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qemu-e2k/block/nvme.c
Li Feng 2916405a11 block/nvme: optimize the performance of nvme driver based on vfio-pci 
When the IO size is larger than 2 pages, we move the the pointer one by
one in the pagelist, this is inefficient.

This is a simple benchmark result:

Before:
$ qemu-io -c 'write 0 1G' nvme://0000:00:04.0/1

wrote 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.41 (424.504 MiB/sec and 0.4146 ops/sec)

 $ qemu-io -c 'read 0 1G' nvme://0000:00:04.0/1

read 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.03 (503.055 MiB/sec and 0.4913 ops/sec)

After:
$ qemu-io -c 'write 0 1G' nvme://0000:00:04.0/1

wrote 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:02.17 (471.517 MiB/sec and 0.4605 ops/sec)

 $ qemu-io -c 'read 0 1G' nvme://0000:00:04.0/1

read 1073741824/1073741824 bytes at offset 0
1 GiB, 1 ops; 0:00:01.94 (526.770 MiB/sec and 0.5144 ops/sec)

Signed-off-by: Li Feng <lifeng1519@gmail.com>
Message-Id: <20181101103807.25862-1-lifeng1519@gmail.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2019-01-09 09:38:34 +08:00

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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/cutils.h"
#include "qemu/option.h"
#include "qemu/vfio-helpers.h"
#include "block/block_int.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_BAR_SIZE 8192
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;
bool busy;
} NVMeRequest;
typedef struct {
CoQueue free_req_queue;
QemuMutex lock;
/* Fields protected by BQL */
int index;
uint8_t *prp_list_pages;
/* Fields protected by @lock */
NVMeQueue sq, cq;
int cq_phase;
NVMeRequest reqs[NVME_QUEUE_SIZE];
bool busy;
int need_kick;
int inflight;
} NVMeQueuePair;
/* Memory mapped registers */
typedef volatile struct {
uint64_t cap;
uint32_t vs;
uint32_t intms;
uint32_t intmc;
uint32_t cc;
uint32_t reserved0;
uint32_t csts;
uint32_t nssr;
uint32_t aqa;
uint64_t asq;
uint64_t acq;
uint32_t cmbloc;
uint32_t cmbsz;
uint8_t reserved1[0xec0];
uint8_t cmd_set_specfic[0x100];
uint32_t doorbells[];
} QEMU_PACKED NVMeRegs;
QEMU_BUILD_BUG_ON(offsetof(NVMeRegs, doorbells) != 0x1000);
typedef struct {
AioContext *aio_context;
QEMUVFIOState *vfio;
NVMeRegs *regs;
/* The submission/completion queue pairs.
* [0]: admin queue.
* [1..]: io queues.
*/
NVMeQueuePair **queues;
int nr_queues;
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;
uint64_t nsze; /* Namespace size reported by identify command */
int nsid; /* The namespace id to read/write data. */
uint64_t max_transfer;
bool plugged;
CoMutex dma_map_lock;
CoQueue dma_flush_queue;
/* Total size of mapped qiov, accessed under dma_map_lock */
int dma_map_count;
} BDRVNVMeState;
#define NVME_BLOCK_OPT_DEVICE "device"
#define NVME_BLOCK_OPT_NAMESPACE "namespace"
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 */ }
},
};
static void nvme_init_queue(BlockDriverState *bs, NVMeQueue *q,
int nentries, int entry_bytes, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
size_t bytes;
int r;
bytes = ROUND_UP(nentries * entry_bytes, s->page_size);
q->head = q->tail = 0;
q->queue = qemu_try_blockalign0(bs, bytes);
if (!q->queue) {
error_setg(errp, "Cannot allocate queue");
return;
}
r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova);
if (r) {
error_setg(errp, "Cannot map queue");
}
}
static void nvme_free_queue_pair(BlockDriverState *bs, NVMeQueuePair *q)
{
qemu_vfree(q->prp_list_pages);
qemu_vfree(q->sq.queue);
qemu_vfree(q->cq.queue);
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 (qemu_co_enter_next(&q->free_req_queue, &q->lock)) {
/* Retry all pending requests */
}
qemu_mutex_unlock(&q->lock);
