1	// SPDX-License-Identifier: GPL-2.0-only
2	//#define DEBUG
3	#include <linux/spinlock.h>
4	#include <linux/slab.h>
5	#include <linux/blkdev.h>
6	#include <linux/hdreg.h>
7	#include <linux/module.h>
8	#include <linux/mutex.h>
9	#include <linux/interrupt.h>
10	#include <linux/virtio.h>
11	#include <linux/virtio_blk.h>
12	#include <linux/scatterlist.h>
13	#include <linux/string_helpers.h>
14	#include <linux/idr.h>
15	#include <linux/blk-mq.h>
16	#include <linux/blk-mq-virtio.h>
17	#include <linux/numa.h>
18	#include <linux/vmalloc.h>
19	#include <uapi/linux/virtio_ring.h>
20
21	#define PART_BITS 4
22	#define VQ_NAME_LEN 16
23	#define MAX_DISCARD_SEGMENTS 256u
24
25	/* The maximum number of sg elements that fit into a virtqueue */
26	#define VIRTIO_BLK_MAX_SG_ELEMS 32768
27
28	#ifdef CONFIG_ARCH_NO_SG_CHAIN
29	#define VIRTIO_BLK_INLINE_SG_CNT 0
30	#else
31	#define VIRTIO_BLK_INLINE_SG_CNT 2
32	#endif
33
34	static unsigned int num_request_queues;
35	module_param(num_request_queues, uint, 0644);
36	MODULE_PARM_DESC(num_request_queues,
37	"Limit the number of request queues to use for blk device. "
38	"0 for no limit. "
39	"Values > nr_cpu_ids truncated to nr_cpu_ids.");
40
41	static unsigned int poll_queues;
42	module_param(poll_queues, uint, 0644);
43	MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O");
44
45	static int major;
46	static DEFINE_IDA(vd_index_ida);
47
48	static struct workqueue_struct *virtblk_wq;
49
50	struct virtio_blk_vq {
51	struct virtqueue *vq;
52	spinlock_t lock;
53	char name[VQ_NAME_LEN];
54	} ____cacheline_aligned_in_smp;
55
56	struct virtio_blk {
57	/*
58	* This mutex must be held by anything that may run after
59	* virtblk_remove() sets vblk->vdev to NULL.
60	*
61	* blk-mq, virtqueue processing, and sysfs attribute code paths are
62	* shut down before vblk->vdev is set to NULL and therefore do not need
63	* to hold this mutex.
64	*/
65	struct mutex vdev_mutex;
66	struct virtio_device *vdev;
67
68	/* The disk structure for the kernel. */
69	struct gendisk *disk;
70
71	/* Block layer tags. */
72	struct blk_mq_tag_set tag_set;
73
74	/* Process context for config space updates */
75	struct work_struct config_work;
76
77	/* Ida index - used to track minor number allocations. */
78	int index;
79
80	/* num of vqs */
81	int num_vqs;
82	int io_queues[HCTX_MAX_TYPES];
83	struct virtio_blk_vq *vqs;
84
85	/* For zoned device */
86	unsigned int zone_sectors;
87	};
88
89	struct virtblk_req {
90	/* Out header */
91	struct virtio_blk_outhdr out_hdr;
92
93	/* In header */
94	union {
95	u8 status;
96
97	/*
98	* The zone append command has an extended in header.
99	* The status field in zone_append_in_hdr must always
100	* be the last byte.
101	*/
102	struct {
103	__virtio64 sector;
104	u8 status;
105	} zone_append;
106	} in_hdr;
107
108	size_t in_hdr_len;
109
110	struct sg_table sg_table;
111	struct scatterlist sg[];
112	};
113
114	static inline blk_status_t virtblk_result(u8 status)
115	{
116	switch (status) {
117	case VIRTIO_BLK_S_OK:
118	return BLK_STS_OK;
119	case VIRTIO_BLK_S_UNSUPP:
120	return BLK_STS_NOTSUPP;
121	case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE:
122	return BLK_STS_ZONE_OPEN_RESOURCE;
123	case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE:
124	return BLK_STS_ZONE_ACTIVE_RESOURCE;
125	case VIRTIO_BLK_S_IOERR:
126	case VIRTIO_BLK_S_ZONE_UNALIGNED_WP:
127	default:
128	return BLK_STS_IOERR;
129	}
130	}
131
132	static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx)
133	{
134	struct virtio_blk *vblk = hctx->queue->queuedata;
135	struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
136
137	return vq;
138	}
139
140	static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
141	{
142	struct scatterlist out_hdr, in_hdr, *sgs[3];
143	unsigned int num_out = 0, num_in = 0;
144
145	sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
146	sgs[num_out++] = &out_hdr;
147
148	if (vbr->sg_table.nents) {
149	if (vbr->out_hdr.type & cpu_to_virtio32(vdev: vq->vdev, VIRTIO_BLK_T_OUT))
150	sgs[num_out++] = vbr->sg_table.sgl;
151	else
152	sgs[num_out + num_in++] = vbr->sg_table.sgl;
153	}
154
155	sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len);
156	sgs[num_out + num_in++] = &in_hdr;
157
158	return virtqueue_add_sgs(vq, sgs, out_sgs: num_out, in_sgs: num_in, data: vbr, GFP_ATOMIC);
159	}
160
161	static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap)
162	{
163	unsigned short segments = blk_rq_nr_discard_segments(rq: req);
164	unsigned short n = 0;
165	struct virtio_blk_discard_write_zeroes *range;
166	struct bio *bio;
167	u32 flags = 0;
168
169	if (unmap)
170	flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
171
172	range = kmalloc_array(n: segments, size: sizeof(*range), GFP_ATOMIC);
173	if (!range)
174	return -ENOMEM;
175
176	/*
177	* Single max discard segment means multi-range discard isn't
178	* supported, and block layer only runs contiguity merge like
179	* normal RW request. So we can't reply on bio for retrieving
180	* each range info.
