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2023-08-19net/smc: support max links per lgr negotiation in clc handshakeGuangguan Wang
Support max links per lgr negotiation in clc handshake for SMCR v2.1, which is one of smc v2.1 features. Server makes decision for the final value of max links based on the client preferred max links and self-preferred max links. Here use the minimum value of the client preferred max links and server preferred max links. Client Server Proposal(max links(client preferred)) --------------------------------------> Accept(max links(accepted value)) accepted value=min(client preferred, server preferred) <------------------------------------- Confirm(max links(accepted value)) -------------------------------------> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-19net/smc: support max connections per lgr negotiationGuangguan Wang
Support max connections per lgr negotiation for SMCR v2.1, which is one of smc v2.1 features. Server makes decision for the final value of max conns based on the client preferred max conns and self-preferred max conns. Here use the minimum value of client preferred max conns and server preferred max conns. Client Server Proposal(max conns(client preferred)) ------------------------------------> Accept(max conns(accepted value)) accepted value=min(client preferred, server preferred) <----------------------------------- Confirm(max conns(accepted value)) -----------------------------------> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Jan Karcher <jaka@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-06-03net/smc: Avoid to access invalid RMBs' MRs in SMCRv1 ADD LINK CONTWen Gu
SMCRv1 has a similar issue to SMCRv2 (see link below) that may access invalid MRs of RMBs when construct LLC ADD LINK CONT messages. BUG: kernel NULL pointer dereference, address: 0000000000000014 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 5 PID: 48 Comm: kworker/5:0 Kdump: loaded Tainted: G W E 6.4.0-rc3+ #49 Workqueue: events smc_llc_add_link_work [smc] RIP: 0010:smc_llc_add_link_cont+0x160/0x270 [smc] RSP: 0018:ffffa737801d3d50 EFLAGS: 00010286 RAX: ffff964f82144000 RBX: ffffa737801d3dd8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff964f81370c30 RBP: ffffa737801d3dd4 R08: ffff964f81370000 R09: ffffa737801d3db0 R10: 0000000000000001 R11: 0000000000000060 R12: ffff964f82e70000 R13: ffff964f81370c38 R14: ffffa737801d3dd3 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff9652bfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000014 CR3: 000000008fa20004 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> smc_llc_srv_rkey_exchange+0xa7/0x190 [smc] smc_llc_srv_add_link+0x3ae/0x5a0 [smc] smc_llc_add_link_work+0xb8/0x140 [smc] process_one_work+0x1e5/0x3f0 worker_thread+0x4d/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK> When an alernate RNIC is available in system, SMC will try to add a new link based on the RNIC for resilience. All the RMBs in use will be mapped to the new link. Then the RMBs' MRs corresponding to the new link will be filled into LLC messages. For SMCRv1, they are ADD LINK CONT messages. However smc_llc_add_link_cont() may mistakenly access to unused RMBs which haven't been mapped to the new link and have no valid MRs, thus causing a crash. So this patch fixes it. Fixes: 87f88cda2128 ("net/smc: rkey processing for a new link as SMC client") Link: https://lore.kernel.org/r/1685101741-74826-3-git-send-email-guwen@linux.alibaba.com Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Reviewed-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-30net/smc: Don't use RMBs not mapped to new link in SMCRv2 ADD LINKWen Gu
We encountered a crash when using SMCRv2. It is caused by a logical error in smc_llc_fill_ext_v2(). BUG: kernel NULL pointer dereference, address: 0000000000000014 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 7 PID: 453 Comm: kworker/7:4 Kdump: loaded Tainted: G W E 6.4.0-rc3+ #44 Workqueue: events smc_llc_add_link_work [smc] RIP: 0010:smc_llc_fill_ext_v2+0x117/0x280 [smc] RSP: 0018:ffffacb5c064bd88 EFLAGS: 00010282 RAX: ffff9a6bc1c3c02c RBX: ffff9a6be3558000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 000000000000000a RBP: ffffacb5c064bdb8 R08: 0000000000000040 R09: 000000000000000c R10: ffff9a6bc0910300 R11: 0000000000000002 R12: 0000000000000000 R13: 0000000000000002 R14: ffff9a6bc1c3c02c R15: ffff9a6be3558250 FS: 0000000000000000(0000) GS:ffff9a6eefdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000014 CR3: 000000010b078003 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> smc_llc_send_add_link+0x1ae/0x2f0 [smc] smc_llc_srv_add_link+0x2c9/0x5a0 [smc] ? cc_mkenc+0x40/0x60 smc_llc_add_link_work+0xb8/0x140 [smc] process_one_work+0x1e5/0x3f0 worker_thread+0x4d/0x2f0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK> When an alernate RNIC is available in system, SMC will try to add a new link based on the RNIC for resilience. All the RMBs in use will be mapped to the new link. Then the RMBs' MRs corresponding to the new link will be filled into SMCRv2 LLC ADD LINK messages. However, smc_llc_fill_ext_v2() mistakenly accesses to unused RMBs which haven't been mapped to the new link and have no valid MRs, thus causing a crash. So this patch fixes the logic. Fixes: b4ba4652b3f8 ("net/smc: extend LLC layer for SMC-Rv2") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-30net/smc: Scan from current RMB list when no position specifiedWen Gu
When finding the first RMB of link group, it should start from the current RMB list whose index is 0. So fix it. Fixes: b4ba4652b3f8 ("net/smc: extend LLC layer for SMC-Rv2") Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-02-04net/smc: replace mutex rmbs_lock and sndbufs_lock with rw_semaphoreD. Wythe
It's clear that rmbs_lock and sndbufs_lock are aims to protect the rmbs list or the sndbufs list. During connection establieshment, smc_buf_get_slot() will always be invoked, and it only performs read semantics in rmbs list and sndbufs list. Based on the above considerations, we replace mutex with rw_semaphore. Only smc_buf_get_slot() use down_read() to allow smc_buf_get_slot() run concurrently, other part use down_write() to keep exclusive semantics. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-04net/smc: llc_conf_mutex refactor, replace it with rw_semaphoreD. Wythe
llc_conf_mutex was used to protect links and link related configurations in the same link group, for example, add or delete links. However, in most cases, the protected critical area has only read semantics and with no write semantics at all, such as obtaining a usable link or an available rmb_desc. This patch do simply code refactoring, replace mutex with rw_semaphore, replace mutex_lock with down_write and replace mutex_unlock with up_write. Theoretically, this replacement is equivalent, but after this patch, we can distinguish lock granularity according to different semantics of critical areas. Signed-off-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-22net/smc: Introduce a specific sysctl for TEST_LINK timeWen Gu
SMC-R tests the viability of link by sending out TEST_LINK LLC messages over RoCE fabric when connections on link have been idle for a time longer than keepalive interval (testlink time). But using tcp_keepalive_time as testlink time maybe not quite suitable because it is default no less than two hours[1], which is too long for single link to find peer dead. The active host will still use peer-dead link (QP) sending messages, and can't find out until get IB_WC_RETRY_EXC_ERR error CQEs, which takes more time than TEST_LINK timeout (SMC_LLC_WAIT_TIME) normally. So this patch introduces a independent sysctl for SMC-R to set link keepalive time, in order to detect link down in time. The default value is 30 seconds. [1] https://www.rfc-editor.org/rfc/rfc1122#page-101 Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-18tcp: Fix data-races around keepalive sysctl knobs.Kuniyuki Iwashima
While reading sysctl_tcp_keepalive_(time|probes|intvl), they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18net/smc: Allow virtually contiguous sndbufs or RMBs for SMC-RWen Gu
On long-running enterprise production servers, high-order contiguous memory pages are usually very rare and in most cases we can only get fragmented pages. When replacing TCP with SMC-R in such production scenarios, attempting to allocate high-order physically contiguous sndbufs and RMBs may result in frequent memory compaction, which will cause unexpected hung issue and further stability risks. So this patch is aimed to allow SMC-R link group to use virtually contiguous sndbufs and RMBs to avoid potential issues mentioned above. Whether to use physically or virtually contiguous buffers can be set by sysctl smcr_buf_type. Note that using virtually contiguous buffers will bring an acceptable performance regression, which can be mainly divided into two parts: 1) regression in data path, which is brought by additional address translation of sndbuf by RNIC in Tx. But in general, translating address through MTT is fast. Taking 256KB sndbuf and RMB as an example, the comparisons in qperf latency and bandwidth test with physically and virtually contiguous buffers are as follows: - client: smc_run taskset -c <cpu> qperf <server> -oo msg_size:1:64K:*2\ -t 5 -vu