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qemu-e2k/block/nvme.c
Stefan Hajnoczi 826cc32423 aio-posix: split poll check from ready handler 
Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significant amount of time, making it look like polling was running for
a long time when in fact the event handler was running for a long time.

For example, on Linux the io_submit(2) syscall invoked when a virtio-blk
device's virtqueue becomes ready can take 10s of microseconds. This
can exceed the default polling interval (32 microseconds) and cause
adaptive polling to stop polling.

By excluding the handler's execution time from the polling check we make
the adaptive polling calculation more accurate. As a result, the event
loop now stays in polling mode where previously it would have fallen
back to file descriptor monitoring.

The following data was collected with virtio-blk num-queues=2
event_idx=off using an IOThread. Before:

168k IOPS, IOThread syscalls:

  9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0)    = 16
  9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8)                         = 8
  9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3
  9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512)                        = 8
  9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0)    = 32

174k IOPS (+3.6%), IOThread syscalls:

  9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0)    = 32
  9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8)                         = 8
  9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50)    = 32

Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because
the IOThread stays in polling mode instead of falling back to file
descriptor monitoring.

As usual, polling is not implemented on Windows so this patch ignores
the new io_poll_read() callback in aio-win32.c.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-2-stefanha@redhat.com

[Fixed up aio_set_event_notifier() calls in
tests/unit/test-fdmon-epoll.c added after this series was queued.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-01-12 17:09:39 +00:00

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/*
* NVMe block driver based on vfio
*
* Copyright 2016 - 2018 Red Hat, Inc.
*
* Authors:
* Fam Zheng <famz@redhat.com>
* Paolo Bonzini <pbonzini@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include <linux/vfio.h>
#include "qapi/error.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qstring.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "qemu/cutils.h"
#include "qemu/option.h"
#include "qemu/vfio-helpers.h"
#include "block/block_int.h"
#include "sysemu/replay.h"
#include "trace.h"
#include "block/nvme.h"
#define NVME_SQ_ENTRY_BYTES 64
#define NVME_CQ_ENTRY_BYTES 16
#define NVME_QUEUE_SIZE 128
#define NVME_DOORBELL_SIZE 4096
/*
* We have to leave one slot empty as that is the full queue case where
* head == tail + 1.
*/
#define NVME_NUM_REQS (NVME_QUEUE_SIZE - 1)
typedef struct BDRVNVMeState BDRVNVMeState;
/* Same index is used for queues and IRQs */
#define INDEX_ADMIN 0
#define INDEX_IO(n) (1 + n)
/* This driver shares a single MSIX IRQ for the admin and I/O queues */
enum {
MSIX_SHARED_IRQ_IDX = 0,
MSIX_IRQ_COUNT = 1
};
typedef struct {
int32_t head, tail;
uint8_t *queue;
uint64_t iova;
/* Hardware MMIO register */
volatile uint32_t *doorbell;
} NVMeQueue;
typedef struct {
BlockCompletionFunc *cb;
void *opaque;
int cid;
void *prp_list_page;
uint64_t prp_list_iova;
int free_req_next; /* q->reqs[] index of next free req */
} NVMeRequest;
typedef struct {
QemuMutex lock;
/* Read from I/O code path, initialized under BQL */
BDRVNVMeState *s;
int index;
/* Fields protected by BQL */
uint8_t *prp_list_pages;
/* Fields protected by @lock */
CoQueue free_req_queue;
NVMeQueue sq, cq;
int cq_phase;
int free_req_head;
NVMeRequest reqs[NVME_NUM_REQS];
int need_kick;
int inflight;
/* Thread-safe, no lock necessary */
QEMUBH *completion_bh;
} NVMeQueuePair;
struct BDRVNVMeState {
AioContext *aio_context;
QEMUVFIOState *vfio;
void *bar0_wo_map;
/* Memory mapped registers */
volatile struct {
uint32_t sq_tail;
uint32_t cq_head;
} *doorbells;
/* The submission/completion queue pairs.
* [0]: admin queue.
* [1..]: io queues.
*/
NVMeQueuePair **queues;
unsigned queue_count;
size_t page_size;
/* How many uint32_t elements does each doorbell entry take. */
size_t doorbell_scale;
bool write_cache_supported;
EventNotifier irq_notifier[MSIX_IRQ_COUNT];
uint64_t nsze; /* Namespace size reported by identify command */
int nsid; /* The namespace id to read/write data. */
int blkshift;
uint64_t max_transfer;
bool plugged;
bool supports_write_zeroes;
bool supports_discard;
CoMutex dma_map_lock;
CoQueue dma_flush_queue;
/* Total size of mapped qiov, accessed under dma_map_lock */
int dma_map_count;
/* PCI address (required for nvme_refresh_filename()) */
char *device;
struct {
uint64_t completion_errors;
uint64_t aligned_accesses;
uint64_t unaligned_accesses;
} stats;
};
#define NVME_BLOCK_OPT_DEVICE "device"
#define NVME_BLOCK_OPT_NAMESPACE "namespace"
static void nvme_process_completion_bh(void *opaque);
static QemuOptsList runtime_opts = {
.name = "nvme",
.head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
.desc = {
{
.name = NVME_BLOCK_OPT_DEVICE,
.type = QEMU_OPT_STRING,
.help = "NVMe PCI device address",
},
{
.name = NVME_BLOCK_OPT_NAMESPACE,
.type = QEMU_OPT_NUMBER,
.help = "NVMe namespace",
},
{ /* end of list */ }
