block/nvme.c

   1 /*
   2  * NVMe block driver based on vfio
   3  *
   4  * Copyright 2016 - 2018 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *   Fam Zheng <[email protected]>
   8  *   Paolo Bonzini <[email protected]>
   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 /* Same index is used for queues and IRQs */
  45 #define INDEX_ADMIN     0
  46 #define INDEX_IO(n)     (1 + n)
  47
  48 /* This driver shares a single MSIX IRQ for the admin and I/O queues */
  49 enum {
  50     MSIX_SHARED_IRQ_IDX = 0,
  51     MSIX_IRQ_COUNT = 1
  52 };
  53
  54 typedef struct {
  55     int32_t  head, tail;
  56     uint8_t  *queue;
  57     uint64_t iova;
  58     /* Hardware MMIO register */
  59     volatile uint32_t *doorbell;
  60 } NVMeQueue;
  61
  62 typedef struct {
  63     BlockCompletionFunc *cb;
  64     void *opaque;
  65     int cid;
  66     void *prp_list_page;
  67     uint64_t prp_list_iova;
  68     int free_req_next; /* q->reqs[] index of next free req */
  69 } NVMeRequest;
  70
  71 typedef struct {
  72     QemuMutex   lock;
  73
  74     /* Read from I/O code path, initialized under BQL */
  75     BDRVNVMeState   *s;
  76     int             index;
  77
  78     /* Fields protected by BQL */
  79     uint8_t     *prp_list_pages;
  80
  81     /* Fields protected by @lock */
  82     CoQueue     free_req_queue;
  83     NVMeQueue   sq, cq;
  84     int         cq_phase;
  85     int         free_req_head;
  86     NVMeRequest reqs[NVME_NUM_REQS];
  87     int         need_kick;
  88     int         inflight;
  89
  90     /* Thread-safe, no lock necessary */
  91     QEMUBH      *completion_bh;
  92 } NVMeQueuePair;
  93
  94 struct BDRVNVMeState {
  95     AioContext *aio_context;
  96     QEMUVFIOState *vfio;
  97     void *bar0_wo_map;
  98     /* Memory mapped registers */
  99     volatile struct {
 100         uint32_t sq_tail;
 101         uint32_t cq_head;
 102     } *doorbells;
 103     /* The submission/completion queue pairs.
 104      * [0]: admin queue.
 105      * [1..]: io queues.
 106      */
 107     NVMeQueuePair **queues;
 108     unsigned queue_count;
 109     size_t page_size;
 110     /* How many uint32_t elements does each doorbell entry take. */
 111     size_t doorbell_scale;
 112     bool write_cache_supported;
 113     EventNotifier irq_notifier[MSIX_IRQ_COUNT];
 114
 115     uint64_t nsze; /* Namespace size reported by identify command */
 116     int nsid;      /* The namespace id to read/write data. */
 117     int blkshift;
 118
 119     uint64_t max_transfer;
 120     bool plugged;
 121
 122     bool supports_write_zeroes;
 123     bool supports_discard;
 124
 125     CoMutex dma_map_lock;
 126     CoQueue dma_flush_queue;
 127
 128     /* Total size of mapped qiov, accessed under dma_map_lock */
 129     int dma_map_count;
 130
 131     /* PCI address (required for nvme_refresh_filename()) */
 132     char *device;
 133
 134     struct {
 135         uint64_t completion_errors;
 136         uint64_t aligned_accesses;
 137         uint64_t unaligned_accesses;
 138     } stats;
 139 };
 140
 141 #define NVME_BLOCK_OPT_DEVICE "device"
 142 #define NVME_BLOCK_OPT_NAMESPACE "namespace"
 143
 144 static void nvme_process_completion_bh(void *opaque);
 145
 146 static QemuOptsList runtime_opts = {
 147     .name = "nvme",
 148     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 149     .desc = {
 150         {
 151             .name = NVME_BLOCK_OPT_DEVICE,
 152             .type = QEMU_OPT_STRING,
 153             .help = "NVMe PCI device address",
 154         },
 155         {
 156             .name = NVME_BLOCK_OPT_NAMESPACE,
 157             .type = QEMU_OPT_NUMBER,
 158             .help = "NVMe namespace",
 159         },
 160         { /* end of list */ }
 161     },
 162 };
 163
 164 /* Returns true on success, false on failure. */
 165 static bool nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,
 166                             unsigned nentries, size_t entry_bytes, Error **errp)
 167 {
 168     size_t bytes;
 169     int r;
 170
 171     bytes = ROUND_UP(nentries * entry_bytes, qemu_real_host_page_size);
 172     q->head = q->tail = 0;
 173     q->queue = qemu_try_memalign(qemu_real_host_page_size, bytes);
 174     if (!q->queue) {
 175         error_setg(errp, "Cannot allocate queue");
 176         return false;
 177     }
 178     memset(q->queue, 0, bytes);
 179     r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova);
 180     if (r) {
 181         error_setg(errp, "Cannot map queue");
 182         return false;
 183     }
 184     return true;
 185 }
 186
 187 static void nvme_free_queue_pair(NVMeQueuePair *q)
 188 {
 189     trace_nvme_free_queue_pair(q->index, q);
 190     if (q->completion_bh) {
 191         qemu_bh_delete(q->completion_bh);
 192     }
 193     qemu_vfree(q->prp_list_pages);
 194     qemu_vfree(q->sq.queue);
 195     qemu_vfree(q->cq.queue);
 196     qemu_mutex_destroy(&q->lock);
 197     g_free(q);
 198 }
 199
 200 static void nvme_free_req_queue_cb(void *opaque)
 201 {
 202     NVMeQueuePair *q = opaque;
 203
 204     qemu_mutex_lock(&q->lock);
 205     while (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
 206         /* Retry all pending requests */
 207     }
 208     qemu_mutex_unlock(&q->lock);
 209 }
 210
 211 static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,
 212                                              AioContext *aio_context,
 213                                              unsigned idx, size_t size,
 214                                              Error **errp)
 215 {
 216     int i, r;
 217     NVMeQueuePair *q;
 218     uint64_t prp_list_iova;
 219     size_t bytes;
 220
 221     q = g_try_new0(NVMeQueuePair, 1);
 222     if (!q) {
 223         return NULL;
 224     }
 225     trace_nvme_create_queue_pair(idx, q, size, aio_context,
 226                                  event_notifier_get_fd(s->irq_notifier));
 227     bytes = QEMU_ALIGN_UP(s->page_size * NVME_NUM_REQS,
 228                           qemu_real_host_page_size);
 229     q->prp_list_pages = qemu_try_memalign(qemu_real_host_page_size, bytes);
 230     if (!q->prp_list_pages) {
 231         goto fail;
 232     }
 233     memset(q->prp_list_pages, 0, bytes);
 234     qemu_mutex_init(&q->lock);
 235     q->s = s;
 236     q->index = idx;
 237     qemu_co_queue_init(&q->free_req_queue);
 238     q->completion_bh = aio_bh_new(aio_context, nvme_process_completion_bh, q);
 239     r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages, bytes,
 240                           false, &prp_list_iova);
 241     if (r) {
 242         goto fail;