tcp_{bw|lat} - server: smc_run taskset -c <cpu> qperf [latency] msgsize tcp smcr smcr-use-virt-buf 1 11.17 us 7.56 us 7.51 us (-0.67%) 2 10.65 us 7.74 us 7.56 us (-2.31%) 4 11.11 us 7.52 us 7.59 us ( 0.84%) 8 10.83 us 7.55 us 7.51 us (-0.48%) 16 11.21 us 7.46 us 7.51 us ( 0.71%) 32 10.65 us 7.53 us 7.58 us ( 0.61%) 64 10.95 us 7.74 us 7.80 us ( 0.76%) 128 11.14 us 7.83 us 7.87 us ( 0.47%) 256 10.97 us 7.94 us 7.92 us (-0.28%) 512 11.23 us 7.94 us 8.20 us ( 3.25%) 1024 11.60 us 8.12 us 8.20 us ( 0.96%) 2048 14.04 us 8.30 us 8.51 us ( 2.49%) 4096 16.88 us 9.13 us 9.07 us (-0.64%) 8192 22.50 us 10.56 us 11.22 us ( 6.26%) 16384 28.99 us 12.88 us 13.83 us ( 7.37%) 32768 40.13 us 16.76 us 16.95 us ( 1.16%) 65536 68.70 us 24.68 us 24.85 us ( 0.68%) [bandwidth] msgsize tcp smcr smcr-use-virt-buf 1 1.65 MB/s 1.59 MB/s 1.53 MB/s (-3.88%) 2 3.32 MB/s 3.17 MB/s 3.08 MB/s (-2.67%) 4 6.66 MB/s 6.33 MB/s 6.09 MB/s (-3.85%) 8 13.67 MB/s 13.45 MB/s 11.97 MB/s (-10.99%) 16 25.36 MB/s 27.15 MB/s 24.16 MB/s (-11.01%) 32 48.22 MB/s 54.24 MB/s 49.41 MB/s (-8.89%) 64 106.79 MB/s 107.32 MB/s 99.05 MB/s (-7.71%) 128 210.21 MB/s 202.46 MB/s 201.02 MB/s (-0.71%) 256 400.81 MB/s 416.81 MB/s 393.52 MB/s (-5.59%) 512 746.49 MB/s 834.12 MB/s 809.99 MB/s (-2.89%) 1024 1292.33 MB/s 1641.96 MB/s 1571.82 MB/s (-4.27%) 2048 2007.64 MB/s 2760.44 MB/s 2717.68 MB/s (-1.55%) 4096 2665.17 MB/s 4157.44 MB/s 4070.76 MB/s (-2.09%) 8192 3159.72 MB/s 4361.57 MB/s 4270.65 MB/s (-2.08%) 16384 4186.70 MB/s 4574.13 MB/s 4501.17 MB/s (-1.60%) 32768 4093.21 MB/s 4487.42 MB/s 4322.43 MB/s (-3.68%) 65536 4057.14 MB/s 4735.61 MB/s 4555.17 MB/s (-3.81%) 2) regression in buffer initialization and destruction path, which is brought by additional MR operations of sndbufs. But thanks to link group buffer reuse mechanism, the impact of this kind of regression decreases as times of buffer reuse increases. Taking 256KB sndbuf and RMB as an example, latency of some key SMC-R buffer-related function obtained by bpftrace are as follows: Function Phys-bufs Virt-bufs smcr_new_buf_create() 67154 ns 79164 ns smc_ib_buf_map_sg() 525 ns 928 ns smc_ib_get_memory_region() 162294 ns 161191 ns smc_wr_reg_send() 9957 ns 9635 ns smc_ib_put_memory_region() 203548 ns 198374 ns smc_ib_buf_unmap_sg() 508 ns 1158 ns ------------ Test environment notes: 1. Above tests run on 2 VMs within the same Host. 2. The NIC is ConnectX-4Lx, using SRIOV and passing through 2 VFs to the each VM respectively. 3. VMs' vCPUs are binded to different physical CPUs, and the binded physical CPUs are isolated by `isolcpus=xxx` cmdline. 4. NICs' queue number are set to 1. Signed-off-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-02net/smc: Print net namespace in logTony Lu
This adds net namespace ID to the kernel log, net_cookie is unique in the whole system. It is useful in container environment. Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-12-28net/smc: don't send CDC/LLC message if link not readyDust Li
We found smc_llc_send_link_delete_all() sometimes wait for 2s timeout when testing with RDMA link up/down. It is possible when a smc_link is in ACTIVATING state, the underlaying QP is still in RESET or RTR state, which cannot send any messages out. smc_llc_send_link_delete_all() use smc_link_usable() to checks whether the link is usable, if the QP is still in RESET or RTR state, but the smc_link is in ACTIVATING, this LLC message will always fail without any CQE entering the CQ, and we will always wait 2s before timeout. Since we cannot send any messages through the QP before the QP enter RTS. I add a wrapper smc_link_sendable() which checks the state of QP along with the link state. And replace smc_link_usable() with smc_link_sendable() in all LLC & CDC message sending routine. Fixes: 5f08318f617b ("smc: connection data control (CDC)") Signed-off-by: Dust Li <dust.li@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
include/net/sock.h 7b50ecfcc6cd ("net: Rename ->stream_memory_read to ->sock_is_readable") 4c1e34c0dbff ("vsock: Enable y2038 safe timeval for timeout") drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c 0daa55d033b0 ("octeontx2-af: cn10k: debugfs for dumping LMTST map table") e77bcdd1f639 ("octeontx2-af: Display all enabled PF VF rsrc_alloc entries.") Adjacent code addition in both cases, keep both. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-28net/smc: Fix smc_link->llc_testlink_time overflowTony Lu
The value of llc_testlink_time is set to the value stored in net->ipv4.sysctl_tcp_keepalive_time when linkgroup init. The value of sysctl_tcp_keepalive_time is already jiffies, so we don't need to multiply by HZ, which would cause smc_link->llc_testlink_time overflow, and test_link send flood. Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Reviewed-by: Wen Gu <guwen@linux.alibaba.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-16net/smc: extend LLC layer for SMC-Rv2Karsten Graul
