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/numa.h>
17	#include <linux/vmalloc.h>
18	#include <uapi/linux/virtio_ring.h>
19
20	#define PART_BITS 4
21	#define VQ_NAME_LEN 16
22	#define MAX_DISCARD_SEGMENTS 256u
23
24	/* The maximum number of sg elements that fit into a virtqueue */
25	#define VIRTIO_BLK_MAX_SG_ELEMS 32768
26
27	#ifdef CONFIG_ARCH_NO_SG_CHAIN
28	#define VIRTIO_BLK_INLINE_SG_CNT 0
29	#else
30	#define VIRTIO_BLK_INLINE_SG_CNT 2
31	#endif
32
33	static unsigned int num_request_queues;
34	module_param(num_request_queues, uint, 0644);
35	MODULE_PARM_DESC(num_request_queues,
36	"Limit the number of request queues to use for blk device. "
37	"0 for no limit. "
38	"Values > nr_cpu_ids truncated to nr_cpu_ids.");
39
40	static unsigned int poll_queues;
41	module_param(poll_queues, uint, 0644);
42	MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O");
43
44	static int major;
45	static DEFINE_IDA(vd_index_ida);
46
47	static struct workqueue_struct *virtblk_wq;
48
49	struct virtio_blk_vq {
50	struct virtqueue *vq;
51	spinlock_t lock;
52	char name[VQ_NAME_LEN];
53	} ____cacheline_aligned_in_smp;
54
55	struct virtio_blk {
56	/*
57	* This mutex must be held by anything that may run after
58	* virtblk_remove() sets vblk->vdev to NULL.
59	*
60	* blk-mq, virtqueue processing, and sysfs attribute code paths are
61	* shut down before vblk->vdev is set to NULL and therefore do not need
62	* to hold this mutex.
63	*/
64	struct mutex vdev_mutex;
65	struct virtio_device *vdev;
66
67	/* The disk structure for the kernel. */
68	struct gendisk *disk;
69
70	/* Block layer tags. */
71	struct blk_mq_tag_set tag_set;
72
73	/* Process context for config space updates */
74	struct work_struct config_work;
75
76	/* Ida index - used to track minor number allocations. */
77	int index;
78
79	/* num of vqs */
80	int num_vqs;
81	int io_queues[HCTX_MAX_TYPES];
82	struct virtio_blk_vq *vqs;
83
84	/* For zoned device */
85	unsigned int zone_sectors;
86	};
87
88	struct virtblk_req {
89	/* Out header */
90	struct virtio_blk_outhdr out_hdr;
91
92	/* In header */
93	union {
94	u8 status;
95
96	/*
97	* The zone append command has an extended in header.
98	* The status field in zone_append_in_hdr must always
99	* be the last byte.
100	*/
101	struct {
102	__virtio64 sector;
103	u8 status;
104	} zone_append;
105	} in_hdr;
106
107	size_t in_hdr_len;
108
109	struct sg_table sg_table;
110	struct scatterlist sg[];
111	};
112
113	static inline blk_status_t virtblk_result(u8 status)
114	{
115	switch (status) {
116	case VIRTIO_BLK_S_OK:
117	return BLK_STS_OK;
118	case VIRTIO_BLK_S_UNSUPP:
119	return BLK_STS_NOTSUPP;
120	case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE:
121	return BLK_STS_ZONE_OPEN_RESOURCE;
122	case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE:
123	return BLK_STS_ZONE_ACTIVE_RESOURCE;
124	case VIRTIO_BLK_S_IOERR:
125	case VIRTIO_BLK_S_ZONE_UNALIGNED_WP:
126	default:
127	return BLK_STS_IOERR;
128	}
129	}
130
131	static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx)
132	{
133	struct virtio_blk *vblk = hctx->queue->queuedata;
134	struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
135
136	return vq;
137	}
138
139	static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
140	{
141	struct scatterlist out_hdr, in_hdr, *sgs[3];
142	unsigned int num_out = 0, num_in = 0;
143
144	sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
145	sgs[num_out++] = &out_hdr;
146
147	if (vbr->sg_table.nents) {
148	if (vbr->out_hdr.type & cpu_to_virtio32(vdev: vq->vdev, VIRTIO_BLK_T_OUT))
149	sgs[num_out++] = vbr->sg_table.sgl;
150	else
151	sgs[num_out + num_in++] = vbr->sg_table.sgl;
152	}
153
154	sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len);
155	sgs[num_out + num_in++] = &in_hdr;
156
157	return virtqueue_add_sgs(vq, sgs, out_sgs: num_out, in_sgs: num_in, data: vbr, GFP_ATOMIC);
158	}
159
160	static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap)
161	{
162	unsigned short segments = blk_rq_nr_discard_segments(rq: req);
163	unsigned short n = 0;
164	struct virtio_blk_discard_write_zeroes *range;
165	struct bio *bio;
166	u32 flags = 0;
167
168	if (unmap)
169	flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
170
171	range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
172	if (!range)
173	return -ENOMEM;
174
175	/*
176	* Single max discard segment means multi-range discard isn't
177	* supported, and block layer only runs contiguity merge like
178	* normal RW request. So we can't reply on bio for retrieving
179	* each range info.
180	*/
181	if (queue_max_discard_segments(q: req->q) == 1) {
182	range[0].flags = cpu_to_le32(flags);
183	range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
184	range[0].sector = cpu_to_le64(blk_rq_pos(req));
185	n = 1;
186	} else {
187	__rq_for_each_bio(bio, req) {
188	u64 sector = bio->bi_iter.bi_sector;
189	u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
190
191	range[n].flags = cpu_to_le32(flags);
192	range[n].num_sectors = cpu_to_le32(num_sectors);
193	range[n].sector = cpu_to_le64(sector);
194	n++;
195	}
196	}
197
198	WARN_ON_ONCE(n != segments);
199
200	bvec_set_virt(bv: &req->special_vec, vaddr: range, len: sizeof(*range) * segments);
201	req->rq_flags |= RQF_SPECIAL_PAYLOAD;
202
203	return 0;
204	}
205
206	static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
207	{
208	if (blk_rq_nr_phys_segments(rq: req))
209	sg_free_table_chained(table: &vbr->sg_table,
210	VIRTIO_BLK_INLINE_SG_CNT);
211	}
212
213	static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
214	struct virtblk_req *vbr)
215	{
216	int err;
217
218	if (!blk_rq_nr_phys_segments(rq: req))
219	return 0;
220
221	vbr->sg_table.sgl = vbr->sg;
222	err = sg_alloc_table_chained(table: &vbr->sg_table,
223	nents: blk_rq_nr_phys_segments(rq: req),
224	first_chunk: vbr->sg_table.sgl,
225	VIRTIO_BLK_INLINE_SG_CNT);
226	if (unlikely(err))
227	return -ENOMEM;
228
229	return blk_rq_map_sg(rq: req, sglist: vbr->sg_table.sgl);
230	}
231
232	static void virtblk_cleanup_cmd(struct request *req)
233	{
234	if (req->rq_flags & RQF_SPECIAL_PAYLOAD)
235	kfree(objp: bvec_virt(bvec: &req->special_vec));
