1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Virtio SCSI HBA driver |
4 | * |
5 | * Copyright IBM Corp. 2010 |
6 | * Copyright Red Hat, Inc. 2011 |
7 | * |
8 | * Authors: |
9 | * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> |
10 | * Paolo Bonzini <pbonzini@redhat.com> |
11 | */ |
12 | |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | |
15 | #include <linux/module.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/mempool.h> |
18 | #include <linux/interrupt.h> |
19 | #include <linux/virtio.h> |
20 | #include <linux/virtio_ids.h> |
21 | #include <linux/virtio_config.h> |
22 | #include <linux/virtio_scsi.h> |
23 | #include <linux/cpu.h> |
24 | #include <linux/blkdev.h> |
25 | #include <linux/blk-integrity.h> |
26 | #include <scsi/scsi_host.h> |
27 | #include <scsi/scsi_device.h> |
28 | #include <scsi/scsi_cmnd.h> |
29 | #include <scsi/scsi_tcq.h> |
30 | #include <scsi/scsi_devinfo.h> |
31 | #include <linux/seqlock.h> |
32 | #include <linux/blk-mq-virtio.h> |
33 | |
34 | #include "sd.h" |
35 | |
36 | #define VIRTIO_SCSI_MEMPOOL_SZ 64 |
37 | #define VIRTIO_SCSI_EVENT_LEN 8 |
38 | #define VIRTIO_SCSI_VQ_BASE 2 |
39 | |
40 | /* Command queue element */ |
41 | struct virtio_scsi_cmd { |
42 | struct scsi_cmnd *sc; |
43 | struct completion *comp; |
44 | union { |
45 | struct virtio_scsi_cmd_req cmd; |
46 | struct virtio_scsi_cmd_req_pi cmd_pi; |
47 | struct virtio_scsi_ctrl_tmf_req tmf; |
48 | struct virtio_scsi_ctrl_an_req an; |
49 | } req; |
50 | union { |
51 | struct virtio_scsi_cmd_resp cmd; |
52 | struct virtio_scsi_ctrl_tmf_resp tmf; |
53 | struct virtio_scsi_ctrl_an_resp an; |
54 | struct virtio_scsi_event evt; |
55 | } resp; |
56 | } ____cacheline_aligned_in_smp; |
57 | |
58 | struct virtio_scsi_event_node { |
59 | struct virtio_scsi *vscsi; |
60 | struct virtio_scsi_event event; |
61 | struct work_struct work; |
62 | }; |
63 | |
64 | struct virtio_scsi_vq { |
65 | /* Protects vq */ |
66 | spinlock_t vq_lock; |
67 | |
68 | struct virtqueue *vq; |
69 | }; |
70 | |
71 | /* Driver instance state */ |
72 | struct virtio_scsi { |
73 | struct virtio_device *vdev; |
74 | |
75 | /* Get some buffers ready for event vq */ |
76 | struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; |
77 | |
78 | u32 num_queues; |
79 | |
80 | struct hlist_node node; |
81 | |
82 | /* Protected by event_vq lock */ |
83 | bool stop_events; |
84 | |
85 | struct virtio_scsi_vq ctrl_vq; |
86 | struct virtio_scsi_vq event_vq; |
87 | struct virtio_scsi_vq req_vqs[]; |
88 | }; |
89 | |
90 | static struct kmem_cache *virtscsi_cmd_cache; |
91 | static mempool_t *virtscsi_cmd_pool; |
92 | |
93 | static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) |
94 | { |
95 | return vdev->priv; |
96 | } |
97 | |
98 | static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) |
99 | { |
100 | if (resid) |
101 | scsi_set_resid(cmd: sc, min(resid, scsi_bufflen(sc))); |
102 | } |
103 | |
104 | /* |
105 | * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done |
106 | * |
107 | * Called with vq_lock held. |
108 | */ |
109 | static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) |
110 | { |
111 | struct virtio_scsi_cmd *cmd = buf; |
112 | struct scsi_cmnd *sc = cmd->sc; |
113 | struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; |
114 | |
115 | dev_dbg(&sc->device->sdev_gendev, |
116 | "cmd %p response %u status %#02x sense_len %u\n" , |
117 | sc, resp->response, resp->status, resp->sense_len); |
118 | |
119 | sc->result = resp->status; |
120 | virtscsi_compute_resid(sc, resid: virtio32_to_cpu(vdev: vscsi->vdev, val: resp->resid)); |
121 | switch (resp->response) { |
122 | case VIRTIO_SCSI_S_OK: |
123 | set_host_byte(cmd: sc, status: DID_OK); |
124 | break; |
125 | case VIRTIO_SCSI_S_OVERRUN: |
126 | set_host_byte(cmd: sc, status: DID_ERROR); |
127 | break; |
128 | case VIRTIO_SCSI_S_ABORTED: |
129 | set_host_byte(cmd: sc, status: DID_ABORT); |
130 | break; |
131 | case VIRTIO_SCSI_S_BAD_TARGET: |
132 | set_host_byte(cmd: sc, status: DID_BAD_TARGET); |
133 | break; |
134 | case VIRTIO_SCSI_S_RESET: |
135 | set_host_byte(cmd: sc, status: DID_RESET); |
136 | break; |
137 | case VIRTIO_SCSI_S_BUSY: |
138 | set_host_byte(cmd: sc, status: DID_BUS_BUSY); |
139 | break; |
140 | case VIRTIO_SCSI_S_TRANSPORT_FAILURE: |
141 | set_host_byte(cmd: sc, status: DID_TRANSPORT_DISRUPTED); |
142 | break; |
143 | case VIRTIO_SCSI_S_TARGET_FAILURE: |
144 | set_host_byte(cmd: sc, status: DID_BAD_TARGET); |