181	*/
182	if (queue_max_discard_segments(q: req->q) == 1) {
183	range[0].flags = cpu_to_le32(flags);
184	range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
185	range[0].sector = cpu_to_le64(blk_rq_pos(req));
186	n = 1;
187	} else {
188	__rq_for_each_bio(bio, req) {
189	u64 sector = bio->bi_iter.bi_sector;
190	u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
191
192	range[n].flags = cpu_to_le32(flags);
193	range[n].num_sectors = cpu_to_le32(num_sectors);
194	range[n].sector = cpu_to_le64(sector);
195	n++;
196	}
197	}
198
199	WARN_ON_ONCE(n != segments);
200
201	bvec_set_virt(bv: &req->special_vec, vaddr: range, len: sizeof(*range) * segments);
202	req->rq_flags |= RQF_SPECIAL_PAYLOAD;
203
204	return 0;
205	}
206
207	static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
208	{
209	if (blk_rq_nr_phys_segments(rq: req))
210	sg_free_table_chained(table: &vbr->sg_table,
211	VIRTIO_BLK_INLINE_SG_CNT);
212	}
213
214	static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
215	struct virtblk_req *vbr)
216	{
217	int err;
218
219	if (!blk_rq_nr_phys_segments(rq: req))
220	return 0;
221
222	vbr->sg_table.sgl = vbr->sg;
223	err = sg_alloc_table_chained(table: &vbr->sg_table,
224	nents: blk_rq_nr_phys_segments(rq: req),
225	first_chunk: vbr->sg_table.sgl,
226	VIRTIO_BLK_INLINE_SG_CNT);
227	if (unlikely(err))
228	return -ENOMEM;
229
230	return blk_rq_map_sg(q: hctx->queue, rq: req, sglist: vbr->sg_table.sgl);
231	}
232
233	static void virtblk_cleanup_cmd(struct request *req)
234	{
235	if (req->rq_flags & RQF_SPECIAL_PAYLOAD)
236	kfree(objp: bvec_virt(bvec: &req->special_vec));
237	}
238
239	static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
240	struct request *req,
241	struct virtblk_req *vbr)
242	{
243	size_t in_hdr_len = sizeof(vbr->in_hdr.status);
244	bool unmap = false;
245	u32 type;
246	u64 sector = 0;
247
248	if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(op: req_op(req)))
249	return BLK_STS_NOTSUPP;
250
251	/* Set fields for all request types */
252	vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, val: req_get_ioprio(req));
253
254	switch (req_op(req)) {
255	case REQ_OP_READ:
256	type = VIRTIO_BLK_T_IN;
257	sector = blk_rq_pos(rq: req);
258	break;
259	case REQ_OP_WRITE:
260	type = VIRTIO_BLK_T_OUT;
261	sector = blk_rq_pos(rq: req);
262	break;
263	case REQ_OP_FLUSH:
264	type = VIRTIO_BLK_T_FLUSH;
265	break;
266	case REQ_OP_DISCARD:
267	type = VIRTIO_BLK_T_DISCARD;
268	break;
269	case REQ_OP_WRITE_ZEROES:
270	type = VIRTIO_BLK_T_WRITE_ZEROES;
271	unmap = !(req->cmd_flags & REQ_NOUNMAP);
272	break;
273	case REQ_OP_SECURE_ERASE:
274	type = VIRTIO_BLK_T_SECURE_ERASE;
275	break;
276	case REQ_OP_ZONE_OPEN:
277	type = VIRTIO_BLK_T_ZONE_OPEN;
278	sector = blk_rq_pos(rq: req);
279	break;
280	case REQ_OP_ZONE_CLOSE:
281	type = VIRTIO_BLK_T_ZONE_CLOSE;
282	sector = blk_rq_pos(rq: req);
283	break;
284	case REQ_OP_ZONE_FINISH:
285	type = VIRTIO_BLK_T_ZONE_FINISH;
286	sector = blk_rq_pos(rq: req);
287	break;
288	case REQ_OP_ZONE_APPEND:
289	type = VIRTIO_BLK_T_ZONE_APPEND;
290	sector = blk_rq_pos(rq: req);
291	in_hdr_len = sizeof(vbr->in_hdr.zone_append);
292	break;
293	case REQ_OP_ZONE_RESET:
294	type = VIRTIO_BLK_T_ZONE_RESET;
295	sector = blk_rq_pos(rq: req);
296	break;
297	case REQ_OP_ZONE_RESET_ALL:
298	type = VIRTIO_BLK_T_ZONE_RESET_ALL;
299	break;
300	case REQ_OP_DRV_IN:
301	/*
302	* Out header has already been prepared by the caller (virtblk_get_id()
303	* or virtblk_submit_zone_report()), nothing to do here.
304	*/
305	return 0;
306	default:
307	WARN_ON_ONCE(1);
308	return BLK_STS_IOERR;
309	}
310
311	/* Set fields for non-REQ_OP_DRV_IN request types */
312	vbr->in_hdr_len = in_hdr_len;
313	vbr->out_hdr.type = cpu_to_virtio32(vdev, val: type);
314	vbr->out_hdr.sector = cpu_to_virtio64(vdev, val: sector);
315
316	if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
317	type == VIRTIO_BLK_T_SECURE_ERASE) {
318	if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
319	return BLK_STS_RESOURCE;
320	}
321
322	return 0;
323	}
324
325	/*
326	* The status byte is always the last byte of the virtblk request
327	* in-header. This helper fetches its value for all in-header formats
328	* that are currently defined.
329	*/
330	static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
331	{
332	return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
333	}
334
335	static inline void virtblk_request_done(struct request *req)
336	{
337	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
338	blk_status_t status = virtblk_result(status: virtblk_vbr_status(vbr));
339	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
340
341	virtblk_unmap_data(req, vbr);
342	virtblk_cleanup_cmd(req);
343
344	if (req_op(req) == REQ_OP_ZONE_APPEND)
345	req->__sector = virtio64_to_cpu(vdev: vblk->vdev,
346	val: vbr->in_hdr.zone_append.sector);
347
348	blk_mq_end_request(rq: req, error: status);
349	}
350
351	static void virtblk_done(struct virtqueue *vq)
352	{
353	struct virtio_blk *vblk = vq->vdev->priv;
354	bool req_done = false;
355	int qid = vq->index;
356	struct virtblk_req *vbr;
357	unsigned long flags;
358	unsigned int len;
359
360	spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
361	do {
362	virtqueue_disable_cb(vq);
363	while ((vbr = virtqueue_get_buf(vq: vblk->vqs[qid].vq, len: &len)) != NULL) {
364	struct request *req = blk_mq_rq_from_pdu(pdu: vbr);
365
366	if (likely(!blk_should_fake_timeout(req->q)))
367	blk_mq_complete_request(rq: req);
368	req_done = true;
369	}
370	} while (!virtqueue_enable_cb(vq));
371
372	/* In case queue is stopped waiting for more buffers. */
373	if (req_done)
374	blk_mq_start_stopped_hw_queues(q: vblk->disk->queue, async: true);
375	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
376	}
377
378	static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
379	{
380	struct virtio_blk *vblk = hctx->queue->queuedata;
381	struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
382	bool kick;
383
384	spin_lock_irq(lock: &vq->lock);
385	kick = virtqueue_kick_prepare(vq: vq->vq);
386	spin_unlock_irq(lock: &vq->lock);
387
388	if (kick)
389	virtqueue_notify(vq: vq->vq);
390	}
391
392	static blk_status_t virtblk_fail_to_queue(struct request *req, int rc)
393	{
394	virtblk_cleanup_cmd(req);
395	switch (rc) {
396	case -ENOSPC:
397	return BLK_STS_DEV_RESOURCE;
398	case -ENOMEM:
399	return BLK_STS_RESOURCE;
400	default:
401	return BLK_STS_IOERR;
402	}
403	}
404
405	static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
406	struct virtio_blk *vblk,
407	struct request *req,
408	struct virtblk_req *vbr)
409	{
410	blk_status_t status;
411	int num;
412
413	status = virtblk_setup_cmd(vdev: vblk->vdev, req, vbr);
414	if (unlikely(status))
415	return status;
416
417	num = virtblk_map_data(hctx, req, vbr);
418	if (unlikely(num < 0))
419	return virtblk_fail_to_queue(req, rc: -ENOMEM);
420	vbr->sg_table.nents = num;
421
422	blk_mq_start_request(rq: req);
423
424	return BLK_STS_OK;
425	}
426
427	static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
428	const struct blk_mq_queue_data *bd)
429	{
430	struct virtio_blk *vblk = hctx->queue->queuedata;
431	struct request *req = bd->rq;
432	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
433	unsigned long flags;
434	int qid = hctx->queue_num;
435	bool notify = false;
436	blk_status_t status;
437	int err;
438
439	status = virtblk_prep_rq(hctx, vblk, req, vbr);
440	if (unlikely(status))
441	return status;
442
443	spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
444	err = virtblk_add_req(vq: vblk->vqs[qid].vq, vbr);
445	if (err) {
446	virtqueue_kick(vq: vblk->vqs[qid].vq);
447	/* Don't stop the queue if -ENOMEM: we may have failed to
448	* bounce the buffer due to global resource outage.