},
};
/* Returns true on success, false on failure. */
static bool nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,
unsigned nentries, size_t entry_bytes, Error **errp)
{
size_t bytes;
int r;
bytes = ROUND_UP(nentries * entry_bytes, qemu_real_host_page_size);
q->head = q->tail = 0;
q->queue = qemu_try_memalign(qemu_real_host_page_size, bytes);
if (!q->queue) {
error_setg(errp, "Cannot allocate queue");
return false;
}
memset(q->queue, 0, bytes);
r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova, errp);
if (r) {
error_prepend(errp, "Cannot map queue: ");
}
return r == 0;
}
static void nvme_free_queue(NVMeQueue *q)
{
qemu_vfree(q->queue);
}
static void nvme_free_queue_pair(NVMeQueuePair *q)
{
trace_nvme_free_queue_pair(q->index, q, &q->cq, &q->sq);
if (q->completion_bh) {
qemu_bh_delete(q->completion_bh);
}
nvme_free_queue(&q->sq);
nvme_free_queue(&q->cq);
qemu_vfree(q->prp_list_pages);
qemu_mutex_destroy(&q->lock);
g_free(q);
}
static void nvme_free_req_queue_cb(void *opaque)
{
NVMeQueuePair *q = opaque;
qemu_mutex_lock(&q->lock);
while (q->free_req_head != -1 &&
qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
/* Retry waiting requests */
}
qemu_mutex_unlock(&q->lock);
}
static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,
AioContext *aio_context,
unsigned idx, size_t size,
Error **errp)
{
int i, r;
NVMeQueuePair *q;
uint64_t prp_list_iova;
size_t bytes;
q = g_try_new0(NVMeQueuePair, 1);
if (!q) {
error_setg(errp, "Cannot allocate queue pair");
return NULL;
}
trace_nvme_create_queue_pair(idx, q, size, aio_context,
event_notifier_get_fd(s->irq_notifier));
bytes = QEMU_ALIGN_UP(s->page_size * NVME_NUM_REQS,
qemu_real_host_page_size);
q->prp_list_pages = qemu_try_memalign(qemu_real_host_page_size, bytes);
if (!q->prp_list_pages) {
error_setg(errp, "Cannot allocate PRP page list");
goto fail;
}
memset(q->prp_list_pages, 0, bytes);
qemu_mutex_init(&q->lock);
q->s = s;
q->index = idx;
qemu_co_queue_init(&q->free_req_queue);
q->completion_bh = aio_bh_new(aio_context, nvme_process_completion_bh, q);
r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages, bytes,
false, &prp_list_iova, errp);
if (r) {
error_prepend(errp, "Cannot map buffer for DMA: ");
goto fail;
}
q->free_req_head = -1;
for (i = 0; i < NVME_NUM_REQS; i++) {
NVMeRequest *req = &q->reqs[i];
req->cid = i + 1;
req->free_req_next = q->free_req_head;
q->free_req_head = i;
req->prp_list_page = q->prp_list_pages + i * s->page_size;
req->prp_list_iova = prp_list_iova + i * s->page_size;
}
if (!nvme_init_queue(s, &q->sq, size, NVME_SQ_ENTRY_BYTES, errp)) {
goto fail;
}
q->sq.doorbell = &s->doorbells[idx * s->doorbell_scale].sq_tail;
if (!nvme_init_queue(s, &q->cq, size, NVME_CQ_ENTRY_BYTES, errp)) {
goto fail;
}
q->cq.doorbell = &s->doorbells[idx * s->doorbell_scale].cq_head;
return q;
fail:
nvme_free_queue_pair(q);
return NULL;
}
/* With q->lock */
static void nvme_kick(NVMeQueuePair *q)
{
BDRVNVMeState *s = q->s;
if (s->plugged || !q->need_kick) {
return;
}
trace_nvme_kick(s, q->index);
assert(!(q->sq.tail & 0xFF00));
/* Fence the write to submission queue entry before notifying the device. */
smp_wmb();
*q->sq.doorbell = cpu_to_le32(q->sq.tail);
q->inflight += q->need_kick;
q->need_kick = 0;
}
/* Find a free request element if any, otherwise:
* a) if in coroutine context, try to wait for one to become available;
* b) if not in coroutine, return NULL;
*/
static NVMeRequest *nvme_get_free_req(NVMeQueuePair *q)
{
NVMeRequest *req;
qemu_mutex_lock(&q->lock);
while (q->free_req_head == -1) {
if (qemu_in_coroutine()) {
trace_nvme_free_req_queue_wait(q->s, q->index);
qemu_co_queue_wait(&q->free_req_queue, &q->lock);
} else {
qemu_mutex_unlock(&q->lock);
return NULL;
}
}
req = &q->reqs[q->free_req_head];
q->free_req_head = req->free_req_next;
req->free_req_next = -1;
qemu_mutex_unlock(&q->lock);
return req;
}
/* With q->lock */
static void nvme_put_free_req_locked(NVMeQueuePair *q, NVMeRequest *req)
{
req->free_req_next = q->free_req_head;
q->free_req_head = req - q->reqs;
}
/* With q->lock */
static void nvme_wake_free_req_locked(NVMeQueuePair *q)
{
if (!qemu_co_queue_empty(&q->free_req_queue)) {
replay_bh_schedule_oneshot_event(q->s->aio_context,
nvme_free_req_queue_cb, q);
}
}
/* Insert a request in the freelist and wake waiters */
static void nvme_put_free_req_and_wake(NVMeQueuePair *q, NVMeRequest *req)
{
qemu_mutex_lock(&q->lock);
nvme_put_free_req_locked(q, req);
nvme_wake_free_req_locked(q);
qemu_mutex_unlock(&q->lock);
}
static inline int nvme_translate_error(const NvmeCqe *c)
{
uint16_t status = (le16_to_cpu(c->status) >> 1) & 0xFF;
if (status) {
trace_nvme_error(le32_to_cpu(c->result),
le16_to_cpu(c->sq_head),
le16_to_cpu(c->sq_id),
le16_to_cpu(c->cid),
le16_to_cpu(status));
}
switch (status) {
case 0:
return 0;
case 1:
return -ENOSYS;
case 2:
return -EINVAL;
default:
return -EIO;
}
}
/* With q->lock */
static bool nvme_process_completion(NVMeQueuePair *q)
{
BDRVNVMeState *s = q->s;
bool progress = false;
NVMeRequest *preq;
NVMeRequest req;
NvmeCqe *c;
trace_nvme_process_completion(s, q->index, q->inflight);
if (s->plugged) {
trace_nvme_process_completion_queue_plugged(s, q->index);
return false;
}
/*
* Support re-entrancy when a request cb() function invokes aio_poll().
* Pending completions must be visible to aio_poll() so that a cb()
* function can wait for the completion of another request.
*
* The aio_poll() loop will execute our BH and we'll resume completion
* processing there.