Add support for large v2 LLC control messages in smc_llc.c. The new large work request buffer allows to combine control messages into one packet that had to be spread over several packets before. Add handling of the new v2 LLC messages. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-16net/smc: save stack space and allocate smc_init_infoKarsten Graul
The struct smc_init_info grew over time, its time to save space on stack and allocate this struct dynamically. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-08net/smc: improved fix wait on already cleared linkKarsten Graul
Commit 8f3d65c16679 ("net/smc: fix wait on already cleared link") introduced link refcounting to avoid waits on already cleared links. This patch extents and improves the refcounting to cover all remaining possible cases for this kind of error situation. Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-09net/smc: fix wait on already cleared linkKarsten Graul
There can be a race between the waiters for a tx work request buffer and the link down processing that finally clears the link. Although all waiters are woken up before the link is cleared there might be waiters which did not yet get back control and are still waiting. This results in an access to a cleared wait queue head. Fix this by introducing atomic reference counting around the wait calls, and wait with the link clear processing until all waiters have finished. Move the work request layer related calls into smc_wr.c and set the link state to INACTIVE before calling smcr_link_clear() in smc_llc_srv_add_link(). Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Minor conflicts in net/mptcp/protocol.h and tools/testing/selftests/net/Makefile. In both cases code was added on both sides in the same place so just keep both. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15net/smc: fix use-after-free of delayed eventsKarsten Graul
When a delayed event is enqueued then the event worker will send this event the next time it is running and no other flow is currently active. The event handler is called for the delayed event, and the pointer to the event keeps set in lgr->delayed_event. This pointer is cleared later in the processing by smc_llc_flow_start(). This can lead to a use-after-free condition when the processing does not reach smc_llc_flow_start(), but frees the event because of an error situation. Then the delayed_event pointer is still set but the event is freed. Fix this by always clearing the delayed event pointer when the event is provided to the event handler for processing, and remove the code to clear it in smc_llc_flow_start(). Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10net: smc: fix missing brace warning for old compilersPujin Shi
For older versions of gcc, the array = {0}; will cause warnings: net/smc/smc_llc.c: In function 'smc_llc_add_link_local': net/smc/smc_llc.c:1212:9: warning: missing braces around initializer [-Wmissing-braces] struct smc_llc_msg_add_link add_llc = {0}; ^ net/smc/smc_llc.c:1212:9: warning: (near initialization for 'add_llc.hd') [-Wmissing-braces] net/smc/smc_llc.c: In function 'smc_llc_srv_delete_link_local': net/smc/smc_llc.c:1245:9: warning: missing braces around initializer [-Wmissing-braces] struct smc_llc_msg_del_link del_llc = {0}; ^ net/smc/smc_llc.c:1245:9: warning: (near initialization for 'del_llc.hd') [-Wmissing-braces] 2 warnings generated Fixes: 4dadd151b265 ("net/smc: enqueue local LLC messages") Signed-off-by: Pujin Shi <shipujin.t@gmail.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10net: smc: fix missing brace warning for old compilersPujin Shi
For older versions of gcc, the array = {0}; will cause warnings: net/smc/smc_llc.c: In function 'smc_llc_send_link_delete_all': net/smc/smc_llc.c:1317:9: warning: missing braces around initializer [-Wmissing-braces] struct smc_llc_msg_del_link delllc = {0}; ^ net/smc/smc_llc.c:1317:9: warning: (near initialization for 'delllc.hd') [-Wmissing-braces] 1 warnings generated Fixes: f3811fd7bc97 ("net/smc: send DELETE_LINK, ALL message and wait for send to complete") Signed-off-by: Pujin Shi <shipujin.t@gmail.com> Acked-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-10net/smc: use separate work queues for different worker typesKarsten Graul