145 | break; |
146 | case VIRTIO_SCSI_S_NEXUS_FAILURE: |
147 | set_status_byte(cmd: sc, status: SAM_STAT_RESERVATION_CONFLICT); |
148 | break; |
149 | default: |
150 | scmd_printk(KERN_WARNING, sc, "Unknown response %d" , |
151 | resp->response); |
152 | fallthrough; |
153 | case VIRTIO_SCSI_S_FAILURE: |
154 | set_host_byte(cmd: sc, status: DID_ERROR); |
155 | break; |
156 | } |
157 | |
158 | WARN_ON(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > |
159 | VIRTIO_SCSI_SENSE_SIZE); |
160 | if (resp->sense_len) { |
161 | memcpy(sc->sense_buffer, resp->sense, |
162 | min_t(u32, |
163 | virtio32_to_cpu(vscsi->vdev, resp->sense_len), |
164 | VIRTIO_SCSI_SENSE_SIZE)); |
165 | } |
166 | |
167 | scsi_done(cmd: sc); |
168 | } |
169 | |
170 | static void virtscsi_vq_done(struct virtio_scsi *vscsi, |
171 | struct virtio_scsi_vq *virtscsi_vq, |
172 | void (*fn)(struct virtio_scsi *vscsi, void *buf)) |
173 | { |
174 | void *buf; |
175 | unsigned int len; |
176 | unsigned long flags; |
177 | struct virtqueue *vq = virtscsi_vq->vq; |
178 | |
179 | spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); |
180 | do { |
181 | virtqueue_disable_cb(vq); |
182 | while ((buf = virtqueue_get_buf(vq, len: &len)) != NULL) |
183 | fn(vscsi, buf); |
184 | |
185 | if (unlikely(virtqueue_is_broken(vq))) |
186 | break; |
187 | } while (!virtqueue_enable_cb(vq)); |
188 | spin_unlock_irqrestore(lock: &virtscsi_vq->vq_lock, flags); |
189 | } |
190 | |
191 | static void virtscsi_req_done(struct virtqueue *vq) |
192 | { |
193 | struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev); |
194 | struct virtio_scsi *vscsi = shost_priv(shost: sh); |
195 | int index = vq->index - VIRTIO_SCSI_VQ_BASE; |
196 | struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; |
197 | |
198 | virtscsi_vq_done(vscsi, virtscsi_vq: req_vq, fn: virtscsi_complete_cmd); |
199 | }; |
200 | |
201 | static void virtscsi_poll_requests(struct virtio_scsi *vscsi) |
202 | { |
203 | int i, num_vqs; |
204 | |
205 | num_vqs = vscsi->num_queues; |
206 | for (i = 0; i < num_vqs; i++) |
207 | virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->req_vqs[i], |
208 | fn: virtscsi_complete_cmd); |
209 | } |
210 | |
211 | static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) |
212 | { |
213 | struct virtio_scsi_cmd *cmd = buf; |
214 | |
215 | if (cmd->comp) |
216 | complete(cmd->comp); |
217 | } |
218 | |
219 | static void virtscsi_ctrl_done(struct virtqueue *vq) |
220 | { |
221 | struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev); |
222 | struct virtio_scsi *vscsi = shost_priv(shost: sh); |
223 | |
224 | virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->ctrl_vq, fn: virtscsi_complete_free); |
225 | }; |
226 | |
227 | static void virtscsi_handle_event(struct work_struct *work); |
228 | |
229 | static int virtscsi_kick_event(struct virtio_scsi *vscsi, |
230 | struct virtio_scsi_event_node *event_node) |
231 | { |
232 | int err; |
233 | struct scatterlist sg; |
234 | unsigned long flags; |
235 | |
236 | INIT_WORK(&event_node->work, virtscsi_handle_event); |
237 | sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); |
238 | |
239 | spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); |
240 | |
241 | err = virtqueue_add_inbuf(vq: vscsi->event_vq.vq, sg: &sg, num: 1, data: event_node, |
242 | GFP_ATOMIC); |
243 | if (!err) |
244 | virtqueue_kick(vq: vscsi->event_vq.vq); |
245 | |
246 | spin_unlock_irqrestore(lock: &vscsi->event_vq.vq_lock, flags); |
247 | |
248 | return err; |
249 | } |
250 | |
251 | static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) |
252 | { |
253 | int i; |
254 | |
255 | for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { |
256 | vscsi->event_list[i].vscsi = vscsi; |
257 | virtscsi_kick_event(vscsi, event_node: &vscsi->event_list[i]); |
258 | } |
259 | |
260 | return 0; |
261 | } |
262 | |
263 | static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) |
264 | { |
265 | int i; |
266 | |
267 | /* Stop scheduling work before calling cancel_work_sync. */ |
268 | spin_lock_irq(lock: &vscsi->event_vq.vq_lock); |
269 | vscsi->stop_events = true; |
270 | spin_unlock_irq(lock: &vscsi->event_vq.vq_lock); |
271 | |
272 | for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) |
273 | cancel_work_sync(work: &vscsi->event_list[i].work); |
274 | } |
275 | |
276 | static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, |