236	}
237
238	static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
239	struct request *req,
240	struct virtblk_req *vbr)
241	{
242	size_t in_hdr_len = sizeof(vbr->in_hdr.status);
243	bool unmap = false;
244	u32 type;
245	u64 sector = 0;
246
247	if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(op: req_op(req)))
248	return BLK_STS_NOTSUPP;
249
250	/* Set fields for all request types */
251	vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, val: req_get_ioprio(req));
252
253	switch (req_op(req)) {
254	case REQ_OP_READ:
255	type = VIRTIO_BLK_T_IN;
256	sector = blk_rq_pos(rq: req);
257	break;
258	case REQ_OP_WRITE:
259	type = VIRTIO_BLK_T_OUT;
260	sector = blk_rq_pos(rq: req);
261	break;
262	case REQ_OP_FLUSH:
263	type = VIRTIO_BLK_T_FLUSH;
264	break;
265	case REQ_OP_DISCARD:
266	type = VIRTIO_BLK_T_DISCARD;
267	break;
268	case REQ_OP_WRITE_ZEROES:
269	type = VIRTIO_BLK_T_WRITE_ZEROES;
270	unmap = !(req->cmd_flags & REQ_NOUNMAP);
271	break;
272	case REQ_OP_SECURE_ERASE:
273	type = VIRTIO_BLK_T_SECURE_ERASE;
274	break;
275	case REQ_OP_ZONE_OPEN:
276	type = VIRTIO_BLK_T_ZONE_OPEN;
277	sector = blk_rq_pos(rq: req);
278	break;
279	case REQ_OP_ZONE_CLOSE:
280	type = VIRTIO_BLK_T_ZONE_CLOSE;
281	sector = blk_rq_pos(rq: req);
282	break;
283	case REQ_OP_ZONE_FINISH:
284	type = VIRTIO_BLK_T_ZONE_FINISH;
285	sector = blk_rq_pos(rq: req);
286	break;
287	case REQ_OP_ZONE_APPEND:
288	type = VIRTIO_BLK_T_ZONE_APPEND;
289	sector = blk_rq_pos(rq: req);
290	in_hdr_len = sizeof(vbr->in_hdr.zone_append);
291	break;
292	case REQ_OP_ZONE_RESET:
293	type = VIRTIO_BLK_T_ZONE_RESET;
294	sector = blk_rq_pos(rq: req);
295	break;
296	case REQ_OP_ZONE_RESET_ALL:
297	type = VIRTIO_BLK_T_ZONE_RESET_ALL;
298	break;
299	case REQ_OP_DRV_IN:
300	/*
301	* Out header has already been prepared by the caller (virtblk_get_id()
302	* or virtblk_submit_zone_report()), nothing to do here.
303	*/
304	return 0;
305	default:
306	WARN_ON_ONCE(1);
307	return BLK_STS_IOERR;
308	}
309
310	/* Set fields for non-REQ_OP_DRV_IN request types */
311	vbr->in_hdr_len = in_hdr_len;
312	vbr->out_hdr.type = cpu_to_virtio32(vdev, val: type);
313	vbr->out_hdr.sector = cpu_to_virtio64(vdev, val: sector);
314
315	if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
316	type == VIRTIO_BLK_T_SECURE_ERASE) {
317	if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
318	return BLK_STS_RESOURCE;
319	}
320
321	return 0;
322	}
323
324	/*
325	* The status byte is always the last byte of the virtblk request
326	* in-header. This helper fetches its value for all in-header formats
327	* that are currently defined.
328	*/
329	static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
330	{
331	return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
332	}
333
334	static inline void virtblk_request_done(struct request *req)
335	{
336	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
337	blk_status_t status = virtblk_result(status: virtblk_vbr_status(vbr));
338	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
339
340	virtblk_unmap_data(req, vbr);
341	virtblk_cleanup_cmd(req);
342
343	if (req_op(req) == REQ_OP_ZONE_APPEND)
344	req->__sector = virtio64_to_cpu(vdev: vblk->vdev,
345	val: vbr->in_hdr.zone_append.sector);
346
347	blk_mq_end_request(rq: req, error: status);
348	}
349
350	static void virtblk_done(struct virtqueue *vq)
351	{
352	struct virtio_blk *vblk = vq->vdev->priv;
353	bool req_done = false;
354	int qid = vq->index;
355	struct virtblk_req *vbr;
356	unsigned long flags;
357	unsigned int len;
358
359	spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
360	do {
361	virtqueue_disable_cb(vq);
362	while ((vbr = virtqueue_get_buf(vq: vblk->vqs[qid].vq, len: &len)) != NULL) {
363	struct request *req = blk_mq_rq_from_pdu(pdu: vbr);
364
365	if (likely(!blk_should_fake_timeout(req->q)))
366	blk_mq_complete_request(rq: req);
367	req_done = true;
368	}
369	} while (!virtqueue_enable_cb(vq));
370
371	/* In case queue is stopped waiting for more buffers. */
372	if (req_done)
373	blk_mq_start_stopped_hw_queues(q: vblk->disk->queue, async: true);
374	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
375	}
376
377	static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
378	{
379	struct virtio_blk *vblk = hctx->queue->queuedata;
380	struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
381	bool kick;
382
383	spin_lock_irq(lock: &vq->lock);
384	kick = virtqueue_kick_prepare(vq: vq->vq);
385	spin_unlock_irq(lock: &vq->lock);
386
387	if (kick)
388	virtqueue_notify(vq: vq->vq);
389	}
390
391	static blk_status_t virtblk_fail_to_queue(struct request *req, int rc)
392	{
393	virtblk_cleanup_cmd(req);
394	switch (rc) {
395	case -ENOSPC:
396	return BLK_STS_DEV_RESOURCE;
397	case -ENOMEM:
398	return BLK_STS_RESOURCE;
399	default:
400	return BLK_STS_IOERR;
401	}
402	}
403
404	static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
405	struct virtio_blk *vblk,
406	struct request *req,
407	struct virtblk_req *vbr)
408	{
409	blk_status_t status;
410	int num;
411
412	status = virtblk_setup_cmd(vdev: vblk->vdev, req, vbr);
413	if (unlikely(status))
414	return status;
415
416	num = virtblk_map_data(hctx, req, vbr);
417	if (unlikely(num < 0))
418	return virtblk_fail_to_queue(req, rc: -ENOMEM);
419	vbr->sg_table.nents = num;
420
421	blk_mq_start_request(rq: req);
422
423	return BLK_STS_OK;
424	}
425
426	static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
427	const struct blk_mq_queue_data *bd)
428	{
429	struct virtio_blk *vblk = hctx->queue->queuedata;
430	struct request *req = bd->rq;
431	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
432	unsigned long flags;
433	int qid = hctx->queue_num;
434	bool notify = false;
435	blk_status_t status;
436	int err;
437
438	status = virtblk_prep_rq(hctx, vblk, req, vbr);
439	if (unlikely(status))
440	return status;
441
442	spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
443	err = virtblk_add_req(vq: vblk->vqs[qid].vq, vbr);
444	if (err) {
445	virtqueue_kick(vq: vblk->vqs[qid].vq);
446	/* Don't stop the queue if -ENOMEM: we may have failed to
447	* bounce the buffer due to global resource outage.