*/
qemu_bh_schedule(q->completion_bh);
assert(q->inflight >= 0);
while (q->inflight) {
int ret;
int16_t cid;
c = (NvmeCqe *)&q->cq.queue[q->cq.head * NVME_CQ_ENTRY_BYTES];
if ((le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
break;
}
ret = nvme_translate_error(c);
if (ret) {
s->stats.completion_errors++;
}
q->cq.head = (q->cq.head + 1) % NVME_QUEUE_SIZE;
if (!q->cq.head) {
q->cq_phase = !q->cq_phase;
}
cid = le16_to_cpu(c->cid);
if (cid == 0 || cid > NVME_QUEUE_SIZE) {
warn_report("NVMe: Unexpected CID in completion queue: %"PRIu32", "
"queue size: %u", cid, NVME_QUEUE_SIZE);
continue;
}
trace_nvme_complete_command(s, q->index, cid);
preq = &q->reqs[cid - 1];
req = *preq;
assert(req.cid == cid);
assert(req.cb);
nvme_put_free_req_locked(q, preq);
preq->cb = preq->opaque = NULL;
q->inflight--;
qemu_mutex_unlock(&q->lock);
req.cb(req.opaque, ret);
qemu_mutex_lock(&q->lock);
progress = true;
}
if (progress) {
/* Notify the device so it can post more completions. */
smp_mb_release();
*q->cq.doorbell = cpu_to_le32(q->cq.head);
nvme_wake_free_req_locked(q);
}
qemu_bh_cancel(q->completion_bh);
return progress;
}
static void nvme_process_completion_bh(void *opaque)
{
NVMeQueuePair *q = opaque;
/*
* We're being invoked because a nvme_process_completion() cb() function
* called aio_poll(). The callback may be waiting for further completions
* so notify the device that it has space to fill in more completions now.
*/
smp_mb_release();
*q->cq.doorbell = cpu_to_le32(q->cq.head);
nvme_wake_free_req_locked(q);
nvme_process_completion(q);
}
static void nvme_trace_command(const NvmeCmd *cmd)
{
int i;
if (!trace_event_get_state_backends(TRACE_NVME_SUBMIT_COMMAND_RAW)) {
return;
}
for (i = 0; i < 8; ++i) {
uint8_t *cmdp = (uint8_t *)cmd + i * 8;
trace_nvme_submit_command_raw(cmdp[0], cmdp[1], cmdp[2], cmdp[3],
cmdp[4], cmdp[5], cmdp[6], cmdp[7]);
}
}
static void nvme_submit_command(NVMeQueuePair *q, NVMeRequest *req,
NvmeCmd *cmd, BlockCompletionFunc cb,
void *opaque)
{
assert(!req->cb);
req->cb = cb;
req->opaque = opaque;
cmd->cid = cpu_to_le16(req->cid);
trace_nvme_submit_command(q->s, q->index, req->cid);
nvme_trace_command(cmd);
qemu_mutex_lock(&q->lock);
memcpy((uint8_t *)q->sq.queue +
q->sq.tail * NVME_SQ_ENTRY_BYTES, cmd, sizeof(*cmd));
q->sq.tail = (q->sq.tail + 1) % NVME_QUEUE_SIZE;
q->need_kick++;
nvme_kick(q);
nvme_process_completion(q);
qemu_mutex_unlock(&q->lock);
}
static void nvme_admin_cmd_sync_cb(void *opaque, int ret)
{
int *pret = opaque;
*pret = ret;
aio_wait_kick();
}
static int nvme_admin_cmd_sync(BlockDriverState *bs, NvmeCmd *cmd)
{
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *q = s->queues[INDEX_ADMIN];
AioContext *aio_context = bdrv_get_aio_context(bs);
NVMeRequest *req;
int ret = -EINPROGRESS;
req = nvme_get_free_req(q);
if (!req) {
return -EBUSY;
}
nvme_submit_command(q, req, cmd, nvme_admin_cmd_sync_cb, &ret);
AIO_WAIT_WHILE(aio_context, ret == -EINPROGRESS);
return ret;
}
/* Returns true on success, false on failure. */
static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
bool ret = false;
QEMU_AUTO_VFREE union {
NvmeIdCtrl ctrl;
NvmeIdNs ns;
} *id = NULL;
NvmeLBAF *lbaf;
uint16_t oncs;
int r;
uint64_t iova;
NvmeCmd cmd = {
.opcode = NVME_ADM_CMD_IDENTIFY,
.cdw10 = cpu_to_le32(0x1),
};
size_t id_size = QEMU_ALIGN_UP(sizeof(*id), qemu_real_host_page_size);
id = qemu_try_memalign(qemu_real_host_page_size, id_size);
if (!id) {
error_setg(errp, "Cannot allocate buffer for identify response");
goto out;
}
r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova, errp);
if (r) {
error_prepend(errp, "Cannot map buffer for DMA: ");
goto out;
}
memset(id, 0, id_size);
cmd.dptr.prp1 = cpu_to_le64(iova);
if (nvme_admin_cmd_sync(bs, &cmd)) {
error_setg(errp, "Failed to identify controller");
goto out;
}
if (le32_to_cpu(id->ctrl.nn) < namespace) {
error_setg(errp, "Invalid namespace");
goto out;
}
s->write_cache_supported = le32_to_cpu(id->ctrl.vwc) & 0x1;
s->max_transfer = (id->ctrl.mdts ? 1 << id->ctrl.mdts : 0) * s->page_size;
/* For now the page list buffer per command is one page, to hold at most
* s->page_size / sizeof(uint64_t) entries. */
s->max_transfer = MIN_NON_ZERO(s->max_transfer,
s->page_size / sizeof(uint64_t) * s->page_size);
oncs = le16_to_cpu(id->ctrl.oncs);
s->supports_write_zeroes = !!(oncs & NVME_ONCS_WRITE_ZEROES);
s->supports_discard = !!(oncs & NVME_ONCS_DSM);
memset(id, 0, id_size);
cmd.cdw10 = 0;
cmd.nsid = cpu_to_le32(namespace);
if (nvme_admin_cmd_sync(bs, &cmd)) {
error_setg(errp, "Failed to identify namespace");
goto out;
}
s->nsze = le64_to_cpu(id->ns.nsze);
lbaf = &id->ns.lbaf[NVME_ID_NS_FLBAS_INDEX(id->ns.flbas)];
if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(id->ns.dlfeat) &&
NVME_ID_NS_DLFEAT_READ_BEHAVIOR(id->ns.dlfeat) ==
NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROES) {
bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
}
if (lbaf->ms) {
error_setg(errp, "Namespaces with metadata are not yet supported");
goto out;
}
if (lbaf->ds < BDRV_SECTOR_BITS || lbaf->ds > 12 ||
(1 << lbaf->ds) > s->page_size)
{
error_setg(errp, "Namespace has unsupported block size (2^%d)",
lbaf->ds);
goto out;
}
ret = true;
s->blkshift = lbaf->ds;
out:
qemu_vfio_dma_unmap(s->vfio, id);
return ret;
}
static void nvme_poll_queue(NVMeQueuePair *q)
{
const size_t cqe_offset = q->cq.head * NVME_CQ_ENTRY_BYTES;
NvmeCqe *cqe = (NvmeCqe *)&q->cq.queue[cqe_offset];
trace_nvme_poll_queue(q->s, q->index);
/*
* Do an early check for completions. q->lock isn't needed because
* nvme_process_completion() only runs in the event loop thread and
* cannot race with itself.