 243     }
 244     q->free_req_head = -1;
 245     for (i = 0; i < NVME_NUM_REQS; i++) {
 246         NVMeRequest *req = &q->reqs[i];
 247         req->cid = i + 1;
 248         req->free_req_next = q->free_req_head;
 249         q->free_req_head = i;
 250         req->prp_list_page = q->prp_list_pages + i * s->page_size;
 251         req->prp_list_iova = prp_list_iova + i * s->page_size;
 252     }
 253
 254     if (!nvme_init_queue(s, &q->sq, size, NVME_SQ_ENTRY_BYTES, errp)) {
 255         goto fail;
 256     }
 257     q->sq.doorbell = &s->doorbells[idx * s->doorbell_scale].sq_tail;
 258
 259     if (!nvme_init_queue(s, &q->cq, size, NVME_CQ_ENTRY_BYTES, errp)) {
 260         goto fail;
 261     }
 262     q->cq.doorbell = &s->doorbells[idx * s->doorbell_scale].cq_head;
 263
 264     return q;
 265 fail:
 266     nvme_free_queue_pair(q);
 267     return NULL;
 268 }
 269
 270 /* With q->lock */
 271 static void nvme_kick(NVMeQueuePair *q)
 272 {
 273     BDRVNVMeState *s = q->s;
 274
 275     if (s->plugged || !q->need_kick) {
 276         return;
 277     }
 278     trace_nvme_kick(s, q->index);
 279     assert(!(q->sq.tail & 0xFF00));
 280     /* Fence the write to submission queue entry before notifying the device. */
 281     smp_wmb();
 282     *q->sq.doorbell = cpu_to_le32(q->sq.tail);
 283     q->inflight += q->need_kick;
 284     q->need_kick = 0;
 285 }
 286
 287 /* Find a free request element if any, otherwise:
 288  * a) if in coroutine context, try to wait for one to become available;
 289  * b) if not in coroutine, return NULL;
 290  */
 291 static NVMeRequest *nvme_get_free_req(NVMeQueuePair *q)
 292 {
 293     NVMeRequest *req;
 294
 295     qemu_mutex_lock(&q->lock);
 296
 297     while (q->free_req_head == -1) {
 298         if (qemu_in_coroutine()) {
 299             trace_nvme_free_req_queue_wait(q->s, q->index);
 300             qemu_co_queue_wait(&q->free_req_queue, &q->lock);
 301         } else {
 302             qemu_mutex_unlock(&q->lock);
 303             return NULL;
 304         }
 305     }
 306
 307     req = &q->reqs[q->free_req_head];
 308     q->free_req_head = req->free_req_next;
 309     req->free_req_next = -1;
 310
 311     qemu_mutex_unlock(&q->lock);
 312     return req;
 313 }
 314
 315 /* With q->lock */
 316 static void nvme_put_free_req_locked(NVMeQueuePair *q, NVMeRequest *req)
 317 {
 318     req->free_req_next = q->free_req_head;
 319     q->free_req_head = req - q->reqs;
 320 }
 321
 322 /* With q->lock */
 323 static void nvme_wake_free_req_locked(NVMeQueuePair *q)
 324 {
 325     if (!qemu_co_queue_empty(&q->free_req_queue)) {
 326         replay_bh_schedule_oneshot_event(q->s->aio_context,
 327                 nvme_free_req_queue_cb, q);
 328     }
 329 }
 330
 331 /* Insert a request in the freelist and wake waiters */
 332 static void nvme_put_free_req_and_wake(NVMeQueuePair *q, NVMeRequest *req)
 333 {
 334     qemu_mutex_lock(&q->lock);
 335     nvme_put_free_req_locked(q, req);
 336     nvme_wake_free_req_locked(q);
 337     qemu_mutex_unlock(&q->lock);
 338 }
 339
 340 static inline int nvme_translate_error(const NvmeCqe *c)
 341 {
 342     uint16_t status = (le16_to_cpu(c->status) >> 1) & 0xFF;
 343     if (status) {
 344         trace_nvme_error(le32_to_cpu(c->result),
 345                          le16_to_cpu(c->sq_head),
 346                          le16_to_cpu(c->sq_id),
 347                          le16_to_cpu(c->cid),
 348                          le16_to_cpu(status));
 349     }
 350     switch (status) {
 351     case 0:
 352         return 0;
 353     case 1:
 354         return -ENOSYS;
 355     case 2:
 356         return -EINVAL;
 357     default:
 358         return -EIO;
 359     }
 360 }
 361
 362 /* With q->lock */
 363 static bool nvme_process_completion(NVMeQueuePair *q)
 364 {
 365     BDRVNVMeState *s = q->s;
 366     bool progress = false;
 367     NVMeRequest *preq;
 368     NVMeRequest req;
 369     NvmeCqe *c;
 370
 371     trace_nvme_process_completion(s, q->index, q->inflight);
 372     if (s->plugged) {
 373         trace_nvme_process_completion_queue_plugged(s, q->index);
 374         return false;
 375     }
 376
 377     /*
 378      * Support re-entrancy when a request cb() function invokes aio_poll().
 379      * Pending completions must be visible to aio_poll() so that a cb()
 380      * function can wait for the completion of another request.
 381      *
 382      * The aio_poll() loop will execute our BH and we'll resume completion
 383      * processing there.
 384      */
 385     qemu_bh_schedule(q->completion_bh);
 386
 387     assert(q->inflight >= 0);
 388     while (q->inflight) {
 389         int ret;
 390         int16_t cid;
 391
 392         c = (NvmeCqe *)&q->cq.queue[q->cq.head * NVME_CQ_ENTRY_BYTES];
 393         if ((le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
 394             break;
 395         }
 396         ret = nvme_translate_error(c);
 397         if (ret) {
 398             s->stats.completion_errors++;
 399         }
 400         q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
 401         if (!q->cq.head) {
 402             q->cq_phase = !q->cq_phase;
 403         }
 404         cid = le16_to_cpu(c->cid);
 405         if (cid == 0 || cid > NVME_QUEUE_SIZE) {
 406             warn_report("NVMe: Unexpected CID in completion queue: %"PRIu32", "
 407                         "queue size: %u", cid, NVME_QUEUE_SIZE);
 408             continue;
 409         }
 410         trace_nvme_complete_command(s, q->index, cid);
 411         preq = &q->reqs[cid - 1];
 412         req = *preq;
 413         assert(req.cid == cid);
 414         assert(req.cb);
 415         nvme_put_free_req_locked(q, preq);
 416         preq->cb = preq->opaque = NULL;
 417         q->inflight--;
 418         qemu_mutex_unlock(&q->lock);
 419         req.cb(req.opaque, ret);
 420         qemu_mutex_lock(&q->lock);
 421         progress = true;
 422     }
 423     if (progress) {
 424         /* Notify the device so it can post more completions. */
 425         smp_mb_release();
 426         *q->cq.doorbell = cpu_to_le32(q->cq.head);
 427         nvme_wake_free_req_locked(q);
 428     }
 429
 430     qemu_bh_cancel(q->completion_bh);
 431
 432     return progress;
 433 }
 434
 435 static void nvme_process_completion_bh(void *opaque)
 436 {
 437     NVMeQueuePair *q = opaque;
 438
 439     /*
 440      * We're being invoked because a nvme_process_completion() cb() function
 441      * called aio_poll(). The callback may be waiting for further completions
 442      * so notify the device that it has space to fill in more completions now.