There are 6 types of workers which exist per smc connection. 3 of them are used for listen and handshake processing, another 2 are used for close and abort processing and 1 is the tx worker that moves calls to sleeping functions into a worker. To prevent flooding of the system work queue when many connections are opened or closed at the same time (some pattern uperf implements), move those workers to one of 3 smc-specific work queues. Two work queues are module-global and used for handshake and close workers. The third work queue is defined per link group and used by the tx workers that may sleep waiting for resources of this link group. And in smc_llc_enqueue() queue the llc_event_work work to the system prio work queue because its critical that this work is started fast. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-03net/smc: fix toleration of fake add_link messagesKarsten Graul
Older SMCR implementations had no link failover support and used one link only. Because the handshake protocol requires to try the establishment of a second link the old code sent a fake add_link message and declined any server response afterwards. The current code supports multiple links and inspects the received fake add_link message more closely. To tolerate the fake add_link messages smc_llc_is_local_add_link() needs an improved check of the message to be able to separate between locally enqueued and fake add_link messages. And smc_llc_cli_add_link() needs to check if the provided qp_mtu size is invalid and reject the add_link request in that case. Fixes: c48254fa48e5 ("net/smc: move add link processing for new device into llc layer") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: do not call dma sync for unmapped memoryKarsten Graul
The dma related ...sync_sg... functions check the link state before the dma function is actually called. But the check in smc_link_usable() allows links in ACTIVATING state which are not yet mapped to dma memory. Under high load it may happen that the sync_sg functions are called for such a link which results in an debug output like DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync DMA memory it has not allocated [device address=0x0000000103370000] [size=65536 bytes] To fix that introduce a helper to check for the link state ACTIVE and use it where appropriate. And move the link state update to ACTIVATING to the end of smcr_link_init() when most initial setup is done. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: d854fcbfaeda ("net/smc: add new link state and related helpers") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: fix handling of delete link requestsKarsten Graul
As smc client the delete link requests are assigned to the flow when _any_ flow is active. This may break other flows that do not expect delete link requests during their handling. Fix that by assigning the request only when an add link flow is active. With that fix the code for smc client and smc server is the same, so remove the separate handling. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 9ec6bf19ec8b ("net/smc: llc_del_link_work and use the LLC flow for delete link") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: move add link processing for new device into llc layerKarsten Graul
When a new ib device is up smc will send an add link invitation to the peer if needed. This is currently done with rudimentary flow control. Under high workload these add link invitations can disturb other llc flows because they arrive unexpected. Fix this by integrating the invitations into the normal llc event flow and handle them as a flow. While at it, check for already assigned requests in the flow before the new add link request is assigned. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 1f90a05d9ff9 ("net/smc: add smcr_port_add() and smcr_link_up() processing") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: drop out-of-flow llc response messagesKarsten Graul
To be save from unexpected or late llc response messages check if the arrived message fits to the current flow type and drop out-of-flow messages. And drop it when there is already a response assigned to the flow. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: ef79d439cd12 ("net/smc: process llc responses in tasklet context") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/smc: handle unexpected response types for confirm linkKarsten Graul
A delete link could arrive during confirm link processing. Handle this situation directly in smc_llc_srv_conf_link() rather than using the logic in smc_llc_wait() to avoid the unexpected message handling there. Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Fixes: 1551c95b6124 ("net/smc: final part of add link processing as SMC server") Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: fix work request handlingKarsten Graul