449	*/
450	if (err == -ENOSPC)
451	blk_mq_stop_hw_queue(hctx);
452	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
453	virtblk_unmap_data(req, vbr);
454	return virtblk_fail_to_queue(req, rc: err);
455	}
456
457	if (bd->last && virtqueue_kick_prepare(vq: vblk->vqs[qid].vq))
458	notify = true;
459	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
460
461	if (notify)
462	virtqueue_notify(vq: vblk->vqs[qid].vq);
463	return BLK_STS_OK;
464	}
465
466	static bool virtblk_prep_rq_batch(struct request *req)
467	{
468	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
469	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
470
471	return virtblk_prep_rq(hctx: req->mq_hctx, vblk, req, vbr) == BLK_STS_OK;
472	}
473
474	static bool virtblk_add_req_batch(struct virtio_blk_vq *vq,
475	struct request **rqlist)
476	{
477	unsigned long flags;
478	int err;
479	bool kick;
480
481	spin_lock_irqsave(&vq->lock, flags);
482
483	while (!rq_list_empty(*rqlist)) {
484	struct request *req = rq_list_pop(rqlist);
485	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
486
487	err = virtblk_add_req(vq: vq->vq, vbr);
488	if (err) {
489	virtblk_unmap_data(req, vbr);
490	virtblk_cleanup_cmd(req);
491	blk_mq_requeue_request(rq: req, kick_requeue_list: true);
492	}
493	}
494
495	kick = virtqueue_kick_prepare(vq: vq->vq);
496	spin_unlock_irqrestore(lock: &vq->lock, flags);
497
498	return kick;
499	}
500
501	static void virtio_queue_rqs(struct request **rqlist)
502	{
503	struct request *req, *next, *prev = NULL;
504	struct request *requeue_list = NULL;
505
506	rq_list_for_each_safe(rqlist, req, next) {
507	struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx: req->mq_hctx);
508	bool kick;
509
510	if (!virtblk_prep_rq_batch(req)) {
511	rq_list_move(src: rqlist, dst: &requeue_list, rq: req, prev);
512	req = prev;
513	if (!req)
514	continue;
515	}
516
517	if (!next || req->mq_hctx != next->mq_hctx) {
518	req->rq_next = NULL;
519	kick = virtblk_add_req_batch(vq, rqlist);
520	if (kick)
521	virtqueue_notify(vq: vq->vq);
522
523	*rqlist = next;
524	prev = NULL;
525	} else
526	prev = req;
527	}
528
529	*rqlist = requeue_list;
530	}
531
532	#ifdef CONFIG_BLK_DEV_ZONED
533	static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk,
534	unsigned int nr_zones,
535	size_t *buflen)
536	{
537	struct request_queue *q = vblk->disk->queue;
538	size_t bufsize;
539	void *buf;
540
541	nr_zones = min_t(unsigned int, nr_zones,
542	get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors));
543
544	bufsize = sizeof(struct virtio_blk_zone_report) +
545	nr_zones * sizeof(struct virtio_blk_zone_descriptor);
546	bufsize = min_t(size_t, bufsize,
547	queue_max_hw_sectors(q) << SECTOR_SHIFT);
548	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
549
550	while (bufsize >= sizeof(struct virtio_blk_zone_report)) {
551	buf = __vmalloc(size: bufsize, GFP_KERNEL | __GFP_NORETRY);
552	if (buf) {
553	*buflen = bufsize;
554	return buf;
555	}
556	bufsize >>= 1;
557	}
558
559	return NULL;
560	}
561
562	static int virtblk_submit_zone_report(struct virtio_blk *vblk,
563	char *report_buf, size_t report_len,
564	sector_t sector)
565	{
566	struct request_queue *q = vblk->disk->queue;
567	struct request *req;
568	struct virtblk_req *vbr;
569	int err;
570
571	req = blk_mq_alloc_request(q, opf: REQ_OP_DRV_IN, flags: 0);
572	if (IS_ERR(ptr: req))
573	return PTR_ERR(ptr: req);
574
575	vbr = blk_mq_rq_to_pdu(rq: req);
576	vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
577	vbr->out_hdr.type = cpu_to_virtio32(vdev: vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
578	vbr->out_hdr.sector = cpu_to_virtio64(vdev: vblk->vdev, val: sector);
579
580	err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL);
581	if (err)
582	goto out;
583
584	blk_execute_rq(rq: req, at_head: false);
585	err = blk_status_to_errno(status: virtblk_result(status: vbr->in_hdr.status));
586	out:
587	blk_mq_free_request(rq: req);
588	return err;
589	}
590
591	static int virtblk_parse_zone(struct virtio_blk *vblk,
592	struct virtio_blk_zone_descriptor *entry,
593	unsigned int idx, report_zones_cb cb, void *data)
594	{
595	struct blk_zone zone = { };
596
597	zone.start = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_start);
598	if (zone.start + vblk->zone_sectors <= get_capacity(disk: vblk->disk))
599	zone.len = vblk->zone_sectors;
600	else
601	zone.len = get_capacity(disk: vblk->disk) - zone.start;
602	zone.capacity = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_cap);
603	zone.wp = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_wp);
604
605	switch (entry->z_type) {
606	case VIRTIO_BLK_ZT_SWR:
607	zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ;
608	break;
609	case VIRTIO_BLK_ZT_SWP:
610	zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF;
611	break;
612	case VIRTIO_BLK_ZT_CONV:
613	zone.type = BLK_ZONE_TYPE_CONVENTIONAL;
614	break;
615	default:
616	dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n",
617	zone.start, entry->z_type);
618	return -EIO;
619	}
620
621	switch (entry->z_state) {
622	case VIRTIO_BLK_ZS_EMPTY:
623	zone.cond = BLK_ZONE_COND_EMPTY;
624	break;
625	case VIRTIO_BLK_ZS_CLOSED:
626	zone.cond = BLK_ZONE_COND_CLOSED;
627	break;
628	case VIRTIO_BLK_ZS_FULL:
629	zone.cond = BLK_ZONE_COND_FULL;
630	zone.wp = zone.start + zone.len;
631	break;
632	case VIRTIO_BLK_ZS_EOPEN:
633	zone.cond = BLK_ZONE_COND_EXP_OPEN;
634	break;
635	case VIRTIO_BLK_ZS_IOPEN:
636	zone.cond = BLK_ZONE_COND_IMP_OPEN;
637	break;
638	case VIRTIO_BLK_ZS_NOT_WP:
639	zone.cond = BLK_ZONE_COND_NOT_WP;
640	break;
641	case VIRTIO_BLK_ZS_RDONLY:
642	zone.cond = BLK_ZONE_COND_READONLY;
643	zone.wp = ULONG_MAX;
644	break;
645	case VIRTIO_BLK_ZS_OFFLINE:
646	zone.cond = BLK_ZONE_COND_OFFLINE;
647	zone.wp = ULONG_MAX;
648	break;
649	default:
650	dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n",
651	zone.start, entry->z_state);
652	return -EIO;
653	}
654
655	/*
656	* The callback below checks the validity of the reported
657	* entry data, no need to further validate it here.