*/
if ((le16_to_cpu(cqe->status) & 0x1) == q->cq_phase) {
return;
}
qemu_mutex_lock(&q->lock);
while (nvme_process_completion(q)) {
/* Keep polling */
}
qemu_mutex_unlock(&q->lock);
}
static void nvme_poll_queues(BDRVNVMeState *s)
{
int i;
for (i = 0; i < s->queue_count; i++) {
nvme_poll_queue(s->queues[i]);
}
}
static void nvme_handle_event(EventNotifier *n)
{
BDRVNVMeState *s = container_of(n, BDRVNVMeState,
irq_notifier[MSIX_SHARED_IRQ_IDX]);
trace_nvme_handle_event(s);
event_notifier_test_and_clear(n);
nvme_poll_queues(s);
}
static bool nvme_add_io_queue(BlockDriverState *bs, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
unsigned n = s->queue_count;
NVMeQueuePair *q;
NvmeCmd cmd;
unsigned queue_size = NVME_QUEUE_SIZE;
assert(n <= UINT16_MAX);
q = nvme_create_queue_pair(s, bdrv_get_aio_context(bs),
n, queue_size, errp);
if (!q) {
return false;
}
cmd = (NvmeCmd) {
.opcode = NVME_ADM_CMD_CREATE_CQ,
.dptr.prp1 = cpu_to_le64(q->cq.iova),
.cdw10 = cpu_to_le32(((queue_size - 1) << 16) | n),
.cdw11 = cpu_to_le32(NVME_CQ_IEN | NVME_CQ_PC),
};
if (nvme_admin_cmd_sync(bs, &cmd)) {
error_setg(errp, "Failed to create CQ io queue [%u]", n);
goto out_error;
}
cmd = (NvmeCmd) {
.opcode = NVME_ADM_CMD_CREATE_SQ,
.dptr.prp1 = cpu_to_le64(q->sq.iova),
.cdw10 = cpu_to_le32(((queue_size - 1) << 16) | n),
.cdw11 = cpu_to_le32(NVME_SQ_PC | (n << 16)),
};
if (nvme_admin_cmd_sync(bs, &cmd)) {
error_setg(errp, "Failed to create SQ io queue [%u]", n);
goto out_error;
}
s->queues = g_renew(NVMeQueuePair *, s->queues, n + 1);
s->queues[n] = q;
s->queue_count++;
return true;
out_error:
nvme_free_queue_pair(q);
return false;
}
static bool nvme_poll_cb(void *opaque)
{
EventNotifier *e = opaque;
BDRVNVMeState *s = container_of(e, BDRVNVMeState,
irq_notifier[MSIX_SHARED_IRQ_IDX]);
int i;
for (i = 0; i < s->queue_count; i++) {
NVMeQueuePair *q = s->queues[i];
const size_t cqe_offset = q->cq.head * NVME_CQ_ENTRY_BYTES;
NvmeCqe *cqe = (NvmeCqe *)&q->cq.queue[cqe_offset];
/*
* q->lock isn't needed because nvme_process_completion() only runs in
* the event loop thread and cannot race with itself.
*/
if ((le16_to_cpu(cqe->status) & 0x1) != q->cq_phase) {
return true;
}
}
return false;
}
static void nvme_poll_ready(EventNotifier *e)
{
BDRVNVMeState *s = container_of(e, BDRVNVMeState,
irq_notifier[MSIX_SHARED_IRQ_IDX]);
nvme_poll_queues(s);
}
static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
Error **errp)
{
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *q;
AioContext *aio_context = bdrv_get_aio_context(bs);
int ret;
uint64_t cap;
uint32_t ver;
uint64_t timeout_ms;
uint64_t deadline, now;
volatile NvmeBar *regs = NULL;
qemu_co_mutex_init(&s->dma_map_lock);
qemu_co_queue_init(&s->dma_flush_queue);
s->device = g_strdup(device);
s->nsid = namespace;
s->aio_context = bdrv_get_aio_context(bs);
ret = event_notifier_init(&s->irq_notifier[MSIX_SHARED_IRQ_IDX], 0);
if (ret) {
error_setg(errp, "Failed to init event notifier");
return ret;
}
s->vfio = qemu_vfio_open_pci(device, errp);
if (!s->vfio) {
ret = -EINVAL;
goto out;
}
regs = qemu_vfio_pci_map_bar(s->vfio, 0, 0, sizeof(NvmeBar),
PROT_READ | PROT_WRITE, errp);
if (!regs) {
ret = -EINVAL;
goto out;
}
/* Perform initialize sequence as described in NVMe spec "7.6.1
* Initialization". */
cap = le64_to_cpu(regs->cap);
trace_nvme_controller_capability_raw(cap);
trace_nvme_controller_capability("Maximum Queue Entries Supported",
1 + NVME_CAP_MQES(cap));
trace_nvme_controller_capability("Contiguous Queues Required",
NVME_CAP_CQR(cap));
trace_nvme_controller_capability("Doorbell Stride",
1 << (2 + NVME_CAP_DSTRD(cap)));
trace_nvme_controller_capability("Subsystem Reset Supported",
NVME_CAP_NSSRS(cap));
trace_nvme_controller_capability("Memory Page Size Minimum",
1 << (12 + NVME_CAP_MPSMIN(cap)));
trace_nvme_controller_capability("Memory Page Size Maximum",
1 << (12 + NVME_CAP_MPSMAX(cap)));
if (!NVME_CAP_CSS(cap)) {
error_setg(errp, "Device doesn't support NVMe command set");
ret = -EINVAL;
goto out;
}
s->page_size = 1u << (12 + NVME_CAP_MPSMIN(cap));
s->doorbell_scale = (4 << NVME_CAP_DSTRD(cap)) / sizeof(uint32_t);
bs->bl.opt_mem_alignment = s->page_size;
bs->bl.request_alignment = s->page_size;
timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
ver = le32_to_cpu(regs->vs);
trace_nvme_controller_spec_version(extract32(ver, 16, 16),
extract32(ver, 8, 8),
extract32(ver, 0, 8));
/* Reset device to get a clean state. */
regs->cc = cpu_to_le32(le32_to_cpu(regs->cc) & 0xFE);
/* Wait for CSTS.RDY = 0. */
deadline = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ms * SCALE_MS;
while (NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
error_setg(errp, "Timeout while waiting for device to reset (%"
PRId64 " ms)",
timeout_ms);
ret = -ETIMEDOUT;
goto out;
}
}
s->bar0_wo_map = qemu_vfio_pci_map_bar(s->vfio, 0, 0,
sizeof(NvmeBar) + NVME_DOORBELL_SIZE,
PROT_WRITE, errp);
s->doorbells = (void *)((uintptr_t)s->bar0_wo_map + sizeof(NvmeBar));
if (!s->doorbells) {
ret = -EINVAL;
goto out;
}
/* Set up admin queue. */
s->queues = g_new(NVMeQueuePair *, 1);
q = nvme_create_queue_pair(s, aio_context, 0, NVME_QUEUE_SIZE, errp);
if (!q) {
ret = -EINVAL;
goto out;
}
s->queues[INDEX_ADMIN] = q;
s->queue_count = 1;
QEMU_BUILD_BUG_ON((NVME_QUEUE_SIZE - 1) & 0xF000);
regs->aqa = cpu_to_le32(((NVME_QUEUE_SIZE - 1) << AQA_ACQS_SHIFT) |
((NVME_QUEUE_SIZE - 1) << AQA_ASQS_SHIFT));
regs->asq = cpu_to_le64(q->sq.iova);
regs->acq = cpu_to_le64(q->cq.iova);
/* After setting up all control registers we can enable device now. */
regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << CC_IOCQES_SHIFT) |
(ctz32(NVME_SQ_ENTRY_BYTES) << CC_IOSQES_SHIFT) |
CC_EN_MASK);
