xref: /openbmc/qemu/block/nvme.c (revision e6b5a071)
1 /*
2  * NVMe block driver based on vfio
3  *
4  * Copyright 2016 - 2018 Red Hat, Inc.
5  *
6  * Authors:
7  *   Fam Zheng <famz@redhat.com>
8  *   Paolo Bonzini <pbonzini@redhat.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include <linux/vfio.h>
16 #include "qapi/error.h"
17 #include "qapi/qmp/qdict.h"
18 #include "qapi/qmp/qstring.h"
19 #include "qemu/error-report.h"
20 #include "qemu/main-loop.h"
21 #include "qemu/module.h"
22 #include "qemu/cutils.h"
23 #include "qemu/option.h"
24 #include "qemu/vfio-helpers.h"
25 #include "block/block_int.h"
26 #include "sysemu/replay.h"
27 #include "trace.h"
28 
29 #include "block/nvme.h"
30 
31 #define NVME_SQ_ENTRY_BYTES 64
32 #define NVME_CQ_ENTRY_BYTES 16
33 #define NVME_QUEUE_SIZE 128
34 #define NVME_DOORBELL_SIZE 4096
35 
36 /*
37  * We have to leave one slot empty as that is the full queue case where
38  * head == tail + 1.
39  */
40 #define NVME_NUM_REQS (NVME_QUEUE_SIZE - 1)
41 
42 typedef struct BDRVNVMeState BDRVNVMeState;
43 
44 typedef struct {
45     int32_t  head, tail;
46     uint8_t  *queue;
47     uint64_t iova;
48     /* Hardware MMIO register */
49     volatile uint32_t *doorbell;
50 } NVMeQueue;
51 
52 typedef struct {
53     BlockCompletionFunc *cb;
54     void *opaque;
55     int cid;
56     void *prp_list_page;
57     uint64_t prp_list_iova;
58     int free_req_next; /* q->reqs[] index of next free req */
59 } NVMeRequest;
60 
61 typedef struct {
62     QemuMutex   lock;
63 
64     /* Read from I/O code path, initialized under BQL */
65     BDRVNVMeState   *s;
66     int             index;
67 
68     /* Fields protected by BQL */
69     uint8_t     *prp_list_pages;
70 
71     /* Fields protected by @lock */
72     CoQueue     free_req_queue;
73     NVMeQueue   sq, cq;
74     int         cq_phase;
75     int         free_req_head;
76     NVMeRequest reqs[NVME_NUM_REQS];
77     int         need_kick;
78     int         inflight;
79 
80     /* Thread-safe, no lock necessary */
81     QEMUBH      *completion_bh;
82 } NVMeQueuePair;
83 
84 #define INDEX_ADMIN     0
85 #define INDEX_IO(n)     (1 + n)
86 
87 /* This driver shares a single MSIX IRQ for the admin and I/O queues */
88 enum {
89     MSIX_SHARED_IRQ_IDX = 0,
90     MSIX_IRQ_COUNT = 1
91 };
92 
93 struct BDRVNVMeState {
94     AioContext *aio_context;
95     QEMUVFIOState *vfio;
96     /* Memory mapped registers */
97     volatile struct {
98         uint32_t sq_tail;
99         uint32_t cq_head;
100     } *doorbells;
101     /* The submission/completion queue pairs.
102      * [0]: admin queue.
103      * [1..]: io queues.
104      */
105     NVMeQueuePair **queues;
106     int nr_queues;
107     size_t page_size;
108     /* How many uint32_t elements does each doorbell entry take. */
109     size_t doorbell_scale;
110     bool write_cache_supported;
111     EventNotifier irq_notifier[MSIX_IRQ_COUNT];
112 
113     uint64_t nsze; /* Namespace size reported by identify command */
114     int nsid;      /* The namespace id to read/write data. */
115     int blkshift;
116 
117     uint64_t max_transfer;
118     bool plugged;
119 
120     bool supports_write_zeroes;
121     bool supports_discard;
122 
123     CoMutex dma_map_lock;
124     CoQueue dma_flush_queue;
125 
126     /* Total size of mapped qiov, accessed under dma_map_lock */
127     int dma_map_count;
128 
129     /* PCI address (required for nvme_refresh_filename()) */
130     char *device;
131 };
132 
133 #define NVME_BLOCK_OPT_DEVICE "device"
134 #define NVME_BLOCK_OPT_NAMESPACE "namespace"
135 
136 static void nvme_process_completion_bh(void *opaque);
137 
138 static QemuOptsList runtime_opts = {
139     .name = "nvme",
140     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
141     .desc = {
142         {
143             .name = NVME_BLOCK_OPT_DEVICE,
144             .type = QEMU_OPT_STRING,
145             .help = "NVMe PCI device address",
146         },
147         {
148             .name = NVME_BLOCK_OPT_NAMESPACE,
149             .type = QEMU_OPT_NUMBER,
150             .help = "NVMe namespace",
151         },
152         { /* end of list */ }
153     },
154 };
155 
156 static void nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,
157                             int nentries, int entry_bytes, Error **errp)
158 {
159     size_t bytes;
160     int r;
161 
162     bytes = ROUND_UP(nentries * entry_bytes, s->page_size);
163     q->head = q->tail = 0;
164     q->queue = qemu_try_memalign(s->page_size, bytes);
165     if (!q->queue) {
166         error_setg(errp, "Cannot allocate queue");
167         return;
168     }
169     memset(q->queue, 0, bytes);
170     r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova);
171     if (r) {
172         error_setg(errp, "Cannot map queue");
173     }
174 }
175 
176 static void nvme_free_queue_pair(NVMeQueuePair *q)
177 {
178     if (q->completion_bh) {
179         qemu_bh_delete(q->completion_bh);
180     }
181     qemu_vfree(q->prp_list_pages);
182     qemu_vfree(q->sq.queue);
183     qemu_vfree(q->cq.queue);
184     qemu_mutex_destroy(&q->lock);
185     g_free(q);
186 }
187 
188 static void nvme_free_req_queue_cb(void *opaque)
189 {
190     NVMeQueuePair *q = opaque;
191 
192     qemu_mutex_lock(&q->lock);
193     while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
194         /* Retry all pending requests */
195     }
196     qemu_mutex_unlock(&q->lock);
197 }
198 
199 static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,
200                                              AioContext *aio_context,
201                                              int idx, int size,
202                                              Error **errp)
203 {
204     int i, r;
205     Error *local_err = NULL;
206     NVMeQueuePair *q;
207     uint64_t prp_list_iova;
208 
209     q = g_try_new0(NVMeQueuePair, 1);
210     if (!q) {
211         return NULL;
212     }
213     q->prp_list_pages = qemu_try_memalign(s->page_size,
214                                           s->page_size * NVME_NUM_REQS);
215     if (!q->prp_list_pages) {
216         goto fail;
217     }
218     memset(q->prp_list_pages, 0, s->page_size * NVME_NUM_REQS);
219     qemu_mutex_init(&q->lock);
220     q->s = s;
221     q->index = idx;
222     qemu_co_queue_init(&q->free_req_queue);
223     q->completion_bh = aio_bh_new(aio_context, nvme_process_completion_bh, q);
224     r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages,
225                           s->page_size * NVME_NUM_REQS,