448	*/
449	if (err == -ENOSPC)
450	blk_mq_stop_hw_queue(hctx);
451	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
452	virtblk_unmap_data(req, vbr);
453	return virtblk_fail_to_queue(req, rc: err);
454	}
455
456	if (bd->last && virtqueue_kick_prepare(vq: vblk->vqs[qid].vq))
457	notify = true;
458	spin_unlock_irqrestore(lock: &vblk->vqs[qid].lock, flags);
459
460	if (notify)
461	virtqueue_notify(vq: vblk->vqs[qid].vq);
462	return BLK_STS_OK;
463	}
464
465	static bool virtblk_prep_rq_batch(struct request *req)
466	{
467	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
468	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
469
470	return virtblk_prep_rq(hctx: req->mq_hctx, vblk, req, vbr) == BLK_STS_OK;
471	}
472
473	static void virtblk_add_req_batch(struct virtio_blk_vq *vq,
474	struct rq_list *rqlist)
475	{
476	struct request *req;
477	unsigned long flags;
478	bool kick;
479
480	spin_lock_irqsave(&vq->lock, flags);
481
482	while ((req = rq_list_pop(rl: rqlist))) {
483	struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq: req);
484	int err;
485
486	err = virtblk_add_req(vq: vq->vq, vbr);
487	if (err) {
488	virtblk_unmap_data(req, vbr);
489	virtblk_cleanup_cmd(req);
490	blk_mq_requeue_request(rq: req, kick_requeue_list: true);
491	}
492	}
493
494	kick = virtqueue_kick_prepare(vq: vq->vq);
495	spin_unlock_irqrestore(lock: &vq->lock, flags);
496
497	if (kick)
498	virtqueue_notify(vq: vq->vq);
499	}
500
501	static void virtio_queue_rqs(struct rq_list *rqlist)
502	{
503	struct rq_list submit_list = { };
504	struct rq_list requeue_list = { };
505	struct virtio_blk_vq *vq = NULL;
506	struct request *req;
507
508	while ((req = rq_list_pop(rl: rqlist))) {
509	struct virtio_blk_vq *this_vq = get_virtio_blk_vq(hctx: req->mq_hctx);
510
511	if (vq && vq != this_vq)
512	virtblk_add_req_batch(vq, rqlist: &submit_list);
513	vq = this_vq;
514
515	if (virtblk_prep_rq_batch(req))
516	rq_list_add_tail(rl: &submit_list, rq: req);
517	else
518	rq_list_add_tail(rl: &requeue_list, rq: req);
519	}
520
521	if (vq)
522	virtblk_add_req_batch(vq, rqlist: &submit_list);
523	*rqlist = requeue_list;
524	}
525
526	#ifdef CONFIG_BLK_DEV_ZONED
527	static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk,
528	unsigned int nr_zones,
529	size_t *buflen)
530	{
531	struct request_queue *q = vblk->disk->queue;
532	size_t bufsize;
533	void *buf;
534
535	nr_zones = min_t(unsigned int, nr_zones,
536	get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors));
537
538	bufsize = sizeof(struct virtio_blk_zone_report) +
539	nr_zones * sizeof(struct virtio_blk_zone_descriptor);
540	bufsize = min_t(size_t, bufsize,
541	queue_max_hw_sectors(q) << SECTOR_SHIFT);
542	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
543
544	while (bufsize >= sizeof(struct virtio_blk_zone_report)) {
545	buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
546	if (buf) {
547	*buflen = bufsize;
548	return buf;
549	}
550	bufsize >>= 1;
551	}
552
553	return NULL;
554	}
555
556	static int virtblk_submit_zone_report(struct virtio_blk *vblk,
557	char *report_buf, size_t report_len,
558	sector_t sector)
559	{
560	struct request_queue *q = vblk->disk->queue;
561	struct request *req;
562	struct virtblk_req *vbr;
563	int err;
564
565	req = blk_mq_alloc_request(q, opf: REQ_OP_DRV_IN, flags: 0);
566	if (IS_ERR(ptr: req))
567	return PTR_ERR(ptr: req);
568
569	vbr = blk_mq_rq_to_pdu(rq: req);
570	vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
571	vbr->out_hdr.type = cpu_to_virtio32(vdev: vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
572	vbr->out_hdr.sector = cpu_to_virtio64(vdev: vblk->vdev, val: sector);
573
574	err = blk_rq_map_kern(rq: req, kbuf: report_buf, len: report_len, GFP_KERNEL);
575	if (err)
576	goto out;
577
578	blk_execute_rq(rq: req, at_head: false);
579	err = blk_status_to_errno(status: virtblk_result(status: vbr->in_hdr.status));
580	out:
581	blk_mq_free_request(rq: req);
582	return err;
583	}
584
585	static int virtblk_parse_zone(struct virtio_blk *vblk,
586	struct virtio_blk_zone_descriptor *entry,
587	unsigned int idx,
588	struct blk_report_zones_args *args)
589	{
590	struct blk_zone zone = { };
591
592	zone.start = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_start);
593	if (zone.start + vblk->zone_sectors <= get_capacity(disk: vblk->disk))
594	zone.len = vblk->zone_sectors;
595	else
596	zone.len = get_capacity(disk: vblk->disk) - zone.start;
597	zone.capacity = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_cap);
598	zone.wp = virtio64_to_cpu(vdev: vblk->vdev, val: entry->z_wp);
599
600	switch (entry->z_type) {
601	case VIRTIO_BLK_ZT_SWR:
602	zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ;
603	break;
604	case VIRTIO_BLK_ZT_SWP:
605	zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF;
606	break;
607	case VIRTIO_BLK_ZT_CONV:
608	zone.type = BLK_ZONE_TYPE_CONVENTIONAL;
609	break;
610	default:
611	dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n",
612	zone.start, entry->z_type);
613	return -EIO;
614	}
615
616	switch (entry->z_state) {
617	case VIRTIO_BLK_ZS_EMPTY:
618	zone.cond = BLK_ZONE_COND_EMPTY;
619	break;
620	case VIRTIO_BLK_ZS_CLOSED:
621	zone.cond = BLK_ZONE_COND_CLOSED;
622	break;
623	case VIRTIO_BLK_ZS_FULL:
624	zone.cond = BLK_ZONE_COND_FULL;
625	zone.wp = zone.start + zone.len;
626	break;
627	case VIRTIO_BLK_ZS_EOPEN:
628	zone.cond = BLK_ZONE_COND_EXP_OPEN;
629	break;
630	case VIRTIO_BLK_ZS_IOPEN:
631	zone.cond = BLK_ZONE_COND_IMP_OPEN;
632	break;
633	case VIRTIO_BLK_ZS_NOT_WP:
634	zone.cond = BLK_ZONE_COND_NOT_WP;
635	break;
636	case VIRTIO_BLK_ZS_RDONLY:
637	zone.cond = BLK_ZONE_COND_READONLY;
638	zone.wp = ULONG_MAX;
639	break;
640	case VIRTIO_BLK_ZS_OFFLINE:
641	zone.cond = BLK_ZONE_COND_OFFLINE;
642	zone.wp = ULONG_MAX;
643	break;
644	default:
645	dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n",
646	zone.start, entry->z_state);
647	return -EIO;
648	}
649
650	/*
651	* The callback below checks the validity of the reported
652	* entry data, no need to further validate it here.