277 | struct virtio_scsi_event *event) |
278 | { |
279 | struct scsi_device *sdev; |
280 | struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev); |
281 | unsigned int target = event->lun[1]; |
282 | unsigned int lun = (event->lun[2] << 8) | event->lun[3]; |
283 | |
284 | switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason)) { |
285 | case VIRTIO_SCSI_EVT_RESET_RESCAN: |
286 | if (lun == 0) { |
287 | scsi_scan_target(parent: &shost->shost_gendev, channel: 0, id: target, |
288 | SCAN_WILD_CARD, rescan: SCSI_SCAN_INITIAL); |
289 | } else { |
290 | scsi_add_device(host: shost, channel: 0, target, lun); |
291 | } |
292 | break; |
293 | case VIRTIO_SCSI_EVT_RESET_REMOVED: |
294 | sdev = scsi_device_lookup(shost, 0, target, lun); |
295 | if (sdev) { |
296 | scsi_remove_device(sdev); |
297 | scsi_device_put(sdev); |
298 | } else { |
299 | pr_err("SCSI device %d 0 %d %d not found\n" , |
300 | shost->host_no, target, lun); |
301 | } |
302 | break; |
303 | default: |
304 | pr_info("Unsupported virtio scsi event reason %x\n" , event->reason); |
305 | } |
306 | } |
307 | |
308 | static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, |
309 | struct virtio_scsi_event *event) |
310 | { |
311 | struct scsi_device *sdev; |
312 | struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev); |
313 | unsigned int target = event->lun[1]; |
314 | unsigned int lun = (event->lun[2] << 8) | event->lun[3]; |
315 | u8 asc = virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason) & 255; |
316 | u8 ascq = virtio32_to_cpu(vdev: vscsi->vdev, val: event->reason) >> 8; |
317 | |
318 | sdev = scsi_device_lookup(shost, 0, target, lun); |
319 | if (!sdev) { |
320 | pr_err("SCSI device %d 0 %d %d not found\n" , |
321 | shost->host_no, target, lun); |
322 | return; |
323 | } |
324 | |
325 | /* Handle "Parameters changed", "Mode parameters changed", and |
326 | "Capacity data has changed". */ |
327 | if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) |
328 | scsi_rescan_device(sdev); |
329 | |
330 | scsi_device_put(sdev); |
331 | } |
332 | |
333 | static int virtscsi_rescan_hotunplug(struct virtio_scsi *vscsi) |
334 | { |
335 | struct scsi_device *sdev; |
336 | struct Scsi_Host *shost = virtio_scsi_host(vdev: vscsi->vdev); |
337 | unsigned char scsi_cmd[MAX_COMMAND_SIZE]; |
338 | int result, inquiry_len, inq_result_len = 256; |
339 | char *inq_result = kmalloc(size: inq_result_len, GFP_KERNEL); |
340 | |
341 | if (!inq_result) |
342 | return -ENOMEM; |
343 | |
344 | shost_for_each_device(sdev, shost) { |
345 | inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; |
346 | |
347 | memset(scsi_cmd, 0, sizeof(scsi_cmd)); |
348 | scsi_cmd[0] = INQUIRY; |
349 | scsi_cmd[4] = (unsigned char) inquiry_len; |
350 | |
351 | memset(inq_result, 0, inq_result_len); |
352 | |
353 | result = scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN, |
354 | buffer: inq_result, bufflen: inquiry_len, |
355 | SD_TIMEOUT, SD_MAX_RETRIES, NULL); |
356 | |
357 | if (result == 0 && inq_result[0] >> 5) { |
358 | /* PQ indicates the LUN is not attached */ |
359 | scsi_remove_device(sdev); |
360 | } else if (result > 0 && host_byte(result) == DID_BAD_TARGET) { |
361 | /* |
362 | * If all LUNs of a virtio-scsi device are unplugged |
363 | * it will respond with BAD TARGET on any INQUIRY |
364 | * command. |
365 | * Remove the device in this case as well. |
366 | */ |
367 | scsi_remove_device(sdev); |
368 | } |
369 | } |
370 | |
371 | kfree(objp: inq_result); |
372 | return 0; |
373 | } |
374 | |
375 | static void virtscsi_handle_event(struct work_struct *work) |
376 | { |
377 | struct virtio_scsi_event_node *event_node = |
378 | container_of(work, struct virtio_scsi_event_node, work); |
379 | struct virtio_scsi *vscsi = event_node->vscsi; |
380 | struct virtio_scsi_event *event = &event_node->event; |
381 | |
382 | if (event->event & |
383 | cpu_to_virtio32(vdev: vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { |
384 | int ret; |
385 | |
386 | event->event &= ~cpu_to_virtio32(vdev: vscsi->vdev, |
387 | VIRTIO_SCSI_T_EVENTS_MISSED); |
388 | ret = virtscsi_rescan_hotunplug(vscsi); |
389 | if (ret) |
390 | return; |
391 | scsi_scan_host(virtio_scsi_host(vdev: vscsi->vdev)); |
392 | } |
393 | |
394 | switch (virtio32_to_cpu(vdev: vscsi->vdev, val: event->event)) { |
395 | case VIRTIO_SCSI_T_NO_EVENT: |
396 | break; |
397 | case VIRTIO_SCSI_T_TRANSPORT_RESET: |
398 | virtscsi_handle_transport_reset(vscsi, event); |