658	*/
659	return cb(&zone, idx, data);
660	}
661
662	static int virtblk_report_zones(struct gendisk *disk, sector_t sector,
663	unsigned int nr_zones, report_zones_cb cb,
664	void *data)
665	{
666	struct virtio_blk *vblk = disk->private_data;
667	struct virtio_blk_zone_report *report;
668	unsigned long long nz, i;
669	size_t buflen;
670	unsigned int zone_idx = 0;
671	int ret;
672
673	if (WARN_ON_ONCE(!vblk->zone_sectors))
674	return -EOPNOTSUPP;
675
676	report = virtblk_alloc_report_buffer(vblk, nr_zones, buflen: &buflen);
677	if (!report)
678	return -ENOMEM;
679
680	mutex_lock(&vblk->vdev_mutex);
681
682	if (!vblk->vdev) {
683	ret = -ENXIO;
684	goto fail_report;
685	}
686
687	while (zone_idx < nr_zones && sector < get_capacity(disk: vblk->disk)) {
688	memset(report, 0, buflen);
689
690	ret = virtblk_submit_zone_report(vblk, report_buf: (char *)report,
691	report_len: buflen, sector);
692	if (ret)
693	goto fail_report;
694
695	nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones),
696	nr_zones);
697	if (!nz)
698	break;
699
700	for (i = 0; i < nz && zone_idx < nr_zones; i++) {
701	ret = virtblk_parse_zone(vblk, entry: &report->zones[i],
702	idx: zone_idx, cb, data);
703	if (ret)
704	goto fail_report;
705
706	sector = virtio64_to_cpu(vdev: vblk->vdev,
707	val: report->zones[i].z_start) +
708	vblk->zone_sectors;
709	zone_idx++;
710	}
711	}
712
713	if (zone_idx > 0)
714	ret = zone_idx;
715	else
716	ret = -EINVAL;
717	fail_report:
718	mutex_unlock(lock: &vblk->vdev_mutex);
719	kvfree(addr: report);
720	return ret;
721	}
722
723	static int virtblk_read_zoned_limits(struct virtio_blk *vblk,
724	struct queue_limits *lim)
725	{
726	struct virtio_device *vdev = vblk->vdev;
727	u32 v, wg;
728
729	dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
730
731	lim->zoned = true;
732
733	virtio_cread(vdev, struct virtio_blk_config,
734	zoned.max_open_zones, &v);
735	lim->max_open_zones = v;
736	dev_dbg(&vdev->dev, "max open zones = %u\n", v);
737
738	virtio_cread(vdev, struct virtio_blk_config,
739	zoned.max_active_zones, &v);
740	lim->max_active_zones = v;
741	dev_dbg(&vdev->dev, "max active zones = %u\n", v);
742
743	virtio_cread(vdev, struct virtio_blk_config,
744	zoned.write_granularity, &wg);
745	if (!wg) {
746	dev_warn(&vdev->dev, "zero write granularity reported\n");
747	return -ENODEV;
748	}
749	lim->physical_block_size = wg;
750	lim->io_min = wg;
751
752	dev_dbg(&vdev->dev, "write granularity = %u\n", wg);
753
754	/*
755	* virtio ZBD specification doesn't require zones to be a power of
756	* two sectors in size, but the code in this driver expects that.
757	*/
758	virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors,
759	&vblk->zone_sectors);
760	if (vblk->zone_sectors == 0 || !is_power_of_2(n: vblk->zone_sectors)) {
761	dev_err(&vdev->dev,
762	"zoned device with non power of two zone size %u\n",
763	vblk->zone_sectors);
764	return -ENODEV;
765	}
766	lim->chunk_sectors = vblk->zone_sectors;
767	dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors);
768
769	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
770	dev_warn(&vblk->vdev->dev,
771	"ignoring negotiated F_DISCARD for zoned device\n");
772	lim->max_hw_discard_sectors = 0;
773	}
774
775	virtio_cread(vdev, struct virtio_blk_config,
776	zoned.max_append_sectors, &v);
777	if (!v) {
778	dev_warn(&vdev->dev, "zero max_append_sectors reported\n");
779	return -ENODEV;
780	}
781	if ((v << SECTOR_SHIFT) < wg) {
782	dev_err(&vdev->dev,
783	"write granularity %u exceeds max_append_sectors %u limit\n",
784	wg, v);
785	return -ENODEV;
786	}
787	lim->max_zone_append_sectors = v;
788	dev_dbg(&vdev->dev, "max append sectors = %u\n", v);
789
790	return 0;
791	}
792	#else
793	/*
794	* Zoned block device support is not configured in this kernel, host-managed
795	* zoned devices can't be supported.
