1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * NVMe Over Fabrics Target Passthrough command implementation.
4 *
5 * Copyright (c) 2017-2018 Western Digital Corporation or its
6 * affiliates.
7 * Copyright (c) 2019-2020, Eideticom Inc.
8 *
9 */
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/module.h>
12
13 #include "../host/nvme.h"
14 #include "nvmet.h"
15
16 MODULE_IMPORT_NS(NVME_TARGET_PASSTHRU);
17
18 /*
19 * xarray to maintain one passthru subsystem per nvme controller.
20 */
21 static DEFINE_XARRAY(passthru_subsystems);
22
nvmet_passthru_override_id_ctrl(struct nvmet_req * req)23 static u16 nvmet_passthru_override_id_ctrl(struct nvmet_req *req)
24 {
25 struct nvmet_ctrl *ctrl = req->sq->ctrl;
26 struct nvme_ctrl *pctrl = ctrl->subsys->passthru_ctrl;
27 u16 status = NVME_SC_SUCCESS;
28 struct nvme_id_ctrl *id;
29 int max_hw_sectors;
30 int page_shift;
31
32 id = kzalloc(sizeof(*id), GFP_KERNEL);
33 if (!id)
34 return NVME_SC_INTERNAL;
35
36 status = nvmet_copy_from_sgl(req, 0, id, sizeof(*id));
37 if (status)
38 goto out_free;
39
40 id->cntlid = cpu_to_le16(ctrl->cntlid);
41 id->ver = cpu_to_le32(ctrl->subsys->ver);
42
43 /*
44 * The passthru NVMe driver may have a limit on the number of segments
45 * which depends on the host's memory fragementation. To solve this,
46 * ensure mdts is limited to the pages equal to the number of segments.
47 */
48 max_hw_sectors = min_not_zero(pctrl->max_segments << (PAGE_SHIFT - 9),
49 pctrl->max_hw_sectors);
50
51 /*
52 * nvmet_passthru_map_sg is limitted to using a single bio so limit
53 * the mdts based on BIO_MAX_PAGES as well
54 */
55 max_hw_sectors = min_not_zero(BIO_MAX_PAGES << (PAGE_SHIFT - 9),
56 max_hw_sectors);
57
58 page_shift = NVME_CAP_MPSMIN(ctrl->cap) + 12;
59
60 id->mdts = ilog2(max_hw_sectors) + 9 - page_shift;
61
62 id->acl = 3;
63 /*
64 * We export aerl limit for the fabrics controller, update this when
65 * passthru based aerl support is added.
66 */
67 id->aerl = NVMET_ASYNC_EVENTS - 1;
68
69 /* emulate kas as most of the PCIe ctrl don't have a support for kas */
70 id->kas = cpu_to_le16(NVMET_KAS);
71
72 /* don't support host memory buffer */
73 id->hmpre = 0;
74 id->hmmin = 0;
75
76 id->sqes = min_t(__u8, ((0x6 << 4) | 0x6), id->sqes);
77 id->cqes = min_t(__u8, ((0x4 << 4) | 0x4), id->cqes);
78 id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);
79
80 /* don't support fuse commands */
81 id->fuses = 0;
82
83 id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
84 if (ctrl->ops->flags & NVMF_KEYED_SGLS)
85 id->sgls |= cpu_to_le32(1 << 2);
86 if (req->port->inline_data_size)
87 id->sgls |= cpu_to_le32(1 << 20);
88
89 /*
90 * When passsthru controller is setup using nvme-loop transport it will
91 * export the passthru ctrl subsysnqn (PCIe NVMe ctrl) and will fail in
92 * the nvme/host/core.c in the nvme_init_subsystem()->nvme_active_ctrl()
93 * code path with duplicate ctr subsynqn. In order to prevent that we
94 * mask the passthru-ctrl subsysnqn with the target ctrl subsysnqn.
