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qemu-e2k/block/nvme.c
Stefan Hajnoczi 66547f416a block/nvme: invoke blk_io_plug_call() outside q->lock 
blk_io_plug_call() is invoked outside a blk_io_plug()/blk_io_unplug()
section while opening the NVMe drive from:

  nvme_file_open() ->
  nvme_init() ->
  nvme_identify() ->
  nvme_admin_cmd_sync() ->
  nvme_submit_command() ->
  blk_io_plug_call()

blk_io_plug_call() immediately invokes the given callback when the
current thread is not plugged, as is the case during nvme_file_open().

Unfortunately, nvme_submit_command() calls blk_io_plug_call() with
q->lock still held:

    ...
    q->sq.tail = (q->sq.tail + 1) % NVME_QUEUE_SIZE;
    q->need_kick++;
    blk_io_plug_call(nvme_unplug_fn, q);
    qemu_mutex_unlock(&q->lock);
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^

nvme_unplug_fn() deadlocks trying to acquire q->lock because the lock is
already acquired by the same thread. The symptom is that QEMU hangs
during startup while opening the NVMe drive.

Fix this by moving the blk_io_plug_call() outside q->lock. This is safe
because no other thread runs code related to this queue and
blk_io_plug_call()'s internal state is immune to thread safety issues
since it is thread-local.

Reported-by: Lukáš Doktor <ldoktor@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Lukas Doktor <ldoktor@redhat.com>
Message-id: 20230712191628.252806-1-stefanha@redhat.com
Fixes: f2e590002b ("block/nvme: convert to blk_io_plug_call() API")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-07-17 09:17:41 -04:00

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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/memalign.h"
#include "qemu/vfio-helpers.h"
#include "block/block-io.h"
#include "block/block_int.h"
#include "sysemu/block-backend.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 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 (!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;
}
static NVMeRequest *nvme_get_free_req_nofail_locked(NVMeQueuePair *q)
{
NVMeRequest *req;
req = &q->reqs[q->free_req_head];
q->free_req_head = req->free_req_next;
req->free_req_next = -1;
return req;
}
/* Return a free request element if any, otherwise return NULL. */
static NVMeRequest *nvme_get_free_req_nowait(NVMeQueuePair *q)
{
QEMU_LOCK_GUARD(&q->lock);
if (q->free_req_head == -1) {
return NULL;
}
return nvme_get_free_req_nofail_locked(q);
}
/*
* Wait for a free request to become available if necessary, then
* return it.
*/
static coroutine_fn NVMeRequest *nvme_get_free_req(NVMeQueuePair *q)
{
QEMU_LOCK_GUARD(&q->lock);
while (q->free_req_head == -1) {
trace_nvme_free_req_queue_wait(q->s, q->index);
qemu_co_queue_wait(&q->free_req_queue, &q->lock);
}
return nvme_get_free_req_nofail_locked(q);
}
/* 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);
/*
* 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_unplug_fn(void *opaque)
{
NVMeQueuePair *q = opaque;
QEMU_LOCK_GUARD(&q->lock);
nvme_kick(q);
nvme_process_completion(q);
}
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++;
qemu_mutex_unlock(&q->lock);
blk_io_plug_call(nvme_unplug_fn, q);
}
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_nowait(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],
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],
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 coroutine_fn nvme_co_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 coroutine_fn 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_co_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],
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],
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 bool nvme_register_buf(BlockDriverState *bs, void *host, size_t size,
Error **errp)
{
int ret;
BDRVNVMeState *s = bs->opaque;
/*
* 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.
*/
ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL, errp);
return ret == 0;
}
static void nvme_unregister_buf(BlockDriverState *bs, void *host, size_t size)
{
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_co_getlength = nvme_co_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_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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