 443      */
 444     smp_mb_release();
 445     *q->cq.doorbell = cpu_to_le32(q->cq.head);
 446     nvme_wake_free_req_locked(q);
 447
 448     nvme_process_completion(q);
 449 }
 450
 451 static void nvme_trace_command(const NvmeCmd *cmd)
 452 {
 453     int i;
 454
 455     if (!trace_event_get_state_backends(TRACE_NVME_SUBMIT_COMMAND_RAW)) {
 456         return;
 457     }
 458     for (i = 0; i < 8; ++i) {
 459         uint8_t *cmdp = (uint8_t *)cmd + i * 8;
 460         trace_nvme_submit_command_raw(cmdp[0], cmdp[1], cmdp[2], cmdp[3],
 461                                       cmdp[4], cmdp[5], cmdp[6], cmdp[7]);
 462     }
 463 }
 464
 465 static void nvme_submit_command(NVMeQueuePair *q, NVMeRequest *req,
 466                                 NvmeCmd *cmd, BlockCompletionFunc cb,
 467                                 void *opaque)
 468 {
 469     assert(!req->cb);
 470     req->cb = cb;
 471     req->opaque = opaque;
 472     cmd->cid = cpu_to_le16(req->cid);
 473
 474     trace_nvme_submit_command(q->s, q->index, req->cid);
 475     nvme_trace_command(cmd);
 476     qemu_mutex_lock(&q->lock);
 477     memcpy((uint8_t *)q->sq.queue +
 478            q->sq.tail * NVME_SQ_ENTRY_BYTES, cmd, sizeof(*cmd));
 479     q->sq.tail = (q->sq.tail + 1) % NVME_QUEUE_SIZE;
 480     q->need_kick++;
 481     nvme_kick(q);
 482     nvme_process_completion(q);
 483     qemu_mutex_unlock(&q->lock);
 484 }
 485
 486 static void nvme_admin_cmd_sync_cb(void *opaque, int ret)
 487 {
 488     int *pret = opaque;
 489     *pret = ret;
 490     aio_wait_kick();
 491 }
 492
 493 static int nvme_admin_cmd_sync(BlockDriverState *bs, NvmeCmd *cmd)
 494 {
 495     BDRVNVMeState *s = bs->opaque;
 496     NVMeQueuePair *q = s->queues[INDEX_ADMIN];
 497     AioContext *aio_context = bdrv_get_aio_context(bs);
 498     NVMeRequest *req;
 499     int ret = -EINPROGRESS;
 500     req = nvme_get_free_req(q);
 501     if (!req) {
 502         return -EBUSY;
 503     }
 504     nvme_submit_command(q, req, cmd, nvme_admin_cmd_sync_cb, &ret);
 505
 506     AIO_WAIT_WHILE(aio_context, ret == -EINPROGRESS);
 507     return ret;
 508 }
 509
 510 /* Returns true on success, false on failure. */
 511 static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
 512 {
 513     BDRVNVMeState *s = bs->opaque;
 514     bool ret = false;
 515     union {
 516         NvmeIdCtrl ctrl;
 517         NvmeIdNs ns;
 518     } *id;
 519     NvmeLBAF *lbaf;
 520     uint16_t oncs;
 521     int r;
 522     uint64_t iova;
 523     NvmeCmd cmd = {
 524         .opcode = NVME_ADM_CMD_IDENTIFY,
 525         .cdw10 = cpu_to_le32(0x1),
 526     };
 527     size_t id_size = QEMU_ALIGN_UP(sizeof(*id), qemu_real_host_page_size);
 528
 529     id = qemu_try_memalign(qemu_real_host_page_size, id_size);
 530     if (!id) {
 531         error_setg(errp, "Cannot allocate buffer for identify response");
 532         goto out;
 533     }
 534     r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova);
 535     if (r) {
 536         error_setg(errp, "Cannot map buffer for DMA");
 537         goto out;
 538     }
 539
 540     memset(id, 0, id_size);
 541     cmd.dptr.prp1 = cpu_to_le64(iova);
 542     if (nvme_admin_cmd_sync(bs, &cmd)) {
 543         error_setg(errp, "Failed to identify controller");
 544         goto out;
 545     }
 546
 547     if (le32_to_cpu(id->ctrl.nn) < namespace) {
 548         error_setg(errp, "Invalid namespace");
 549         goto out;
 550     }
 551     s->write_cache_supported = le32_to_cpu(id->ctrl.vwc) & 0x1;
 552     s->max_transfer = (id->ctrl.mdts ? 1 << id->ctrl.mdts : 0) * s->page_size;
 553     /* For now the page list buffer per command is one page, to hold at most
 554      * s->page_size / sizeof(uint64_t) entries. */
 555     s->max_transfer = MIN_NON_ZERO(s->max_transfer,
 556                           s->page_size / sizeof(uint64_t) * s->page_size);
 557
 558     oncs = le16_to_cpu(id->ctrl.oncs);
 559     s->supports_write_zeroes = !!(oncs & NVME_ONCS_WRITE_ZEROES);
 560     s->supports_discard = !!(oncs & NVME_ONCS_DSM);
 561
 562     memset(id, 0, id_size);
 563     cmd.cdw10 = 0;
 564     cmd.nsid = cpu_to_le32(namespace);
 565     if (nvme_admin_cmd_sync(bs, &cmd)) {
 566         error_setg(errp, "Failed to identify namespace");
 567         goto out;
 568     }
 569
 570     s->nsze = le64_to_cpu(id->ns.nsze);
 571     lbaf = &id->ns.lbaf[NVME_ID_NS_FLBAS_INDEX(id->ns.flbas)];
 572
 573     if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(id->ns.dlfeat) &&
 574             NVME_ID_NS_DLFEAT_READ_BEHAVIOR(id->ns.dlfeat) ==
 575                     NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROES) {
 576         bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
 577     }
 578
 579     if (lbaf->ms) {
 580         error_setg(errp, "Namespaces with metadata are not yet supported");
 581         goto out;
 582     }
 583
 584     if (lbaf->ds < BDRV_SECTOR_BITS || lbaf->ds > 12 ||
 585         (1 << lbaf->ds) > s->page_size)
 586     {
 587         error_setg(errp, "Namespace has unsupported block size (2^%d)",
 588                    lbaf->ds);
 589         goto out;
 590     }
 591
 592     ret = true;
 593     s->blkshift = lbaf->ds;
 594 out:
 595     qemu_vfio_dma_unmap(s->vfio, id);
 596     qemu_vfree(id);
 597
 598     return ret;
 599 }
 600
 601 static bool nvme_poll_queue(NVMeQueuePair *q)
 602 {
 603     bool progress = false;
 604
 605     const size_t cqe_offset = q->cq.head * NVME_CQ_ENTRY_BYTES;
 606     NvmeCqe *cqe = (NvmeCqe *)&q->cq.queue[cqe_offset];
 607
 608     trace_nvme_poll_queue(q->s, q->index);
 609     /*
 610      * Do an early check for completions. q->lock isn't needed because
 611      * nvme_process_completion() only runs in the event loop thread and
 612      * cannot race with itself.