399 | break; |
400 | case VIRTIO_SCSI_T_PARAM_CHANGE: |
401 | virtscsi_handle_param_change(vscsi, event); |
402 | break; |
403 | default: |
404 | pr_err("Unsupported virtio scsi event %x\n" , event->event); |
405 | } |
406 | virtscsi_kick_event(vscsi, event_node); |
407 | } |
408 | |
409 | static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) |
410 | { |
411 | struct virtio_scsi_event_node *event_node = buf; |
412 | |
413 | if (!vscsi->stop_events) |
414 | queue_work(wq: system_freezable_wq, work: &event_node->work); |
415 | } |
416 | |
417 | static void virtscsi_event_done(struct virtqueue *vq) |
418 | { |
419 | struct Scsi_Host *sh = virtio_scsi_host(vdev: vq->vdev); |
420 | struct virtio_scsi *vscsi = shost_priv(shost: sh); |
421 | |
422 | virtscsi_vq_done(vscsi, virtscsi_vq: &vscsi->event_vq, fn: virtscsi_complete_event); |
423 | }; |
424 | |
425 | static int __virtscsi_add_cmd(struct virtqueue *vq, |
426 | struct virtio_scsi_cmd *cmd, |
427 | size_t req_size, size_t resp_size) |
428 | { |
429 | struct scsi_cmnd *sc = cmd->sc; |
430 | struct scatterlist *sgs[6], req, resp; |
431 | struct sg_table *out, *in; |
432 | unsigned out_num = 0, in_num = 0; |
433 | |
434 | out = in = NULL; |
435 | |
436 | if (sc && sc->sc_data_direction != DMA_NONE) { |
437 | if (sc->sc_data_direction != DMA_FROM_DEVICE) |
438 | out = &sc->sdb.table; |
439 | if (sc->sc_data_direction != DMA_TO_DEVICE) |
440 | in = &sc->sdb.table; |
441 | } |
442 | |
443 | /* Request header. */ |
444 | sg_init_one(&req, &cmd->req, req_size); |
445 | sgs[out_num++] = &req; |
446 | |
447 | /* Data-out buffer. */ |
448 | if (out) { |
449 | /* Place WRITE protection SGLs before Data OUT payload */ |
450 | if (scsi_prot_sg_count(cmd: sc)) |
451 | sgs[out_num++] = scsi_prot_sglist(cmd: sc); |
452 | sgs[out_num++] = out->sgl; |
453 | } |
454 | |
455 | /* Response header. */ |
456 | sg_init_one(&resp, &cmd->resp, resp_size); |
457 | sgs[out_num + in_num++] = &resp; |
458 | |
459 | /* Data-in buffer */ |
460 | if (in) { |
461 | /* Place READ protection SGLs before Data IN payload */ |
462 | if (scsi_prot_sg_count(cmd: sc)) |
463 | sgs[out_num + in_num++] = scsi_prot_sglist(cmd: sc); |
464 | sgs[out_num + in_num++] = in->sgl; |
465 | } |
466 | |
467 | return virtqueue_add_sgs(vq, sgs, out_sgs: out_num, in_sgs: in_num, data: cmd, GFP_ATOMIC); |
468 | } |
469 | |
470 | static void virtscsi_kick_vq(struct virtio_scsi_vq *vq) |
471 | { |
472 | bool needs_kick; |
473 | unsigned long flags; |
474 | |
475 | spin_lock_irqsave(&vq->vq_lock, flags); |
476 | needs_kick = virtqueue_kick_prepare(vq: vq->vq); |
477 | spin_unlock_irqrestore(lock: &vq->vq_lock, flags); |
478 | |
479 | if (needs_kick) |
480 | virtqueue_notify(vq: vq->vq); |
481 | } |
482 | |
483 | /** |
484 | * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue, optionally kick it |
485 | * @vq : the struct virtqueue we're talking about |
486 | * @cmd : command structure |
487 | * @req_size : size of the request buffer |
488 | * @resp_size : size of the response buffer |
489 | * @kick : whether to kick the virtqueue immediately |
490 | */ |
491 | static int virtscsi_add_cmd(struct virtio_scsi_vq *vq, |
492 | struct virtio_scsi_cmd *cmd, |
493 | size_t req_size, size_t resp_size, |
494 | bool kick) |
495 | { |
496 | unsigned long flags; |
497 | int err; |
498 | bool needs_kick = false; |
499 | |
500 | spin_lock_irqsave(&vq->vq_lock, flags); |
501 | err = __virtscsi_add_cmd(vq: vq->vq, cmd, req_size, resp_size); |
502 | if (!err && kick) |
503 | needs_kick = virtqueue_kick_prepare(vq: vq->vq); |
504 | |
505 | spin_unlock_irqrestore(lock: &vq->vq_lock, flags); |
506 | |
507 | if (needs_kick) |
508 | virtqueue_notify(vq: vq->vq); |
509 | return err; |
510 | } |
511 | |
512 | static void virtio_scsi_init_hdr(struct virtio_device *vdev, |
513 | struct virtio_scsi_cmd_req *cmd, |
514 | struct scsi_cmnd *sc) |
515 | { |
516 | cmd->lun[0] = 1; |
517 | cmd->lun[1] = sc->device->id; |
518 | cmd->lun[2] = (sc->device->lun >> 8) | 0x40; |
519 | cmd->lun[3] = sc->device->lun & 0xff; |
520 | cmd->tag = cpu_to_virtio64(vdev, val: (unsigned long)sc); |
521 | cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; |
522 | cmd->prio = 0; |
523 | cmd->crn = 0; |
524 | } |
525 | |
526 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
527 | static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, |
528 | struct virtio_scsi_cmd_req_pi *cmd_pi, |