226                           false, &prp_list_iova);
227     if (r) {
228         goto fail;
229     }
230     q->free_req_head = -1;
231     for (i = 0; i < NVME_NUM_REQS; i++) {
232         NVMeRequest *req = &q->reqs[i];
233         req->cid = i + 1;
234         req->free_req_next = q->free_req_head;
235         q->free_req_head = i;
236         req->prp_list_page = q->prp_list_pages + i * s->page_size;
237         req->prp_list_iova = prp_list_iova + i * s->page_size;
238     }
239 
240     nvme_init_queue(s, &q->sq, size, NVME_SQ_ENTRY_BYTES, &local_err);
241     if (local_err) {
242         error_propagate(errp, local_err);
243         goto fail;
244     }
245     q->sq.doorbell = &s->doorbells[idx * s->doorbell_scale].sq_tail;
246 
247     nvme_init_queue(s, &q->cq, size, NVME_CQ_ENTRY_BYTES, &local_err);
248     if (local_err) {
249         error_propagate(errp, local_err);
250         goto fail;
251     }
252     q->cq.doorbell = &s->doorbells[idx * s->doorbell_scale].cq_head;
253 
254     return q;
255 fail:
256     nvme_free_queue_pair(q);
257     return NULL;
258 }
259 
260 /* With q->lock */
261 static void nvme_kick(NVMeQueuePair *q)
262 {
263     BDRVNVMeState *s = q->s;
264 
265     if (s->plugged || !q->need_kick) {
266         return;
267     }
268     trace_nvme_kick(s, q->index);
269     assert(!(q->sq.tail & 0xFF00));
270     /* Fence the write to submission queue entry before notifying the device. */
271     smp_wmb();
272     *q->sq.doorbell = cpu_to_le32(q->sq.tail);
273     q->inflight += q->need_kick;
274     q->need_kick = 0;
275 }
276 
277 /* Find a free request element if any, otherwise:
278  * a) if in coroutine context, try to wait for one to become available;
279  * b) if not in coroutine, return NULL;
280  */
281 static NVMeRequest *nvme_get_free_req(NVMeQueuePair *q)
282 {
283     NVMeRequest *req;
284 
285     qemu_mutex_lock(&q->lock);
286 
287     while (q->free_req_head == -1) {
288         if (qemu_in_coroutine()) {
289             trace_nvme_free_req_queue_wait(q);
290             qemu_co_queue_wait(&q->free_req_queue, &q->lock);
291         } else {
292             qemu_mutex_unlock(&q->lock);
293             return NULL;
294         }
295     }
296 
297     req = &q->reqs[q->free_req_head];
298     q->free_req_head = req->free_req_next;
299     req->free_req_next = -1;
300 
301     qemu_mutex_unlock(&q->lock);
302     return req;
303 }
304 
305 /* With q->lock */
306 static void nvme_put_free_req_locked(NVMeQueuePair *q, NVMeRequest *req)
307 {
308     req->free_req_next = q->free_req_head;
309     q->free_req_head = req - q->reqs;
310 }
311 
312 /* With q->lock */
313 static void nvme_wake_free_req_locked(NVMeQueuePair *q)
314 {
315     if (!qemu_co_queue_empty(&q->free_req_queue)) {
316         replay_bh_schedule_oneshot_event(q->s->aio_context,
317                 nvme_free_req_queue_cb, q);
318     }
319 }
320 
321 /* Insert a request in the freelist and wake waiters */
322 static void nvme_put_free_req_and_wake(NVMeQueuePair *q, NVMeRequest *req)
323 {
324     qemu_mutex_lock(&q->lock);
325     nvme_put_free_req_locked(q, req);
326     nvme_wake_free_req_locked(q);
327     qemu_mutex_unlock(&q->lock);
328 }
329 
330 static inline int nvme_translate_error(const NvmeCqe *c)
331 {
332     uint16_t status = (le16_to_cpu(c->status) >> 1) & 0xFF;
333     if (status) {
334         trace_nvme_error(le32_to_cpu(c->result),
335                          le16_to_cpu(c->sq_head),
336                          le16_to_cpu(c->sq_id),
337                          le16_to_cpu(c->cid),
338                          le16_to_cpu(status));
339     }
340     switch (status) {
341     case 0:
342         return 0;
343     case 1:
344         return -ENOSYS;
345     case 2:
346         return -EINVAL;
347     default:
348         return -EIO;
349     }
350 }
351 
352 /* With q->lock */
353 static bool nvme_process_completion(NVMeQueuePair *q)
354 {
355     BDRVNVMeState *s = q->s;
356     bool progress = false;
357     NVMeRequest *preq;
358     NVMeRequest req;
359     NvmeCqe *c;
360 
361     trace_nvme_process_completion(s, q->index, q->inflight);
362     if (s->plugged) {
363         trace_nvme_process_completion_queue_plugged(s, q->index);
364         return false;
365     }
366 
367     /*
368      * Support re-entrancy when a request cb() function invokes aio_poll().
369      * Pending completions must be visible to aio_poll() so that a cb()
370      * function can wait for the completion of another request.
371      *
372      * The aio_poll() loop will execute our BH and we'll resume completion
373      * processing there.
374      */
375     qemu_bh_schedule(q->completion_bh);
376 
377     assert(q->inflight >= 0);
378     while (q->inflight) {
379         int ret;
380         int16_t cid;
381 
382         c = (NvmeCqe *)&q->cq.queue[q->cq.head * NVME_CQ_ENTRY_BYTES];
383         if ((le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
384             break;
385         }
386         ret = nvme_translate_error(c);
387         q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
388         if (!q->cq.head) {
389             q->cq_phase = !q->cq_phase;
390         }
391         cid = le16_to_cpu(c->cid);
392         if (cid == 0 || cid > NVME_QUEUE_SIZE) {
393             fprintf(stderr, "Unexpected CID in completion queue: %" PRIu32 "\n",
394                     cid);
395             continue;
396         }
397         trace_nvme_complete_command(s, q->index, cid);
398         preq = &q->reqs[cid - 1];
399         req = *preq;
400         assert(req.cid == cid);
401         assert(req.cb);
402         nvme_put_free_req_locked(q, preq);
403         preq->cb = preq->opaque = NULL;
404         q->inflight--;
405         qemu_mutex_unlock(&q->lock);
406         req.cb(req.opaque, ret);
407         qemu_mutex_lock(&q->lock);
408         progress = true;
409     }
410     if (progress) {
411         /* Notify the device so it can post more completions. */
412         smp_mb_release();
413         *q->cq.doorbell = cpu_to_le32(q->cq.head);
414         nvme_wake_free_req_locked(q);
415     }
416 
417     qemu_bh_cancel(q->completion_bh);
418 
419     return progress;
420 }
421 
422 static void nvme_process_completion_bh(void *opaque)
423 {
424     NVMeQueuePair *q = opaque;
425 
426     /*
427      * We're being invoked because a nvme_process_completion() cb() function
428      * called aio_poll(). The callback may be waiting for further completions
429      * so notify the device that it has space to fill in more completions now.