 613      */
 614     if ((le16_to_cpu(cqe->status) & 0x1) == q->cq_phase) {
 615         return false;
 616     }
 617
 618     qemu_mutex_lock(&q->lock);
 619     while (nvme_process_completion(q)) {
 620         /* Keep polling */
 621         progress = true;
 622     }
 623     qemu_mutex_unlock(&q->lock);
 624
 625     return progress;
 626 }
 627
 628 static bool nvme_poll_queues(BDRVNVMeState *s)
 629 {
 630     bool progress = false;
 631     int i;
 632
 633     for (i = 0; i < s->queue_count; i++) {
 634         if (nvme_poll_queue(s->queues[i])) {
 635             progress = true;
 636         }
 637     }
 638     return progress;
 639 }
 640
 641 static void nvme_handle_event(EventNotifier *n)
 642 {
 643     BDRVNVMeState *s = container_of(n, BDRVNVMeState,
 644                                     irq_notifier[MSIX_SHARED_IRQ_IDX]);
 645
 646     trace_nvme_handle_event(s);
 647     event_notifier_test_and_clear(n);
 648     nvme_poll_queues(s);
 649 }
 650
 651 static bool nvme_add_io_queue(BlockDriverState *bs, Error **errp)
 652 {
 653     BDRVNVMeState *s = bs->opaque;
 654     unsigned n = s->queue_count;
 655     NVMeQueuePair *q;
 656     NvmeCmd cmd;
 657     unsigned queue_size = NVME_QUEUE_SIZE;
 658
 659     assert(n <= UINT16_MAX);
 660     q = nvme_create_queue_pair(s, bdrv_get_aio_context(bs),
 661                                n, queue_size, errp);
 662     if (!q) {
 663         return false;
 664     }
 665     cmd = (NvmeCmd) {
 666         .opcode = NVME_ADM_CMD_CREATE_CQ,
 667         .dptr.prp1 = cpu_to_le64(q->cq.iova),
 668         .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | n),
 669         .cdw11 = cpu_to_le32(NVME_CQ_IEN | NVME_CQ_PC),
 670     };
 671     if (nvme_admin_cmd_sync(bs, &cmd)) {
 672         error_setg(errp, "Failed to create CQ io queue [%u]", n);
 673         goto out_error;
 674     }
 675     cmd = (NvmeCmd) {
 676         .opcode = NVME_ADM_CMD_CREATE_SQ,
 677         .dptr.prp1 = cpu_to_le64(q->sq.iova),
 678         .cdw10 = cpu_to_le32(((queue_size - 1) << 16) | n),
 679         .cdw11 = cpu_to_le32(NVME_SQ_PC | (n << 16)),
 680     };
 681     if (nvme_admin_cmd_sync(bs, &cmd)) {
 682         error_setg(errp, "Failed to create SQ io queue [%u]", n);
 683         goto out_error;
 684     }
 685     s->queues = g_renew(NVMeQueuePair *, s->queues, n + 1);
 686     s->queues[n] = q;
 687     s->queue_count++;
 688     return true;
 689 out_error:
 690     nvme_free_queue_pair(q);
 691     return false;
 692 }
 693
 694 static bool nvme_poll_cb(void *opaque)
 695 {
 696     EventNotifier *e = opaque;
 697     BDRVNVMeState *s = container_of(e, BDRVNVMeState,
 698                                     irq_notifier[MSIX_SHARED_IRQ_IDX]);
 699
 700     return nvme_poll_queues(s);
 701 }
 702
 703 static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
 704                      Error **errp)
 705 {
 706     BDRVNVMeState *s = bs->opaque;
 707     NVMeQueuePair *q;
 708     AioContext *aio_context = bdrv_get_aio_context(bs);
 709     int ret;
 710     uint64_t cap;
 711     uint32_t ver;
 712     uint64_t timeout_ms;
 713     uint64_t deadline, now;
 714     volatile NvmeBar *regs = NULL;
 715
 716     qemu_co_mutex_init(&s->dma_map_lock);
 717     qemu_co_queue_init(&s->dma_flush_queue);
 718     s->device = g_strdup(device);
 719     s->nsid = namespace;
 720     s->aio_context = bdrv_get_aio_context(bs);
 721     ret = event_notifier_init(&s->irq_notifier[MSIX_SHARED_IRQ_IDX], 0);
 722     if (ret) {
 723         error_setg(errp, "Failed to init event notifier");
 724         return ret;
 725     }
 726
 727     s->vfio = qemu_vfio_open_pci(device, errp);
 728     if (!s->vfio) {
 729         ret = -EINVAL;
 730         goto out;
 731     }
 732
 733     regs = qemu_vfio_pci_map_bar(s->vfio, 0, 0, sizeof(NvmeBar),
 734                                  PROT_READ | PROT_WRITE, errp);
 735     if (!regs) {
 736         ret = -EINVAL;
 737         goto out;
 738     }
 739     /* Perform initialize sequence as described in NVMe spec "7.6.1
 740      * Initialization". */
 741
 742     cap = le64_to_cpu(regs->cap);
 743     trace_nvme_controller_capability_raw(cap);
 744     trace_nvme_controller_capability("Maximum Queue Entries Supported",
 745                                      1 + NVME_CAP_MQES(cap));
 746     trace_nvme_controller_capability("Contiguous Queues Required",
 747                                      NVME_CAP_CQR(cap));
 748     trace_nvme_controller_capability("Doorbell Stride",
 749                                      1 << (2 + NVME_CAP_DSTRD(cap)));
 750     trace_nvme_controller_capability("Subsystem Reset Supported",
 751                                      NVME_CAP_NSSRS(cap));
 752     trace_nvme_controller_capability("Memory Page Size Minimum",
 753                                      1 << (12 + NVME_CAP_MPSMIN(cap)));
 754     trace_nvme_controller_capability("Memory Page Size Maximum",
 755                                      1 << (12 + NVME_CAP_MPSMAX(cap)));
 756     if (!NVME_CAP_CSS(cap)) {
 757         error_setg(errp, "Device doesn't support NVMe command set");
 758         ret = -EINVAL;
 759         goto out;
 760     }
 761
 762     s->page_size = 1u << (12 + NVME_CAP_MPSMIN(cap));
 763     s->doorbell_scale = (4 << NVME_CAP_DSTRD(cap)) / sizeof(uint32_t);
 764     bs->bl.opt_mem_alignment = s->page_size;
 765     bs->bl.request_alignment = s->page_size;
 766     timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
 767
 768     ver = le32_to_cpu(regs->vs);
 769     trace_nvme_controller_spec_version(extract32(ver, 16, 16),
 770                                        extract32(ver, 8, 8),
 771                                        extract32(ver, 0, 8));
 772
 773     /* Reset device to get a clean state. */
 774     regs->cc = cpu_to_le32(le32_to_cpu(regs->cc) & 0xFE);
 775     /* Wait for CSTS.RDY = 0. */
 776     deadline = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ms * SCALE_MS;
 777     while (NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
 778         if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
 779             error_setg(errp, "Timeout while waiting for device to reset (%"
 780                              PRId64 " ms)",
 781                        timeout_ms);
 782             ret = -ETIMEDOUT;
 783             goto out;
 784         }
 785     }
 786
 787     s->bar0_wo_map = qemu_vfio_pci_map_bar(s->vfio, 0, 0,
 788                                            sizeof(NvmeBar) + NVME_DOORBELL_SIZE,
 789                                            PROT_WRITE, errp);
 790     s->doorbells = (void *)((uintptr_t)s->bar0_wo_map + sizeof(NvmeBar));
 791     if (!s->doorbells) {
 792         ret = -EINVAL;
 793         goto out;
 794     }
 795
 796     /* Set up admin queue. */