653	*/
654	return disk_report_zone(disk: vblk->disk, zone: &zone, idx, args);
655	}
656
657	static int virtblk_report_zones(struct gendisk *disk, sector_t sector,
658	unsigned int nr_zones,
659	struct blk_report_zones_args *args)
660	{
661	struct virtio_blk *vblk = disk->private_data;
662	struct virtio_blk_zone_report *report;
663	unsigned long long nz, i;
664	size_t buflen;
665	unsigned int zone_idx = 0;
666	int ret;
667
668	if (WARN_ON_ONCE(!vblk->zone_sectors))
669	return -EOPNOTSUPP;
670
671	report = virtblk_alloc_report_buffer(vblk, nr_zones, buflen: &buflen);
672	if (!report)
673	return -ENOMEM;
674
675	mutex_lock(&vblk->vdev_mutex);
676
677	if (!vblk->vdev) {
678	ret = -ENXIO;
679	goto fail_report;
680	}
681
682	while (zone_idx < nr_zones && sector < get_capacity(disk: vblk->disk)) {
683	memset(report, 0, buflen);
684
685	ret = virtblk_submit_zone_report(vblk, report_buf: (char *)report,
686	report_len: buflen, sector);
687	if (ret)
688	goto fail_report;
689
690	nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones),
691	nr_zones);
692	if (!nz)
693	break;
694
695	for (i = 0; i < nz && zone_idx < nr_zones; i++) {
696	ret = virtblk_parse_zone(vblk, entry: &report->zones[i],
697	idx: zone_idx, args);
698	if (ret)
699	goto fail_report;
700
701	sector = virtio64_to_cpu(vdev: vblk->vdev,
702	val: report->zones[i].z_start) +
703	vblk->zone_sectors;
704	zone_idx++;
705	}
706	}
707
708	if (zone_idx > 0)
709	ret = zone_idx;
710	else
711	ret = -EINVAL;
712	fail_report:
713	mutex_unlock(lock: &vblk->vdev_mutex);
714	kvfree(addr: report);
715	return ret;
716	}
717
718	static int virtblk_read_zoned_limits(struct virtio_blk *vblk,
719	struct queue_limits *lim)
720	{
721	struct virtio_device *vdev = vblk->vdev;
722	u32 v, wg;
723
724	dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
725
726	lim->features |= BLK_FEAT_ZONED;
727
728	virtio_cread(vdev, struct virtio_blk_config,
729	zoned.max_open_zones, &v);
730	lim->max_open_zones = v;
731	dev_dbg(&vdev->dev, "max open zones = %u\n", v);
732
733	virtio_cread(vdev, struct virtio_blk_config,
734	zoned.max_active_zones, &v);
735	lim->max_active_zones = v;
736	dev_dbg(&vdev->dev, "max active zones = %u\n", v);
737
738	virtio_cread(vdev, struct virtio_blk_config,
739	zoned.write_granularity, &wg);
740	if (!wg) {
741	dev_warn(&vdev->dev, "zero write granularity reported\n");
742	return -ENODEV;
743	}
744	lim->physical_block_size = wg;
745	lim->io_min = wg;
746
747	dev_dbg(&vdev->dev, "write granularity = %u\n", wg);
748
749	/*
750	* virtio ZBD specification doesn't require zones to be a power of
751	* two sectors in size, but the code in this driver expects that.
752	*/
753	virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors,
754	&vblk->zone_sectors);
755	if (vblk->zone_sectors == 0 || !is_power_of_2(n: vblk->zone_sectors)) {
756	dev_err(&vdev->dev,
757	"zoned device with non power of two zone size %u\n",
758	vblk->zone_sectors);
759	return -ENODEV;
760	}
761	lim->chunk_sectors = vblk->zone_sectors;
762	dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors);
763
764	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
765	dev_warn(&vblk->vdev->dev,
766	"ignoring negotiated F_DISCARD for zoned device\n");
767	lim->max_hw_discard_sectors = 0;
768	}
769
770	virtio_cread(vdev, struct virtio_blk_config,
771	zoned.max_append_sectors, &v);
772	if (!v) {
773	dev_warn(&vdev->dev, "zero max_append_sectors reported\n");
774	return -ENODEV;
775	}
776	if ((v << SECTOR_SHIFT) < wg) {
777	dev_err(&vdev->dev,
778	"write granularity %u exceeds max_append_sectors %u limit\n",
779	wg, v);
780	return -ENODEV;
781	}
782	lim->max_hw_zone_append_sectors = v;
783	dev_dbg(&vdev->dev, "max append sectors = %u\n", v);
784
785	return 0;
786	}
787	#else
788	/*
789	* Zoned block device support is not configured in this kernel, host-managed
790	* zoned devices can't be supported.
791	*/
792	#define virtblk_report_zones NULL
793	static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk,
794	struct queue_limits *lim)
795	{
796	dev_err(&vblk->vdev->dev,
797	"virtio_blk: zoned devices are not supported");
798	return -EOPNOTSUPP;
799	}
800	#endif /* CONFIG_BLK_DEV_ZONED */
801
802	/* return id (s/n) string for *disk to *id_str
803	*/
804	static int virtblk_get_id(struct gendisk *disk, char *id_str)
805	{
806	struct virtio_blk *vblk = disk->private_data;
807	struct request_queue *q = vblk->disk->queue;
808	struct request *req;
809	struct virtblk_req *vbr;
810	int err;
811
812	req = blk_mq_alloc_request(q, opf: REQ_OP_DRV_IN, flags: 0);
813	if (IS_ERR(ptr: req))
814	return PTR_ERR(ptr: req);
815
816	vbr = blk_mq_rq_to_pdu(rq: req);
817	vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
818	vbr->out_hdr.type = cpu_to_virtio32(vdev: vblk->vdev, VIRTIO_BLK_T_GET_ID);
819	vbr->out_hdr.sector = 0;
820
821	err = blk_rq_map_kern(rq: req, kbuf: id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
822	if (err)
823	goto out;
824
825	blk_execute_rq(rq: req, at_head: false);
826	err = blk_status_to_errno(status: virtblk_result(status: vbr->in_hdr.status));
827	out:
828	blk_mq_free_request(rq: req);
829	return err;
830	}
831
832	/* We provide getgeo only to please some old bootloader/partitioning tools */
833	static int virtblk_getgeo(struct gendisk *disk, struct hd_geometry *geo)
834	{
835	struct virtio_blk *vblk = disk->private_data;
836	int ret = 0;
837
838	mutex_lock(&vblk->vdev_mutex);
839
840	if (!vblk->vdev) {
841	ret = -ENXIO;
842	goto out;
843	}
844
845	/* see if the host passed in geometry config */
846	if (virtio_has_feature(vdev: vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
847	virtio_cread(vblk->vdev, struct virtio_blk_config,
848	geometry.cylinders, &geo->cylinders);
849	virtio_cread(vblk->vdev, struct virtio_blk_config,
850	geometry.heads, &geo->heads);
851	virtio_cread(vblk->vdev, struct virtio_blk_config,
852	geometry.sectors, &geo->sectors);
853	} else {
854	/* some standard values, similar to sd */
855	geo->heads = 1 << 6;
856	geo->sectors = 1 << 5;
857	geo->cylinders = get_capacity(disk) >> 11;
858	}
859	out:
860	mutex_unlock(lock: &vblk->vdev_mutex);
861	return ret;
862	}
863
864	static void virtblk_free_disk(struct gendisk *disk)
865	{
866	struct virtio_blk *vblk = disk->private_data;
867
868	ida_free(&vd_index_ida, id: vblk->index);
869	mutex_destroy(lock: &vblk->vdev_mutex);
870	kfree(objp: vblk);
871	}
872
873	static const struct block_device_operations virtblk_fops = {
874	.owner = THIS_MODULE,
875	.getgeo = virtblk_getgeo,
876	.free_disk = virtblk_free_disk,
877	.report_zones = virtblk_report_zones,
878	};
879
880	static int index_to_minor(int index)
881	{
882	return index << PART_BITS;
883	}
884
885	static int minor_to_index(int minor)
886	{
887	return minor >> PART_BITS;
888	}
889
890	static ssize_t serial_show(struct device *dev,
891	struct device_attribute *attr, char *buf)
892	{
893	struct gendisk *disk = dev_to_disk(dev);
894	int err;
895
896	/* sysfs gives us a PAGE_SIZE buffer */
897	BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
898
899	buf[VIRTIO_BLK_ID_BYTES] = '\0';
900	err = virtblk_get_id(disk, id_str: buf);
901	if (!err)
902	return strlen(buf);
903
904	if (err == -EIO) /* Unsupported? Make it empty. */
905	return 0;
906
907	return err;
908	}
909
910	static DEVICE_ATTR_RO(serial);
911
912	/* The queue's logical block size must be set before calling this */
913	static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
914	{
915	struct virtio_device *vdev = vblk->vdev;
916	struct request_queue *q = vblk->disk->queue;
917	char cap_str_2[10], cap_str_10[10];
918	unsigned long long nblocks;
919	u64 capacity;
920
921	/* Host must always specify the capacity. */
922	virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
923
924	nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
925
926	string_get_size(size: nblocks, blk_size: queue_logical_block_size(q),
927	units: STRING_UNITS_2, buf: cap_str_2, len: sizeof(cap_str_2));
928	string_get_size(size: nblocks, blk_size: queue_logical_block_size(q),
929	units: STRING_UNITS_10, buf: cap_str_10, len: sizeof(cap_str_10));
930
931	dev_notice(&vdev->dev,
932	"[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
933	vblk->disk->disk_name,
934	resize ? "new size: " : "",
935	nblocks,
936	queue_logical_block_size(q),
937	cap_str_10,
938	cap_str_2);
939
940	set_capacity_and_notify(disk: vblk->disk, size: capacity);
941	}
942
943	static void virtblk_config_changed_work(struct work_struct *work)
944	{
945	struct virtio_blk *vblk =
946	container_of(work, struct virtio_blk, config_work);
947
948	virtblk_update_capacity(vblk, resize: true);
949	}
950
951	static void virtblk_config_changed(struct virtio_device *vdev)
952	{
953	struct virtio_blk *vblk = vdev->priv;
954
955	queue_work(wq: virtblk_wq, work: &vblk->config_work);
956	}
957
958	static int init_vq(struct virtio_blk *vblk)
959	{
960	int err;
961	unsigned short i;
962	struct virtqueue_info *vqs_info;
963	struct virtqueue **vqs;
964	unsigned short num_vqs;
965	unsigned short num_poll_vqs;
966	struct virtio_device *vdev = vblk->vdev;
967	struct irq_affinity desc = { 0, };
968
969	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
970	struct virtio_blk_config, num_queues,
971	&num_vqs);
972	if (err)
973	num_vqs = 1;
974
975	if (!err && !num_vqs) {
976	dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
977	return -EINVAL;
978	}
979
980	num_vqs = blk_mq_num_possible_queues(
981	min_not_zero(num_request_queues, num_vqs));
982
983	num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
984
985	vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
986	vblk->io_queues[HCTX_TYPE_READ] = 0;
987	vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
988
989	dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
990	vblk->io_queues[HCTX_TYPE_DEFAULT],
991	vblk->io_queues[HCTX_TYPE_READ],
992	vblk->io_queues[HCTX_TYPE_POLL]);
993
994	vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
995	if (!vblk->vqs)
996	return -ENOMEM;
997
998	vqs_info = kcalloc(num_vqs, sizeof(*vqs_info), GFP_KERNEL);
999	vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
1000	if (!vqs_info || !vqs) {
1001	err = -ENOMEM;
1002	goto out;
1003	}
1004
1005	for (i = 0; i < num_vqs - num_poll_vqs; i++) {
1006	vqs_info[i].callback = virtblk_done;
1007	snprintf(buf: vblk->vqs[i].name, VQ_NAME_LEN, fmt: "req.%u", i);
1008	vqs_info[i].name = vblk->vqs[i].name;
1009	}
1010
1011	for (; i < num_vqs; i++) {
1012	snprintf(buf: vblk->vqs[i].name, VQ_NAME_LEN, fmt: "req_poll.%u", i);
1013	vqs_info[i].name = vblk->vqs[i].name;
1014	}
1015
1016	/* Discover virtqueues and write information to configuration. */
1017	err = virtio_find_vqs(vdev, nvqs: num_vqs, vqs, vqs_info, desc: &desc);
1018	if (err)
1019	goto out;
1020
1021	for (i = 0; i < num_vqs; i++) {
1022	spin_lock_init(&vblk->vqs[i].lock);
1023	vblk->vqs[i].vq = vqs[i];
1024	}
1025	vblk->num_vqs = num_vqs;
1026
1027	out:
1028	kfree(objp: vqs);
1029	kfree(objp: vqs_info);
1030	if (err) {
1031	kfree(objp: vblk->vqs);
1032	/*
1033	* Set to NULL to prevent freeing vqs again during freezing.
1034	*/
1035	vblk->vqs = NULL;
1036	}
1037	return err;
1038	}
1039
1040	/*
1041	* Legacy naming scheme used for virtio devices. We are stuck with it for
1042	* virtio blk but don't ever use it for any new driver.
1043	*/
1044	static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
1045	{
1046	const int base = 'z' - 'a' + 1;
1047	char *begin = buf + strlen(prefix);
1048	char *end = buf + buflen;
1049	char *p;
1050	int unit;
1051
1052	p = end - 1;
1053	*p = '\0';
1054	unit = base;
1055	do {
1056	if (p == begin)
1057	return -EINVAL;
1058	*--p = 'a' + (index % unit);
1059	index = (index / unit) - 1;
1060	} while (index >= 0);
1061
1062	memmove(begin, p, end - p);
1063	memcpy(buf, prefix, strlen(prefix));
1064
1065	return 0;
1066	}
1067
1068	static int virtblk_get_cache_mode(struct virtio_device *vdev)
1069	{
1070	u8 writeback;
1071	int err;
1072
1073	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
1074	struct virtio_blk_config, wce,
1075	&writeback);
1076
1077	/*
1078	* If WCE is not configurable and flush is not available,
1079	* assume no writeback cache is in use.