}
static NVMeQueuePair *nvme_create_queue_pair(BlockDriverState *bs,
int idx, int size,
Error **errp)
{
int i, r;
BDRVNVMeState *s = bs->opaque;
Error *local_err = NULL;
NVMeQueuePair *q = g_new0(NVMeQueuePair, 1);
uint64_t prp_list_iova;
qemu_mutex_init(&q->lock);
q->index = idx;
qemu_co_queue_init(&q->free_req_queue);
q->prp_list_pages = qemu_blockalign0(bs, s->page_size * NVME_QUEUE_SIZE);
r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages,
s->page_size * NVME_QUEUE_SIZE,
false, &prp_list_iova);
if (r) {
goto fail;
}
for (i = 0; i < NVME_QUEUE_SIZE; i++) {
NVMeRequest *req = &q->reqs[i];
req->cid = i + 1;
req->prp_list_page = q->prp_list_pages + i * s->page_size;
req->prp_list_iova = prp_list_iova + i * s->page_size;
}
nvme_init_queue(bs, &q->sq, size, NVME_SQ_ENTRY_BYTES, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto fail;
}
q->sq.doorbell = &s->regs->doorbells[idx * 2 * s->doorbell_scale];
nvme_init_queue(bs, &q->cq, size, NVME_CQ_ENTRY_BYTES, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto fail;
}
q->cq.doorbell = &s->regs->doorbells[idx * 2 * s->doorbell_scale + 1];
return q;
fail:
nvme_free_queue_pair(bs, q);
return NULL;
}
/* With q->lock */
static void nvme_kick(BDRVNVMeState *s, NVMeQueuePair *q)
{
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)
{
int i;
NVMeRequest *req = NULL;
qemu_mutex_lock(&q->lock);
while (q->inflight + q->need_kick > NVME_QUEUE_SIZE - 2) {
/* We have to leave one slot empty as that is the full queue case (head
* == tail + 1). */
if (qemu_in_coroutine()) {
trace_nvme_free_req_queue_wait(q);
qemu_co_queue_wait(&q->free_req_queue, &q->lock);
} else {
qemu_mutex_unlock(&q->lock);
return NULL;
}
}
for (i = 0; i < NVME_QUEUE_SIZE; i++) {
if (!q->reqs[i].busy) {
q->reqs[i].busy = true;
req = &q->reqs[i];
break;
}
}
/* We have checked inflight and need_kick while holding q->lock, so one
* free req must be available. */
assert(req);
qemu_mutex_unlock(&q->lock);
return req;
}
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(BDRVNVMeState *s, NVMeQueuePair *q)
{
bool progress = false;
NVMeRequest *preq;
NVMeRequest req;
NvmeCqe *c;
trace_nvme_process_completion(s, q->index, q->inflight);
if (q->busy || s->plugged) {
trace_nvme_process_completion_queue_busy(s, q->index);
return false;
}
q->busy = true;
assert(q->inflight >= 0);
while (q->inflight) {
int16_t cid;
c = (NvmeCqe *)&q->cq.queue[q->cq.head * NVME_CQ_ENTRY_BYTES];
if (!c->cid || (le16_to_cpu(c->status) & 0x1) == q->cq_phase) {
break;
}
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) {
fprintf(stderr, "Unexpected CID in completion queue: %" PRIu32 "\n",
cid);
continue;
}
assert(cid <= NVME_QUEUE_SIZE);
trace_nvme_complete_command(s, q->index, cid);
preq = &q->reqs[cid - 1];
req = *preq;
assert(req.cid == cid);
assert(req.cb);
preq->busy = false;
preq->cb = preq->opaque = NULL;
qemu_mutex_unlock(&q->lock);
req.cb(req.opaque, nvme_translate_error(c));
qemu_mutex_lock(&q->lock);
c->cid = cpu_to_le16(0);
q->inflight--;
/* Flip Phase Tag bit. */
c->status = cpu_to_le16(le16_to_cpu(c->status) ^ 0x1);
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);
if (!qemu_co_queue_empty(&q->free_req_queue)) {
aio_bh_schedule_oneshot(s->aio_context, nvme_free_req_queue_cb, q);
}
}
q->busy = false;
return progress;
}
static void nvme_trace_command(const NvmeCmd *cmd)
{
int i;
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(BDRVNVMeState *s, NVMeQueuePair *q,
NVMeRequest *req,
NvmeCmd *cmd, BlockCompletionFunc cb,
void *opaque)
{
assert(!req->cb);
req->cb = cb;
req->opaque = opaque;
cmd->cid = cpu_to_le32(req->cid);
trace_nvme_submit_command(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(s, q);