 797     s->queues = g_new(NVMeQueuePair *, 1);
 798     q = nvme_create_queue_pair(s, aio_context, 0, NVME_QUEUE_SIZE, errp);
 799     if (!q) {
 800         ret = -EINVAL;
 801         goto out;
 802     }
 803     s->queues[INDEX_ADMIN] = q;
 804     s->queue_count = 1;
 805     QEMU_BUILD_BUG_ON((NVME_QUEUE_SIZE - 1) & 0xF000);
 806     regs->aqa = cpu_to_le32(((NVME_QUEUE_SIZE - 1) << AQA_ACQS_SHIFT) |
 807                             ((NVME_QUEUE_SIZE - 1) << AQA_ASQS_SHIFT));
 808     regs->asq = cpu_to_le64(q->sq.iova);
 809     regs->acq = cpu_to_le64(q->cq.iova);
 810
 811     /* After setting up all control registers we can enable device now. */
 812     regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << CC_IOCQES_SHIFT) |
 813                            (ctz32(NVME_SQ_ENTRY_BYTES) << CC_IOSQES_SHIFT) |
 814                            CC_EN_MASK);
 815     /* Wait for CSTS.RDY = 1. */
 816     now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
 817     deadline = now + timeout_ms * SCALE_MS;
 818     while (!NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
 819         if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
 820             error_setg(errp, "Timeout while waiting for device to start (%"
 821                              PRId64 " ms)",
 822                        timeout_ms);
 823             ret = -ETIMEDOUT;
 824             goto out;
 825         }
 826     }
 827
 828     ret = qemu_vfio_pci_init_irq(s->vfio, s->irq_notifier,
 829                                  VFIO_PCI_MSIX_IRQ_INDEX, errp);
 830     if (ret) {
 831         goto out;
 832     }
 833     aio_set_event_notifier(bdrv_get_aio_context(bs),
 834                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
 835                            false, nvme_handle_event, nvme_poll_cb);
 836
 837     if (!nvme_identify(bs, namespace, errp)) {
 838         ret = -EIO;
 839         goto out;
 840     }
 841
 842     /* Set up command queues. */
 843     if (!nvme_add_io_queue(bs, errp)) {
 844         ret = -EIO;
 845     }
 846 out:
 847     if (regs) {
 848         qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)regs, 0, sizeof(NvmeBar));
 849     }
 850
 851     /* Cleaning up is done in nvme_file_open() upon error. */
 852     return ret;
 853 }
 854
 855 /* Parse a filename in the format of nvme://XXXX:XX:XX.X/X. Example:
 856  *
 857  *     nvme://0000:44:00.0/1
 858  *
 859  * where the "nvme://" is a fixed form of the protocol prefix, the middle part
 860  * is the PCI address, and the last part is the namespace number starting from
 861  * 1 according to the NVMe spec. */
 862 static void nvme_parse_filename(const char *filename, QDict *options,
 863                                 Error **errp)
 864 {
 865     int pref = strlen("nvme://");
 866
 867     if (strlen(filename) > pref && !strncmp(filename, "nvme://", pref)) {
 868         const char *tmp = filename + pref;
 869         char *device;
 870         const char *namespace;
 871         unsigned long ns;
 872         const char *slash = strchr(tmp, '/');
 873         if (!slash) {
 874             qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, tmp);
 875             return;
 876         }
 877         device = g_strndup(tmp, slash - tmp);
 878         qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, device);
 879         g_free(device);
 880         namespace = slash + 1;
 881         if (*namespace && qemu_strtoul(namespace, NULL, 10, &ns)) {
 882             error_setg(errp, "Invalid namespace '%s', positive number expected",
 883                        namespace);
 884             return;
 885         }
 886         qdict_put_str(options, NVME_BLOCK_OPT_NAMESPACE,
 887                       *namespace ? namespace : "1");
 888     }
 889 }
 890
 891 static int nvme_enable_disable_write_cache(BlockDriverState *bs, bool enable,
 892                                            Error **errp)
 893 {
 894     int ret;
 895     BDRVNVMeState *s = bs->opaque;
 896     NvmeCmd cmd = {
 897         .opcode = NVME_ADM_CMD_SET_FEATURES,
 898         .nsid = cpu_to_le32(s->nsid),
 899         .cdw10 = cpu_to_le32(0x06),
 900         .cdw11 = cpu_to_le32(enable ? 0x01 : 0x00),
 901     };
 902
 903     ret = nvme_admin_cmd_sync(bs, &cmd);
 904     if (ret) {
 905         error_setg(errp, "Failed to configure NVMe write cache");
 906     }
 907     return ret;
 908 }
 909
 910 static void nvme_close(BlockDriverState *bs)
 911 {
 912     BDRVNVMeState *s = bs->opaque;
 913
 914     for (unsigned i = 0; i < s->queue_count; ++i) {
 915         nvme_free_queue_pair(s->queues[i]);
 916     }
 917     g_free(s->queues);
 918     aio_set_event_notifier(bdrv_get_aio_context(bs),
 919                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
 920                            false, NULL, NULL);
 921     event_notifier_cleanup(&s->irq_notifier[MSIX_SHARED_IRQ_IDX]);
 922     qemu_vfio_pci_unmap_bar(s->vfio, 0, s->bar0_wo_map,
 923                             0, sizeof(NvmeBar) + NVME_DOORBELL_SIZE);
 924     qemu_vfio_close(s->vfio);
 925
 926     g_free(s->device);
 927 }
 928
 929 static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
 930                           Error **errp)
 931 {
 932     const char *device;
 933     QemuOpts *opts;
 934     int namespace;
 935     int ret;
 936     BDRVNVMeState *s = bs->opaque;
 937
 938     bs->supported_write_flags = BDRV_REQ_FUA;
 939
 940     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 941     qemu_opts_absorb_qdict(opts, options, &error_abort);
 942     device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
 943     if (!device) {
 944         error_setg(errp, "'" NVME_BLOCK_OPT_DEVICE "' option is required");
 945         qemu_opts_del(opts);
 946         return -EINVAL;
 947     }
 948
 949     namespace = qemu_opt_get_number(opts, NVME_BLOCK_OPT_NAMESPACE, 1);
 950     ret = nvme_init(bs, device, namespace, errp);
 951     qemu_opts_del(opts);
 952     if (ret) {
 953         goto fail;
 954     }
 955     if (flags & BDRV_O_NOCACHE) {
 956         if (!s->write_cache_supported) {
 957             error_setg(errp,
 958                        "NVMe controller doesn't support write cache configuration");
 959             ret = -EINVAL;
 960         } else {
 961             ret = nvme_enable_disable_write_cache(bs, !(flags & BDRV_O_NOCACHE),
 962                                                   errp);
 963         }
 964         if (ret) {
 965             goto fail;
 966         }
 967     }
 968     return 0;
 969 fail:
 970     nvme_close(bs);
 971     return ret;
 972 }
 973
 974 static int64_t nvme_getlength(BlockDriverState *bs)
 975 {
 976     BDRVNVMeState *s = bs->opaque;
 977     return s->nsze << s->blkshift;
 978 }
 979
 980 static uint32_t nvme_get_blocksize(BlockDriverState *bs)