/* Wait for CSTS.RDY = 1. */
now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
deadline = now + timeout_ms * SCALE_MS;
while (!NVME_CSTS_RDY(le32_to_cpu(regs->csts))) {
if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) > deadline) {
error_setg(errp, "Timeout while waiting for device to start (%"
PRId64 " ms)",
timeout_ms);
ret = -ETIMEDOUT;
goto out;
}
}
ret = qemu_vfio_pci_init_irq(s->vfio, s->irq_notifier,
VFIO_PCI_MSIX_IRQ_INDEX, errp);
if (ret) {
goto out;
}
aio_set_event_notifier(bdrv_get_aio_context(bs),
&s->irq_notifier[MSIX_SHARED_IRQ_IDX],
false, nvme_handle_event, nvme_poll_cb,
nvme_poll_ready);
if (!nvme_identify(bs, namespace, errp)) {
ret = -EIO;
goto out;
}
/* Set up command queues. */
if (!nvme_add_io_queue(bs, errp)) {
ret = -EIO;
}
out:
if (regs) {
qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)regs, 0, sizeof(NvmeBar));
}
/* Cleaning up is done in nvme_file_open() upon error. */
return ret;
}
/* Parse a filename in the format of nvme://XXXX:XX:XX.X/X. Example:
*
* nvme://0000:44:00.0/1
*
* where the "nvme://" is a fixed form of the protocol prefix, the middle part
* is the PCI address, and the last part is the namespace number starting from
* 1 according to the NVMe spec. */
static void nvme_parse_filename(const char *filename, QDict *options,
Error **errp)
{
int pref = strlen("nvme://");
if (strlen(filename) > pref && !strncmp(filename, "nvme://", pref)) {
const char *tmp = filename + pref;
char *device;
const char *namespace;
unsigned long ns;
const char *slash = strchr(tmp, '/');
if (!slash) {
qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, tmp);
return;
}
device = g_strndup(tmp, slash - tmp);
qdict_put_str(options, NVME_BLOCK_OPT_DEVICE, device);
g_free(device);
namespace = slash + 1;
if (*namespace && qemu_strtoul(namespace, NULL, 10, &ns)) {
error_setg(errp, "Invalid namespace '%s', positive number expected",
namespace);
return;
}
qdict_put_str(options, NVME_BLOCK_OPT_NAMESPACE,
*namespace ? namespace : "1");
}
}
static int nvme_enable_disable_write_cache(BlockDriverState *bs, bool enable,
Error **errp)
{
int ret;
BDRVNVMeState *s = bs->opaque;
NvmeCmd cmd = {
.opcode = NVME_ADM_CMD_SET_FEATURES,
.nsid = cpu_to_le32(s->nsid),
.cdw10 = cpu_to_le32(0x06),
.cdw11 = cpu_to_le32(enable ? 0x01 : 0x00),
};
ret = nvme_admin_cmd_sync(bs, &cmd);
if (ret) {
error_setg(errp, "Failed to configure NVMe write cache");
}
return ret;
}
static void nvme_close(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
for (unsigned i = 0; i < s->queue_count; ++i) {
nvme_free_queue_pair(s->queues[i]);
}
g_free(s->queues);
aio_set_event_notifier(bdrv_get_aio_context(bs),
&s->irq_notifier[MSIX_SHARED_IRQ_IDX],
false, NULL, NULL, NULL);
event_notifier_cleanup(&s->irq_notifier[MSIX_SHARED_IRQ_IDX]);
qemu_vfio_pci_unmap_bar(s->vfio, 0, s->bar0_wo_map,
0, sizeof(NvmeBar) + NVME_DOORBELL_SIZE);
qemu_vfio_close(s->vfio);
g_free(s->device);
}
static int nvme_file_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
const char *device;
QemuOpts *opts;
int namespace;
int ret;
BDRVNVMeState *s = bs->opaque;
bs->supported_write_flags = BDRV_REQ_FUA;
opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
qemu_opts_absorb_qdict(opts, options, &error_abort);
device = qemu_opt_get(opts, NVME_BLOCK_OPT_DEVICE);
if (!device) {
error_setg(errp, "'" NVME_BLOCK_OPT_DEVICE "' option is required");
qemu_opts_del(opts);
return -EINVAL;
}
namespace = qemu_opt_get_number(opts, NVME_BLOCK_OPT_NAMESPACE, 1);
ret = nvme_init(bs, device, namespace, errp);
qemu_opts_del(opts);
if (ret) {
goto fail;
}
if (flags & BDRV_O_NOCACHE) {
if (!s->write_cache_supported) {
error_setg(errp,
"NVMe controller doesn't support write cache configuration");
ret = -EINVAL;
} else {
ret = nvme_enable_disable_write_cache(bs, !(flags & BDRV_O_NOCACHE),
errp);
}
if (ret) {
goto fail;
}
}
return 0;
fail:
nvme_close(bs);
return ret;
}
static int64_t nvme_getlength(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
return s->nsze << s->blkshift;
}
static uint32_t nvme_get_blocksize(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
assert(s->blkshift >= BDRV_SECTOR_BITS && s->blkshift <= 12);
return UINT32_C(1) << s->blkshift;
}
static int nvme_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
{
uint32_t blocksize = nvme_get_blocksize(bs);
bsz->phys = blocksize;
bsz->log = blocksize;
return 0;
}
/* Called with s->dma_map_lock */
static coroutine_fn int nvme_cmd_unmap_qiov(BlockDriverState *bs,
QEMUIOVector *qiov)
{
int r = 0;
BDRVNVMeState *s = bs->opaque;
s->dma_map_count -= qiov->size;
if (!s->dma_map_count && !qemu_co_queue_empty(&s->dma_flush_queue)) {
r = qemu_vfio_dma_reset_temporary(s->vfio);
if (!r) {
qemu_co_queue_restart_all(&s->dma_flush_queue);
}
}
return r;
}
/* Called with s->dma_map_lock */
static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,
NVMeRequest *req, QEMUIOVector *qiov)
{
BDRVNVMeState *s = bs->opaque;
uint64_t *pagelist = req->prp_list_page;
int i, j, r;
int entries = 0;
Error *local_err = NULL, **errp = NULL;
assert(qiov->size);
assert(QEMU_IS_ALIGNED(qiov->size, s->page_size));
assert(qiov->size / s->page_size <= s->page_size / sizeof(uint64_t));
for (i = 0; i < qiov->niov; ++i) {
bool retry = true;
uint64_t iova;
size_t len = QEMU_ALIGN_UP(qiov->iov[i].iov_len,
qemu_real_host_page_size);
try_map:
r = qemu_vfio_dma_map(s->vfio,
qiov->iov[i].iov_base,
len, true, &iova, errp);
if (r == -ENOSPC) {
/*
* In addition to the -ENOMEM error, the VFIO_IOMMU_MAP_DMA
* ioctl returns -ENOSPC to signal the user exhausted the DMA
* mappings available for a container since Linux kernel commit
* 492855939bdb ("vfio/type1: Limit DMA mappings per container",
* April 2019, see CVE-2019-3882).