nvme_process_completion(s, q);
qemu_mutex_unlock(&q->lock);
}
static void nvme_cmd_sync_cb(void *opaque, int ret)
{
int *pret = opaque;
*pret = ret;
}
static int nvme_cmd_sync(BlockDriverState *bs, NVMeQueuePair *q,
NvmeCmd *cmd)
{
NVMeRequest *req;
BDRVNVMeState *s = bs->opaque;
int ret = -EINPROGRESS;
req = nvme_get_free_req(q);
if (!req) {
return -EBUSY;
}
nvme_submit_command(s, q, req, cmd, nvme_cmd_sync_cb, &ret);
BDRV_POLL_WHILE(bs, ret == -EINPROGRESS);
return ret;
}
static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
NvmeIdCtrl *idctrl;
NvmeIdNs *idns;
uint8_t *resp;
int r;
uint64_t iova;
NvmeCmd cmd = {
.opcode = NVME_ADM_CMD_IDENTIFY,
.cdw10 = cpu_to_le32(0x1),
};
resp = qemu_try_blockalign0(bs, sizeof(NvmeIdCtrl));
if (!resp) {
error_setg(errp, "Cannot allocate buffer for identify response");
goto out;
}
idctrl = (NvmeIdCtrl *)resp;
idns = (NvmeIdNs *)resp;
r = qemu_vfio_dma_map(s->vfio, resp, sizeof(NvmeIdCtrl), true, &iova);
if (r) {
error_setg(errp, "Cannot map buffer for DMA");
goto out;
}
cmd.prp1 = cpu_to_le64(iova);
if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
error_setg(errp, "Failed to identify controller");
goto out;
}
if (le32_to_cpu(idctrl->nn) < namespace) {
error_setg(errp, "Invalid namespace");
goto out;
}
s->write_cache_supported = le32_to_cpu(idctrl->vwc) & 0x1;
s->max_transfer = (idctrl->mdts ? 1 << idctrl->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);
memset(resp, 0, 4096);
cmd.cdw10 = 0;
cmd.nsid = cpu_to_le32(namespace);
if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
error_setg(errp, "Failed to identify namespace");
goto out;
}
s->nsze = le64_to_cpu(idns->nsze);
out:
qemu_vfio_dma_unmap(s->vfio, resp);
qemu_vfree(resp);
}
static bool nvme_poll_queues(BDRVNVMeState *s)
{
bool progress = false;
int i;
for (i = 0; i < s->nr_queues; i++) {
NVMeQueuePair *q = s->queues[i];
qemu_mutex_lock(&q->lock);
while (nvme_process_completion(s, q)) {
/* Keep polling */
progress = true;
}
qemu_mutex_unlock(&q->lock);
}
return progress;
}
static void nvme_handle_event(EventNotifier *n)
{
BDRVNVMeState *s = container_of(n, BDRVNVMeState, irq_notifier);
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;
int n = s->nr_queues;
NVMeQueuePair *q;
NvmeCmd cmd;
int queue_size = NVME_QUEUE_SIZE;
q = nvme_create_queue_pair(bs, n, queue_size, errp);
if (!q) {
return false;
}
cmd = (NvmeCmd) {
.opcode = NVME_ADM_CMD_CREATE_CQ,
.prp1 = cpu_to_le64(q->cq.iova),
.cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
.cdw11 = cpu_to_le32(0x3),
};
if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
error_setg(errp, "Failed to create io queue [%d]", n);
nvme_free_queue_pair(bs, q);
return false;
}
cmd = (NvmeCmd) {
.opcode = NVME_ADM_CMD_CREATE_SQ,
.prp1 = cpu_to_le64(q->sq.iova),
.cdw10 = cpu_to_le32(((queue_size - 1) << 16) | (n & 0xFFFF)),
.cdw11 = cpu_to_le32(0x1 | (n << 16)),
};
if (nvme_cmd_sync(bs, s->queues[0], &cmd)) {
error_setg(errp, "Failed to create io queue [%d]", n);
nvme_free_queue_pair(bs, q);
return false;
}
s->queues = g_renew(NVMeQueuePair *, s->queues, n + 1);
s->queues[n] = q;
s->nr_queues++;
return true;
}
static bool nvme_poll_cb(void *opaque)
{
EventNotifier *e = opaque;
BDRVNVMeState *s = container_of(e, BDRVNVMeState, irq_notifier);
bool progress = false;
trace_nvme_poll_cb(s);
progress = nvme_poll_queues(s);
return progress;
}
static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
Error **errp)
{
BDRVNVMeState *s = bs->opaque;
int ret;
uint64_t cap;
uint64_t timeout_ms;
uint64_t deadline, now;
Error *local_err = NULL;
qemu_co_mutex_init(&s->dma_map_lock);
qemu_co_queue_init(&s->dma_flush_queue);