 981 {
 982     BDRVNVMeState *s = bs->opaque;
 983     assert(s->blkshift >= BDRV_SECTOR_BITS && s->blkshift <= 12);
 984     return UINT32_C(1) << s->blkshift;
 985 }
 986
 987 static int nvme_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
 988 {
 989     uint32_t blocksize = nvme_get_blocksize(bs);
 990     bsz->phys = blocksize;
 991     bsz->log = blocksize;
 992     return 0;
 993 }
 994
 995 /* Called with s->dma_map_lock */
 996 static coroutine_fn int nvme_cmd_unmap_qiov(BlockDriverState *bs,
 997                                             QEMUIOVector *qiov)
 998 {
 999     int r = 0;
1000     BDRVNVMeState *s = bs->opaque;
1001
1002     s->dma_map_count -= qiov->size;
1003     if (!s->dma_map_count && !qemu_co_queue_empty(&s->dma_flush_queue)) {
1004         r = qemu_vfio_dma_reset_temporary(s->vfio);
1005         if (!r) {
1006             qemu_co_queue_restart_all(&s->dma_flush_queue);
1007         }
1008     }
1009     return r;
1010 }
1011
1012 /* Called with s->dma_map_lock */
1013 static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,
1014                                           NVMeRequest *req, QEMUIOVector *qiov)
1015 {
1016     BDRVNVMeState *s = bs->opaque;
1017     uint64_t *pagelist = req->prp_list_page;
1018     int i, j, r;
1019     int entries = 0;
1020
1021     assert(qiov->size);
1022     assert(QEMU_IS_ALIGNED(qiov->size, s->page_size));
1023     assert(qiov->size / s->page_size <= s->page_size / sizeof(uint64_t));
1024     for (i = 0; i < qiov->niov; ++i) {
1025         bool retry = true;
1026         uint64_t iova;
1027         size_t len = QEMU_ALIGN_UP(qiov->iov[i].iov_len,
1028                                    qemu_real_host_page_size);
1029 try_map:
1030         r = qemu_vfio_dma_map(s->vfio,
1031                               qiov->iov[i].iov_base,
1032                               len, true, &iova);
1033         if (r == -ENOMEM && retry) {
1034             retry = false;
1035             trace_nvme_dma_flush_queue_wait(s);
1036             if (s->dma_map_count) {
1037                 trace_nvme_dma_map_flush(s);
1038                 qemu_co_queue_wait(&s->dma_flush_queue, &s->dma_map_lock);
1039             } else {
1040                 r = qemu_vfio_dma_reset_temporary(s->vfio);
1041                 if (r) {
1042                     goto fail;
1043                 }
1044             }
1045             goto try_map;
1046         }
1047         if (r) {
1048             goto fail;
1049         }
1050
1051         for (j = 0; j < qiov->iov[i].iov_len / s->page_size; j++) {
1052             pagelist[entries++] = cpu_to_le64(iova + j * s->page_size);
1053         }
1054         trace_nvme_cmd_map_qiov_iov(s, i, qiov->iov[i].iov_base,
1055                                     qiov->iov[i].iov_len / s->page_size);
1056     }
1057
1058     s->dma_map_count += qiov->size;
1059
1060     assert(entries <= s->page_size / sizeof(uint64_t));
1061     switch (entries) {
1062     case 0:
1063         abort();
1064     case 1:
1065         cmd->dptr.prp1 = pagelist[0];
1066         cmd->dptr.prp2 = 0;
1067         break;
1068     case 2:
1069         cmd->dptr.prp1 = pagelist[0];
1070         cmd->dptr.prp2 = pagelist[1];
1071         break;
1072     default:
1073         cmd->dptr.prp1 = pagelist[0];
1074         cmd->dptr.prp2 = cpu_to_le64(req->prp_list_iova + sizeof(uint64_t));
1075         break;
1076     }
1077     trace_nvme_cmd_map_qiov(s, cmd, req, qiov, entries);
1078     for (i = 0; i < entries; ++i) {
1079         trace_nvme_cmd_map_qiov_pages(s, i, pagelist[i]);
1080     }
1081     return 0;
1082 fail:
1083     /* No need to unmap [0 - i) iovs even if we've failed, since we don't
1084      * increment s->dma_map_count. This is okay for fixed mapping memory areas
1085      * because they are already mapped before calling this function; for
1086      * temporary mappings, a later nvme_cmd_(un)map_qiov will reclaim by
1087      * calling qemu_vfio_dma_reset_temporary when necessary. */
1088     return r;
1089 }
1090
1091 typedef struct {
1092     Coroutine *co;
1093     int ret;
1094     AioContext *ctx;
1095 } NVMeCoData;
1096
1097 static void nvme_rw_cb_bh(void *opaque)
1098 {
1099     NVMeCoData *data = opaque;
1100     qemu_coroutine_enter(data->co);
1101 }
1102
1103 static void nvme_rw_cb(void *opaque, int ret)
1104 {
1105     NVMeCoData *data = opaque;
1106     data->ret = ret;
1107     if (!data->co) {
1108         /* The rw coroutine hasn't yielded, don't try to enter. */
1109         return;
1110     }
1111     replay_bh_schedule_oneshot_event(data->ctx, nvme_rw_cb_bh, data);
1112 }
1113
1114 static coroutine_fn int nvme_co_prw_aligned(BlockDriverState *bs,
1115                                             uint64_t offset, uint64_t bytes,
1116                                             QEMUIOVector *qiov,
1117                                             bool is_write,
1118                                             int flags)
1119 {
1120     int r;
1121     BDRVNVMeState *s = bs->opaque;
1122     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1123     NVMeRequest *req;
1124
1125     uint32_t cdw12 = (((bytes >> s->blkshift) - 1) & 0xFFFF) |
1126                        (flags & BDRV_REQ_FUA ? 1 << 30 : 0);
1127     NvmeCmd cmd = {
1128         .opcode = is_write ? NVME_CMD_WRITE : NVME_CMD_READ,
1129         .nsid = cpu_to_le32(s->nsid),
1130         .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
1131         .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
1132         .cdw12 = cpu_to_le32(cdw12),
1133     };
1134     NVMeCoData data = {
1135         .ctx = bdrv_get_aio_context(bs),
1136         .ret = -EINPROGRESS,
1137     };
1138
1139     trace_nvme_prw_aligned(s, is_write, offset, bytes, flags, qiov->niov);
1140     assert(s->queue_count > 1);
1141     req = nvme_get_free_req(ioq);
1142     assert(req);
1143
1144     qemu_co_mutex_lock(&s->dma_map_lock);
1145     r = nvme_cmd_map_qiov(bs, &cmd, req, qiov);
1146     qemu_co_mutex_unlock(&s->dma_map_lock);
1147     if (r) {
1148         nvme_put_free_req_and_wake(ioq, req);
1149         return r;
1150     }
1151     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1152
1153     data.co = qemu_coroutine_self();
1154     while (data.ret == -EINPROGRESS) {
1155         qemu_coroutine_yield();
1156     }
1157
1158     qemu_co_mutex_lock(&s->dma_map_lock);
1159     r = nvme_cmd_unmap_qiov(bs, qiov);
1160     qemu_co_mutex_unlock(&s->dma_map_lock);
1161     if (r) {
1162         return r;
1163     }
1164
1165     trace_nvme_rw_done(s, is_write, offset, bytes, data.ret);
1166     return data.ret;
1167 }
1168
1169 static inline bool nvme_qiov_aligned(BlockDriverState *bs,
1170                                      const QEMUIOVector *qiov)
1171 {
1172     int i;
1173     BDRVNVMeState *s = bs->opaque;
1174