1080	*/
1081	if (err)
1082	writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH);
1083
1084	return writeback;
1085	}
1086
1087	static const char *const virtblk_cache_types[] = {
1088	"write through", "write back"
1089	};
1090
1091	static ssize_t
1092	cache_type_store(struct device *dev, struct device_attribute *attr,
1093	const char *buf, size_t count)
1094	{
1095	struct gendisk *disk = dev_to_disk(dev);
1096	struct virtio_blk *vblk = disk->private_data;
1097	struct virtio_device *vdev = vblk->vdev;
1098	struct queue_limits lim;
1099	int i;
1100
1101	BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
1102	i = sysfs_match_string(virtblk_cache_types, buf);
1103	if (i < 0)
1104	return i;
1105
1106	virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), val: i);
1107
1108	lim = queue_limits_start_update(q: disk->queue);
1109	if (virtblk_get_cache_mode(vdev))
1110	lim.features |= BLK_FEAT_WRITE_CACHE;
1111	else
1112	lim.features &= ~BLK_FEAT_WRITE_CACHE;
1113	i = queue_limits_commit_update_frozen(q: disk->queue, lim: &lim);
1114	if (i)
1115	return i;
1116	return count;
1117	}
1118
1119	static ssize_t
1120	cache_type_show(struct device *dev, struct device_attribute *attr, char *buf)
1121	{
1122	struct gendisk *disk = dev_to_disk(dev);
1123	struct virtio_blk *vblk = disk->private_data;
1124	u8 writeback = virtblk_get_cache_mode(vdev: vblk->vdev);
1125
1126	BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
1127	return sysfs_emit(buf, fmt: "%s\n", virtblk_cache_types[writeback]);
1128	}
1129
1130	static DEVICE_ATTR_RW(cache_type);
1131
1132	static struct attribute *virtblk_attrs[] = {
1133	&dev_attr_serial.attr,
1134	&dev_attr_cache_type.attr,
1135	NULL,
1136	};
1137
1138	static umode_t virtblk_attrs_are_visible(struct kobject *kobj,
1139	struct attribute *a, int n)
1140	{
1141	struct device *dev = kobj_to_dev(kobj);
1142	struct gendisk *disk = dev_to_disk(dev);
1143	struct virtio_blk *vblk = disk->private_data;
1144	struct virtio_device *vdev = vblk->vdev;
1145
1146	if (a == &dev_attr_cache_type.attr &&
1147	!virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
1148	return S_IRUGO;
1149
1150	return a->mode;
1151	}
1152
1153	static const struct attribute_group virtblk_attr_group = {
1154	.attrs = virtblk_attrs,
1155	.is_visible = virtblk_attrs_are_visible,
1156	};
1157
1158	static const struct attribute_group *virtblk_attr_groups[] = {
1159	&virtblk_attr_group,
1160	NULL,
1161	};
1162
1163	static void virtblk_map_queues(struct blk_mq_tag_set *set)
1164	{
1165	struct virtio_blk *vblk = set->driver_data;
1166	int i, qoff;
1167
1168	for (i = 0, qoff = 0; i < set->nr_maps; i++) {
1169	struct blk_mq_queue_map *map = &set->map[i];
1170
1171	map->nr_queues = vblk->io_queues[i];
1172	map->queue_offset = qoff;
1173	qoff += map->nr_queues;
1174
1175	if (map->nr_queues == 0)
1176	continue;
1177
1178	/*
1179	* Regular queues have interrupts and hence CPU affinity is
1180	* defined by the core virtio code, but polling queues have
1181	* no interrupts so we let the block layer assign CPU affinity.
1182	*/
1183	if (i == HCTX_TYPE_POLL)
1184	blk_mq_map_queues(qmap: &set->map[i]);
1185	else
1186	blk_mq_map_hw_queues(qmap: &set->map[i],
1187	dev: &vblk->vdev->dev, offset: 0);
1188	}
1189	}
1190
1191	static void virtblk_complete_batch(struct io_comp_batch *iob)
1192	{
1193	struct request *req;
1194
1195	rq_list_for_each(&iob->req_list, req) {
1196	virtblk_unmap_data(req, vbr: blk_mq_rq_to_pdu(rq: req));
1197	virtblk_cleanup_cmd(req);
1198	}
1199	blk_mq_end_request_batch(ib: iob);
1200	}
1201
1202	static int virtblk_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
1203	{
1204	struct virtio_blk *vblk = hctx->queue->queuedata;
1205	struct virtio_blk_vq *vq = get_virtio_blk_vq(hctx);
1206	struct virtblk_req *vbr;
1207	unsigned long flags;
1208	unsigned int len;
1209	int found = 0;
1210
1211	spin_lock_irqsave(&vq->lock, flags);
1212
1213	while ((vbr = virtqueue_get_buf(vq: vq->vq, len: &len)) != NULL) {
1214	struct request *req = blk_mq_rq_from_pdu(pdu: vbr);
1215	u8 status = virtblk_vbr_status(vbr);
1216
1217	found++;
1218	if (!blk_mq_complete_request_remote(rq: req) &&
1219	!blk_mq_add_to_batch(req, iob, is_error: status != VIRTIO_BLK_S_OK,
1220	complete: virtblk_complete_batch))
1221	virtblk_request_done(req);
1222	}
1223
1224	if (found)
1225	blk_mq_start_stopped_hw_queues(q: vblk->disk->queue, async: true);
1226
1227	spin_unlock_irqrestore(lock: &vq->lock, flags);
1228
1229	return found;
1230	}
1231
1232	static const struct blk_mq_ops virtio_mq_ops = {
1233	.queue_rq = virtio_queue_rq,
1234	.queue_rqs = virtio_queue_rqs,
1235	.commit_rqs = virtio_commit_rqs,
1236	.complete = virtblk_request_done,
1237	.map_queues = virtblk_map_queues,
1238	.poll = virtblk_poll,
1239	};
1240
1241	static unsigned int virtblk_queue_depth;
1242	module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
1243
1244	static int virtblk_read_limits(struct virtio_blk *vblk,
1245	struct queue_limits *lim)
1246	{
1247	struct virtio_device *vdev = vblk->vdev;
1248	u32 v, max_size, sg_elems, opt_io_size;
1249	u32 max_discard_segs = 0;
1250	u32 discard_granularity = 0;
1251	u16 min_io_size;
1252	u8 physical_block_exp, alignment_offset;
1253	size_t max_dma_size;
1254	int err;
1255
1256	/* We need to know how many segments before we allocate. */
1257	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
1258	struct virtio_blk_config, seg_max,
1259	&sg_elems);
1260
1261	/* We need at least one SG element, whatever they say. */
1262	if (err || !sg_elems)
1263	sg_elems = 1;
1264
1265	/* Prevent integer overflows and honor max vq size */
1266	sg_elems = min_t(u32, sg_elems, VIRTIO_BLK_MAX_SG_ELEMS - 2);
1267
1268	/* We can handle whatever the host told us to handle. */
1269	lim->max_segments = sg_elems;
1270
1271	/* No real sector limit. */
1272	lim->max_hw_sectors = UINT_MAX;
1273
1274	max_dma_size = virtio_max_dma_size(vdev);
1275	max_size = max_dma_size > U32_MAX ? U32_MAX : max_dma_size;
1276
1277	/* Host can optionally specify maximum segment size and number of
1278	* segments. */
1279	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
1280	struct virtio_blk_config, size_max, &v);
1281	if (!err)
1282	max_size = min(max_size, v);
1283
1284	lim->max_segment_size = max_size;
1285
1286	/* Host can optionally specify the block size of the device */
1287	virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
1288	struct virtio_blk_config, blk_size,
1289	&lim->logical_block_size);
1290
1291	/* Use topology information if available */
1292	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1293	struct virtio_blk_config, physical_block_exp,
1294	&physical_block_exp);
1295	if (!err && physical_block_exp)
1296	lim->physical_block_size =
1297	lim->logical_block_size * (1 << physical_block_exp);
1298
1299	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1300	struct virtio_blk_config, alignment_offset,
1301	&alignment_offset);
1302	if (!err && alignment_offset)
1303	lim->alignment_offset =
1304	lim->logical_block_size * alignment_offset;
1305
1306	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1307	struct virtio_blk_config, min_io_size,
1308	&min_io_size);
1309	if (!err && min_io_size)
1310	lim->io_min = lim->logical_block_size * min_io_size;
1311
1312	err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
1313	struct virtio_blk_config, opt_io_size,
1314	&opt_io_size);
1315	if (!err && opt_io_size)
1316	lim->io_opt = lim->logical_block_size * opt_io_size;
1317
1318	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
1319	virtio_cread(vdev, struct virtio_blk_config,
1320	discard_sector_alignment, &discard_granularity);
1321
1322	virtio_cread(vdev, struct virtio_blk_config,
1323	max_discard_sectors, &v);
1324	lim->max_hw_discard_sectors = v ? v : UINT_MAX;
1325
1326	virtio_cread(vdev, struct virtio_blk_config, max_discard_seg,
1327	&max_discard_segs);
1328	}
1329
1330	if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) {
1331	virtio_cread(vdev, struct virtio_blk_config,
1332	max_write_zeroes_sectors, &v);
1333	lim->max_write_zeroes_sectors = v ? v : UINT_MAX;
1334	}
1335
1336	/* The discard and secure erase limits are combined since the Linux
1337	* block layer uses the same limit for both commands.