*
* This block driver already handles this error path by checking
* for the -ENOMEM error, so we directly replace -ENOSPC by
* -ENOMEM. Beside, -ENOSPC has a specific meaning for blockdev
* coroutines: it triggers BLOCKDEV_ON_ERROR_ENOSPC and
* BLOCK_ERROR_ACTION_STOP which stops the VM, asking the operator
* to add more storage to the blockdev. Not something we can do
* easily with an IOMMU :)
*/
r = -ENOMEM;
}
if (r == -ENOMEM && retry) {
/*
* We exhausted the DMA mappings available for our container:
* recycle the volatile IOVA mappings.
*/
retry = false;
trace_nvme_dma_flush_queue_wait(s);
if (s->dma_map_count) {
trace_nvme_dma_map_flush(s);
qemu_co_queue_wait(&s->dma_flush_queue, &s->dma_map_lock);
} else {
r = qemu_vfio_dma_reset_temporary(s->vfio);
if (r) {
goto fail;
}
}
errp = &local_err;
goto try_map;
}
if (r) {
goto fail;
}
for (j = 0; j < qiov->iov[i].iov_len / s->page_size; j++) {
pagelist[entries++] = cpu_to_le64(iova + j * s->page_size);
}
trace_nvme_cmd_map_qiov_iov(s, i, qiov->iov[i].iov_base,
qiov->iov[i].iov_len / s->page_size);
}
s->dma_map_count += qiov->size;
assert(entries <= s->page_size / sizeof(uint64_t));
switch (entries) {
case 0:
abort();
case 1:
cmd->dptr.prp1 = pagelist[0];
cmd->dptr.prp2 = 0;
break;
case 2:
cmd->dptr.prp1 = pagelist[0];
cmd->dptr.prp2 = pagelist[1];
break;
default:
cmd->dptr.prp1 = pagelist[0];
cmd->dptr.prp2 = cpu_to_le64(req->prp_list_iova + sizeof(uint64_t));
break;
}
trace_nvme_cmd_map_qiov(s, cmd, req, qiov, entries);
for (i = 0; i < entries; ++i) {
trace_nvme_cmd_map_qiov_pages(s, i, pagelist[i]);
}
return 0;
fail:
/* No need to unmap [0 - i) iovs even if we've failed, since we don't
* increment s->dma_map_count. This is okay for fixed mapping memory areas
* because they are already mapped before calling this function; for
* temporary mappings, a later nvme_cmd_(un)map_qiov will reclaim by
* calling qemu_vfio_dma_reset_temporary when necessary. */
if (local_err) {
error_reportf_err(local_err, "Cannot map buffer for DMA: ");
}
return r;
}
typedef struct {
Coroutine *co;
int ret;
AioContext *ctx;
} NVMeCoData;
static void nvme_rw_cb_bh(void *opaque)
{
NVMeCoData *data = opaque;
qemu_coroutine_enter(data->co);
}
static void nvme_rw_cb(void *opaque, int ret)
{
NVMeCoData *data = opaque;
data->ret = ret;
if (!data->co) {
/* The rw coroutine hasn't yielded, don't try to enter. */
return;
}
replay_bh_schedule_oneshot_event(data->ctx, nvme_rw_cb_bh, data);
}
static coroutine_fn int nvme_co_prw_aligned(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov,
bool is_write,
int flags)
{
int r;
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
NVMeRequest *req;
uint32_t cdw12 = (((bytes >> s->blkshift) - 1) & 0xFFFF) |
(flags & BDRV_REQ_FUA ? 1 << 30 : 0);
NvmeCmd cmd = {
.opcode = is_write ? NVME_CMD_WRITE : NVME_CMD_READ,
.nsid = cpu_to_le32(s->nsid),
.cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
.cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
.cdw12 = cpu_to_le32(cdw12),
};
NVMeCoData data = {
.ctx = bdrv_get_aio_context(bs),
.ret = -EINPROGRESS,
};
trace_nvme_prw_aligned(s, is_write, offset, bytes, flags, qiov->niov);
assert(s->queue_count > 1);
req = nvme_get_free_req(ioq);
assert(req);
qemu_co_mutex_lock(&s->dma_map_lock);
r = nvme_cmd_map_qiov(bs, &cmd, req, qiov);
qemu_co_mutex_unlock(&s->dma_map_lock);
if (r) {
nvme_put_free_req_and_wake(ioq, req);
return r;
}
nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
data.co = qemu_coroutine_self();
while (data.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
qemu_co_mutex_lock(&s->dma_map_lock);
r = nvme_cmd_unmap_qiov(bs, qiov);
qemu_co_mutex_unlock(&s->dma_map_lock);
if (r) {
return r;
}
trace_nvme_rw_done(s, is_write, offset, bytes, data.ret);
return data.ret;
}
static inline bool nvme_qiov_aligned(BlockDriverState *bs,
const QEMUIOVector *qiov)
{
int i;
BDRVNVMeState *s = bs->opaque;
for (i = 0; i < qiov->niov; ++i) {
if (!QEMU_PTR_IS_ALIGNED(qiov->iov[i].iov_base,
qemu_real_host_page_size) ||