430      */
431     smp_mb_release();
432     *q->cq.doorbell = cpu_to_le32(q->cq.head);
433     nvme_wake_free_req_locked(q);
434 
435     nvme_process_completion(q);
436 }
437 
438 static void nvme_trace_command(const NvmeCmd *cmd)
439 {
440     int i;
441 
442     if (!trace_event_get_state_backends(TRACE_NVME_SUBMIT_COMMAND_RAW)) {
443         return;
444     }
445     for (i = 0; i < 8; ++i) {
446         uint8_t *cmdp = (uint8_t *)cmd + i * 8;
447         trace_nvme_submit_command_raw(cmdp[0], cmdp[1], cmdp[2], cmdp[3],
448                                       cmdp[4], cmdp[5], cmdp[6], cmdp[7]);
449     }
450 }
451 
452 static void nvme_submit_command(NVMeQueuePair *q, NVMeRequest *req,
453                                 NvmeCmd *cmd, BlockCompletionFunc cb,
454                                 void *opaque)
455 {
456     assert(!req->cb);
457     req->cb = cb;
458     req->opaque = opaque;
459     cmd->cid = cpu_to_le32(req->cid);
460 
461     trace_nvme_submit_command(q->s, q->index, req->cid);
462     nvme_trace_command(cmd);
463     qemu_mutex_lock(&q->lock);
464     memcpy((uint8_t *)q->sq.queue +
465            q->sq.tail * NVME_SQ_ENTRY_BYTES, cmd, sizeof(*cmd));
466     q->sq.tail = (q->sq.tail + 1) % NVME_QUEUE_SIZE;
467     q->need_kick++;
468     nvme_kick(q);
469     nvme_process_completion(q);
470     qemu_mutex_unlock(&q->lock);
471 }
472 
473 static void nvme_cmd_sync_cb(void *opaque, int ret)
474 {
475     int *pret = opaque;
476     *pret = ret;
477     aio_wait_kick();
478 }
479 
480 static int nvme_cmd_sync(BlockDriverState *bs, NVMeQueuePair *q,
481                          NvmeCmd *cmd)
482 {
483     AioContext *aio_context = bdrv_get_aio_context(bs);
484     NVMeRequest *req;
485     int ret = -EINPROGRESS;
486     req = nvme_get_free_req(q);
487     if (!req) {
488         return -EBUSY;
489     }
490     nvme_submit_command(q, req, cmd, nvme_cmd_sync_cb, &ret);
491 
492     AIO_WAIT_WHILE(aio_context, ret == -EINPROGRESS);
493     return ret;
494 }
495 
496 static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
497 {
498     BDRVNVMeState *s = bs->opaque;
499     union {
500         NvmeIdCtrl ctrl;
501         NvmeIdNs ns;
502     } *id;
503     NvmeLBAF *lbaf;
504     uint16_t oncs;
505     int r;
506     uint64_t iova;
507     NvmeCmd cmd = {
508         .opcode = NVME_ADM_CMD_IDENTIFY,
509         .cdw10 = cpu_to_le32(0x1),
510     };
511 
512     id = qemu_try_memalign(s->page_size, sizeof(*id));
513     if (!id) {
514         error_setg(errp, "Cannot allocate buffer for identify response");
515         goto out;
516     }
517     r = qemu_vfio_dma_map(s->vfio, id, sizeof(*id), true, &iova);
518     if (r) {
519         error_setg(errp, "Cannot map buffer for DMA");
520         goto out;
521     }
522 
523     memset(id, 0, sizeof(*id));
524     cmd.dptr.prp1 = cpu_to_le64(iova);
525     if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
526         error_setg(errp, "Failed to identify controller");
527         goto out;
528     }
529 
530     if (le32_to_cpu(id->ctrl.nn) < namespace) {
531         error_setg(errp, "Invalid namespace");
532         goto out;
533     }
534     s->write_cache_supported = le32_to_cpu(id->ctrl.vwc) & 0x1;
535     s->max_transfer = (id->ctrl.mdts ? 1 << id->ctrl.mdts : 0) * s->page_size;
536     /* For now the page list buffer per command is one page, to hold at most
537      * s->page_size / sizeof(uint64_t) entries. */
538     s->max_transfer = MIN_NON_ZERO(s->max_transfer,
539                           s->page_size / sizeof(uint64_t) * s->page_size);
540 
541     oncs = le16_to_cpu(id->ctrl.oncs);
542     s->supports_write_zeroes = !!(oncs & NVME_ONCS_WRITE_ZEROES);
543     s->supports_discard = !!(oncs & NVME_ONCS_DSM);
544 
545     memset(id, 0, sizeof(*id));
546     cmd.cdw10 = 0;
547     cmd.nsid = cpu_to_le32(namespace);
548     if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
549         error_setg(errp, "Failed to identify namespace");
550         goto out;
551     }
552 
553     s->nsze = le64_to_cpu(id->ns.nsze);
554     lbaf = &id->ns.lbaf[NVME_ID_NS_FLBAS_INDEX(id->ns.flbas)];
555 
556     if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(id->ns.dlfeat) &&
557             NVME_ID_NS_DLFEAT_READ_BEHAVIOR(id->ns.dlfeat) ==
558                     NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROES) {
559         bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
560     }
561 
562     if (lbaf->ms) {
563         error_setg(errp, "Namespaces with metadata are not yet supported");
564         goto out;
565     }
566 
567     if (lbaf->ds < BDRV_SECTOR_BITS || lbaf->ds > 12 ||
568         (1 << lbaf->ds) > s->page_size)
569     {
570         error_setg(errp, "Namespace has unsupported block size (2^%d)",
571                    lbaf->ds);
572         goto out;
573     }
574 
575     s->blkshift = lbaf->ds;
576 out:
577     qemu_vfio_dma_unmap(s->vfio, id);
578     qemu_vfree(id);
579 }
580 
581 static bool nvme_poll_queue(NVMeQueuePair *q)
582 {
583     bool progress = false;
584 
585     const size_t cqe_offset = q->cq.head * NVME_CQ_ENTRY_BYTES;
586     NvmeCqe *cqe = (NvmeCqe *)&q->cq.queue[cqe_offset];
587 
588     /*
589      * Do an early check for completions. q->lock isn't needed because
590      * nvme_process_completion() only runs in the event loop thread and
591      * cannot race with itself.