1175     for (i = 0; i < qiov->niov; ++i) {
1176         if (!QEMU_PTR_IS_ALIGNED(qiov->iov[i].iov_base,
1177                                  qemu_real_host_page_size) ||
1178             !QEMU_IS_ALIGNED(qiov->iov[i].iov_len, qemu_real_host_page_size)) {
1179             trace_nvme_qiov_unaligned(qiov, i, qiov->iov[i].iov_base,
1180                                       qiov->iov[i].iov_len, s->page_size);
1181             return false;
1182         }
1183     }
1184     return true;
1185 }
1186
1187 static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
1188                        QEMUIOVector *qiov, bool is_write, int flags)
1189 {
1190     BDRVNVMeState *s = bs->opaque;
1191     int r;
1192     uint8_t *buf = NULL;
1193     QEMUIOVector local_qiov;
1194     size_t len = QEMU_ALIGN_UP(bytes, qemu_real_host_page_size);
1195     assert(QEMU_IS_ALIGNED(offset, s->page_size));
1196     assert(QEMU_IS_ALIGNED(bytes, s->page_size));
1197     assert(bytes <= s->max_transfer);
1198     if (nvme_qiov_aligned(bs, qiov)) {
1199         s->stats.aligned_accesses++;
1200         return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
1201     }
1202     s->stats.unaligned_accesses++;
1203     trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
1204     buf = qemu_try_memalign(qemu_real_host_page_size, len);
1205
1206     if (!buf) {
1207         return -ENOMEM;
1208     }
1209     qemu_iovec_init(&local_qiov, 1);
1210     if (is_write) {
1211         qemu_iovec_to_buf(qiov, 0, buf, bytes);
1212     }
1213     qemu_iovec_add(&local_qiov, buf, bytes);
1214     r = nvme_co_prw_aligned(bs, offset, bytes, &local_qiov, is_write, flags);
1215     qemu_iovec_destroy(&local_qiov);
1216     if (!r && !is_write) {
1217         qemu_iovec_from_buf(qiov, 0, buf, bytes);
1218     }
1219     qemu_vfree(buf);
1220     return r;
1221 }
1222
1223 static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
1224                                        uint64_t offset, uint64_t bytes,
1225                                        QEMUIOVector *qiov, int flags)
1226 {
1227     return nvme_co_prw(bs, offset, bytes, qiov, false, flags);
1228 }
1229
1230 static coroutine_fn int nvme_co_pwritev(BlockDriverState *bs,
1231                                         uint64_t offset, uint64_t bytes,
1232                                         QEMUIOVector *qiov, int flags)
1233 {
1234     return nvme_co_prw(bs, offset, bytes, qiov, true, flags);
1235 }
1236
1237 static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
1238 {
1239     BDRVNVMeState *s = bs->opaque;
1240     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1241     NVMeRequest *req;
1242     NvmeCmd cmd = {
1243         .opcode = NVME_CMD_FLUSH,
1244         .nsid = cpu_to_le32(s->nsid),
1245     };
1246     NVMeCoData data = {
1247         .ctx = bdrv_get_aio_context(bs),
1248         .ret = -EINPROGRESS,
1249     };
1250
1251     assert(s->queue_count > 1);
1252     req = nvme_get_free_req(ioq);
1253     assert(req);
1254     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1255
1256     data.co = qemu_coroutine_self();
1257     if (data.ret == -EINPROGRESS) {
1258         qemu_coroutine_yield();
1259     }
1260
1261     return data.ret;
1262 }
1263
1264
1265 static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
1266                                               int64_t offset,
1267                                               int bytes,
1268                                               BdrvRequestFlags flags)
1269 {
1270     BDRVNVMeState *s = bs->opaque;
1271     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1272     NVMeRequest *req;
1273
1274     uint32_t cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
1275
1276     if (!s->supports_write_zeroes) {
1277         return -ENOTSUP;
1278     }
1279
1280     NvmeCmd cmd = {
1281         .opcode = NVME_CMD_WRITE_ZEROES,
1282         .nsid = cpu_to_le32(s->nsid),
1283         .cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
1284         .cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
1285     };
1286
1287     NVMeCoData data = {
1288         .ctx = bdrv_get_aio_context(bs),
1289         .ret = -EINPROGRESS,
1290     };
1291
1292     if (flags & BDRV_REQ_MAY_UNMAP) {
1293         cdw12 |= (1 << 25);
1294     }
1295
1296     if (flags & BDRV_REQ_FUA) {
1297         cdw12 |= (1 << 30);
1298     }
1299
1300     cmd.cdw12 = cpu_to_le32(cdw12);
1301
1302     trace_nvme_write_zeroes(s, offset, bytes, flags);
1303     assert(s->queue_count > 1);
1304     req = nvme_get_free_req(ioq);
1305     assert(req);
1306
1307     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1308
1309     data.co = qemu_coroutine_self();
1310     while (data.ret == -EINPROGRESS) {
1311         qemu_coroutine_yield();
1312     }
1313
1314     trace_nvme_rw_done(s, true, offset, bytes, data.ret);
1315     return data.ret;
1316 }
1317
1318
1319 static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
1320                                          int64_t offset,
1321                                          int bytes)
1322 {
1323     BDRVNVMeState *s = bs->opaque;
1324     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
1325     NVMeRequest *req;
1326     NvmeDsmRange *buf;
1327     QEMUIOVector local_qiov;
1328     int ret;
1329
1330     NvmeCmd cmd = {
1331         .opcode = NVME_CMD_DSM,
1332         .nsid = cpu_to_le32(s->nsid),
1333         .cdw10 = cpu_to_le32(0), /*number of ranges - 0 based*/
1334         .cdw11 = cpu_to_le32(1 << 2), /*deallocate bit*/
1335     };
1336
1337     NVMeCoData data = {
1338         .ctx = bdrv_get_aio_context(bs),
1339         .ret = -EINPROGRESS,
1340     };
1341
1342     if (!s->supports_discard) {
1343         return -ENOTSUP;
1344     }
1345
1346     assert(s->queue_count > 1);
1347
1348     buf = qemu_try_memalign(s->page_size, s->page_size);
1349     if (!buf) {
1350         return -ENOMEM;
1351     }
1352     memset(buf, 0, s->page_size);
1353     buf->nlb = cpu_to_le32(bytes >> s->blkshift);
1354     buf->slba = cpu_to_le64(offset >> s->blkshift);
1355     buf->cattr = 0;
1356
1357     qemu_iovec_init(&local_qiov, 1);
1358     qemu_iovec_add(&local_qiov, buf, 4096);
1359
1360     req = nvme_get_free_req(ioq);
1361     assert(req);
1362
1363     qemu_co_mutex_lock(&s->dma_map_lock);
1364     ret = nvme_cmd_map_qiov(bs, &cmd, req, &local_qiov);
1365     qemu_co_mutex_unlock(&s->dma_map_lock);
1366
1367     if (ret) {
1368         nvme_put_free_req_and_wake(ioq, req);
1369         goto out;
1370     }
1371
1372     trace_nvme_dsm(s, offset, bytes);
1373
1374     nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
1375
1376     data.co = qemu_coroutine_self();
1377     while (data.ret == -EINPROGRESS) {
1378         qemu_coroutine_yield();
1379     }
1380
1381     qemu_co_mutex_lock(&s->dma_map_lock);