95 */
96 memcpy(id->subnqn, ctrl->subsysnqn, sizeof(id->subnqn));
97
98 /* use fabric id-ctrl values */
99 id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +
100 req->port->inline_data_size) / 16);
101 id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);
102
103 id->msdbd = ctrl->ops->msdbd;
104
105 /* Support multipath connections with fabrics */
106 id->cmic |= 1 << 1;
107
108 /* Disable reservations, see nvmet_parse_passthru_io_cmd() */
109 id->oncs &= cpu_to_le16(~NVME_CTRL_ONCS_RESERVATIONS);
110
111 status = nvmet_copy_to_sgl(req, 0, id, sizeof(struct nvme_id_ctrl));
112
113 out_free:
114 kfree(id);
115 return status;
116 }
117
nvmet_passthru_override_id_ns(struct nvmet_req * req)118 static u16 nvmet_passthru_override_id_ns(struct nvmet_req *req)
119 {
120 u16 status = NVME_SC_SUCCESS;
121 struct nvme_id_ns *id;
122 int i;
123
124 id = kzalloc(sizeof(*id), GFP_KERNEL);
125 if (!id)
126 return NVME_SC_INTERNAL;
127
128 status = nvmet_copy_from_sgl(req, 0, id, sizeof(struct nvme_id_ns));
129 if (status)
130 goto out_free;
131
132 for (i = 0; i < (id->nlbaf + 1); i++)
133 if (id->lbaf[i].ms)
134 memset(&id->lbaf[i], 0, sizeof(id->lbaf[i]));
135
136 id->flbas = id->flbas & ~(1 << 4);
137
138 /*
139 * Presently the NVMEof target code does not support sending
140 * metadata, so we must disable it here. This should be updated
141 * once target starts supporting metadata.
142 */
143 id->mc = 0;
144
145 status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
146
147 out_free:
148 kfree(id);
149 return status;
150 }
151
nvmet_passthru_execute_cmd_work(struct work_struct * w)152 static void nvmet_passthru_execute_cmd_work(struct work_struct *w)
153 {
154 struct nvmet_req *req = container_of(w, struct nvmet_req, p.work);
155 struct request *rq = req->p.rq;
156 u16 status;
157
158 nvme_execute_passthru_rq(rq);
159
160 status = nvme_req(rq)->status;
161 if (status == NVME_SC_SUCCESS &&
162 req->cmd->common.opcode == nvme_admin_identify) {
163 switch (req->cmd->identify.cns) {
164 case NVME_ID_CNS_CTRL:
165 nvmet_passthru_override_id_ctrl(req);
166 break;
167 case NVME_ID_CNS_NS:
168 nvmet_passthru_override_id_ns(req);
169 break;
170 }
171 }
172
173 req->cqe->result = nvme_req(rq)->result;
174 nvmet_req_complete(req, status);
175 blk_mq_free_request(rq);
176 }
177
nvmet_passthru_req_done(struct request * rq,blk_status_t blk_status)178 static void nvmet_passthru_req_done(struct request *rq,
179 blk_status_t blk_status)
180 {
181 struct nvmet_req *req = rq->end_io_data;
182
183 req->cqe->result = nvme_req(rq)->result;
184 nvmet_req_complete(req, nvme_req(rq)->status);
185 blk_mq_free_request(rq);
186 }
187
nvmet_passthru_map_sg(struct nvmet_req * req,struct request * rq)188 static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
189 {
190 struct scatterlist *sg;
191 int op_flags = 0;
192 struct bio *bio;
193 int i, ret;
194
195 if (req->sg_cnt > BIO_MAX_PAGES)
196 return -EINVAL;
197
198 if (req->cmd->common.opcode == nvme_cmd_flush)
199 op_flags = REQ_FUA;
200 else if (nvme_is_write(req->cmd))
201 op_flags = REQ_SYNC | REQ_IDLE;
202
203 bio = bio_alloc(GFP_KERNEL, req->sg_cnt);
204 bio->bi_end_io = bio_put;
205 bio->bi_opf = req_op(rq) | op_flags;
206
207 for_each_sg(req->sg, sg, req->sg_cnt, i) {
208 if (bio_add_pc_page(rq->q, bio, sg_page(sg), sg->length,
209 sg->offset) < sg->length) {
210 bio_put(bio);
211 return -EINVAL;
212 }
213 }
214
215 ret = blk_rq_append_bio(rq, &bio);
216 if (unlikely(ret)) {
217 bio_put(bio);
218 return ret;
219 }
220
221 return 0;
222 }
223
nvmet_passthru_execute_cmd(struct nvmet_req * req)224 static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
225 {
226 struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
227 struct request_queue *q = ctrl->admin_q;
228 struct nvme_ns *ns = NULL;
229 struct request *rq = NULL;
230 u32 effects;
231 u16 status;
232 int ret;
233
234 if (likely(req->sq->qid != 0)) {
235 u32 nsid = le32_to_cpu(req->cmd->common.nsid);
236
237 ns = nvme_find_get_ns(ctrl, nsid);
238 if (unlikely(!ns)) {
239 pr_err("failed to get passthru ns nsid:%u\n", nsid);
240 status = NVME_SC_INVALID_NS | NVME_SC_DNR;
241 goto out;
242 }
243
244 q = ns->queue;
245 }
246
247 rq = nvme_alloc_request(q, req->cmd, 0);
248 if (IS_ERR(rq)) {
249 status = NVME_SC_INTERNAL;
250 goto out_put_ns;
251 }
252
253 if (req->sg_cnt) {
254 ret = nvmet_passthru_map_sg(req, rq);
255 if (unlikely(ret)) {
256 status = NVME_SC_INTERNAL;
257 goto out_put_req;
258 }
259 }
260
261 /*
262 * If a command needs post-execution fixups, or there are any
263 * non-trivial effects, make sure to execute the command synchronously
264 * in a workqueue so that nvme_passthru_end gets called.