592      */
593     if ((le16_to_cpu(cqe->status) & 0x1) == q->cq_phase) {
594         return false;
595     }
596 
597     qemu_mutex_lock(&q->lock);
598     while (nvme_process_completion(q)) {
599         /* Keep polling */
600         progress = true;
601     }
602     qemu_mutex_unlock(&q->lock);
603 
604     return progress;
605 }
606 
607 static bool nvme_poll_queues(BDRVNVMeState *s)
608 {
609     bool progress = false;
610     int i;
611 
612     for (i = 0; i < s->nr_queues; i++) {
613         if (nvme_poll_queue(s->queues[i])) {
614             progress = true;
615         }
616     }
617     return progress;
618 }
619 
620 static void nvme_handle_event(EventNotifier *n)
621 {
622     BDRVNVMeState *s = container_of(n, BDRVNVMeState,
623                                     irq_notifier[MSIX_SHARED_IRQ_IDX]);
624 
625     trace_nvme_handle_event(s);
626     event_notifier_test_and_clear(n);
627     nvme_poll_queues(s);
628 }
629 
630 static bool nvme_add_io_queue(BlockDriverState *bs, Error **errp)
631 {
632     BDRVNVMeState *s = bs->opaque;
633     int n = s->nr_queues;
634     NVMeQueuePair *q;
635     NvmeCmd cmd;
636     int queue_size = NVME_QUEUE_SIZE;
637 
638     q = nvme_create_queue_pair(s, bdrv_get_aio_context(bs),
639                                n, queue_size, errp);
640     if (!q) {
641         return false;
642     }
643     cmd = (NvmeCmd) {
644         .opcode = NVME_ADM_CMD_CREATE_CQ,
645         .dptr.prp1 = cpu_to_le64(q->cq.iova),
646         .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
647         .cdw11 = cpu_to_le32(0x3),
648     };
649     if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
650         error_setg(errp, "Failed to create CQ io queue [%d]", n);
651         goto out_error;
652     }
653     cmd = (NvmeCmd) {
654         .opcode = NVME_ADM_CMD_CREATE_SQ,
655         .dptr.prp1 = cpu_to_le64(q->sq.iova),
656         .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
657         .cdw11 = cpu_to_le32(0x1 | (n << 16)),
658     };
659     if (nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd)) {
660         error_setg(errp, "Failed to create SQ io queue [%d]", n);
661         goto out_error;
662     }
663     s->queues = g_renew(NVMeQueuePair *, s->queues, n + 1);
664     s->queues[n] = q;
665     s->nr_queues++;
666     return true;
667 out_error:
668     nvme_free_queue_pair(q);
669     return false;
670 }
671 
672 static bool nvme_poll_cb(void *opaque)
673 {
674     EventNotifier *e = opaque;
675     BDRVNVMeState *s = container_of(e, BDRVNVMeState,
676                                     irq_notifier[MSIX_SHARED_IRQ_IDX]);
677 
678     trace_nvme_poll_cb(s);
679     return nvme_poll_queues(s);
680 }
681 
682 static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
683                      Error **errp)
684 {
685     BDRVNVMeState *s = bs->opaque;
686     AioContext *aio_context = bdrv_get_aio_context(bs);
687     int ret;
688     uint64_t cap;
689     uint64_t timeout_ms;
690     uint64_t deadline, now;
691     Error *local_err = NULL;
692     volatile NvmeBar *regs = NULL;
693 
694     qemu_co_mutex_init(&s->dma_map_lock);
695     qemu_co_queue_init(&s->dma_flush_queue);
696     s->device = g_strdup(device);
697     s->nsid = namespace;
698     s->aio_context = bdrv_get_aio_context(bs);
699     ret = event_notifier_init(&s->irq_notifier[MSIX_SHARED_IRQ_IDX], 0);
700     if (ret) {
701         error_setg(errp, "Failed to init event notifier");
702         return ret;
703     }
704 
705     s->vfio = qemu_vfio_open_pci(device, errp);
706     if (!s->vfio) {
707         ret = -EINVAL;
708         goto out;
709     }
710 
711     regs = qemu_vfio_pci_map_bar(s->vfio, 0, 0, sizeof(NvmeBar),
712                                  PROT_READ | PROT_WRITE, errp);
713     if (!regs) {
714         ret = -EINVAL;
715         goto out;
716     }
717     /* Perform initialize sequence as described in NVMe spec "7.6.1
718      * Initialization". */
719 
720     cap = le64_to_cpu(regs->cap);
721     if (!NVME_CAP_CSS(cap)) {
722         error_setg(errp, "Device doesn't support NVMe command set");
723         ret = -EINVAL;
724         goto out;
725     }
726 
727     s->page_size = MAX(4096, 1 << NVME_CAP_MPSMIN(cap));
728     s->doorbell_scale = (4 << NVME_CAP_DSTRD(cap)) / sizeof(uint32_t);
729     bs->bl.opt_mem_alignment = s->page_size;
730     timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
731 
732     /* Reset device to get a clean state. */
733     regs->cc = cpu_to_le32(le32_to_cpu(regs->cc) & 0xFE);
734     /* Wait for CSTS.RDY = 0. */
735     deadline = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ms * SCALE_MS;
736     while (NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
737         if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
738             error_setg(errp, "Timeout while waiting for device to reset (%"
739                              PRId64 " ms)",
740                        timeout_ms);
741             ret = -ETIMEDOUT;
742             goto out;
743         }
744     }
745 
746     s->doorbells = qemu_vfio_pci_map_bar(s->vfio, 0, sizeof(NvmeBar),
747                                          NVME_DOORBELL_SIZE, PROT_WRITE, errp);
748     if (!s->doorbells) {
749         ret = -EINVAL;
750         goto out;
751     }
752 
753     /* Set up admin queue. */
754     s->queues = g_new(NVMeQueuePair *, 1);
755     s->queues[INDEX_ADMIN] = nvme_create_queue_pair(s, aio_context, 0,
756                                                           NVME_QUEUE_SIZE,
757                                                           errp);
758     if (!s->queues[INDEX_ADMIN]) {
759         ret = -EINVAL;
760         goto out;
761     }
762     s->nr_queues = 1;
763     QEMU_BUILD_BUG_ON(NVME_QUEUE_SIZE & 0xF000);
764     regs->aqa = cpu_to_le32((NVME_QUEUE_SIZE << AQA_ACQS_SHIFT) |
765                             (NVME_QUEUE_SIZE << AQA_ASQS_SHIFT));
766     regs->asq = cpu_to_le64(s->queues[INDEX_ADMIN]->sq.iova);
767     regs->acq = cpu_to_le64(s->queues[INDEX_ADMIN]->cq.iova);
768 
769     /* After setting up all control registers we can enable device now. */
770     regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << CC_IOCQES_SHIFT) |
