From b454abfab52543c44b581afc807b9f97fc1e7a3a Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 5 Dec 2024 16:55:18 +0200 Subject: net: mscc: ocelot: be resilient to loss of PTP packets during transmission The Felix DSA driver presents unique challenges that make the simplistic ocelot PTP TX timestamping procedure unreliable: any transmitted packet may be lost in hardware before it ever leaves our local system. This may happen because there is congestion on the DSA conduit, the switch CPU port or even user port (Qdiscs like taprio may delay packets indefinitely by design). The technical problem is that the kernel, i.e. ocelot_port_add_txtstamp_skb(), runs out of timestamp IDs eventually, because it never detects that packets are lost, and keeps the IDs of the lost packets on hold indefinitely. The manifestation of the issue once the entire timestamp ID range becomes busy looks like this in dmesg: mscc_felix 0000:00:00.5: port 0 delivering skb without TX timestamp mscc_felix 0000:00:00.5: port 1 delivering skb without TX timestamp At the surface level, we need a timeout timer so that the kernel knows a timestamp ID is available again. But there is a deeper problem with the implementation, which is the monotonically increasing ocelot_port->ts_id. In the presence of packet loss, it will be impossible to detect that and reuse one of the holes created in the range of free timestamp IDs. What we actually need is a bitmap of 63 timestamp IDs tracking which one is available. That is able to use up holes caused by packet loss, but also gives us a unique opportunity to not implement an actual timer_list for the timeout timer (very complicated in terms of locking). We could only declare a timestamp ID stale on demand (lazily), aka when there's no other timestamp ID available. There are pros and cons to this approach: the implementation is much more simple than per-packet timers would be, but most of the stale packets would be quasi-leaked - not really leaked, but blocked in driver memory, since this algorithm sees no reason to free them. An improved technique would be to check for stale timestamp IDs every time we allocate a new one. Assuming a constant flux of PTP packets, this avoids stale packets being blocked in memory, but of course, packets lost at the end of the flux are still blocked until the flux resumes (nobody left to kick them out). Since implementing per-packet timers is way too complicated, this should be good enough. Testing procedure: Persistently block traffic class 5 and try to run PTP on it: $ tc qdisc replace dev swp3 parent root taprio num_tc 8 \ map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \ base-time 0 sched-entry S 0xdf 100000 flags 0x2 [ 126.948141] mscc_felix 0000:00:00.5: port 3 tc 5 min gate length 0 ns not enough for max frame size 1526 at 1000 Mbps, dropping frames over 1 octets including FCS $ ptp4l -i swp3 -2 -P -m --socket_priority 5 --fault_reset_interval ASAP --logSyncInterval -3 ptp4l[70.351]: port 1 (swp3): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[70.354]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[70.358]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE [ 70.394583] mscc_felix 0000:00:00.5: port 3 timestamp id 0 ptp4l[70.406]: timed out while polling for tx timestamp ptp4l[70.406]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[70.406]: port 1 (swp3): send peer delay response failed ptp4l[70.407]: port 1 (swp3): clearing fault immediately ptp4l[70.952]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1 [ 71.394858] mscc_felix 0000:00:00.5: port 3 timestamp id 1 ptp4l[71.400]: timed out while polling for tx timestamp ptp4l[71.400]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[71.401]: port 1 (swp3): send peer delay response failed ptp4l[71.401]: port 1 (swp3): clearing fault immediately [ 72.393616] mscc_felix 0000:00:00.5: port 3 timestamp id 2 ptp4l[72.401]: timed out while polling for tx timestamp ptp4l[72.402]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[72.402]: port 1 (swp3): send peer delay response failed ptp4l[72.402]: port 1 (swp3): clearing fault immediately ptp4l[72.952]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1 [ 73.395291] mscc_felix 0000:00:00.5: port 3 timestamp id 3 ptp4l[73.400]: timed out while polling for tx timestamp ptp4l[73.400]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[73.400]: port 1 (swp3): send peer delay response failed ptp4l[73.400]: port 1 (swp3): clearing fault immediately [ 74.394282] mscc_felix 0000:00:00.5: port 3 timestamp id 4 ptp4l[74.400]: timed out while polling for tx timestamp ptp4l[74.401]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[74.401]: port 1 (swp3): send peer delay response failed ptp4l[74.401]: port 1 (swp3): clearing fault immediately ptp4l[74.953]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1 [ 75.396830] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 0 which seems lost [ 75.405760] mscc_felix 0000:00:00.5: port 3 timestamp id 0 ptp4l[75.410]: timed out while polling for tx timestamp ptp4l[75.411]: increasing tx_timestamp_timeout or increasing kworker priority may correct this issue, but a driver bug likely causes it ptp4l[75.411]: port 1 (swp3): send peer delay response failed ptp4l[75.411]: port 1 (swp3): clearing fault immediately (...) Remove the blocking condition and see that the port recovers: $ same tc command as above, but use "sched-entry S 0xff" instead $ same ptp4l command as above ptp4l[99.489]: port 1 (swp3): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[99.490]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[99.492]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE [ 100.403768] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 0 which seems lost [ 100.412545] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 1 which seems lost [ 100.421283] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 2 which seems lost [ 100.430015] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 3 which seems lost [ 100.438744] mscc_felix 0000:00:00.5: port 3 invalidating stale timestamp ID 4 which seems lost [ 100.447470] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 100.505919] mscc_felix 0000:00:00.5: port 3 timestamp id 0 ptp4l[100.963]: port 1 (swp3): new foreign master d858d7.fffe.00ca6d-1 [ 101.405077] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 101.507953] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 102.405405] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 102.509391] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 103.406003] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 103.510011] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 104.405601] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 104.510624] mscc_felix 0000:00:00.5: port 3 timestamp id 0 ptp4l[104.965]: selected best master clock d858d7.fffe.00ca6d ptp4l[104.966]: port 1 (swp3): assuming the grand master role ptp4l[104.967]: port 1 (swp3): LISTENING to GRAND_MASTER on RS_GRAND_MASTER [ 105.106201] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.232420] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.359001] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.405500] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.485356] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.511220] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.610938] mscc_felix 0000:00:00.5: port 3 timestamp id 0 [ 105.737237] mscc_felix 0000:00:00.5: port 3 timestamp id 0 (...) Notice that in this new usage pattern, a non-congested port should basically use timestamp ID 0 all the time, progressing to higher numbers only if there are unacknowledged timestamps in flight. Compare this to the old usage, where the timestamp ID used to monotonically increase modulo OCELOT_MAX_PTP_ID. In terms of implementation, this simplifies the bookkeeping of the ocelot_port :: ts_id and ptp_skbs_in_flight. Since we need to traverse the list of two-step timestampable skbs for each new packet anyway, the information can already be computed and does not need to be stored. Also, ocelot_port->tx_skbs is always accessed under the switch-wide ocelot->ts_id_lock IRQ-unsafe spinlock, so we don't need the skb queue's lock and can use the unlocked primitives safely. This problem was actually detected using the tc-taprio offload, and is causing trouble in TSN scenarios, which Felix (NXP LS1028A / VSC9959) supports but Ocelot (VSC7514) does not. Thus, I've selected the commit to blame as the one adding initial timestamping support for the Felix switch. Fixes: c0bcf537667c ("net: dsa: ocelot: add hardware timestamping support for Felix") Signed-off-by: Vladimir Oltean Link: https://patch.msgid.link/20241205145519.1236778-5-vladimir.oltean@nxp.com Signed-off-by: Jakub Kicinski --- include/linux/dsa/ocelot.