1338	*
1339	* If both VIRTIO_BLK_F_SECURE_ERASE and VIRTIO_BLK_F_DISCARD features
1340	* are negotiated, we will use the minimum between the limits.
1341	*
1342	* discard sector alignment is set to the minimum between discard_sector_alignment
1343	* and secure_erase_sector_alignment.
1344	*
1345	* max discard sectors is set to the minimum between max_discard_seg and
1346	* max_secure_erase_seg.
1347	*/
1348	if (virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1349
1350	virtio_cread(vdev, struct virtio_blk_config,
1351	secure_erase_sector_alignment, &v);
1352
1353	/* secure_erase_sector_alignment should not be zero, the device should set a
1354	* valid number of sectors.
1355	*/
1356	if (!v) {
1357	dev_err(&vdev->dev,
1358	"virtio_blk: secure_erase_sector_alignment can't be 0\n");
1359	return -EINVAL;
1360	}
1361
1362	discard_granularity = min_not_zero(discard_granularity, v);
1363
1364	virtio_cread(vdev, struct virtio_blk_config,
1365	max_secure_erase_sectors, &v);
1366
1367	/* max_secure_erase_sectors should not be zero, the device should set a
1368	* valid number of sectors.
1369	*/
1370	if (!v) {
1371	dev_err(&vdev->dev,
1372	"virtio_blk: max_secure_erase_sectors can't be 0\n");
1373	return -EINVAL;
1374	}
1375
1376	lim->max_secure_erase_sectors = v;
1377
1378	virtio_cread(vdev, struct virtio_blk_config,
1379	max_secure_erase_seg, &v);
1380
1381	/* max_secure_erase_seg should not be zero, the device should set a
1382	* valid number of segments
1383	*/
1384	if (!v) {
1385	dev_err(&vdev->dev,
1386	"virtio_blk: max_secure_erase_seg can't be 0\n");
1387	return -EINVAL;
1388	}
1389
1390	max_discard_segs = min_not_zero(max_discard_segs, v);
1391	}
1392
1393	if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD) ||
1394	virtio_has_feature(vdev, VIRTIO_BLK_F_SECURE_ERASE)) {
1395	/* max_discard_seg and discard_granularity will be 0 only
1396	* if max_discard_seg and discard_sector_alignment fields in the virtio
1397	* config are 0 and VIRTIO_BLK_F_SECURE_ERASE feature is not negotiated.
1398	* In this case, we use default values.
1399	*/
1400	if (!max_discard_segs)
1401	max_discard_segs = sg_elems;
1402
1403	lim->max_discard_segments =
1404	min(max_discard_segs, MAX_DISCARD_SEGMENTS);
1405
1406	if (discard_granularity)
1407	lim->discard_granularity =
1408	discard_granularity << SECTOR_SHIFT;
1409	else
1410	lim->discard_granularity = lim->logical_block_size;
1411	}
1412
1413	if (virtio_has_feature(vdev, VIRTIO_BLK_F_ZONED)) {
1414	u8 model;
1415
1416	virtio_cread(vdev, struct virtio_blk_config, zoned.model, &model);
1417	switch (model) {
1418	case VIRTIO_BLK_Z_NONE:
1419	case VIRTIO_BLK_Z_HA:
1420	/* treat host-aware devices as non-zoned */
1421	return 0;
1422	case VIRTIO_BLK_Z_HM:
1423	err = virtblk_read_zoned_limits(vblk, lim);
1424	if (err)
1425	return err;
1426	break;
1427	default:
1428	dev_err(&vdev->dev, "unsupported zone model %d\n", model);
1429	return -EINVAL;
1430	}
1431	}
1432
1433	return 0;
1434	}
1435
1436	static int virtblk_probe(struct virtio_device *vdev)
1437	{
1438	struct virtio_blk *vblk;
1439	struct queue_limits lim = {
1440	.features = BLK_FEAT_ROTATIONAL,
1441	.logical_block_size = SECTOR_SIZE,
1442	};
1443	int err, index;
1444	unsigned int queue_depth;
1445
1446	if (!vdev->config->get) {
1447	dev_err(&vdev->dev, "%s failure: config access disabled\n",
1448	__func__);
1449	return -EINVAL;
1450	}
1451
1452	err = ida_alloc_range(&vd_index_ida, min: 0,
1453	max: minor_to_index(minor: 1 << MINORBITS) - 1, GFP_KERNEL);
1454	if (err < 0)
1455	goto out;
1456	index = err;
1457
1458	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
1459	if (!vblk) {
1460	err = -ENOMEM;
1461	goto out_free_index;
1462	}
1463
1464	mutex_init(&vblk->vdev_mutex);
1465
1466	vblk->vdev = vdev;
1467
1468	INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
1469
1470	err = init_vq(vblk);
1471	if (err)
1472	goto out_free_vblk;
1473
1474	/* Default queue sizing is to fill the ring. */
1475	if (!virtblk_queue_depth) {
1476	queue_depth = vblk->vqs[0].vq->num_free;
1477	/* ... but without indirect descs, we use 2 descs per req */
1478	if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
1479	queue_depth /= 2;
1480	} else {
1481	queue_depth = virtblk_queue_depth;
1482	}
1483
1484	memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
1485	vblk->tag_set.ops = &virtio_mq_ops;
1486	vblk->tag_set.queue_depth = queue_depth;
1487	vblk->tag_set.numa_node = NUMA_NO_NODE;
1488	vblk->tag_set.cmd_size =
1489	sizeof(struct virtblk_req) +
1490	sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT;
1491	vblk->tag_set.driver_data = vblk;
1492	vblk->tag_set.nr_hw_queues = vblk->num_vqs;
1493	vblk->tag_set.nr_maps = 1;
1494	if (vblk->io_queues[HCTX_TYPE_POLL])
1495	vblk->tag_set.nr_maps = 3;
1496
1497	err = blk_mq_alloc_tag_set(set: &vblk->tag_set);
1498	if (err)
1499	goto out_free_vq;
1500
1501	err = virtblk_read_limits(vblk, lim: &lim);
1502	if (err)
1503	goto out_free_tags;
1504
1505	if (virtblk_get_cache_mode(vdev))
1506	lim.features |= BLK_FEAT_WRITE_CACHE;
1507
1508	vblk->disk = blk_mq_alloc_disk(&vblk->tag_set, &lim, vblk);
1509	if (IS_ERR(ptr: vblk->disk)) {
1510	err = PTR_ERR(ptr: vblk->disk);
1511	goto out_free_tags;
1512	}
1513
1514	virtblk_name_format(prefix: "vd", index, buf: vblk->disk->disk_name, DISK_NAME_LEN);
1515
1516	vblk->disk->major = major;
1517	vblk->disk->first_minor = index_to_minor(index);
1518	vblk->disk->minors = 1 << PART_BITS;
1519	vblk->disk->private_data = vblk;
1520	vblk->disk->fops = &virtblk_fops;
1521	vblk->index = index;
1522
1523	/* If disk is read-only in the host, the guest should obey */
1524	if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
1525	set_disk_ro(disk: vblk->disk, read_only: 1);
1526
1527	virtblk_update_capacity(vblk, resize: false);
1528	virtio_device_ready(dev: vdev);
1529
1530	/*
1531	* All steps that follow use the VQs therefore they need to be
1532	* placed after the virtio_device_ready() call above.