771                            (ctz32(NVME_SQ_ENTRY_BYTES) << CC_IOSQES_SHIFT) |
772                            CC_EN_MASK);
773     /* Wait for CSTS.RDY = 1. */
774     now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
775     deadline = now + timeout_ms * SCALE_MS;
776     while (!NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
777         if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
778             error_setg(errp, "Timeout while waiting for device to start (%"
779                              PRId64 " ms)",
780                        timeout_ms);
781             ret = -ETIMEDOUT;
782             goto out;
783         }
784     }
785 
786     ret = qemu_vfio_pci_init_irq(s->vfio, s->irq_notifier,
787                                  VFIO_PCI_MSIX_IRQ_INDEX, errp);
788     if (ret) {
789         goto out;
790     }
791     aio_set_event_notifier(bdrv_get_aio_context(bs),
792                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
793                            false, nvme_handle_event, nvme_poll_cb);
794 
795     nvme_identify(bs, namespace, &local_err);
796     if (local_err) {
797         error_propagate(errp, local_err);
798         ret = -EIO;
799         goto out;
800     }
801 
802     /* Set up command queues. */
803     if (!nvme_add_io_queue(bs, errp)) {
804         ret = -EIO;
805     }
806 out:
807     if (regs) {
808         qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)regs, 0, sizeof(NvmeBar));
809     }
810 
811     /* Cleaning up is done in nvme_file_open() upon error. */
812     return ret;
813 }
814 
815 /* Parse a filename in the format of nvme://XXXX:XX:XX.X/X. Example:
816  *
817  *     nvme://0000:44:00.0/1
818  *
819  * where the "nvme://" is a fixed form of the protocol prefix, the middle part
820  * is the PCI address, and the last part is the namespace number starting from
821  * 1 according to the NVMe spec. */
822 static void nvme_parse_filename(const char *filename, QDict *options,
823                                 Error **errp)
824 {
825     int pref = strlen("nvme://");
826 
827     if (strlen(filename) > pref && !strncmp(filename, "nvme://", pref)) {
828         const char *tmp = filename + pref;
829         char *device;
830         const char *namespace;
831         unsigned long ns;
832         const char *slash = strchr(tmp, '/');
833         if (!slash) {
834             qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, tmp);
835             return;
836         }
837         device = g_strndup(tmp, slash - tmp);
838         qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, device);
839         g_free(device);
840         namespace = slash + 1;
841         if (*namespace && qemu_strtoul(namespace, NULL, 10, &ns)) {
842             error_setg(errp, "Invalid namespace '%s', positive number expected",
843                        namespace);
844             return;
845         }
846         qdict_put_str(options, NVME_BLOCK_OPT_NAMESPACE,
847                       *namespace ? namespace : "1");
848     }
849 }
850 
851 static int nvme_enable_disable_write_cache(BlockDriverState *bs, bool enable,
852                                            Error **errp)
853 {
854     int ret;
855     BDRVNVMeState *s = bs->opaque;
856     NvmeCmd cmd = {
857         .opcode = NVME_ADM_CMD_SET_FEATURES,
858         .nsid = cpu_to_le32(s->nsid),
859         .cdw10 = cpu_to_le32(0x06),
860         .cdw11 = cpu_to_le32(enable ? 0x01 : 0x00),
861     };
862 
863     ret = nvme_cmd_sync(bs, s->queues[INDEX_ADMIN], &cmd);
864     if (ret) {
865         error_setg(errp, "Failed to configure NVMe write cache");
866     }
867     return ret;
868 }
869 
870 static void nvme_close(BlockDriverState *bs)
871 {
872     int i;
873     BDRVNVMeState *s = bs->opaque;
874 
875     for (i = 0; i < s->nr_queues; ++i) {
876         nvme_free_queue_pair(s->queues[i]);
877     }
878     g_free(s->queues);
879     aio_set_event_notifier(bdrv_get_aio_context(bs),
880                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
881                            false, NULL, NULL);
882     event_notifier_cleanup(&s->irq_notifier[MSIX_SHARED_IRQ_IDX]);
883     qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->doorbells,
884                             sizeof(NvmeBar), NVME_DOORBELL_SIZE);
885     qemu_vfio_close(s->vfio);
886 
887     g_free(s->device);
888 }
889 
890 static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
891                           Error **errp)
892 {
893     const char *device;
894     QemuOpts *opts;
895     int namespace;
896     int ret;
897     BDRVNVMeState *s = bs->opaque;
898 
899     bs->supported_write_flags = BDRV_REQ_FUA;
900 
901     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
902     qemu_opts_absorb_qdict(opts, options, &error_abort);
903     device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
904     if (!device) {
905         error_setg(errp, "'" NVME_BLOCK_OPT_DEVICE "' option is required");
906         qemu_opts_del(opts);
907         return -EINVAL;
908     }
909 
910     namespace = qemu_opt_get_number(opts, NVME_BLOCK_OPT_NAMESPACE, 1);
911     ret = nvme_init(bs, device, namespace, errp);
912     qemu_opts_del(opts);
913     if (ret) {
914         goto fail;
915     }
916     if (flags & BDRV_O_NOCACHE) {
917         if (!s->write_cache_supported) {
918             error_setg(errp,
919                        "NVMe controller doesn't support write cache configuration");
920             ret = -EINVAL;
921         } else {
922             ret = nvme_enable_disable_write_cache(bs, !(flags & BDRV_O_NOCACHE),
923                                                   errp);
924         }
925         if (ret) {
926             goto fail;
927         }
928     }
929     return 0;
930 fail:
931     nvme_close(bs);
932     return ret;
933 }
934 
935 static int64_t nvme_getlength(BlockDriverState *bs)
936 {
937     BDRVNVMeState *s = bs->opaque;
938     return s->nsze << s->blkshift;
939 }
940 
941 static uint32_t nvme_get_blocksize(BlockDriverState *bs)
942 {
943     BDRVNVMeState *s = bs->opaque;
944     assert(s->blkshift >= BDRV_SECTOR_BITS && s->blkshift <= 12);