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/dsa/ocelot.h b/include/linux/dsa/ocelot.h index 6fbfbde68a37..620a3260fc08 100644 --- a/include/linux/dsa/ocelot.h +++ b/include/linux/dsa/ocelot.h @@ -15,6 +15,7 @@ struct ocelot_skb_cb { struct sk_buff *clone; unsigned int ptp_class; /* valid only for clones */ + unsigned long ptp_tx_time; /* valid only for clones */ u32 tstamp_lo; u8 ptp_cmd; u8 ts_id; -- cgit v1.2.3 From 8d6712c892019b9b9dc5c7039edd3c9d770b510b Mon Sep 17 00:00:00 2001 From: Koichiro Den Date: Fri, 6 Dec 2024 10:10:44 +0900 Subject: virtio_ring: add a func argument 'recycle_done' to virtqueue_resize() When virtqueue_resize() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when the recycle really occurs. Cc: # v6.11+ Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni --- drivers/net/virtio_net.c | 4 ++-- drivers/virtio/virtio_ring.c | 6 +++++- include/linux/virtio.h | 3 ++- 3 files changed, 9 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fc89c5e1a207..e10bc9e6b072 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3331,7 +3331,7 @@ static int virtnet_rx_resize(struct virtnet_info *vi, virtnet_rx_pause(vi, rq); - err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_unmap_free_buf); + err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_unmap_free_buf, NULL); if (err) netdev_err(vi->dev, "resize rx fail: rx queue index: %d err: %d\n", qindex, err); @@ -3394,7 +3394,7 @@ static int virtnet_tx_resize(struct virtnet_info *vi, struct send_queue *sq, virtnet_tx_pause(vi, sq); - err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf); + err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf, NULL); if (err) netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 82a7d2cbc704..6af8cf6a619e 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2772,6 +2772,7 @@ EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma); * @_vq: the struct virtqueue we're talking about. * @num: new ring num * @recycle: callback to recycle unused buffers + * @recycle_done: callback to be invoked when recycle for all unused buffers done * * When it is really necessary to create a new vring, it will set the current vq * into the reset state. Then call the passed callback to recycle the buffer @@ -2792,7 +2793,8 @@ EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma); * */ int virtqueue_resize(struct virtqueue *_vq, u32 num, - void (*recycle)(struct virtqueue *vq, void *buf)) + void (*recycle)(struct virtqueue *vq, void *buf), + void (*recycle_done)(struct virtqueue *vq)) { struct vring_virtqueue *vq = to_vvq(_vq); int err; @@ -2809,6 +2811,8 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num, err = virtqueue_disable_and_recycle(_vq, recycle); if (err) return err; + if (recycle_done) + recycle_done(_vq); if (vq->packed_ring) err = virtqueue_resize_packed(_vq, num); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 57cc4b07fd17..0aa7df4ed5ca 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -109,7 +109,8 @@ dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq); dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq); int virtqueue_resize(struct virtqueue *vq, u32 num, - void (*recycle)(struct virtqueue *vq, void *buf)); + void (*recycle)(struct virtqueue *vq, void *buf), + void (*recycle_done)(struct virtqueue *vq)); int virtqueue_reset(struct virtqueue *vq, void (*recycle)(struct virtqueue *vq, void *buf)); -- cgit v1.2.3 From 8d2da07c813ad333c20eb803e15f8c4541f25350 Mon Sep 17 00:00:00 2001 From: Koichiro Den Date: Fri, 6 Dec 2024 10:10:46 +0900 Subject: virtio_ring: add a func argument 'recycle_done' to virtqueue_reset() When virtqueue_reset() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when it really occurs. Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni --- drivers/net/virtio_net.c | 4 ++-- drivers/virtio/virtio_ring.c | 6 +++++- include/linux/virtio.h | 3 ++- 3 files changed, 9 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 3a0341cc6085..5cf4b2b20431 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -5711,7 +5711,7 @@ static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queu virtnet_rx_pause(vi, rq); - err = virtqueue_reset(rq->vq, virtnet_rq_unmap_free_buf); + err = virtqueue_reset(rq->vq, virtnet_rq_unmap_free_buf, NULL); if (err) { netdev_err(vi->dev, "reset rx fail: rx queue index: %d err: %d\n", qindex, err); @@ -5740,7 +5740,7 @@ static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi, virtnet_tx_pause(vi, sq); - err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf); + err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf, NULL); if (err) { netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err); pool = NULL; diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 6af8cf6a619e..fdd2d2b07b5a 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2827,6 +2827,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize); * virtqueue_reset - detach and recycle all unused buffers * @_vq: the struct virtqueue we're talking about. * @recycle: callback to recycle unused buffers + * @recycle_done: callback to be invoked when recycle for all unused buffers done * * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). @@ -2838,7 +2839,8 @@ EXPORT_SYMBOL_GPL(virtqueue_resize); * -EPERM: Operation not permitted */ int virtqueue_reset(struct virtqueue *_vq, - void (*recycle)(struct virtqueue *vq, void *buf)) + void (*recycle)(struct virtqueue *vq, void *buf), + void (*recycle_done)(struct virtqueue *vq)) { struct vring_virtqueue *vq = to_vvq(_vq); int err; @@ -2846,6 +2848,8 @@ int virtqueue_reset(struct virtqueue *_vq, err = virtqueue_disable_and_recycle(_vq, recycle); if (err) return err; + if (recycle_done) + recycle_done(_vq); if (vq->packed_ring) virtqueue_reinit_packed(vq); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 0aa7df4ed5ca..dd88682e27e3 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -112,7 +112,8 @@ int virtqueue_resize(struct virtqueue *vq, u32 num, void (*recycle)(struct virtqueue *vq, void *buf), void (*recycle_done)(struct virtqueue *vq)); int virtqueue_reset(struct virtqueue *vq, - void (*recycle)(struct virtqueue *vq, void *buf)); + void (*recycle)(struct virtqueue *vq, void *buf), + void (*recycle_done)(struct virtqueue *vq)); struct virtio_admin_cmd { __le16 opcode; -- cgit v1.2.3 From d2516c3a53705f783bb6868df0f4a2b977898a71 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 10 Dec 2024 15:12:41 +0100 Subject: net, team, bonding: Add netdev_base_features helper Both bonding and team driver have logic to derive the base feature flags before iterating over their slave devices to refine the set via netdev_increment_features(). Add a small helper netdev_base_features() so this can be reused instead of having it open-coded multiple times. Signed-off-by: Daniel Borkmann Cc: Nikolay Aleksandrov Cc: Ido Schimmel Cc: Jiri Pirko Reviewed-by: Hangbin Liu Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20241210141245.327886-1-daniel@iogearbox.net Signed-off-by: Paolo Abeni --- drivers/net/bonding/bond_main.c | 4 +--- drivers/net/team/team_core.c | 3 +-- include/linux/netdev_features.h | 7 +++++++ 3 files changed, 9 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 49dd4fe195e5..42c835c60cd8 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1520,9 +1520,7 @@ static netdev_features_t bond_fix_features(struct net_device *dev, struct slave *slave; mask = features; - - features &= ~NETIF_F_ONE_FOR_ALL; - features |= NETIF_F_ALL_FOR_ALL; + features = netdev_base_features(features); bond_for_each_slave(bond, slave, iter) { features = netdev_increment_features(features, diff --git a/drivers/net/team/team_core.c b/drivers/net/team/team_core.c index a1b27b69f010..1df062c67640 100644 --- a/drivers/net/team/team_core.c +++ b/drivers/net/team/team_core.c @@ -2011,8 +2011,7 @@ static netdev_features_t team_fix_features(struct net_device *dev, netdev_features_t mask; mask = features; - features &= ~NETIF_F_ONE_FOR_ALL; - features |= NETIF_F_ALL_FOR_ALL; + features = netdev_base_features(features); rcu_read_lock(); list_for_each_entry_rcu(port, &team->port_list, list) { diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index 66e7d26b70a4..11be70a7929f 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -253,4 +253,11 @@ static inline int find_next_netdev_feature(u64 feature, unsigned long start) NETIF_F_GSO_UDP_TUNNEL | \ NETIF_F_GSO_UDP_TUNNEL_CSUM) +static inline netdev_features_t netdev_base_features(netdev_features_t features) +{ + features &= ~NETIF_F_ONE_FOR_ALL; + features |= NETIF_F_ALL_FOR_ALL; + return features; +} + #endif /* _LINUX_NETDEV_FEATURES_H */ -- cgit v1.2.3