529 | struct scsi_cmnd *sc) |
530 | { |
531 | struct request *rq = scsi_cmd_to_rq(scmd: sc); |
532 | struct blk_integrity *bi; |
533 | |
534 | virtio_scsi_init_hdr(vdev, cmd: (struct virtio_scsi_cmd_req *)cmd_pi, sc); |
535 | |
536 | if (!rq || !scsi_prot_sg_count(cmd: sc)) |
537 | return; |
538 | |
539 | bi = blk_get_integrity(disk: rq->q->disk); |
540 | |
541 | if (sc->sc_data_direction == DMA_TO_DEVICE) |
542 | cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, |
543 | val: bio_integrity_bytes(bi, |
544 | sectors: blk_rq_sectors(rq))); |
545 | else if (sc->sc_data_direction == DMA_FROM_DEVICE) |
546 | cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, |
547 | val: bio_integrity_bytes(bi, |
548 | sectors: blk_rq_sectors(rq))); |
549 | } |
550 | #endif |
551 | |
552 | static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, |
553 | struct scsi_cmnd *sc) |
554 | { |
555 | u32 tag = blk_mq_unique_tag(rq: scsi_cmd_to_rq(scmd: sc)); |
556 | u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag: tag); |
557 | |
558 | return &vscsi->req_vqs[hwq]; |
559 | } |
560 | |
561 | static int virtscsi_queuecommand(struct Scsi_Host *shost, |
562 | struct scsi_cmnd *sc) |
563 | { |
564 | struct virtio_scsi *vscsi = shost_priv(shost); |
565 | struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); |
566 | struct virtio_scsi_cmd *cmd = scsi_cmd_priv(cmd: sc); |
567 | bool kick; |
568 | unsigned long flags; |
569 | int req_size; |
570 | int ret; |
571 | |
572 | BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); |
573 | |
574 | /* TODO: check feature bit and fail if unsupported? */ |
575 | BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); |
576 | |
577 | dev_dbg(&sc->device->sdev_gendev, |
578 | "cmd %p CDB: %#02x\n" , sc, sc->cmnd[0]); |
579 | |
580 | cmd->sc = sc; |
581 | |
582 | BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); |
583 | |
584 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
585 | if (virtio_has_feature(vdev: vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { |
586 | virtio_scsi_init_hdr_pi(vdev: vscsi->vdev, cmd_pi: &cmd->req.cmd_pi, sc); |
587 | memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); |
588 | req_size = sizeof(cmd->req.cmd_pi); |
589 | } else |
590 | #endif |
591 | { |
592 | virtio_scsi_init_hdr(vdev: vscsi->vdev, cmd: &cmd->req.cmd, sc); |
593 | memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); |
594 | req_size = sizeof(cmd->req.cmd); |
595 | } |
596 | |
597 | kick = (sc->flags & SCMD_LAST) != 0; |
598 | ret = virtscsi_add_cmd(vq: req_vq, cmd, req_size, resp_size: sizeof(cmd->resp.cmd), kick); |
599 | if (ret == -EIO) { |
600 | cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; |
601 | spin_lock_irqsave(&req_vq->vq_lock, flags); |
602 | virtscsi_complete_cmd(vscsi, buf: cmd); |
603 | spin_unlock_irqrestore(lock: &req_vq->vq_lock, flags); |
604 | } else if (ret != 0) { |
605 | return SCSI_MLQUEUE_HOST_BUSY; |
606 | } |
607 | return 0; |
608 | } |
609 | |
610 | static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) |
611 | { |
612 | DECLARE_COMPLETION_ONSTACK(comp); |
613 | int ret = FAILED; |
614 | |
615 | cmd->comp = ∁ |
616 | if (virtscsi_add_cmd(vq: &vscsi->ctrl_vq, cmd, |
617 | req_size: sizeof cmd->req.tmf, resp_size: sizeof cmd->resp.tmf, kick: true) < 0) |
618 | goto out; |
619 | |
620 | wait_for_completion(&comp); |
621 | if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || |
622 | cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) |
623 | ret = SUCCESS; |
624 | |
625 | /* |
626 | * The spec guarantees that all requests related to the TMF have |
627 | * been completed, but the callback might not have run yet if |
628 | * we're using independent interrupts (e.g. MSI). Poll the |
629 | * virtqueues once. |
630 | * |
631 | * In the abort case, scsi_done() will do nothing, because the |
632 | * command timed out and hence SCMD_STATE_COMPLETE has been set. |
633 | */ |
634 | virtscsi_poll_requests(vscsi); |
635 | |
636 | out: |
637 | mempool_free(element: cmd, pool: virtscsi_cmd_pool); |
638 | return ret; |
639 | } |
640 | |
641 | static int virtscsi_device_reset(struct scsi_cmnd *sc) |
642 | { |
643 | struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host); |
644 | struct virtio_scsi_cmd *cmd; |
645 | |
646 | sdev_printk(KERN_INFO, sc->device, "device reset\n" ); |
647 | cmd = mempool_alloc(pool: virtscsi_cmd_pool, GFP_NOIO); |
648 | if (!cmd) |
649 | return FAILED; |
