
1..12
ok 1 hds.get_hds
ok 2 hds.get_hds_thresh
ok 3 hds.set_hds_disable
ok 4 hds.set_hds_enable
ok 5 hds.set_hds_thresh_zero
ok 6 hds.set_hds_thresh_max
ok 7 hds.set_hds_thresh_gt
ok 8 hds.set_xdp
ok 9 hds.enabled_set_xdp
ok 10 hds.ioctl
ok 11 hds.ioctl_set_xdp
ok 12 hds.ioctl_enabled_set_xdp
# Totals: pass:12 fail:0 xfail:0 xpass:0 skip:0 error:0
Netdevsim needs a sane default for tx/rx ring size.
ethtool 6.11 is needed for the --disable-netlink option.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Tested-by: Taehee Yoo <ap420073@gmail.com>
Link: https://patch.msgid.link/20250221025141.1132944-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Syzbot reports:
BUG: KMSAN: uninit-value in nsim_get_ringparam+0xa8/0xe0 drivers/net/netdevsim/ethtool.c:77
nsim_get_ringparam+0xa8/0xe0 drivers/net/netdevsim/ethtool.c:77
ethtool_set_ringparam+0x268/0x570 net/ethtool/ioctl.c:2072
__dev_ethtool net/ethtool/ioctl.c:3209 [inline]
dev_ethtool+0x126d/0x2a40 net/ethtool/ioctl.c:3398
dev_ioctl+0xb0e/0x1280 net/core/dev_ioctl.c:759
This is the SET path, where we call GET to either check user request
against max values, or check if any of the settings will change.
The logic in netdevsim is trying to report the default (ENABLED)
if user has not requested any specific setting. The user setting
is recorded in dev->cfg, don't depend on kernel_ringparam being
pre-populated with it.
Fixes: 928459bbda ("net: ethtool: populate the default HDS params in the core")
Reported-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot+b3bcd80232d00091e061@syzkaller.appspotmail.com
Tested-by: syzbot+b3bcd80232d00091e061@syzkaller.appspotmail.com
Link: https://patch.msgid.link/20250123221410.1067678-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The core has the current HDS config, it can pre-populate the values
for the drivers. While at it, remove the zero-setting in netdevsim.
Zero are the default values since the config is zalloc'ed.
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250119020518.1962249-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Separate the HDS config from the ethtool state struct.
The HDS config contains just simple parameters, not state.
Having it as a separate struct will make it easier to clone / copy
and also long term potentially make it per-queue.
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250119020518.1962249-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add helpers for locking the netdev instance, use it in drivers
and the shaper code. This will make grepping for the lock usage
much easier, as we extend the lock to cover more fields.
Reviewed-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://patch.msgid.link/20250115035319.559603-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
HDS options(tcp-data-split, hds-thresh) have dependencies between other
features like XDP. Basic dependencies are checked in the core API.
netdevsim is very useful to check basic dependencies.
The default tcp-data-split mode is UNKNOWN but netdevsim driver
returns ENABLED when ethtool dumps tcp-data-split mode.
The default value of HDS threshold is 0 and the maximum value is 1024.
ethtool shows like this.
ethtool -g eni1np1
Ring parameters for eni1np1:
Pre-set maximums:
...
HDS thresh: 1024
Current hardware settings:
...
TCP data split: on
HDS thresh: 0
ethtool -G eni1np1 tcp-data-split on hds-thresh 1024
ethtool -g eni1np1
Ring parameters for eni1np1:
Pre-set maximums:
...
HDS thresh: 1024
Current hardware settings:
...
TCP data split: on
HDS thresh: 1024
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Link: https://patch.msgid.link/20250114142852.3364986-10-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.
Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Real devices should implement qstats. Devices which support
pause or FEC configuration should also report the relevant stats.
nsim was missing FEC stats completely, some of the qstats
and pause stats required toggling a debugfs knob.
Note that the tests which used pause always initialize the setting
so they shouldn't be affected by the different starting value.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I'd like to make netdevsim offload tc-taprio, but currently, this Qdisc
emits a ETHTOOL_GET_TS_INFO call to the driver to make sure that it has
a PTP clock, so that it is reasonably capable of offloading the schedule.
By using the mock PHC driver, that becomes possible.
Hardware timestamping is not necessary, and netdevsim does not support
packet I/O anyway.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230807193324.4128292-8-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Ethtool ring feature has _max_pending attributes read-only.
Set only read-write attributes in nsim_set_ringparam.
This patch is useful, if netdevsim device is set-up using NetworkManager,
because NetworkManager sends 0 as MAX values, as it is pointless to
retrieve them in extra call, because they should be read-only. Then,
the device is left in incosistent state (value > MAX).
Fixes: a7fc6db099 ("netdevsim: support ethtool ring and coalesce settings")
Signed-off-by: Filip Pokryvka <fpokryvk@redhat.com>
Link: https://lore.kernel.org/r/20211210175032.411872-1-fpokryvk@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add two new parameters kernel_ringparam and extack for
.get_ringparam and .set_ringparam to extend more ring params
through netlink.
Signed-off-by: Hao Chen <chenhao288@hisilicon.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For testing visibility of mq/mqprio default children.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to support more coalesce parameters through netlink,
add two new parameter kernel_coal and extack for .set_coalesce
and .get_coalesce, then some extra info can return to user with
the netlink API.
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add support for ethtool FEC and some ethtool error injection.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add ethtool ring and coalesce settings support for testing.
Signed-off-by: Antonio Cardace <acardace@redhat.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This will help the refactoring in the next commit
when coalesce and ring settings are added.
Signed-off-by: Antonio Cardace <acardace@redhat.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The "ethtool" debugfs directory holds per-netdev knobs, so move
it from the device instance directory to the port directory.
This fixes the following warning when creating multiple ports:
debugfs: Directory 'ethtool' with parent 'netdevsim1' already present!
Fixes: ff1f7c17fb ("netdevsim: add pause frame stats")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add minimal ethtool interface for testing ethtool pause stats.
v2: add missing static on nsim_ethtool_ops
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