796	*/
797	#define virtblk_report_zones NULL
798	static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk,
799	struct queue_limits *lim)
800	{
801	dev_err(&vblk->vdev->dev,
802	"virtio_blk: zoned devices are not supported");
803	return -EOPNOTSUPP;
804	}
805	#endif /* CONFIG_BLK_DEV_ZONED */
806
807	/* return id (s/n) string for *disk to *id_str
808	*/
809	static int virtblk_get_id(struct gendisk *disk, char *id_str)
810	{
811	struct virtio_blk *vblk = disk->private_data;
812	struct request_queue *q = vblk->disk->queue;
813	struct request *req;
814	struct virtblk_req *vbr;
815	int err;
816
817	req = blk_mq_alloc_request(q, opf: REQ_OP_DRV_IN, flags: 0);
818	if (IS_ERR(ptr: req))
819	return PTR_ERR(ptr: req);
820
821	vbr = blk_mq_rq_to_pdu(rq: req);
822	vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
823	vbr->out_hdr.type = cpu_to_virtio32(vdev: vblk->vdev, VIRTIO_BLK_T_GET_ID);
824	vbr->out_hdr.sector = 0;
825
826	err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
827	if (err)
828	goto out;
829
830	blk_execute_rq(rq: req, at_head: false);
831	err = blk_status_to_errno(status: virtblk_result(status: vbr->in_hdr.status));
832	out:
833	blk_mq_free_request(rq: req);
834	return err;
835	}
836
837	/* We provide getgeo only to please some old bootloader/partitioning tools */
838	static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
839	{
840	struct virtio_blk *vblk = bd->bd_disk->private_data;
841	int ret = 0;
842
843	mutex_lock(&vblk->vdev_mutex);
844
845	if (!vblk->vdev) {
846	ret = -ENXIO;
847	goto out;
848	}
849
850	/* see if the host passed in geometry config */
851	if (virtio_has_feature(vdev: vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
852	virtio_cread(vblk->vdev, struct virtio_blk_config,
853	geometry.cylinders, &geo->cylinders);
854	virtio_cread(vblk->vdev, struct virtio_blk_config,
855	geometry.heads, &geo->heads);
856	virtio_cread(vblk->vdev, struct virtio_blk_config,
857	geometry.sectors, &geo->sectors);
858	} else {
859	/* some standard values, similar to sd */
860	geo->heads = 1 << 6;
861	geo->sectors = 1 << 5;
862	geo->cylinders = get_capacity(disk: bd->bd_disk) >> 11;
863	}
864	out:
865	mutex_unlock(lock: &vblk->vdev_mutex);
866	return ret;
867	}
868
869	static void virtblk_free_disk(struct gendisk *disk)
870	{
871	struct virtio_blk *vblk = disk->private_data;
872
873	ida_free(&vd_index_ida, id: vblk->index);
874	mutex_destroy(lock: &vblk->vdev_mutex);
875	kfree(objp: vblk);
876	}
877
878	static const struct block_device_operations virtblk_fops = {
879	.owner = THIS_MODULE,
880	.getgeo = virtblk_getgeo,
881	.free_disk = virtblk_free_disk,
882	.report_zones = virtblk_report_zones,
883	};
884
885	static int index_to_minor(int index)
886	{
887	return index << PART_BITS;
888	}
889
890	static int minor_to_index(int minor)
891	{
892	return minor >> PART_BITS;
893	}
894
895	static ssize_t serial_show(struct device *dev,
896	struct device_attribute *attr, char *buf)
897	{
898	struct gendisk *disk = dev_to_disk(dev);
899	int err;
900
901	/* sysfs gives us a PAGE_SIZE buffer */
902	BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
903
904	buf[VIRTIO_BLK_ID_BYTES] = '\0';
905	err = virtblk_get_id(disk, id_str: buf);
906	if (!err)
907	return strlen(buf);
908
909	if (err == -EIO) /* Unsupported? Make it empty. */
910	return 0;
911
912	return err;
913	}
914
915	static DEVICE_ATTR_RO(serial);
916
917	/* The queue's logical block size must be set before calling this */
918	static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
919	{
920	struct virtio_device *vdev = vblk->vdev;
921	struct request_queue *q = vblk->disk->queue;
922	char cap_str_2[10], cap_str_10[10];
923	unsigned long long nblocks;
924	u64 capacity;
925
926	/* Host must always specify the capacity. */
927	virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
928
929	nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
930
931	string_get_size(size: nblocks, blk_size: queue_logical_block_size(q),
932	units: STRING_UNITS_2, buf: cap_str_2, len: sizeof(cap_str_2));
933	string_get_size(size: nblocks, blk_size: queue_logical_block_size(q),
934	units: STRING_UNITS_10, buf: cap_str_10, len: sizeof(cap_str_10));
935
936	dev_notice(&vdev->dev,
937	"[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
938	vblk->disk->disk_name,
939	resize ? "new size: " : "",
940	nblocks,
941	queue_logical_block_size(q),
942	cap_str_10,
943	cap_str_2);
944
945	set_capacity_and_notify(disk: vblk->disk, size: capacity);
946	}
947
948	static void virtblk_config_changed_work(struct work_struct *work)
949	{
950	struct virtio_blk *vblk =
951	container_of(work, struct virtio_blk, config_work);
952
953	virtblk_update_capacity(vblk, resize: true);
954	}
955
956	static void virtblk_config_changed(struct virtio_device *vdev)
957	{
958	struct virtio_blk *vblk = vdev->priv;
959
960	queue_work(wq: virtblk_wq, work: &vblk->config_work);
961	}
962
963	static int init_vq(struct virtio_blk *vblk)
964	{
965	int err;
966	unsigned short i;
967	vq_callback_t **callbacks;
968	const char **names;
969	struct virtqueue **vqs;
970	unsigned short num_vqs;
971	unsigned short num_poll_vqs;
972	struct virtio_device *vdev = vblk->vdev;
973	struct irq_affinity desc = { 0, };
974
975	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
976	struct virtio_blk_config, num_queues,
977	&num_vqs);
978	if (err)
979	num_vqs = 1;
980
981	if (!err && !num_vqs) {
982	dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
983	return -EINVAL;
984	}
985
986	num_vqs = min_t(unsigned int,
987	min_not_zero(num_request_queues, nr_cpu_ids),
988	num_vqs);
989
990	num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
991
992	vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
993	vblk->io_queues[HCTX_TYPE_READ] = 0;
994	vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
995
996	dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
997	vblk->io_queues[HCTX_TYPE_DEFAULT],
998	vblk->io_queues[HCTX_TYPE_READ],
999	vblk->io_queues[HCTX_TYPE_POLL]);
1000
1001	vblk->vqs = kmalloc_array(n: num_vqs, size: sizeof(*vblk->vqs), GFP_KERNEL);
1002	if (!vblk->vqs)
1003	return -ENOMEM;
1004
1005	names = kmalloc_array(n: num_vqs, size: sizeof(*names), GFP_KERNEL);
1006	callbacks = kmalloc_array(n: num_vqs, size: sizeof(*callbacks), GFP_KERNEL);
1007	vqs = kmalloc_array(n: num_vqs, size: sizeof(*vqs), GFP_KERNEL);
1008	if (!names || !callbacks || !vqs) {
1009	err = -ENOMEM;
1010	goto out;
1011	}
1012
1013	for (i = 0; i < num_vqs - num_poll_vqs; i++) {
1014	callbacks[i] = virtblk_done;
1015	snprintf(buf: vblk->vqs[i].name, VQ_NAME_LEN, fmt: "req.%u", i);
1016	names[i] = vblk->vqs[i].name;
1017	}
1018
1019	for (; i < num_vqs; i++) {
1020	callbacks[i] = NULL;
1021	snprintf(buf: vblk->vqs[i].name, VQ_NAME_LEN, fmt: "req_poll.%u", i);
1022	names[i] = vblk->vqs[i].name;
1023	}
1024
1025	/* Discover virtqueues and write information to configuration. */
1026	err = virtio_find_vqs(vdev, nvqs: num_vqs, vqs, callbacks, names, desc: &desc);
1027	if (err)
1028	goto out;
1029
1030	for (i = 0; i < num_vqs; i++) {
1031	spin_lock_init(&vblk->vqs[i].lock);
1032	vblk->vqs[i].vq = vqs[i];
1033	}
1034	vblk->num_vqs = num_vqs;
1035
1036	out:
1037	kfree(objp: vqs);
1038	kfree(objp: callbacks);
1039	kfree(objp: names);
1040	if (err)
1041	kfree(objp: vblk->vqs);
1042	return err;
1043	}
1044
1045	/*
1046	* Legacy naming scheme used for virtio devices. We are stuck with it for
1047	* virtio blk but don't ever use it for any new driver.
1048	*/
1049	static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
1050	{
1051	const int base = 'z' - 'a' + 1;
1052	char *begin = buf + strlen(prefix);
1053	char *end = buf + buflen;
1054	char *p;
1055	int unit;
1056
1057	p = end - 1;
1058	*p = '\0';
1059	unit = base;
1060	do {
1061	if (p == begin)
1062	return -EINVAL;
1063	*--p = 'a' + (index % unit);
1064	index = (index / unit) - 1;
1065	} while (index >= 0);
1066
1067	memmove(begin, p, end - p);
1068	memcpy(buf, prefix, strlen(prefix));
1069
1070	return 0;
1071	}
1072
1073	static int virtblk_get_cache_mode(struct virtio_device *vdev)
1074	{
1075	u8 writeback;
1076	int err;
1077
1078	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
1079	struct virtio_blk_config, wce,
1080	&writeback);
1081
1082	/*
1083	* If WCE is not configurable and flush is not available,
1084	* assume no writeback cache is in use.