945     return UINT32_C(1) << s->blkshift;
946 }
947 
948 static int nvme_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
949 {
950     uint32_t blocksize = nvme_get_blocksize(bs);
951     bsz->phys = blocksize;
952     bsz->log = blocksize;
953     return 0;
954 }
955 
956 /* Called with s->dma_map_lock */
957 static coroutine_fn int nvme_cmd_unmap_qiov(BlockDriverState *bs,
958                                             QEMUIOVector *qiov)
959 {
960     int r = 0;
961     BDRVNVMeState *s = bs->opaque;
962 
963     s->dma_map_count -= qiov->size;
964     if (!s->dma_map_count && !qemu_co_queue_empty(&s->dma_flush_queue)) {
965         r = qemu_vfio_dma_reset_temporary(s->vfio);
966         if (!r) {
967             qemu_co_queue_restart_all(&s->dma_flush_queue);
968         }
969     }
970     return r;
971 }
972 
973 /* Called with s->dma_map_lock */
974 static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,
975                                           NVMeRequest *req, QEMUIOVector *qiov)
976 {
977     BDRVNVMeState *s = bs->opaque;
978     uint64_t *pagelist = req->prp_list_page;
979     int i, j, r;
980     int entries = 0;
981 
982     assert(qiov->size);
983     assert(QEMU_IS_ALIGNED(qiov->size, s->page_size));
984     assert(qiov->size / s->page_size <= s->page_size / sizeof(uint64_t));
985     for (i = 0; i < qiov->niov; ++i) {
986         bool retry = true;
987         uint64_t iova;
988 try_map:
989         r = qemu_vfio_dma_map(s->vfio,
990                               qiov->iov[i].iov_base,
991                               qiov->iov[i].iov_len,
992                               true, &iova);
993         if (r == -ENOMEM && retry) {
994             retry = false;
995             trace_nvme_dma_flush_queue_wait(s);
996             if (s->dma_map_count) {
997                 trace_nvme_dma_map_flush(s);
998                 qemu_co_queue_wait(&s->dma_flush_queue, &s->dma_map_lock);
999             } else {
1000                 r = qemu_vfio_dma_reset_temporary(s->vfio);
1001                 if (r) {
1002                     goto fail;
1003                 }
1004             }
1005             goto try_map;
1006         }
1007         if (r) {
1008             goto fail;
1009         }
1010 
1011         for (j = 0; j < qiov->iov[i].iov_len / s->page_size; j++) {
1012             pagelist[entries++] = cpu_to_le64(iova + j * s->page_size);
1013         }
1014         trace_nvme_cmd_map_qiov_iov(s, i, qiov->iov[i].iov_base,
1015                                     qiov->iov[i].iov_len / s->page_size);
1016     }
1017 
1018     s->dma_map_count += qiov->size;
1019 
1020     assert(entries <= s->page_size / sizeof(uint64_t));
1021     switch (entries) {
1022     case 0:
1023         abort();
1024     case 1:
1025         cmd->dptr.prp1 = pagelist[0];
1026         cmd->dptr.prp2 = 0;
1027         break;
1028     case 2:
1029         cmd->dptr.prp1 = pagelist[0];
1030         cmd->dptr.prp2 = pagelist[1];
1031         break;
1032     default:
1033         cmd->dptr.prp1 = pagelist[0];
1034         cmd->dptr.prp2 = cpu_to_le64(req->prp_list_iova + sizeof(uint64_t));
1035         break;
1036     }
1037     trace_nvme_cmd_map_qiov(s, cmd, req, qiov, entries);
1038     for (i = 0; i < entries; ++i) {
1039         trace_nvme_cmd_map_qiov_pages(s, i, pagelist[i]);
1040     }
1041     return 0;
1042 fail:
1043     /* No need to unmap [0 - i) iovs even if we've failed, since we don't
1044      * increment s->dma_map_count. This is okay for fixed mapping memory areas
1045      * because they are already mapped before calling this function; for
1046      * temporary mappings, a later nvme_cmd_(un)map_qiov will reclaim by
1047      * calling qemu_vfio_dma_reset_temporary when necessary. */
1048     return r;
1049 }
1050 
1051 typedef struct {
1052     Coroutine *co;
1053     int ret;
1054     AioContext *ctx;
1055 } NVMeCoData;
1056 
1057 static void nvme_rw_cb_bh(void *opaque)
1058 {
1059     NVMeCoData *data = opaque;
1060     qemu_coroutine_enter(data->co);
1061 }
1062 
1063 static void nvme_rw_cb(void *opaque, int ret)
1064 {
1065     NVMeCoData *data = opaque;
1066     data->ret = ret;
1067     if (!data->co) {
1068         /* The rw coroutine hasn't yielded, don't try to enter. */
1069         return;
1070     }
1071     replay_bh_schedule_oneshot_event(data->ctx, nvme_rw_cb_bh, data);
1072 }
1073 
1074 static coroutine_fn int nvme_co_prw_aligned(BlockDriverState *bs,
1075                                             uint64_t offset, uint64_t bytes,
1076                                             QEMUIOVector *qiov,
1077                                             bool is_write,
1078                                             int flags)
1079 {
1080     int r;
1081     BDRVNVMeState *s = bs->opaque;
1082     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1083     NVMeRequest *req;
1084 
1085     uint32_t cdw12 = (((bytes >> s->blkshift) - 1) & 0xFFFF) |
1086                        (flags & BDRV_REQ_FUA ? 1 << 30 : 0);
1087     NvmeCmd cmd = {
1088         .opcode = is_write ? NVME_CMD_WRITE : NVME_CMD_READ,
1089         .nsid = cpu_to_le32(s->nsid),
1090         .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
1091         .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
1092         .cdw12 = cpu_to_le32(cdw12),
1093     };
1094     NVMeCoData data = {
1095         .ctx = bdrv_get_aio_context(bs),
1096         .ret = -EINPROGRESS,
1097     };
1098 
1099     trace_nvme_prw_aligned(s, is_write, offset, bytes, flags, qiov->niov);
1100     assert(s->nr_queues > 1);
1101     req = nvme_get_free_req(ioq);
1102     assert(req);
1103 
1104     qemu_co_mutex_lock(&s->dma_map_lock);
1105     r = nvme_cmd_map_qiov(bs, &cmd, req, qiov);
1106     qemu_co_mutex_unlock(&s->dma_map_lock);
1107     if (r) {
1108         nvme_put_free_req_and_wake(ioq, req);
1109         return r;
1110     }
1111     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1112 
1113     data.co = qemu_coroutine_self();
1114     while (data.ret == -EINPROGRESS) {
1115         qemu_coroutine_yield();
1116     }
1117 
1118     qemu_co_mutex_lock(&s->dma_map_lock);
1119     r = nvme_cmd_unmap_qiov(bs, qiov);