265 */
266 effects = nvme_command_effects(ctrl, ns, req->cmd->common.opcode);
267 if (req->p.use_workqueue ||
268 (effects & ~(NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC))) {
269 INIT_WORK(&req->p.work, nvmet_passthru_execute_cmd_work);
270 req->p.rq = rq;
271 schedule_work(&req->p.work);
272 } else {
273 rq->end_io_data = req;
274 blk_execute_rq_nowait(rq->q, ns ? ns->disk : NULL, rq, 0,
275 nvmet_passthru_req_done);
276 }
277
278 if (ns)
279 nvme_put_ns(ns);
280
281 return;
282
283 out_put_req:
284 blk_mq_free_request(rq);
285 out_put_ns:
286 if (ns)
287 nvme_put_ns(ns);
288 out:
289 nvmet_req_complete(req, status);
290 }
291
292 /*
293 * We need to emulate set host behaviour to ensure that any requested
294 * behaviour of the target's host matches the requested behaviour
295 * of the device's host and fail otherwise.
296 */
nvmet_passthru_set_host_behaviour(struct nvmet_req * req)297 static void nvmet_passthru_set_host_behaviour(struct nvmet_req *req)
298 {
299 struct nvme_ctrl *ctrl = nvmet_req_passthru_ctrl(req);
300 struct nvme_feat_host_behavior *host;
301 u16 status = NVME_SC_INTERNAL;
302 int ret;
303
304 host = kzalloc(sizeof(*host) * 2, GFP_KERNEL);
305 if (!host)
306 goto out_complete_req;
307
308 ret = nvme_get_features(ctrl, NVME_FEAT_HOST_BEHAVIOR, 0,
309 host, sizeof(*host), NULL);
310 if (ret)
311 goto out_free_host;
312
313 status = nvmet_copy_from_sgl(req, 0, &host[1], sizeof(*host));
314 if (status)
315 goto out_free_host;
316
317 if (memcmp(&host[0], &host[1], sizeof(host[0]))) {
318 pr_warn("target host has requested different behaviour from the local host\n");
319 status = NVME_SC_INTERNAL;
320 }
321
322 out_free_host:
323 kfree(host);
324 out_complete_req:
325 nvmet_req_complete(req, status);
326 }
327
nvmet_setup_passthru_command(struct nvmet_req * req)328 static u16 nvmet_setup_passthru_command(struct nvmet_req *req)
329 {
330 req->p.use_workqueue = false;
331 req->execute = nvmet_passthru_execute_cmd;
332 return NVME_SC_SUCCESS;
333 }
334
nvmet_parse_passthru_io_cmd(struct nvmet_req * req)335 u16 nvmet_parse_passthru_io_cmd(struct nvmet_req *req)
336 {
337 /* Reject any commands with non-sgl flags set (ie. fused commands) */
338 if (req->cmd->common.flags & ~NVME_CMD_SGL_ALL)
339 return NVME_SC_INVALID_FIELD;
340
341 switch (req->cmd->common.opcode) {
342 case nvme_cmd_resv_register:
343 case nvme_cmd_resv_report:
344 case nvme_cmd_resv_acquire:
345 case nvme_cmd_resv_release:
346 /*
347 * Reservations cannot be supported properly because the
348 * underlying device has no way of differentiating different
349 * hosts that connect via fabrics. This could potentially be
350 * emulated in the future if regular targets grow support for
351 * this feature.
352 */
353 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
354 }
355
356 return nvmet_setup_passthru_command(req);
357 }
358
359 /*
360 * Only features that are emulated or specifically allowed in the list are
361 * passed down to the controller. This function implements the allow list for
362 * both get and set features.