1085	*/
1086	if (err)
1087	writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
1088
1089	return writeback;
1090	}
1091
1092	static void virtblk_update_cache_mode(struct virtio_device *vdev)
1093	{
1094	u8 writeback = virtblk_get_cache_mode(vdev);
1095	struct virtio_blk *vblk = vdev->priv;
1096
1097	blk_queue_write_cache(q: vblk->disk->queue, enabled: writeback, fua: false);
1098	}
1099
1100	static const char *const virtblk_cache_types[] = {
1101	"write through", "write back"
1102	};
1103
1104	static ssize_t
1105	cache_type_store(struct device *dev, struct device_attribute *attr,
1106	const char *buf, size_t count)
1107	{
1108	struct gendisk *disk = dev_to_disk(dev);
1109	struct virtio_blk *vblk = disk->private_data;
1110	struct virtio_device *vdev = vblk->vdev;
1111	int i;
1112
1113	BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
1114	i = sysfs_match_string(virtblk_cache_types, buf);
1115	if (i < 0)
1116	return i;
1117
1118	virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), val: i);
1119	virtblk_update_cache_mode(vdev);
1120	return count;
1121	}
1122
1123	static ssize_t
1124	cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1125	{
1126	struct gendisk *disk = dev_to_disk(dev);
1127	struct virtio_blk *vblk = disk->private_data;
1128	u8 writeback = virtblk_get_cache_mode(vdev: vblk->vdev);
1129
1130	BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
1131	return sysfs_emit(buf, fmt: "%s\n", virtblk_cache_types[writeback]);
1132	}
1133
1134	static DEVICE_ATTR_RW(cache_type);
1135
1136	static struct attribute *virtblk_attrs[] = {
1137	&dev_attr_serial.attr,
1138	&dev_attr_cache_type.attr,
1139	NULL,
1140	};
1141
1142	static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
1143	struct attribute *a, int n)
1144	{
1145	struct device *dev = kobj_to_dev(kobj);
1146	struct gendisk *disk = dev_to_disk(dev);
1147	struct virtio_blk *vblk = disk->private_data;
1148	struct virtio_device *vdev = vblk->vdev;
1149
1150	if (a == &dev_attr_cache_type.attr &&
1151	!virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
1152	return S_IRUGO;
1153
1154	return a->mode;
1155	}
1156
1157	static const struct attribute_group virtblk_attr_group = {
1158	.attrs = virtblk_attrs,
1159	.is_visible = virtblk_attrs_are_visible,
1160	};
1161
1162	static const struct attribute_group *virtblk_attr_groups[] = {
1163	&virtblk_attr_group,
1164	NULL,
1165	};
1166
1167	static void virtblk_map_queues(struct blk_mq_tag_set *set)
1168	{
1169	struct virtio_blk *vblk = set->driver_data;
1170	int i, qoff;
1171
1172	for (i = 0, qoff = 0; i < set->nr_maps; i++) {
1173	struct blk_mq_queue_map *map = &set->map[i];
1174
1175	map->nr_queues = vblk->io_queues[i];
1176	map->queue_offset = qoff;
1177	qoff += map->nr_queues;
1178
1179	if (map->nr_queues == 0)
1180	continue;
1181
1182	/*
1183	* Regular queues have interrupts and hence CPU affinity is
1184	* defined by the core virtio code, but polling queues have
1185	* no interrupts so we let the block layer assign CPU affinity.
1186	*/
1187	if (i == HCTX_TYPE_POLL)
1188	blk_mq_map_queues(qmap: &set->map[i]);
1189	else
1190	blk_mq_virtio_map_queues(qmap: &set->map[i], vdev: vblk->vdev, first_vec: 0);
1191	}
1192	}
1193
1194	static void virtblk_complete_batch(struct io_comp_batch *iob)
1195	{
1196	struct request *req;
1197
1198	rq_list_for_each(&iob->req_list, req) {
1199	virtblk_unmap_data(req, vbr: blk_mq_rq_to_pdu(rq: req));
1200	virtblk_cleanup_cmd(req);
1201	}
1202	blk_mq_end_request_batch(ib: iob);
1203	}
1204
1205	static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
1206	{
1207	struct virtio_blk *vblk = hctx->queue->queuedata;
1208	struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx);
1209	struct virtblk_req *vbr;
1210	unsigned long flags;
1211	unsigned int len;
1212	int found = 0;
1213
1214	spin_lock_irqsave(&vq->lock, flags);
1215
1216	while ((vbr = virtqueue_get_buf(vq: vq->vq, len: &len)) != NULL) {
1217	struct request *req = blk_mq_rq_from_pdu(pdu: vbr);
1218
1219	found++;
1220	if (!blk_mq_complete_request_remote(rq: req) &&
1221	!blk_mq_add_to_batch(req, iob, ioerror: virtblk_vbr_status(vbr),
1222	complete: virtblk_complete_batch))
1223	virtblk_request_done(req);
1224	}
1225
1226	if (found)
1227	blk_mq_start_stopped_hw_queues(q: vblk->disk->queue, async: true);
1228
1229	spin_unlock_irqrestore(lock: &vq->lock, flags);
1230
1231	return found;
1232	}
1233
1234	static const struct blk_mq_ops virtio_mq_ops = {
1235	.queue_rq = virtio_queue_rq,
1236	.queue_rqs = virtio_queue_rqs,
1237	.commit_rqs = virtio_commit_rqs,
1238	.complete = virtblk_request_done,
1239	.map_queues = virtblk_map_queues,
1240	.poll = virtblk_poll,
1241	};
1242
1243	static unsigned int virtblk_queue_depth;
1244	module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
1245
1246	static int virtblk_read_limits(struct virtio_blk *vblk,
1247	struct queue_limits *lim)
1248	{
1249	struct virtio_device *vdev = vblk->vdev;
1250	u32 v, blk_size, max_size, sg_elems, opt_io_size;
1251	u32 max_discard_segs = 0;
1252	u32 discard_granularity = 0;
1253	u16 min_io_size;
1254	u8 physical_block_exp, alignment_offset;
1255	size_t max_dma_size;
1256	int err;
1257
1258	/* We need to know how many segments before we allocate. */
1259	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
1260	struct virtio_blk_config, seg_max,
1261	&sg_elems);
1262
1263	/* We need at least one SG element, whatever they say. */
1264	if (err || !sg_elems)
1265	sg_elems = 1;
1266
1267	/* Prevent integer overflows and honor max vq size */
1268	sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2);
1269
1270	/* We can handle whatever the host told us to handle. */
1271	lim->max_segments = sg_elems;
1272
1273	/* No real sector limit. */
1274	lim->max_hw_sectors = UINT_MAX;
1275
1276	max_dma_size = virtio_max_dma_size(vdev);
1277	max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size;
1278
1279	/* Host can optionally specify maximum segment size and number of
1280	* segments. */
1281	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
1282	struct virtio_blk_config, size_max, &v);
1283	if (!err)
1284	max_size = min(max_size, v);
1285
1286	lim->max_segment_size = max_size;
1287
1288	/* Host can optionally specify the block size of the device */
1289	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
1290	struct virtio_blk_config, blk_size,
1291	&blk_size);
1292	if (!err) {
1293	err = blk_validate_block_size(bsize: blk_size);
1294	if (err) {
1295	dev_err(&vdev->dev,
1296	"virtio_blk: invalid block size: 0x%x\n",
1297	blk_size);
1298	return err;
1299	}
1300
1301	lim->logical_block_size = blk_size;
1302	} else
1303	blk_size = lim->logical_block_size;
1304
1305	/* Use topology information if available */
1306	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1307	struct virtio_blk_config, physical_block_exp,
1308	&physical_block_exp);
1309	if (!err && physical_block_exp)
1310	lim->physical_block_size = blk_size * (1 << physical_block_exp);
1311
1312	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1313	struct virtio_blk_config, alignment_offset,
1314	&alignment_offset);
1315	if (!err && alignment_offset)