s->nsid = namespace;
s->aio_context = bdrv_get_aio_context(bs);
ret = event_notifier_init(&s->irq_notifier, 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;
}
s->regs = qemu_vfio_pci_map_bar(s->vfio, 0, 0, NVME_BAR_SIZE, errp);
if (!s->regs) {
ret = -EINVAL;
goto out;
}
/* Perform initialize sequence as described in NVMe spec "7.6.1
* Initialization". */
cap = le64_to_cpu(s->regs->cap);
if (!(cap & (1ULL << 37))) {
error_setg(errp, "Device doesn't support NVMe command set");
ret = -EINVAL;
goto out;
}
s->page_size = MAX(4096, 1 << (12 + ((cap >> 48) & 0xF)));
s->doorbell_scale = (4 << (((cap >> 32) & 0xF))) / sizeof(uint32_t);
bs->bl.opt_mem_alignment = s->page_size;
timeout_ms = MIN(500 * ((cap >> 24) & 0xFF), 30000);
/* Reset device to get a clean state. */
s->regs->cc = cpu_to_le32(le32_to_cpu(s->regs->cc) & 0xFE);
/* Wait for CSTS.RDY = 0. */
deadline = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + timeout_ms * 1000000ULL;
while (le32_to_cpu(s->regs->csts) & 0x1) {
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;
}
}
/* Set up admin queue. */
s->queues = g_new(NVMeQueuePair *, 1);
s->nr_queues = 1;
s->queues[0] = nvme_create_queue_pair(bs, 0, NVME_QUEUE_SIZE, errp);
if (!s->queues[0]) {
ret = -EINVAL;
goto out;
}
QEMU_BUILD_BUG_ON(NVME_QUEUE_SIZE & 0xF000);
s->regs->aqa = cpu_to_le32((NVME_QUEUE_SIZE << 16) | NVME_QUEUE_SIZE);
s->regs->asq = cpu_to_le64(s->queues[0]->sq.iova);
s->regs->acq = cpu_to_le64(s->queues[0]->cq.iova);
/* After setting up all control registers we can enable device now. */
s->regs->cc = cpu_to_le32((ctz32(NVME_CQ_ENTRY_BYTES) << 20) |
(ctz32(NVME_SQ_ENTRY_BYTES) << 16) |
0x1);
/* Wait for CSTS.RDY = 1. */
now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
deadline = now + timeout_ms * 1000000;
while (!(le32_to_cpu(s->regs->csts) & 0x1)) {
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,
false, nvme_handle_event, nvme_poll_cb);
nvme_identify(bs, namespace, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EIO;
goto out;
}
/* Set up command queues. */
if (!nvme_add_io_queue(bs, errp)) {
ret = -EIO;
}
out:
/* 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_cmd_sync(bs, s->queues[0], &cmd);
if (ret) {
error_setg(errp, "Failed to configure NVMe write cache");
}
return ret;
}
static void nvme_close(BlockDriverState *bs)
{
int i;
BDRVNVMeState *s = bs->opaque;
for (i = 0; i < s->nr_queues; ++i) {
nvme_free_queue_pair(bs, s->queues[i]);
}
g_free(s->queues);
aio_set_event_notifier(bdrv_get_aio_context(bs), &s->irq_notifier,
false, NULL, NULL);
event_notifier_cleanup(&s->irq_notifier);
qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE);
qemu_vfio_close(s->vfio);
}
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;
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;
}
}
bs->supported_write_flags = BDRV_REQ_FUA;
return 0;
fail:
nvme_close(bs);
return ret;
}
static int64_t nvme_getlength(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
return s->nsze << BDRV_SECTOR_BITS;
}
/* 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;
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;
try_map:
r = qemu_vfio_dma_map(s->vfio,
qiov->iov[i].iov_base,
qiov->iov[i].iov_len,
true, &iova);
if (r == -ENOMEM && retry) {
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;
}
}
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->prp1 = pagelist[0];
cmd->prp2 = 0;
break;
case 2:
cmd->prp1 = pagelist[0];
cmd->prp2 = pagelist[1];
break;
default:
cmd->prp1 = pagelist[0];
cmd->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. */
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;
}