1382     ret = nvme_cmd_unmap_qiov(bs, &local_qiov);
1383     qemu_co_mutex_unlock(&s->dma_map_lock);
1384
1385     if (ret) {
1386         goto out;
1387     }
1388
1389     ret = data.ret;
1390     trace_nvme_dsm_done(s, offset, bytes, ret);
1391 out:
1392     qemu_iovec_destroy(&local_qiov);
1393     qemu_vfree(buf);
1394     return ret;
1395
1396 }
1397
1398 static int coroutine_fn nvme_co_truncate(BlockDriverState *bs, int64_t offset,
1399                                          bool exact, PreallocMode prealloc,
1400                                          BdrvRequestFlags flags, Error **errp)
1401 {
1402     int64_t cur_length;
1403
1404     if (prealloc != PREALLOC_MODE_OFF) {
1405         error_setg(errp, "Unsupported preallocation mode '%s'",
1406                    PreallocMode_str(prealloc));
1407         return -ENOTSUP;
1408     }
1409
1410     cur_length = nvme_getlength(bs);
1411     if (offset != cur_length && exact) {
1412         error_setg(errp, "Cannot resize NVMe devices");
1413         return -ENOTSUP;
1414     } else if (offset > cur_length) {
1415         error_setg(errp, "Cannot grow NVMe devices");
1416         return -EINVAL;
1417     }
1418
1419     return 0;
1420 }
1421
1422 static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
1423                                BlockReopenQueue *queue, Error **errp)
1424 {
1425     return 0;
1426 }
1427
1428 static void nvme_refresh_filename(BlockDriverState *bs)
1429 {
1430     BDRVNVMeState *s = bs->opaque;
1431
1432     snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nvme://%s/%i",
1433              s->device, s->nsid);
1434 }
1435
1436 static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
1437 {
1438     BDRVNVMeState *s = bs->opaque;
1439
1440     bs->bl.opt_mem_alignment = s->page_size;
1441     bs->bl.request_alignment = s->page_size;
1442     bs->bl.max_transfer = s->max_transfer;
1443 }
1444
1445 static void nvme_detach_aio_context(BlockDriverState *bs)
1446 {
1447     BDRVNVMeState *s = bs->opaque;
1448
1449     for (unsigned i = 0; i < s->queue_count; i++) {
1450         NVMeQueuePair *q = s->queues[i];
1451
1452         qemu_bh_delete(q->completion_bh);
1453         q->completion_bh = NULL;
1454     }
1455
1456     aio_set_event_notifier(bdrv_get_aio_context(bs),
1457                            &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
1458                            false, NULL, NULL);
1459 }
1460
1461 static void nvme_attach_aio_context(BlockDriverState *bs,
1462                                     AioContext *new_context)
1463 {
1464     BDRVNVMeState *s = bs->opaque;
1465
1466     s->aio_context = new_context;
1467     aio_set_event_notifier(new_context, &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
1468                            false, nvme_handle_event, nvme_poll_cb);
1469
1470     for (unsigned i = 0; i < s->queue_count; i++) {
1471         NVMeQueuePair *q = s->queues[i];
1472
1473         q->completion_bh =
1474             aio_bh_new(new_context, nvme_process_completion_bh, q);
1475     }
1476 }
1477
1478 static void nvme_aio_plug(BlockDriverState *bs)
1479 {
1480     BDRVNVMeState *s = bs->opaque;
1481     assert(!s->plugged);
1482     s->plugged = true;
1483 }
1484
1485 static void nvme_aio_unplug(BlockDriverState *bs)
1486 {
1487     BDRVNVMeState *s = bs->opaque;
1488     assert(s->plugged);
1489     s->plugged = false;
1490     for (unsigned i = INDEX_IO(0); i < s->queue_count; i++) {
1491         NVMeQueuePair *q = s->queues[i];
1492         qemu_mutex_lock(&q->lock);
1493         nvme_kick(q);
1494         nvme_process_completion(q);
1495         qemu_mutex_unlock(&q->lock);
1496     }
1497 }
1498
1499 static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
1500 {
1501     int ret;
1502     BDRVNVMeState *s = bs->opaque;
1503
1504     ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL);
1505     if (ret) {
1506         /* FIXME: we may run out of IOVA addresses after repeated
1507          * bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap
1508          * doesn't reclaim addresses for fixed mappings. */
1509         error_report("nvme_register_buf failed: %s", strerror(-ret));
1510     }
1511 }
1512
1513 static void nvme_unregister_buf(BlockDriverState *bs, void *host)
1514 {
1515     BDRVNVMeState *s = bs->opaque;
1516
1517     qemu_vfio_dma_unmap(s->vfio, host);
1518 }
1519
1520 static BlockStatsSpecific *nvme_get_specific_stats(BlockDriverState *bs)
1521 {
1522     BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
1523     BDRVNVMeState *s = bs->opaque;
1524
1525     stats->driver = BLOCKDEV_DRIVER_NVME;
1526     stats->u.nvme = (BlockStatsSpecificNvme) {
1527         .completion_errors = s->stats.completion_errors,
1528         .aligned_accesses = s->stats.aligned_accesses,
1529         .unaligned_accesses = s->stats.unaligned_accesses,
1530     };
1531
1532     return stats;
1533 }
1534
1535 static const char *const nvme_strong_runtime_opts[] = {
1536     NVME_BLOCK_OPT_DEVICE,
1537     NVME_BLOCK_OPT_NAMESPACE,
1538
1539     NULL
1540 };
1541
1542 static BlockDriver bdrv_nvme = {
1543     .format_name              = "nvme",
1544     .protocol_name            = "nvme",
1545     .instance_size            = sizeof(BDRVNVMeState),
1546
1547     .bdrv_co_create_opts      = bdrv_co_create_opts_simple,
1548     .create_opts              = &bdrv_create_opts_simple,
1549
1550     .bdrv_parse_filename      = nvme_parse_filename,
1551     .bdrv_file_open           = nvme_file_open,
1552     .bdrv_close               = nvme_close,
1553     .bdrv_getlength           = nvme_getlength,
1554     .bdrv_probe_blocksizes    = nvme_probe_blocksizes,
1555     .bdrv_co_truncate         = nvme_co_truncate,
1556
1557     .bdrv_co_preadv           = nvme_co_preadv,
1558     .bdrv_co_pwritev          = nvme_co_pwritev,
1559
1560     .bdrv_co_pwrite_zeroes    = nvme_co_pwrite_zeroes,
1561     .bdrv_co_pdiscard         = nvme_co_pdiscard,
1562
1563     .bdrv_co_flush_to_disk    = nvme_co_flush,
1564     .bdrv_reopen_prepare      = nvme_reopen_prepare,
1565
1566     .bdrv_refresh_filename    = nvme_refresh_filename,
1567     .bdrv_refresh_limits      = nvme_refresh_limits,
1568     .strong_runtime_opts      = nvme_strong_runtime_opts,
1569     .bdrv_get_specific_stats  = nvme_get_specific_stats,
1570
1571     .bdrv_detach_aio_context  = nvme_detach_aio_context,
1572     .bdrv_attach_aio_context  = nvme_attach_aio_context,
1573
1574     .bdrv_io_plug             = nvme_aio_plug,
1575     .bdrv_io_unplug           = nvme_aio_unplug,
1576
1577     .bdrv_register_buf        = nvme_register_buf,
1578     .bdrv_unregister_buf      = nvme_unregister_buf,
1579 };
1580
1581 static void bdrv_nvme_init(void)
1582 {
1583     bdrv_register(&bdrv_nvme);
1584 }
1585
1586 block_init(bdrv_nvme_init);