1316	lim->alignment_offset = blk_size * alignment_offset;
1317
1318	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1319	struct virtio_blk_config, min_io_size,
1320	&min_io_size);
1321	if (!err && min_io_size)
1322	lim->io_min = blk_size * min_io_size;
1323
1324	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1325	struct virtio_blk_config, opt_io_size,
1326	&opt_io_size);
1327	if (!err && opt_io_size)
1328	lim->io_opt = blk_size * opt_io_size;
1329
1330	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
1331	virtio_cread(vdev, struct virtio_blk_config,
1332	discard_sector_alignment, &discard_granularity);
1333
1334	virtio_cread(vdev, struct virtio_blk_config,
1335	max_discard_sectors, &v);
1336	lim->max_hw_discard_sectors = v ? v : UINT_MAX;
1337
1338	virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
1339	&max_discard_segs);
1340	}
1341
1342	if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
1343	virtio_cread(vdev, struct virtio_blk_config,
1344	max_write_zeroes_sectors, &v);
1345	lim->max_write_zeroes_sectors = v ? v : UINT_MAX;
1346	}
1347
1348	/* The discard and secure erase limits are combined since the Linux
1349	* block layer uses the same limit for both commands.
1350	*
1351	* If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features
1352	* are negotiated, we will use the minimum between the limits.
1353	*
1354	* discard sector alignment is set to the minimum between discard_sector_alignment
1355	* and secure_erase_sector_alignment.
1356	*
1357	* max discard sectors is set to the minimum between max_discard_seg and
1358	* max_secure_erase_seg.
1359	*/
1360	if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1361
1362	virtio_cread(vdev, struct virtio_blk_config,
1363	secure_erase_sector_alignment, &v);
1364
1365	/* secure_erase_sector_alignment should not be zero, the device should set a
1366	* valid number of sectors.
1367	*/
1368	if (!v) {
1369	dev_err(&vdev->dev,
1370	"virtio_blk: secure_erase_sector_alignment can't be 0\n");
1371	return -EINVAL;
1372	}
1373
1374	discard_granularity = min_not_zero(discard_granularity, v);
1375
1376	virtio_cread(vdev, struct virtio_blk_config,
1377	max_secure_erase_sectors, &v);
1378
1379	/* max_secure_erase_sectors should not be zero, the device should set a
1380	* valid number of sectors.
1381	*/
1382	if (!v) {
1383	dev_err(&vdev->dev,
1384	"virtio_blk: max_secure_erase_sectors can't be 0\n");
1385	return -EINVAL;
1386	}
1387
1388	lim->max_secure_erase_sectors = v;
1389
1390	virtio_cread(vdev, struct virtio_blk_config,
1391	max_secure_erase_seg, &v);
1392
1393	/* max_secure_erase_seg should not be zero, the device should set a
1394	* valid number of segments
1395	*/
1396	if (!v) {
1397	dev_err(&vdev->dev,
1398	"virtio_blk: max_secure_erase_seg can't be 0\n");
1399	return -EINVAL;
1400	}
1401
1402	max_discard_segs = min_not_zero(max_discard_segs, v);
1403	}
1404
1405	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) ||
1406	virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1407	/* max_discard_seg and discard_granularity will be 0 only
1408	* if max_discard_seg and discard_sector_alignment fields in the virtio
1409	* config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated.
1410	* In this case, we use default values.
1411	*/
1412	if (!max_discard_segs)
1413	max_discard_segs = sg_elems;
1414
1415	lim->max_discard_segments =
1416	min(max_discard_segs, MAX_DISCARD_SEGMENTS);
1417
1418	if (discard_granularity)
1419	lim->discard_granularity =
1420	discard_granularity << SECTOR_SHIFT;
1421	else
1422	lim->discard_granularity = blk_size;
1423	}
1424
1425	if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
1426	u8 model;
1427
1428	virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model);
1429	switch (model) {
1430	case VIRTIO_BLK_Z_NONE:
1431	case VIRTIO_BLK_Z_HA:
1432	/* treat host-aware devices as non-zoned */
1433	return 0;
1434	case VIRTIO_BLK_Z_HM:
1435	err = virtblk_read_zoned_limits(vblk, lim);
1436	if (err)
1437	return err;
1438	break;
1439	default:
1440	dev_err(&vdev->dev, "unsupported zone model %d\n", model);
1441	return -EINVAL;
1442	}
1443	}
1444
1445	return 0;
1446	}
1447
1448	static int virtblk_probe(struct virtio_device *vdev)
1449	{
1450	struct virtio_blk *vblk;
1451	struct queue_limits lim = { };
1452	int err, index;
1453	unsigned int queue_depth;
1454
1455	if (!vdev->config->get) {
1456	dev_err(&vdev->dev, "%s failure: config access disabled\n",
1457	__func__);
1458	return -EINVAL;
1459	}
1460
1461	err = ida_alloc_range(&vd_index_ida, min: 0,
1462	max: minor_to_index(minor: 1 << MINORBITS) - 1, GFP_KERNEL);
1463	if (err < 0)
1464	goto out;
1465	index = err;
1466
1467	vdev->priv = vblk = kmalloc(size: sizeof(*vblk), GFP_KERNEL);
1468	if (!vblk) {
1469	err = -ENOMEM;
1470	goto out_free_index;
1471	}
1472
1473	mutex_init(&vblk->vdev_mutex);
1474
1475	vblk->vdev = vdev;
1476
1477	INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
1478
1479	err = init_vq(vblk);
1480	if (err)
1481	goto out_free_vblk;
1482
1483	/* Default queue sizing is to fill the ring. */
1484	if (!virtblk_queue_depth) {
1485	queue_depth = vblk->vqs[0].vq->num_free;
1486	/* ... but without indirect descs, we use 2 descs per req */
1487	if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
1488	queue_depth /= 2;
1489	} else {
1490	queue_depth = virtblk_queue_depth;
1491	}
1492
1493	memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
1494	vblk->tag_set.ops = &virtio_mq_ops;
1495	vblk->tag_set.queue_depth = queue_depth;
1496	vblk->tag_set.numa_node = NUMA_NO_NODE;
1497	vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
1498	vblk->tag_set.cmd_size =
1499	sizeof(struct virtblk_req) +
1500	sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
1501	vblk->tag_set.driver_data = vblk;
1502	vblk->tag_set.nr_hw_queues = vblk->num_vqs;
1503	vblk->tag_set.nr_maps = 1;
1504	if (vblk->io_queues[HCTX_TYPE_POLL])
1505	vblk->tag_set.nr_maps = 3;
1506
1507	err = blk_mq_alloc_tag_set(set: &vblk->tag_set);
1508	if (err)
1509	goto out_free_vq;
1510
1511	err = virtblk_read_limits(vblk, lim: &lim);
1512	if (err)
1513	goto out_free_tags;
1514
1515	vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk);
1516	if (IS_ERR(ptr: vblk->disk)) {
1517	err = PTR_ERR(ptr: vblk->disk);
1518	goto out_free_tags;
1519	}
1520
1521	virtblk_name_format(prefix: "vd", index, buf: vblk->disk->disk_name, DISK_NAME_LEN);
1522
1523	vblk->disk->major = major;
1524	vblk->disk->first_minor = index_to_minor(index);
1525	vblk->disk->minors = 1 << PART_BITS;
1526	vblk->disk->private_data = vblk;
1527	vblk->disk->fops = &virtblk_fops;
1528	vblk->index = index;
1529
1530	/* configure queue flush support */
1531	virtblk_update_cache_mode(vdev);
1532
1533	/* If disk is read-only in the host, the guest should obey */
1534	if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
1535	set_disk_ro(disk: vblk->disk, read_only: 1);
1536
1537	virtblk_update_capacity(vblk, resize: false);
1538	virtio_device_ready(dev: vdev);
1539
1540	/*
1541	* All steps that follow use the VQs therefore they need to be
1542	* placed after the virtio_device_ready() call above.