1533	*/
1534	if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
1535	(lim.features & BLK_FEAT_ZONED)) {
1536	err = blk_revalidate_disk_zones(disk: vblk->disk);
1537	if (err)
1538	goto out_cleanup_disk;
1539	}
1540
1541	err = device_add_disk(parent: &vdev->dev, disk: vblk->disk, groups: virtblk_attr_groups);
1542	if (err)
1543	goto out_cleanup_disk;
1544
1545	return 0;
1546
1547	out_cleanup_disk:
1548	put_disk(disk: vblk->disk);
1549	out_free_tags:
1550	blk_mq_free_tag_set(set: &vblk->tag_set);
1551	out_free_vq:
1552	vdev->config->del_vqs(vdev);
1553	kfree(objp: vblk->vqs);
1554	out_free_vblk:
1555	kfree(objp: vblk);
1556	out_free_index:
1557	ida_free(&vd_index_ida, id: index);
1558	out:
1559	return err;
1560	}
1561
1562	static void virtblk_remove(struct virtio_device *vdev)
1563	{
1564	struct virtio_blk *vblk = vdev->priv;
1565
1566	/* Make sure no work handler is accessing the device. */
1567	flush_work(work: &vblk->config_work);
1568
1569	del_gendisk(gp: vblk->disk);
1570	blk_mq_free_tag_set(set: &vblk->tag_set);
1571
1572	mutex_lock(&vblk->vdev_mutex);
1573
1574	/* Stop all the virtqueues. */
1575	virtio_reset_device(dev: vdev);
1576
1577	/* Virtqueues are stopped, nothing can use vblk->vdev anymore. */
1578	vblk->vdev = NULL;
1579
1580	vdev->config->del_vqs(vdev);
1581	kfree(objp: vblk->vqs);
1582
1583	mutex_unlock(lock: &vblk->vdev_mutex);
1584
1585	put_disk(disk: vblk->disk);
1586	}
1587
1588	static int virtblk_freeze_priv(struct virtio_device *vdev)
1589	{
1590	struct virtio_blk *vblk = vdev->priv;
1591	struct request_queue *q = vblk->disk->queue;
1592	unsigned int memflags;
1593
1594	/* Ensure no requests in virtqueues before deleting vqs. */
1595	memflags = blk_mq_freeze_queue(q);
1596	blk_mq_quiesce_queue_nowait(q);
1597	blk_mq_unfreeze_queue(q, memflags);
1598
1599	/* Ensure we don't receive any more interrupts */
1600	virtio_reset_device(dev: vdev);
1601
1602	/* Make sure no work handler is accessing the device. */
1603	flush_work(work: &vblk->config_work);
1604
1605	vdev->config->del_vqs(vdev);
1606	kfree(objp: vblk->vqs);
1607	/*
1608	* Set to NULL to prevent freeing vqs again after a failed vqs
1609	* allocation during resume. Note that kfree() already handles NULL
1610	* pointers safely.
1611	*/
1612	vblk->vqs = NULL;
1613
1614	return 0;
1615	}
1616
1617	static int virtblk_restore_priv(struct virtio_device *vdev)
1618	{
1619	struct virtio_blk *vblk = vdev->priv;
1620	int ret;
1621
1622	ret = init_vq(vblk: vdev->priv);
1623	if (ret)
1624	return ret;
1625
1626	virtio_device_ready(dev: vdev);
1627	blk_mq_unquiesce_queue(q: vblk->disk->queue);
1628
1629	return 0;
1630	}
1631
1632	#ifdef CONFIG_PM_SLEEP
1633	static int virtblk_freeze(struct virtio_device *vdev)
1634	{
1635	return virtblk_freeze_priv(vdev);
1636	}
1637
1638	static int virtblk_restore(struct virtio_device *vdev)
1639	{
1640	return virtblk_restore_priv(vdev);
1641	}
1642	#endif
1643
1644	static int virtblk_reset_prepare(struct virtio_device *vdev)
1645	{
1646	return virtblk_freeze_priv(vdev);
1647	}
1648
1649	static int virtblk_reset_done(struct virtio_device *vdev)
1650	{
1651	return virtblk_restore_priv(vdev);
1652	}
1653
1654	static const struct virtio_device_id id_table[] = {
1655	{ VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
1656	{ 0 },
1657	};
1658
1659	static unsigned int features_legacy[] = {
1660	VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1661	VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1662	VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1663	VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1664	VIRTIO_BLK_F_SECURE_ERASE,
1665	}
1666	;
1667	static unsigned int features[] = {
1668	VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
1669	VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
1670	VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
1671	VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES,
1672	VIRTIO_BLK_F_SECURE_ERASE, VIRTIO_BLK_F_ZONED,
1673	};
1674
1675	static struct virtio_driver virtio_blk = {
1676	.feature_table = features,
1677	.feature_table_size = ARRAY_SIZE(features),
1678	.feature_table_legacy = features_legacy,
1679	.feature_table_size_legacy = ARRAY_SIZE(features_legacy),
1680	.driver.name = KBUILD_MODNAME,
1681	.id_table = id_table,
1682	.probe = virtblk_probe,
1683	.remove = virtblk_remove,
1684	.config_changed = virtblk_config_changed,
1685	#ifdef CONFIG_PM_SLEEP
1686	.freeze = virtblk_freeze,
1687	.restore = virtblk_restore,
1688	#endif
1689	.reset_prepare = virtblk_reset_prepare,
1690	.reset_done = virtblk_reset_done,
1691	};
1692
1693	static int __init virtio_blk_init(void)
1694	{
1695	int error;
1696
1697	virtblk_wq = alloc_workqueue("virtio-blk", WQ_PERCPU, 0);
1698	if (!virtblk_wq)
1699	return -ENOMEM;
1700
1701	major = register_blkdev(0, "virtblk");
1702	if (major < 0) {
1703	error = major;
1704	goto out_destroy_workqueue;
1705	}
1706
1707	error = register_virtio_driver(&virtio_blk);
1708	if (error)
1709	goto out_unregister_blkdev;
1710	return 0;
1711
1712	out_unregister_blkdev:
1713	unregister_blkdev(major, name: "virtblk");
1714	out_destroy_workqueue:
1715	destroy_workqueue(wq: virtblk_wq);
1716	return error;
1717	}
1718
1719	static void __exit virtio_blk_fini(void)
1720	{
1721	unregister_virtio_driver(drv: &virtio_blk);
1722	unregister_blkdev(major, name: "virtblk");
1723	destroy_workqueue(wq: virtblk_wq);
1724	}
1725	module_init(virtio_blk_init);
1726	module_exit(virtio_blk_fini);
1727
1728	MODULE_DEVICE_TABLE(virtio, id_table);
1729	MODULE_DESCRIPTION("Virtio block driver");
1730	MODULE_LICENSE("GPL");
1731