!QEMU_IS_ALIGNED(qiov->iov[i].iov_len, qemu_real_host_page_size)) {
trace_nvme_qiov_unaligned(qiov, i, qiov->iov[i].iov_base,
qiov->iov[i].iov_len, s->page_size);
return false;
}
}
return true;
}
static int nvme_co_prw(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, bool is_write, int flags)
{
BDRVNVMeState *s = bs->opaque;
int r;
QEMU_AUTO_VFREE uint8_t *buf = NULL;
QEMUIOVector local_qiov;
size_t len = QEMU_ALIGN_UP(bytes, qemu_real_host_page_size);
assert(QEMU_IS_ALIGNED(offset, s->page_size));
assert(QEMU_IS_ALIGNED(bytes, s->page_size));
assert(bytes <= s->max_transfer);
if (nvme_qiov_aligned(bs, qiov)) {
s->stats.aligned_accesses++;
return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
}
s->stats.unaligned_accesses++;
trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
buf = qemu_try_memalign(qemu_real_host_page_size, len);
if (!buf) {
return -ENOMEM;
}
qemu_iovec_init(&local_qiov, 1);
if (is_write) {
qemu_iovec_to_buf(qiov, 0, buf, bytes);
}
qemu_iovec_add(&local_qiov, buf, bytes);
r = nvme_co_prw_aligned(bs, offset, bytes, &local_qiov, is_write, flags);
qemu_iovec_destroy(&local_qiov);
if (!r && !is_write) {
qemu_iovec_from_buf(qiov, 0, buf, bytes);
}
return r;
}
static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov,
BdrvRequestFlags flags)
{
return nvme_co_prw(bs, offset, bytes, qiov, false, flags);
}
static coroutine_fn int nvme_co_pwritev(BlockDriverState *bs,
int64_t offset, int64_t bytes,
QEMUIOVector *qiov,
BdrvRequestFlags flags)
{
return nvme_co_prw(bs, offset, bytes, qiov, true, flags);
}
static coroutine_fn int nvme_co_flush(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
NVMeRequest *req;
NvmeCmd cmd = {
.opcode = NVME_CMD_FLUSH,
.nsid = cpu_to_le32(s->nsid),
};
NVMeCoData data = {
.ctx = bdrv_get_aio_context(bs),
.ret = -EINPROGRESS,
};
assert(s->queue_count > 1);
req = nvme_get_free_req(ioq);
assert(req);
nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
data.co = qemu_coroutine_self();
if (data.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
return data.ret;
}
static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset,
int64_t bytes,
BdrvRequestFlags flags)
{
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
NVMeRequest *req;
uint32_t cdw12;
if (!s->supports_write_zeroes) {
return -ENOTSUP;
}
if (bytes == 0) {
return 0;
}
cdw12 = ((bytes >> s->blkshift) - 1) & 0xFFFF;
/*
* We should not lose information. pwrite_zeroes_alignment and
* max_pwrite_zeroes guarantees it.
*/
assert(((cdw12 + 1) << s->blkshift) == bytes);
NvmeCmd cmd = {
.opcode = NVME_CMD_WRITE_ZEROES,
.nsid = cpu_to_le32(s->nsid),
.cdw10 = cpu_to_le32((offset >> s->blkshift) & 0xFFFFFFFF),
.cdw11 = cpu_to_le32(((offset >> s->blkshift) >> 32) & 0xFFFFFFFF),
};
NVMeCoData data = {
.ctx = bdrv_get_aio_context(bs),
.ret = -EINPROGRESS,
};
if (flags & BDRV_REQ_MAY_UNMAP) {
cdw12 |= (1 << 25);
}
if (flags & BDRV_REQ_FUA) {
cdw12 |= (1 << 30);
}
cmd.cdw12 = cpu_to_le32(cdw12);
trace_nvme_write_zeroes(s, offset, bytes, flags);
assert(s->queue_count > 1);
req = nvme_get_free_req(ioq);
assert(req);
nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
data.co = qemu_coroutine_self();
while (data.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
trace_nvme_rw_done(s, true, offset, bytes, data.ret);
return data.ret;
}
static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
int64_t offset,
int64_t bytes)
{
BDRVNVMeState *s = bs->opaque;
NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
NVMeRequest *req;
QEMU_AUTO_VFREE NvmeDsmRange *buf = NULL;
QEMUIOVector local_qiov;
int ret;
NvmeCmd cmd = {
.opcode = NVME_CMD_DSM,
.nsid = cpu_to_le32(s->nsid),
.cdw10 = cpu_to_le32(0), /*number of ranges - 0 based*/
.cdw11 = cpu_to_le32(1 << 2), /*deallocate bit*/
};
NVMeCoData data = {
.ctx = bdrv_get_aio_context(bs),
.ret = -EINPROGRESS,
};
if (!s->supports_discard) {
return -ENOTSUP;
}
assert(s->queue_count > 1);
/*
* Filling the @buf requires @offset and @bytes to satisfy restrictions
* defined in nvme_refresh_limits().