650 | |
651 | memset(cmd, 0, sizeof(*cmd)); |
652 | cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ |
653 | .type = VIRTIO_SCSI_T_TMF, |
654 | .subtype = cpu_to_virtio32(vdev: vscsi->vdev, |
655 | VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET), |
656 | .lun[0] = 1, |
657 | .lun[1] = sc->device->id, |
658 | .lun[2] = (sc->device->lun >> 8) | 0x40, |
659 | .lun[3] = sc->device->lun & 0xff, |
660 | }; |
661 | return virtscsi_tmf(vscsi, cmd); |
662 | } |
663 | |
664 | static int virtscsi_device_alloc(struct scsi_device *sdevice) |
665 | { |
666 | /* |
667 | * Passed through SCSI targets (e.g. with qemu's 'scsi-block') |
668 | * may have transfer limits which come from the host SCSI |
669 | * controller or something on the host side other than the |
670 | * target itself. |
671 | * |
672 | * To make this work properly, the hypervisor can adjust the |
673 | * target's VPD information to advertise these limits. But |
674 | * for that to work, the guest has to look at the VPD pages, |
675 | * which we won't do by default if it is an SPC-2 device, even |
676 | * if it does actually support it. |
677 | * |
678 | * So, set the blist to always try to read the VPD pages. |
679 | */ |
680 | sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; |
681 | |
682 | return 0; |
683 | } |
684 | |
685 | |
686 | /** |
687 | * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth |
688 | * @sdev: Virtscsi target whose queue depth to change |
689 | * @qdepth: New queue depth |
690 | */ |
691 | static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) |
692 | { |
693 | struct Scsi_Host *shost = sdev->host; |
694 | int max_depth = shost->cmd_per_lun; |
695 | |
696 | return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); |
697 | } |
698 | |
699 | static int virtscsi_abort(struct scsi_cmnd *sc) |
700 | { |
701 | struct virtio_scsi *vscsi = shost_priv(shost: sc->device->host); |
702 | struct virtio_scsi_cmd *cmd; |
703 | |
704 | scmd_printk(KERN_INFO, sc, "abort\n" ); |
705 | cmd = mempool_alloc(pool: virtscsi_cmd_pool, GFP_NOIO); |
706 | if (!cmd) |
707 | return FAILED; |
708 | |
709 | memset(cmd, 0, sizeof(*cmd)); |
710 | cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ |
711 | .type = VIRTIO_SCSI_T_TMF, |
712 | .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, |
713 | .lun[0] = 1, |
714 | .lun[1] = sc->device->id, |
715 | .lun[2] = (sc->device->lun >> 8) | 0x40, |
716 | .lun[3] = sc->device->lun & 0xff, |
717 | .tag = cpu_to_virtio64(vdev: vscsi->vdev, val: (unsigned long)sc), |
718 | }; |
719 | return virtscsi_tmf(vscsi, cmd); |
720 | } |
721 | |
722 | static void virtscsi_map_queues(struct Scsi_Host *shost) |
723 | { |
724 | struct virtio_scsi *vscsi = shost_priv(shost); |
725 | struct blk_mq_queue_map *qmap = &shost->tag_set.map[HCTX_TYPE_DEFAULT]; |
726 | |
727 | blk_mq_virtio_map_queues(qmap, vdev: vscsi->vdev, first_vec: 2); |
728 | } |
729 | |
730 | static void virtscsi_commit_rqs(struct Scsi_Host *shost, u16 hwq) |
731 | { |
732 | struct virtio_scsi *vscsi = shost_priv(shost); |
733 | |
734 | virtscsi_kick_vq(vq: &vscsi->req_vqs[hwq]); |
735 | } |
736 | |
737 | /* |
738 | * The host guarantees to respond to each command, although I/O |
739 | * latencies might be higher than on bare metal. Reset the timer |
740 | * unconditionally to give the host a chance to perform EH. |
741 | */ |
742 | static enum scsi_timeout_action virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) |
743 | { |
744 | return SCSI_EH_RESET_TIMER; |
745 | } |
746 | |
747 | static const struct scsi_host_template virtscsi_host_template = { |
748 | .module = THIS_MODULE, |
749 | .name = "Virtio SCSI HBA" , |
750 | .proc_name = "virtio_scsi" , |
751 | .this_id = -1, |
752 | .cmd_size = sizeof(struct virtio_scsi_cmd), |
753 | .queuecommand = virtscsi_queuecommand, |
754 | .commit_rqs = virtscsi_commit_rqs, |
755 | .change_queue_depth = virtscsi_change_queue_depth, |
756 | .eh_abort_handler = virtscsi_abort, |
757 | .eh_device_reset_handler = virtscsi_device_reset, |
758 | .eh_timed_out = virtscsi_eh_timed_out, |
759 | .slave_alloc = virtscsi_device_alloc, |
760 | |
761 | .dma_boundary = UINT_MAX, |
762 | .map_queues = virtscsi_map_queues, |
763 | .track_queue_depth = 1, |
764 | }; |
765 | |
766 | #define virtscsi_config_get(vdev, fld) \ |
767 | ({ \ |
768 | __virtio_native_type(struct virtio_scsi_config, fld) __val; \ |
769 | virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ |
770 | __val; \ |
771 | }) |
772 | |
773 | #define virtscsi_config_set(vdev, fld, val) \ |
774 | do { \ |
775 | __virtio_native_type(struct virtio_scsi_config, fld) __val = (val); \ |
776 | virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ |
777 | } while(0) |
778 | |
779 | static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, |
780 | struct virtqueue *vq) |
781 | { |
782 | spin_lock_init(&virtscsi_vq->vq_lock); |
783 | virtscsi_vq->vq = vq; |
784 | } |
785 | |
786 | static void virtscsi_remove_vqs(struct virtio_device *vdev) |
787 | { |
788 | /* Stop all the virtqueues. */ |
789 | virtio_reset_device(dev: vdev); |
790 | vdev->config->del_vqs(vdev); |
791 | } |
792 | |
793 | static int virtscsi_init(struct virtio_device *vdev, |
794 | struct virtio_scsi *vscsi) |
795 | { |
796 | int err; |
797 | u32 i; |
798 | u32 num_vqs; |
799 | vq_callback_t **callbacks; |
800 | const char **names; |
801 | struct virtqueue **vqs; |
802 | struct irq_affinity desc = { .pre_vectors = 2 }; |
803 | |
804 | num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; |
805 | vqs = kmalloc_array(n: num_vqs, size: sizeof(struct virtqueue *), GFP_KERNEL); |
806 | callbacks = kmalloc_array(n: num_vqs, size: sizeof(vq_callback_t *), |
807 | GFP_KERNEL); |
808 | names = kmalloc_array(n: num_vqs, size: sizeof(char *), GFP_KERNEL); |
809 | |
810 | if (!callbacks || !vqs || !names) { |
811 | err = -ENOMEM; |
812 | goto out; |
813 | } |
814 | |
815 | callbacks[0] = virtscsi_ctrl_done; |
816 | callbacks[1] = virtscsi_event_done; |
817 | names[0] = "control" ; |
818 | names[1] = "event" ; |
819 | for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { |
820 | callbacks[i] = virtscsi_req_done; |
821 | names[i] = "request" ; |
822 | } |
823 | |
824 | /* Discover virtqueues and write information to configuration. */ |
825 | err = virtio_find_vqs(vdev, nvqs: num_vqs, vqs, callbacks, names, desc: &desc); |
826 | if (err) |
827 | goto out; |
828 | |
829 | virtscsi_init_vq(virtscsi_vq: &vscsi->ctrl_vq, vq: vqs[0]); |
830 | virtscsi_init_vq(virtscsi_vq: &vscsi->event_vq, vq: vqs[1]); |
831 | for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) |
832 | virtscsi_init_vq(virtscsi_vq: &vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], |
833 | vq: vqs[i]); |
834 | |
835 | virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); |
836 | virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); |
837 | |
838 | err = 0; |
839 | |
840 | out: |
841 | kfree(objp: names); |
842 | kfree(objp: callbacks); |
843 | kfree(objp: vqs); |
844 | if (err) |
845 | virtscsi_remove_vqs(vdev); |
846 | return err; |
847 | } |
848 | |
849 | static int virtscsi_probe(struct virtio_device *vdev) |
850 | { |
851 | struct Scsi_Host *shost; |
852 | struct virtio_scsi *vscsi; |
853 | int err; |
854 | u32 sg_elems, num_targets; |
855 | u32 cmd_per_lun; |
856 | u32 num_queues; |
857 | |
858 | if (!vdev->config->get) { |
859 | dev_err(&vdev->dev, "%s failure: config access disabled\n" , |
860 | __func__); |
861 | return -EINVAL; |
862 | } |
863 | |
864 | /* We need to know how many queues before we allocate. */ |
865 | num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; |
866 | num_queues = min_t(unsigned int, nr_cpu_ids, num_queues); |
867 | |
868 | num_targets = virtscsi_config_get(vdev, max_target) + 1; |
869 | |
870 | shost = scsi_host_alloc(&virtscsi_host_template, |
871 | struct_size(vscsi, req_vqs, num_queues)); |
872 | if (!shost) |
873 | return -ENOMEM; |
874 | |
875 | sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; |
876 | shost->sg_tablesize = sg_elems; |
877 | vscsi = shost_priv(shost); |
878 | vscsi->vdev = vdev; |
879 | vscsi->num_queues = num_queues; |
880 | vdev->priv = shost; |
881 | |
882 | err = virtscsi_init(vdev, vscsi); |
883 | if (err) |
884 | goto virtscsi_init_failed; |
885 | |
886 | shost->can_queue = virtqueue_get_vring_size(vq: vscsi->req_vqs[0].vq); |
887 | |
888 | cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; |
889 | shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); |
890 | shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; |
891 | |
892 | /* LUNs > 256 are reported with format 1, so they go in the range |
893 | * 16640-32767. |
894 | */ |
895 | shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; |
896 | shost->max_id = num_targets; |
897 | shost->max_channel = 0; |
898 | shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; |