Wait for pending sends only when smc_switch_conns() found a link to move the connections to. Do not wait during link freeing, this can lead to permanent hang situations. And refuse to provide a new tx slot on an unusable link. Fixes: c6f02ebeea3a ("net/smc: switch connections to alternate link") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08net/smc: separate LLC wait queues for flow and messagesKarsten Graul
There might be races in scenarios where both SMC link groups are on the same system. Prevent that by creating separate wait queues for LLC flows and messages. Switch to non-interruptable versions of wait_event() and wake_up() for the llc flow waiter to make sure the waiters get control sequentially. Fine tune the llc_flow_lock to include the assignment of the message. Write to system log when an unexpected message was dropped. And remove an extra indirection and use the existing local variable lgr in smc_llc_enqueue(). Fixes: 555da9af827d ("net/smc: add event-based llc_flow framework") Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-07net/smc: remove set but not used variables 'del_llc, del_llc_resp'YueHaibing
Fixes gcc '-Wunused-but-set-variable' warning: net/smc/smc_llc.c: In function 'smc_llc_cli_conf_link': net/smc/smc_llc.c:753:31: warning: variable 'del_llc' set but not used [-Wunused-but-set-variable] struct smc_llc_msg_del_link *del_llc; ^ net/smc/smc_llc.c: In function 'smc_llc_process_srv_delete_link': net/smc/smc_llc.c:1311:33: warning: variable 'del_llc_resp' set but not used [-Wunused-but-set-variable] struct smc_llc_msg_del_link *del_llc_resp; ^ Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-05net/smc: log important pnetid and state change eventsKarsten Graul
Print to system log when SMC links are available or go down, link group state changes or pnetids are applied to and removed from devices. The log entries are triggered by either user configuration actions or adapter activation/deactivation events and are not expected to happen often. The entries help SMC users to keep track of the SMC link group status and to detect when actions are needed (like to add replacements for failed adapters). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: save SMC-R peer link_uidKarsten Graul
During SMC-R link establishment the peers exchange the link_uid that is used for debugging purposes. Save the peer link_uid in smc_link so it can be retrieved by the smc_diag netlink interface. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: create improved SMC-R link_uidKarsten Graul
The link_uid of an SMC-R link is exchanged between SMC peers and its value can be used for debugging purposes. Create a unique link_uid during link initialization and use it in communication with SMC-R peers. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: add termination reason and handle LLC protocol violationKarsten Graul
Allow to set the reason code for the link group termination, and set meaningful values before termination processing is triggered. This reason code is sent to the peer in the final delete link message. When the LLC request or response layer receives a message type that was not handled, drop a warning and terminate the link group. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: asymmetric link taggingKarsten Graul
New connections must not be assigned to asymmetric links. Add asymmetric link tagging using new link variable link_is_asym. The new helpers smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the state of the link group, and tag all links accordingly. smcr_lgr_conn_assign_link() respects the link tagging and will not assign new connections to links tagged as asymmetric link. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: send DELETE_LINK, ALL message and wait for send to completeKarsten Graul
Add smc_llc_send_message_wait() which uses smc_wr_tx_send_wait() to send an LLC message and waits for the message send to complete. smc_llc_send_link_delete_all() calls the new function to send an DELETE_LINK,ALL LLC message. The RFC states that the sender of this type of message needs to wait for the completion event of the message transmission and can terminate the link afterwards. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04net/smc: switch connections to alternate linkKarsten Graul
Add smc_switch_conns() to switch all connections from a link that is going down. Find an other link to switch the connections to, and switch each connection to the new link. smc_switch_cursor() updates the cursors of a connection to the state of the last successfully sent CDC message. When there is no link to switch to, terminate the link group. Call smc_switch_conns() when a link is going down. And with the possibility that links of connections can switch adapt CDC and TX functions to detect and handle link switches. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: enqueue local LLC messagesKarsten Graul