1120     qemu_co_mutex_unlock(&s->dma_map_lock);
1121     if (r) {
1122         return r;
1123     }
1124 
1125     trace_nvme_rw_done(s, is_write, offset, bytes, data.ret);
1126     return data.ret;
1127 }
1128 
1129 static inline bool nvme_qiov_aligned(BlockDriverState *bs,
1130                                      const QEMUIOVector *qiov)
1131 {
1132     int i;
1133     BDRVNVMeState *s = bs->opaque;
1134 
1135     for (i = 0; i < qiov->niov; ++i) {
1136         if (!QEMU_PTR_IS_ALIGNED(qiov->iov[i].iov_base, s->page_size) ||
1137             !QEMU_IS_ALIGNED(qiov->iov[i].iov_len, s->page_size)) {
1138             trace_nvme_qiov_unaligned(qiov, i, qiov->iov[i].iov_base,
1139                                       qiov->iov[i].iov_len, s->page_size);
1140             return false;
1141         }
1142     }
1143     return true;
1144 }
1145 
1146 static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
1147                        QEMUIOVector *qiov, bool is_write, int flags)
1148 {
1149     BDRVNVMeState *s = bs->opaque;
1150     int r;
1151     uint8_t *buf = NULL;
1152     QEMUIOVector local_qiov;
1153 
1154     assert(QEMU_IS_ALIGNED(offset, s->page_size));
1155     assert(QEMU_IS_ALIGNED(bytes, s->page_size));
1156     assert(bytes <= s->max_transfer);
1157     if (nvme_qiov_aligned(bs, qiov)) {
1158         return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
1159     }
1160     trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
1161     buf = qemu_try_memalign(s->page_size, bytes);
1162 
1163     if (!buf) {
1164         return -ENOMEM;
1165     }
1166     qemu_iovec_init(&local_qiov, 1);
1167     if (is_write) {
1168         qemu_iovec_to_buf(qiov, 0, buf, bytes);
1169     }
1170     qemu_iovec_add(&local_qiov, buf, bytes);
1171     r = nvme_co_prw_aligned(bs, offset, bytes, &local_qiov, is_write, flags);
1172     qemu_iovec_destroy(&local_qiov);
1173     if (!r && !is_write) {
1174         qemu_iovec_from_buf(qiov, 0, buf, bytes);
1175     }
1176     qemu_vfree(buf);
1177     return r;
1178 }
1179 
1180 static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
1181                                        uint64_t offset, uint64_t bytes,
1182                                        QEMUIOVector *qiov, int flags)
1183 {
1184     return nvme_co_prw(bs, offset, bytes, qiov, false, flags);
1185 }
1186 
1187 static coroutine_fn int nvme_co_pwritev(BlockDriverState *bs,
1188                                         uint64_t offset, uint64_t bytes,
1189                                         QEMUIOVector *qiov, int flags)
1190 {
1191     return nvme_co_prw(bs, offset, bytes, qiov, true, flags);
1192 }
1193 
1194 static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
1195 {
1196     BDRVNVMeState *s = bs->opaque;
1197     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1198     NVMeRequest *req;
1199     NvmeCmd cmd = {
1200         .opcode = NVME_CMD_FLUSH,
1201         .nsid = cpu_to_le32(s->nsid),
1202     };
1203     NVMeCoData data = {
1204         .ctx = bdrv_get_aio_context(bs),
1205         .ret = -EINPROGRESS,
1206     };
1207 
1208     assert(s->nr_queues > 1);
1209     req = nvme_get_free_req(ioq);
1210     assert(req);
1211     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1212 
1213     data.co = qemu_coroutine_self();
1214     if (data.ret == -EINPROGRESS) {
1215         qemu_coroutine_yield();
1216     }
1217 
1218     return data.ret;
1219 }
1220 
1221 
1222 static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
1223                                               int64_t offset,
1224                                               int bytes,
1225                                               BdrvRequestFlags flags)
1226 {
1227     BDRVNVMeState *s = bs->opaque;
1228     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1229     NVMeRequest *req;
1230 
1231     uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
1232 
1233     if (!s->supports_write_zeroes) {
1234         return -ENOTSUP;
1235     }
1236 
1237     NvmeCmd cmd = {
1238         .opcode = NVME_CMD_WRITE_ZEROES,
1239         .nsid = cpu_to_le32(s->nsid),
1240         .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
1241         .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
1242     };
1243 
1244     NVMeCoData data = {
1245         .ctx = bdrv_get_aio_context(bs),
1246         .ret = -EINPROGRESS,
1247     };
1248 
1249     if (flags & BDRV_REQ_MAY_UNMAP) {
1250         cdw12 |= (1 << 25);
1251     }
1252 
1253     if (flags & BDRV_REQ_FUA) {
1254         cdw12 |= (1 << 30);
1255     }
1256 
1257     cmd.cdw12 = cpu_to_le32(cdw12);
1258 
1259     trace_nvme_write_zeroes(s, offset, bytes, flags);
1260     assert(s->nr_queues > 1);
1261     req = nvme_get_free_req(ioq);
1262     assert(req);
1263 
1264     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1265 
1266     data.co = qemu_coroutine_self();
1267     while (data.ret == -EINPROGRESS) {
1268         qemu_coroutine_yield();
1269     }
1270 
1271     trace_nvme_rw_done(s, true, offset, bytes, data.ret);
1272     return data.ret;
1273 }
1274 
1275 
1276 static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
1277                                          int64_t offset,
1278                                          int bytes)
1279 {
1280     BDRVNVMeState *s = bs->opaque;
1281     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1282     NVMeRequest *req;
1283     NvmeDsmRange *buf;
1284     QEMUIOVector local_qiov;
1285     int ret;
1286 
1287     NvmeCmd cmd = {
1288         .opcode = NVME_CMD_DSM,
1289         .nsid = cpu_to_le32(s->nsid),
1290         .cdw10 = cpu_to_le32(0), /*number of ranges - 0 based*/
1291         .cdw11 = cpu_to_le32(1 << 2), /*deallocate bit*/
1292     };
1293 
1294     NVMeCoData data = {
1295         .ctx = bdrv_get_aio_context(bs),
1296         .ret = -EINPROGRESS,
1297     };
1298 
1299     if (!s->supports_discard) {
1300         return -ENOTSUP;
1301     }
1302 
1303     assert(s->nr_queues > 1);
1304 
1305     buf = qemu_try_memalign(s->page_size, s->page_size);
1306     if (!buf) {
1307         return -ENOMEM;
1308     }
1309     memset(buf, 0, s->page_size);