899 | shost->nr_hw_queues = num_queues; |
900 | |
901 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
902 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { |
903 | int host_prot; |
904 | |
905 | host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | |
906 | SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | |
907 | SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; |
908 | |
909 | scsi_host_set_prot(shost, mask: host_prot); |
910 | scsi_host_set_guard(shost, type: SHOST_DIX_GUARD_CRC); |
911 | } |
912 | #endif |
913 | |
914 | err = scsi_add_host(host: shost, dev: &vdev->dev); |
915 | if (err) |
916 | goto scsi_add_host_failed; |
917 | |
918 | virtio_device_ready(dev: vdev); |
919 | |
920 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) |
921 | virtscsi_kick_event_all(vscsi); |
922 | |
923 | scsi_scan_host(shost); |
924 | return 0; |
925 | |
926 | scsi_add_host_failed: |
927 | vdev->config->del_vqs(vdev); |
928 | virtscsi_init_failed: |
929 | scsi_host_put(t: shost); |
930 | return err; |
931 | } |
932 | |
933 | static void virtscsi_remove(struct virtio_device *vdev) |
934 | { |
935 | struct Scsi_Host *shost = virtio_scsi_host(vdev); |
936 | struct virtio_scsi *vscsi = shost_priv(shost); |
937 | |
938 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) |
939 | virtscsi_cancel_event_work(vscsi); |
940 | |
941 | scsi_remove_host(shost); |
942 | virtscsi_remove_vqs(vdev); |
943 | scsi_host_put(t: shost); |
944 | } |
945 | |
946 | #ifdef CONFIG_PM_SLEEP |
947 | static int virtscsi_freeze(struct virtio_device *vdev) |
948 | { |
949 | virtscsi_remove_vqs(vdev); |
950 | return 0; |
951 | } |
952 | |
953 | static int virtscsi_restore(struct virtio_device *vdev) |
954 | { |
955 | struct Scsi_Host *sh = virtio_scsi_host(vdev); |
956 | struct virtio_scsi *vscsi = shost_priv(shost: sh); |
957 | int err; |
958 | |
959 | err = virtscsi_init(vdev, vscsi); |
960 | if (err) |
961 | return err; |
962 | |
963 | virtio_device_ready(dev: vdev); |
964 | |
965 | if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) |
966 | virtscsi_kick_event_all(vscsi); |
967 | |
968 | return err; |
969 | } |
970 | #endif |
971 | |
972 | static struct virtio_device_id id_table[] = { |
973 | { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, |
974 | { 0 }, |
975 | }; |
976 | |
977 | static unsigned int features[] = { |
978 | VIRTIO_SCSI_F_HOTPLUG, |
979 | VIRTIO_SCSI_F_CHANGE, |
980 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
981 | VIRTIO_SCSI_F_T10_PI, |
982 | #endif |
983 | }; |
984 | |
985 | static struct virtio_driver virtio_scsi_driver = { |
986 | .feature_table = features, |
987 | .feature_table_size = ARRAY_SIZE(features), |
988 | .driver.name = KBUILD_MODNAME, |
989 | .driver.owner = THIS_MODULE, |
990 | .id_table = id_table, |
991 | .probe = virtscsi_probe, |
992 | #ifdef CONFIG_PM_SLEEP |
993 | .freeze = virtscsi_freeze, |
994 | .restore = virtscsi_restore, |
995 | #endif |
996 | .remove = virtscsi_remove, |
997 | }; |
998 | |
999 | static int __init virtio_scsi_init(void) |
1000 | { |
1001 | int ret = -ENOMEM; |
1002 | |
1003 | virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); |
1004 | if (!virtscsi_cmd_cache) { |
1005 | pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n" ); |
1006 | goto error; |
1007 | } |
1008 | |
1009 | |
1010 | virtscsi_cmd_pool = |
1011 | mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, |
1012 | kc: virtscsi_cmd_cache); |
1013 | if (!virtscsi_cmd_pool) { |
1014 | pr_err("mempool_create() for virtscsi_cmd_pool failed\n" ); |
1015 | goto error; |
1016 | } |
1017 | ret = register_virtio_driver(drv: &virtio_scsi_driver); |
1018 | if (ret < 0) |
1019 | goto error; |
1020 | |
1021 | return 0; |
1022 | |
1023 | error: |
1024 | mempool_destroy(pool: virtscsi_cmd_pool); |
1025 | virtscsi_cmd_pool = NULL; |
1026 | kmem_cache_destroy(s: virtscsi_cmd_cache); |
1027 | virtscsi_cmd_cache = NULL; |
1028 | return ret; |
1029 | } |
1030 | |
1031 | static void __exit virtio_scsi_fini(void) |
1032 | { |
1033 | unregister_virtio_driver(drv: &virtio_scsi_driver); |
1034 | mempool_destroy(pool: virtscsi_cmd_pool); |
1035 | kmem_cache_destroy(s: virtscsi_cmd_cache); |
1036 | } |
1037 | module_init(virtio_scsi_init); |
1038 | module_exit(virtio_scsi_fini); |
1039 | |
1040 | MODULE_DEVICE_TABLE(virtio, id_table); |
1041 | MODULE_DESCRIPTION("Virtio SCSI HBA driver" ); |
1042 | MODULE_LICENSE("GPL" ); |
1043 | |