*/
assert(QEMU_IS_ALIGNED(bytes, 1UL << s->blkshift));
assert(QEMU_IS_ALIGNED(offset, 1UL << s->blkshift));
assert((bytes >> s->blkshift) <= UINT32_MAX);
buf = qemu_try_memalign(s->page_size, s->page_size);
if (!buf) {
return -ENOMEM;
}
memset(buf, 0, s->page_size);
buf->nlb = cpu_to_le32(bytes >> s->blkshift);
buf->slba = cpu_to_le64(offset >> s->blkshift);
buf->cattr = 0;
qemu_iovec_init(&local_qiov, 1);
qemu_iovec_add(&local_qiov, buf, 4096);
req = nvme_get_free_req(ioq);
assert(req);
qemu_co_mutex_lock(&s->dma_map_lock);
ret = nvme_cmd_map_qiov(bs, &cmd, req, &local_qiov);
qemu_co_mutex_unlock(&s->dma_map_lock);
if (ret) {
nvme_put_free_req_and_wake(ioq, req);
goto out;
}
trace_nvme_dsm(s, offset, bytes);
nvme_submit_command(ioq, req, &cmd, nvme_rw_cb, &data);
data.co = qemu_coroutine_self();
while (data.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
qemu_co_mutex_lock(&s->dma_map_lock);
ret = nvme_cmd_unmap_qiov(bs, &local_qiov);
qemu_co_mutex_unlock(&s->dma_map_lock);
if (ret) {
goto out;
}
ret = data.ret;
trace_nvme_dsm_done(s, offset, bytes, ret);
out:
qemu_iovec_destroy(&local_qiov);
return ret;
}
static int coroutine_fn nvme_co_truncate(BlockDriverState *bs, int64_t offset,
bool exact, PreallocMode prealloc,
BdrvRequestFlags flags, Error **errp)
{
int64_t cur_length;
if (prealloc != PREALLOC_MODE_OFF) {
error_setg(errp, "Unsupported preallocation mode '%s'",
PreallocMode_str(prealloc));
return -ENOTSUP;
}
cur_length = nvme_getlength(bs);
if (offset != cur_length && exact) {
error_setg(errp, "Cannot resize NVMe devices");
return -ENOTSUP;
} else if (offset > cur_length) {
error_setg(errp, "Cannot grow NVMe devices");
return -EINVAL;
}
return 0;
}
static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
static void nvme_refresh_filename(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
snprintf(bs->exact_filename, sizeof(bs->exact_filename), "nvme://%s/%i",
s->device, s->nsid);
}
static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
bs->bl.opt_mem_alignment = s->page_size;
bs->bl.request_alignment = s->page_size;
bs->bl.max_transfer = s->max_transfer;
/*
* Look at nvme_co_pwrite_zeroes: after shift and decrement we should get
* at most 0xFFFF
*/
bs->bl.max_pwrite_zeroes = 1ULL << (s->blkshift + 16);
bs->bl.pwrite_zeroes_alignment = MAX(bs->bl.request_alignment,
1UL << s->blkshift);
bs->bl.max_pdiscard = (uint64_t)UINT32_MAX << s->blkshift;
bs->bl.pdiscard_alignment = MAX(bs->bl.request_alignment,
1UL << s->blkshift);
}
static void nvme_detach_aio_context(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
for (unsigned i = 0; i < s->queue_count; i++) {
NVMeQueuePair *q = s->queues[i];
qemu_bh_delete(q->completion_bh);
q->completion_bh = NULL;
}
aio_set_event_notifier(bdrv_get_aio_context(bs),
&s->irq_notifier[MSIX_SHARED_IRQ_IDX],
false, NULL, NULL, NULL);
}
static void nvme_attach_aio_context(BlockDriverState *bs,
AioContext *new_context)
{
BDRVNVMeState *s = bs->opaque;
s->aio_context = new_context;
aio_set_event_notifier(new_context, &s->irq_notifier[MSIX_SHARED_IRQ_IDX],
false, nvme_handle_event, nvme_poll_cb,
nvme_poll_ready);
for (unsigned i = 0; i < s->queue_count; i++) {
NVMeQueuePair *q = s->queues[i];
q->completion_bh =
aio_bh_new(new_context, nvme_process_completion_bh, q);
}
}
static void nvme_aio_plug(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
assert(!s->plugged);
s->plugged = true;
}
static void nvme_aio_unplug(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
assert(s->plugged);
s->plugged = false;
for (unsigned i = INDEX_IO(0); i < s->queue_count; i++) {
NVMeQueuePair *q = s->queues[i];
qemu_mutex_lock(&q->lock);
nvme_kick(q);
nvme_process_completion(q);
qemu_mutex_unlock(&q->lock);
}
}
static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
{
int ret;
Error *local_err = NULL;
BDRVNVMeState *s = bs->opaque;
ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL, &local_err);
if (ret) {
/* FIXME: we may run out of IOVA addresses after repeated
* bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap
* doesn't reclaim addresses for fixed mappings. */
error_reportf_err(local_err, "nvme_register_buf failed: ");
}
}
static void nvme_unregister_buf(BlockDriverState *bs, void *host)
{
BDRVNVMeState *s = bs->opaque;
qemu_vfio_dma_unmap(s->vfio, host);
}
static BlockStatsSpecific *nvme_get_specific_stats(BlockDriverState *bs)
{
BlockStatsSpecific *stats = g_new(BlockStatsSpecific, 1);
BDRVNVMeState *s = bs->opaque;
stats->driver = BLOCKDEV_DRIVER_NVME;
stats->u.nvme = (BlockStatsSpecificNvme) {
.completion_errors = s->stats.completion_errors,
.aligned_accesses = s->stats.aligned_accesses,
.unaligned_accesses = s->stats.unaligned_accesses,
};
return stats;
}
static const char *const nvme_strong_runtime_opts[] = {
NVME_BLOCK_OPT_DEVICE,
NVME_BLOCK_OPT_NAMESPACE,
NULL
};
static BlockDriver bdrv_nvme = {
.format_name = "nvme",
.protocol_name = "nvme",
.instance_size = sizeof(BDRVNVMeState),
.bdrv_co_create_opts = bdrv_co_create_opts_simple,
.create_opts = &bdrv_create_opts_simple,
.bdrv_parse_filename = nvme_parse_filename,
.bdrv_file_open = nvme_file_open,
.bdrv_close = nvme_close,
.bdrv_getlength = nvme_getlength,
.bdrv_probe_blocksizes = nvme_probe_blocksizes,
.bdrv_co_truncate = nvme_co_truncate,
.bdrv_co_preadv = nvme_co_preadv,
.bdrv_co_pwritev = nvme_co_pwritev,
.bdrv_co_pwrite_zeroes = nvme_co_pwrite_zeroes,
.bdrv_co_pdiscard = nvme_co_pdiscard,
.bdrv_co_flush_to_disk = nvme_co_flush,
.bdrv_reopen_prepare = nvme_reopen_prepare,
.bdrv_refresh_filename = nvme_refresh_filename,
.bdrv_refresh_limits = nvme_refresh_limits,
.strong_runtime_opts = nvme_strong_runtime_opts,
.bdrv_get_specific_stats = nvme_get_specific_stats,
.bdrv_detach_aio_context = nvme_detach_aio_context,
.bdrv_attach_aio_context = nvme_attach_aio_context,
.bdrv_io_plug = nvme_aio_plug,
.bdrv_io_unplug = nvme_aio_unplug,
.bdrv_register_buf = nvme_register_buf,
.bdrv_unregister_buf = nvme_unregister_buf,
};
static void bdrv_nvme_init(void)
{
bdrv_register(&bdrv_nvme);
}
block_init(bdrv_nvme_init);
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