1310     buf->nlb = cpu_to_le32(bytes >> s->blkshift);
1311     buf->slba = cpu_to_le64(offset >> s->blkshift);
1312     buf->cattr = 0;
1313 
1314     qemu_iovec_init(&local_qiov, 1);
1315     qemu_iovec_add(&local_qiov, buf, 4096);
1316 
1317     req = nvme_get_free_req(ioq);
1318     assert(req);
1319 
1320     qemu_co_mutex_lock(&s->dma_map_lock);
1321     ret = nvme_cmd_map_qiov(bs, &cmd, req, &local_qiov);
1322     qemu_co_mutex_unlock(&s->dma_map_lock);
1323 
1324     if (ret) {
1325         nvme_put_free_req_and_wake(ioq, req);
1326         goto out;
1327     }
1328 
1329     trace_nvme_dsm(s, offset, bytes);
1330 
1331     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1332 
1333     data.co = qemu_coroutine_self();
1334     while (data.ret == -EINPROGRESS) {
1335         qemu_coroutine_yield();
1336     }
1337 
1338     qemu_co_mutex_lock(&s->dma_map_lock);
1339     ret = nvme_cmd_unmap_qiov(bs, &local_qiov);
1340     qemu_co_mutex_unlock(&s->dma_map_lock);
1341 
1342     if (ret) {
1343         goto out;
1344     }
1345 
1346     ret = data.ret;
1347     trace_nvme_dsm_done(s, offset, bytes, ret);
1348 out:
1349     qemu_iovec_destroy(&local_qiov);
1350     qemu_vfree(buf);
1351     return ret;
1352 
1353 }
1354 
1355 
1356 static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
1357                                BlockReopenQueue *queue, Error **errp)
1358 {
1359     return 0;
1360 }
1361 
1362 static void nvme_refresh_filename(BlockDriverState *bs)
1363 {
1364     BDRVNVMeState *s = bs->opaque;
1365 
1366     snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nvme://%s/%i",
1367              s->device, s->nsid);
1368 }
1369 
1370 static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
1371 {
1372     BDRVNVMeState *s = bs->opaque;
1373 
1374     bs->bl.opt_mem_alignment = s->page_size;
1375     bs->bl.request_alignment = s->page_size;
1376     bs->bl.max_transfer = s->max_transfer;
1377 }
1378 
1379 static void nvme_detach_aio_context(BlockDriverState *bs)
1380 {
1381     BDRVNVMeState *s = bs->opaque;
1382 
1383     for (int i = 0; i < s->nr_queues; i++) {
1384         NVMeQueuePair *q = s->queues[i];
1385 
1386         qemu_bh_delete(q->completion_bh);
1387         q->completion_bh = NULL;
1388     }
1389 
1390     aio_set_event_notifier(bdrv_get_aio_context(bs),
1391                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
1392                            false, NULL, NULL);
1393 }
1394 
1395 static void nvme_attach_aio_context(BlockDriverState *bs,
1396                                     AioContext *new_context)
1397 {
1398     BDRVNVMeState *s = bs->opaque;
1399 
1400     s->aio_context = new_context;
1401     aio_set_event_notifier(new_context, &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
1402                            false, nvme_handle_event, nvme_poll_cb);
1403 
1404     for (int i = 0; i < s->nr_queues; i++) {
1405         NVMeQueuePair *q = s->queues[i];
1406 
1407         q->completion_bh =
1408             aio_bh_new(new_context, nvme_process_completion_bh, q);
1409     }
1410 }
1411 
1412 static void nvme_aio_plug(BlockDriverState *bs)
1413 {
1414     BDRVNVMeState *s = bs->opaque;
1415     assert(!s->plugged);
1416     s->plugged = true;
1417 }
1418 
1419 static void nvme_aio_unplug(BlockDriverState *bs)
1420 {
1421     int i;
1422     BDRVNVMeState *s = bs->opaque;
1423     assert(s->plugged);
1424     s->plugged = false;
1425     for (i = INDEX_IO(0); i < s->nr_queues; i++) {
1426         NVMeQueuePair *q = s->queues[i];
1427         qemu_mutex_lock(&q->lock);
1428         nvme_kick(q);
1429         nvme_process_completion(q);
1430         qemu_mutex_unlock(&q->lock);
1431     }
1432 }
1433 
1434 static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
1435 {
1436     int ret;
1437     BDRVNVMeState *s = bs->opaque;
1438 
1439     ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL);
1440     if (ret) {
1441         /* FIXME: we may run out of IOVA addresses after repeated
1442          * bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap
1443          * doesn't reclaim addresses for fixed mappings. */
1444         error_report("nvme_register_buf failed: %s", strerror(-ret));
1445     }
1446 }
1447 
1448 static void nvme_unregister_buf(BlockDriverState *bs, void *host)
1449 {
1450     BDRVNVMeState *s = bs->opaque;
1451 
1452     qemu_vfio_dma_unmap(s->vfio, host);
1453 }
1454 
1455 static const char *const nvme_strong_runtime_opts[] = {
1456     NVME_BLOCK_OPT_DEVICE,
1457     NVME_BLOCK_OPT_NAMESPACE,
1458 
1459     NULL
1460 };
1461 
1462 static BlockDriver bdrv_nvme = {
1463     .format_name              = "nvme",
1464     .protocol_name            = "nvme",
1465     .instance_size            = sizeof(BDRVNVMeState),
1466 
1467     .bdrv_co_create_opts      = bdrv_co_create_opts_simple,
1468     .create_opts              = &bdrv_create_opts_simple,
1469 
1470     .bdrv_parse_filename      = nvme_parse_filename,
1471     .bdrv_file_open           = nvme_file_open,
1472     .bdrv_close               = nvme_close,
1473     .bdrv_getlength           = nvme_getlength,
1474     .bdrv_probe_blocksizes    = nvme_probe_blocksizes,
1475 
1476     .bdrv_co_preadv           = nvme_co_preadv,
1477     .bdrv_co_pwritev          = nvme_co_pwritev,
1478 
1479     .bdrv_co_pwrite_zeroes    = nvme_co_pwrite_zeroes,
1480     .bdrv_co_pdiscard         = nvme_co_pdiscard,
1481 
1482     .bdrv_co_flush_to_disk    = nvme_co_flush,
1483     .bdrv_reopen_prepare      = nvme_reopen_prepare,
1484 
1485     .bdrv_refresh_filename    = nvme_refresh_filename,
1486     .bdrv_refresh_limits      = nvme_refresh_limits,
1487     .strong_runtime_opts      = nvme_strong_runtime_opts,
1488 
1489     .bdrv_detach_aio_context  = nvme_detach_aio_context,
1490     .bdrv_attach_aio_context  = nvme_attach_aio_context,
1491 
1492     .bdrv_io_plug             = nvme_aio_plug,
1493     .bdrv_io_unplug           = nvme_aio_unplug,
1494 
1495     .bdrv_register_buf        = nvme_register_buf,
1496     .bdrv_unregister_buf      = nvme_unregister_buf,
1497 };
1498 
1499 static void bdrv_nvme_init(void)
1500 {
1501     bdrv_register(&bdrv_nvme);
1502 }
1503 
1504 block_init(bdrv_nvme_init);
1505