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