As SMC server, when a second link was deleted, trigger the setup of an asymmetric link. Do this by enqueueing a local ADD_LINK message which is processed by the LLC layer as if it were received from peer. Do the same when a new IB port became active and a new link could be created. smc_llc_srv_add_link_local() enqueues a local ADD_LINK message. And smc_llc_srv_delete_link_local() is used the same way to enqueue a local DELETE_LINK message. This is used when an IB port is no longer active. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: delete link processing as SMC serverKarsten Graul
Add smc_llc_process_srv_delete_link() to process a DELETE_LINK request as SMC server. When the request is to delete ALL links then terminate the whole link group. If not, find the link to delete by its link_id, send the DELETE_LINK request LLC message and wait for the response. No matter if a response was received, clear the deleted link and update the link group state. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: delete link processing as SMC clientKarsten Graul
Add smc_llc_process_cli_delete_link() to process a DELETE_LINK request as SMC client. When the request is to delete ALL links then terminate the whole link group. If not, find the link to delete by its link_id, send the DELETE_LINK response LLC message and then clear the deleted link. Finally determine and update the link group state. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: llc_del_link_work and use the LLC flow for delete linkKarsten Graul
Introduce a work that is scheduled when a new DELETE_LINK LLC request is received. The work will call either the SMC client or SMC server DELETE_LINK processing. And use the LLC flow framework to process incoming DELETE_LINK LLC messages, scheduling the llc_del_link_work for those events. With these changes smc_lgr_forget() is only called by one function and can be migrated into smc_lgr_cleanup_early(). Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: delete an asymmetric link as SMC serverKarsten Graul
When a link group moved from asymmetric to symmetric state then the dangling asymmetric link can be deleted. Add smc_llc_find_asym_link() to find the respective link and add smc_llc_delete_asym_link() to delete it. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: final part of add link processing as SMC serverKarsten Graul
This patch finalizes the ADD_LINK processing of new links. Send the CONFIRM_LINK request to the peer, receive the response and set link state to ACTIVE. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: rkey processing for a new link as SMC serverKarsten Graul
Part of SMC server new link establishment is the exchange of rkeys for used buffers. Loop over all used RMB buffers and send ADD_LINK_CONTINUE LLC messages to the peer. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: first part of add link processing as SMC serverKarsten Graul
First set of functions to process an ADD_LINK LLC request as an SMC server. Find an alternate IB device, determine the new link group type and get the index for the new link. Then initialize the link and send the ADD_LINK LLC message to the peer. Save the contents of the response, ready the link, map all used buffers and register the buffers with the IB device. If any error occurs, stop the processing and clear the link. And call smc_llc_srv_add_link() in af_smc.c to start second link establishment after the initial link of a link group was created. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: final part of add link processing as SMC clientKarsten Graul
This patch finalizes the ADD_LINK processing of new links. Receive the CONFIRM_LINK request from peer, complete the link initialization, register all used buffers with the IB device and finally send the CONFIRM_LINK response, which completes the ADD_LINK processing. And activate smc_llc_cli_add_link() in af_smc.c. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03net/smc: rkey processing for a new link as SMC clientKarsten Graul
Part of the SMC client new link establishment process is the exchange of rkeys for all used buffers. Add new LLC message type ADD_LINK_CONTINUE which is used to exchange rkeys of all current RMB buffers. Add functions to iterate over all used RMB buffers of the link group, and implement the ADD_LINK_CONTINUE processing. Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>