aio_bh_schedule_oneshot(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[1];
NVMeRequest *req;
uint32_t cdw12 = (((bytes >> BDRV_SECTOR_BITS) - 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 >> BDRV_SECTOR_BITS) & 0xFFFFFFFF),
.cdw11 = cpu_to_le32(((offset >> BDRV_SECTOR_BITS) >> 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->nr_queues > 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) {
req->busy = false;
return r;
}
nvme_submit_command(s, 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, s->page_size) ||
!QEMU_IS_ALIGNED(qiov->iov[i].iov_len, s->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;
uint8_t *buf = NULL;
QEMUIOVector local_qiov;
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)) {
return nvme_co_prw_aligned(bs, offset, bytes, qiov, is_write, flags);
}
trace_nvme_prw_buffered(s, offset, bytes, qiov->niov, is_write);
buf = qemu_try_blockalign(bs, bytes);
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);
}
qemu_vfree(buf);
return r;
}
static coroutine_fn int nvme_co_preadv(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
return nvme_co_prw(bs, offset, bytes, qiov, false, flags);
}
static coroutine_fn int nvme_co_pwritev(BlockDriverState *bs,
uint64_t offset, uint64_t bytes,
QEMUIOVector *qiov, int 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[1];
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->nr_queues > 1);
req = nvme_get_free_req(ioq);
assert(req);
nvme_submit_command(s, ioq, req, &cmd, nvme_rw_cb, &data);
data.co = qemu_coroutine_self();
if (data.ret == -EINPROGRESS) {
qemu_coroutine_yield();
}
return data.ret;
}
static int nvme_reopen_prepare(BDRVReopenState *reopen_state,
BlockReopenQueue *queue, Error **errp)
{
return 0;
}
static void nvme_refresh_filename(BlockDriverState *bs, QDict *opts)
{
qdict_del(opts, "filename");
if (!qdict_size(opts)) {
snprintf(bs->exact_filename, sizeof(bs->exact_filename), "%s://",
bs->drv->format_name);
}
qdict_put_str(opts, "driver", bs->drv->format_name);
bs->full_open_options = qobject_ref(opts);
}
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;
}
static void nvme_detach_aio_context(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
aio_set_event_notifier(bdrv_get_aio_context(bs), &s->irq_notifier,
false, 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,
false, nvme_handle_event, nvme_poll_cb);
}
static void nvme_aio_plug(BlockDriverState *bs)
{
BDRVNVMeState *s = bs->opaque;
assert(!s->plugged);
s->plugged = true;
}
static void nvme_aio_unplug(BlockDriverState *bs)
{
int i;
BDRVNVMeState *s = bs->opaque;
assert(s->plugged);
s->plugged = false;
for (i = 1; i < s->nr_queues; i++) {
NVMeQueuePair *q = s->queues[i];
qemu_mutex_lock(&q->lock);
nvme_kick(s, q);
nvme_process_completion(s, q);
qemu_mutex_unlock(&q->lock);
}
}
static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)
{
int ret;
BDRVNVMeState *s = bs->opaque;
ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL);
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_report("nvme_register_buf failed: %s", strerror(-ret));
}
}
static void nvme_unregister_buf(BlockDriverState *bs, void *host)
{
BDRVNVMeState *s = bs->opaque;
qemu_vfio_dma_unmap(s->vfio, host);
}
static BlockDriver bdrv_nvme = {
.format_name = "nvme",
.protocol_name = "nvme",
.instance_size = sizeof(BDRVNVMeState),
.bdrv_parse_filename = nvme_parse_filename,
.bdrv_file_open = nvme_file_open,
.bdrv_close = nvme_close,
.bdrv_getlength = nvme_getlength,
.bdrv_co_preadv = nvme_co_preadv,
.bdrv_co_pwritev = nvme_co_pwritev,
.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,
.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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