363 */
nvmet_passthru_get_set_features(struct nvmet_req * req)364 static u16 nvmet_passthru_get_set_features(struct nvmet_req *req)
365 {
366 switch (le32_to_cpu(req->cmd->features.fid)) {
367 case NVME_FEAT_ARBITRATION:
368 case NVME_FEAT_POWER_MGMT:
369 case NVME_FEAT_LBA_RANGE:
370 case NVME_FEAT_TEMP_THRESH:
371 case NVME_FEAT_ERR_RECOVERY:
372 case NVME_FEAT_VOLATILE_WC:
373 case NVME_FEAT_WRITE_ATOMIC:
374 case NVME_FEAT_AUTO_PST:
375 case NVME_FEAT_TIMESTAMP:
376 case NVME_FEAT_HCTM:
377 case NVME_FEAT_NOPSC:
378 case NVME_FEAT_RRL:
379 case NVME_FEAT_PLM_CONFIG:
380 case NVME_FEAT_PLM_WINDOW:
381 case NVME_FEAT_HOST_BEHAVIOR:
382 case NVME_FEAT_SANITIZE:
383 case NVME_FEAT_VENDOR_START ... NVME_FEAT_VENDOR_END:
384 return nvmet_setup_passthru_command(req);
385
386 case NVME_FEAT_ASYNC_EVENT:
387 /* There is no support for forwarding ASYNC events */
388 case NVME_FEAT_IRQ_COALESCE:
389 case NVME_FEAT_IRQ_CONFIG:
390 /* The IRQ settings will not apply to the target controller */
391 case NVME_FEAT_HOST_MEM_BUF:
392 /*
393 * Any HMB that's set will not be passed through and will
394 * not work as expected
395 */
396 case NVME_FEAT_SW_PROGRESS:
397 /*
398 * The Pre-Boot Software Load Count doesn't make much
399 * sense for a target to export
400 */
401 case NVME_FEAT_RESV_MASK:
402 case NVME_FEAT_RESV_PERSIST:
403 /* No reservations, see nvmet_parse_passthru_io_cmd() */
404 default:
405 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
406 }
407 }
408
nvmet_parse_passthru_admin_cmd(struct nvmet_req * req)409 u16 nvmet_parse_passthru_admin_cmd(struct nvmet_req *req)
410 {
411 /* Reject any commands with non-sgl flags set (ie. fused commands) */
412 if (req->cmd->common.flags & ~NVME_CMD_SGL_ALL)
413 return NVME_SC_INVALID_FIELD;
414
415 /*
416 * Passthru all vendor specific commands
417 */
418 if (req->cmd->common.opcode >= nvme_admin_vendor_start)
419 return nvmet_setup_passthru_command(req);
420
421 switch (req->cmd->common.opcode) {
422 case nvme_admin_async_event:
423 req->execute = nvmet_execute_async_event;
424 return NVME_SC_SUCCESS;
425 case nvme_admin_keep_alive:
426 /*
427 * Most PCIe ctrls don't support keep alive cmd, we route keep
428 * alive to the non-passthru mode. In future please change this
429 * code when PCIe ctrls with keep alive support available.
430 */
431 req->execute = nvmet_execute_keep_alive;
432 return NVME_SC_SUCCESS;
433 case nvme_admin_set_features:
434 switch (le32_to_cpu(req->cmd->features.fid)) {
435 case NVME_FEAT_ASYNC_EVENT:
436 case NVME_FEAT_KATO:
437 case NVME_FEAT_NUM_QUEUES:
438 case NVME_FEAT_HOST_ID:
439 req->execute = nvmet_execute_set_features;
440 return NVME_SC_SUCCESS;
441 case NVME_FEAT_HOST_BEHAVIOR:
442 req->execute = nvmet_passthru_set_host_behaviour;
443 return NVME_SC_SUCCESS;
444 default:
445 return nvmet_passthru_get_set_features(req);
446 }
447 break;
448 case nvme_admin_get_features:
449 switch (le32_to_cpu(req->cmd->features.fid)) {
450 case NVME_FEAT_ASYNC_EVENT:
451 case NVME_FEAT_KATO:
452 case NVME_FEAT_NUM_QUEUES:
453 case NVME_FEAT_HOST_ID:
454 req->execute = nvmet_execute_get_features;
455 return NVME_SC_SUCCESS;
456 default:
457 return nvmet_passthru_get_set_features(req);
458 }
459 break;
460 case nvme_admin_identify:
461 switch (req->cmd->identify.cns) {
462 case NVME_ID_CNS_CTRL:
463 req->execute = nvmet_passthru_execute_cmd;
464 req->p.use_workqueue = true;
465 return NVME_SC_SUCCESS;
466 case NVME_ID_CNS_CS_CTRL:
467 switch (req->cmd->identify.csi) {
468 case NVME_CSI_ZNS:
469 req->execute = nvmet_passthru_execute_cmd;
470 req->p.use_workqueue = true;
471 return NVME_SC_SUCCESS;
472 }
473 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
474 case NVME_ID_CNS_NS:
475 req->execute = nvmet_passthru_execute_cmd;
476 req->p.use_workqueue = true;
477 return NVME_SC_SUCCESS;
478 case NVME_ID_CNS_CS_NS:
479 switch (req->cmd->identify.csi) {
480 case NVME_CSI_ZNS:
481 req->execute = nvmet_passthru_execute_cmd;
482 req->p.use_workqueue = true;
483 return NVME_SC_SUCCESS;
484 }
485 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
486 default:
487 return nvmet_setup_passthru_command(req);
488 }
489 case nvme_admin_get_log_page:
490 return nvmet_setup_passthru_command(req);
491 default:
492 /* Reject commands not in the allowlist above */
493 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
494 }
495 }
496
nvmet_passthru_ctrl_enable(struct nvmet_subsys * subsys)497 int nvmet_passthru_ctrl_enable(struct nvmet_subsys *subsys)
498 {
499 struct nvme_ctrl *ctrl;
500 struct file *file;
501 int ret = -EINVAL;
502 void *old;
503
504 mutex_lock(&subsys->lock);
505 if (!subsys->passthru_ctrl_path)
506 goto out_unlock;
507 if (subsys->passthru_ctrl)
508 goto out_unlock;
509
510 if (subsys->nr_namespaces) {
511 pr_info("cannot enable both passthru and regular namespaces for a single subsystem");
512 goto out_unlock;
513 }
514
515 file = filp_open(subsys->passthru_ctrl_path, O_RDWR, 0);
516 if (IS_ERR(file)) {
517 ret = PTR_ERR(file);
518 goto out_unlock;
519 }
520
521 ctrl = nvme_ctrl_from_file(file);
522 if (!ctrl) {
523 pr_err("failed to open nvme controller %s\n",
524 subsys->passthru_ctrl_path);
525
526 goto out_put_file;
527 }
528
529 old = xa_cmpxchg(&passthru_subsystems, ctrl->cntlid, NULL,
530 subsys, GFP_KERNEL);
531 if (xa_is_err(old)) {
532 ret = xa_err(old);
533 goto out_put_file;
534 }
535
536 if (old)
537 goto out_put_file;
538
539 subsys->passthru_ctrl = ctrl;
540 subsys->ver = ctrl->vs;
541
542 if (subsys->ver < NVME_VS(1, 2, 1)) {
543 pr_warn("nvme controller version is too old: %llu.%llu.%llu, advertising 1.2.1\n",
544 NVME_MAJOR(subsys->ver), NVME_MINOR(subsys->ver),
545 NVME_TERTIARY(subsys->ver));
546 subsys->ver = NVME_VS(1, 2, 1);
547 }
548 nvme_get_ctrl(ctrl);
549 __module_get(subsys->passthru_ctrl->ops->module);
550 ret = 0;
551
552 out_put_file:
553 filp_close(file, NULL);
554 out_unlock:
555 mutex_unlock(&subsys->lock);
556 return ret;
557 }
558
__nvmet_passthru_ctrl_disable(struct nvmet_subsys * subsys)559 static void __nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
560 {
561 if (subsys->passthru_ctrl) {
562 xa_erase(&passthru_subsystems, subsys->passthru_ctrl->cntlid);
563 module_put(subsys->passthru_ctrl->ops->module);
564 nvme_put_ctrl(subsys->passthru_ctrl);
565 }
566 subsys->passthru_ctrl = NULL;
567 subsys->ver = NVMET_DEFAULT_VS;
568 }
569
nvmet_passthru_ctrl_disable(struct nvmet_subsys * subsys)570 void nvmet_passthru_ctrl_disable(struct nvmet_subsys *subsys)
571 {
572 mutex_lock(&subsys->lock);
573 __nvmet_passthru_ctrl_disable(subsys);
574 mutex_unlock(&subsys->lock);
575 }
576
nvmet_passthru_subsys_free(struct nvmet_subsys * subsys)577 void nvmet_passthru_subsys_free(struct nvmet_subsys *subsys)
578 {
579 mutex_lock(&subsys->lock);
580 __nvmet_passthru_ctrl_disable(subsys);
581 mutex_unlock(&subsys->lock);
582 kfree(subsys->passthru_ctrl_path);
583 }
584