1543	*/
1544	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) && lim.zoned) {
1545	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q: vblk->disk->queue);
1546	err = blk_revalidate_disk_zones(disk: vblk->disk, NULL);
1547	if (err)
1548	goto out_cleanup_disk;
1549	}
1550
1551	err = device_add_disk(parent: &vdev->dev, disk: vblk->disk, groups: virtblk_attr_groups);
1552	if (err)
1553	goto out_cleanup_disk;
1554
1555	return 0;
1556
1557	out_cleanup_disk:
1558	put_disk(disk: vblk->disk);
1559	out_free_tags:
1560	blk_mq_free_tag_set(set: &vblk->tag_set);
1561	out_free_vq:
1562	vdev->config->del_vqs(vdev);
1563	kfree(objp: vblk->vqs);
1564	out_free_vblk:
1565	kfree(objp: vblk);
1566	out_free_index:
1567	ida_free(&vd_index_ida, id: index);
1568	out:
1569	return err;
1570	}
1571
1572	static void virtblk_remove(struct virtio_device *vdev)
1573	{
1574	struct virtio_blk *vblk = vdev->priv;
1575
1576	/* Make sure no work handler is accessing the device. */
1577	flush_work(work: &vblk->config_work);
1578
1579	del_gendisk(gp: vblk->disk);
1580	blk_mq_free_tag_set(set: &vblk->tag_set);
1581
1582	mutex_lock(&vblk->vdev_mutex);
1583
1584	/* Stop all the virtqueues. */
1585	virtio_reset_device(dev: vdev);
1586
1587	/* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
1588	vblk->vdev = NULL;
1589
1590	vdev->config->del_vqs(vdev);
1591	kfree(objp: vblk->vqs);
1592
1593	mutex_unlock(lock: &vblk->vdev_mutex);
1594
1595	put_disk(disk: vblk->disk);
1596	}
1597
1598	#ifdef CONFIG_PM_SLEEP
1599	static int virtblk_freeze(struct virtio_device *vdev)
1600	{
1601	struct virtio_blk *vblk = vdev->priv;
1602
1603	/* Ensure no requests in virtqueues before deleting vqs. */
1604	blk_mq_freeze_queue(q: vblk->disk->queue);
1605
1606	/* Ensure we don't receive any more interrupts */
1607	virtio_reset_device(dev: vdev);
1608
1609	/* Make sure no work handler is accessing the device. */
1610	flush_work(work: &vblk->config_work);
1611
1612	vdev->config->del_vqs(vdev);
1613	kfree(objp: vblk->vqs);
1614
1615	return 0;
1616	}
1617
1618	static int virtblk_restore(struct virtio_device *vdev)
1619	{
1620	struct virtio_blk *vblk = vdev->priv;
1621	int ret;
1622
1623	ret = init_vq(vblk: vdev->priv);
1624	if (ret)
1625	return ret;
1626
1627	virtio_device_ready(dev: vdev);
1628
1629	blk_mq_unfreeze_queue(q: vblk->disk->queue);
1630	return 0;
1631	}
1632	#endif
1633
1634	static const struct virtio_device_id id_table[] = {
1635	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
1636	{ 0 },
1637	};
1638
1639	static unsigned int features_legacy[] = {
1640	VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1641	VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1642	VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1643	VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1644	VIRTIO_BLK_F_SECURE_ERASE,
1645	}
1646	;
1647	static unsigned int features[] = {
1648	VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1649	VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1650	VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1651	VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1652	VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED,
1653	};
1654
1655	static struct virtio_driver virtio_blk = {
1656	.feature_table = features,
1657	.feature_table_size = ARRAY_SIZE(features),
1658	.feature_table_legacy = features_legacy,
1659	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1660	.driver.name = KBUILD_MODNAME,
1661	.driver.owner = THIS_MODULE,
1662	.id_table = id_table,
1663	.probe = virtblk_probe,
1664	.remove = virtblk_remove,
1665	.config_changed = virtblk_config_changed,
1666	#ifdef CONFIG_PM_SLEEP
1667	.freeze = virtblk_freeze,
1668	.restore = virtblk_restore,
1669	#endif
1670	};
1671
1672	static int __init virtio_blk_init(void)
1673	{
1674	int error;
1675
1676	virtblk_wq = alloc_workqueue(fmt: "virtio-blk", flags: 0, max_active: 0);
1677	if (!virtblk_wq)
1678	return -ENOMEM;
1679
1680	major = register_blkdev(0, "virtblk");
1681	if (major < 0) {
1682	error = major;
1683	goto out_destroy_workqueue;
1684	}
1685
1686	error = register_virtio_driver(&virtio_blk);
1687	if (error)
1688	goto out_unregister_blkdev;
1689	return 0;
1690
1691	out_unregister_blkdev:
1692	unregister_blkdev(major, name: "virtblk");
1693	out_destroy_workqueue:
1694	destroy_workqueue(wq: virtblk_wq);
1695	return error;
1696	}
1697
1698	static void __exit virtio_blk_fini(void)
1699	{
1700	unregister_virtio_driver(drv: &virtio_blk);
1701	unregister_blkdev(major, name: "virtblk");
1702	destroy_workqueue(wq: virtblk_wq);
1703	}
1704	module_init(virtio_blk_init);
1705	module_exit(virtio_blk_fini);
1706
1707	MODULE_DEVICE_TABLE(virtio, id_table);
1708	MODULE_DESCRIPTION("Virtio block driver");
1709	MODULE_LICENSE("GPL");
1710