qemu/migration/multifd.c
Li Zhang 077fbb5942 multifd: Shut down the QIO channels to avoid blocking the send threads when they are terminated.
When doing live migration with multifd channels 8, 16 or larger number,
the guest hangs in the presence of the network errors such as missing TCP ACKs.

At sender's side:
The main thread is blocked on qemu_thread_join, migration_fd_cleanup
is called because one thread fails on qio_channel_write_all when
the network problem happens and other send threads are blocked on sendmsg.
They could not be terminated. So the main thread is blocked on qemu_thread_join
to wait for the threads terminated.

(gdb) bt
0  0x00007f30c8dcffc0 in __pthread_clockjoin_ex () at /lib64/libpthread.so.0
1  0x000055cbb716084b in qemu_thread_join (thread=0x55cbb881f418) at ../util/qemu-thread-posix.c:627
2  0x000055cbb6b54e40 in multifd_save_cleanup () at ../migration/multifd.c:542
3  0x000055cbb6b4de06 in migrate_fd_cleanup (s=0x55cbb8024000) at ../migration/migration.c:1808
4  0x000055cbb6b4dfb4 in migrate_fd_cleanup_bh (opaque=0x55cbb8024000) at ../migration/migration.c:1850
5  0x000055cbb7173ac1 in aio_bh_call (bh=0x55cbb7eb98e0) at ../util/async.c:141
6  0x000055cbb7173bcb in aio_bh_poll (ctx=0x55cbb7ebba80) at ../util/async.c:169
7  0x000055cbb715ba4b in aio_dispatch (ctx=0x55cbb7ebba80) at ../util/aio-posix.c:381
8  0x000055cbb7173ffe in aio_ctx_dispatch (source=0x55cbb7ebba80, callback=0x0, user_data=0x0) at ../util/async.c:311
9  0x00007f30c9c8cdf4 in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
10 0x000055cbb71851a2 in glib_pollfds_poll () at ../util/main-loop.c:232
11 0x000055cbb718521c in os_host_main_loop_wait (timeout=42251070366) at ../util/main-loop.c:255
12 0x000055cbb7185321 in main_loop_wait (nonblocking=0) at ../util/main-loop.c:531
13 0x000055cbb6e6ba27 in qemu_main_loop () at ../softmmu/runstate.c:726
14 0x000055cbb6ad6fd7 in main (argc=68, argv=0x7ffc0c578888, envp=0x7ffc0c578ab0) at ../softmmu/main.c:50

To make sure that the send threads could be terminated, IO channels should be
shut down to avoid waiting IO.

Signed-off-by: Li Zhang <lizhang@suse.de>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2021-12-15 10:31:42 +01:00

1239 lines
35 KiB
C

/*
* Multifd common code
*
* Copyright (c) 2019-2020 Red Hat Inc
*
* Authors:
* Juan Quintela <quintela@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 "qemu/rcu.h"
#include "exec/target_page.h"
#include "sysemu/sysemu.h"
#include "exec/ramblock.h"
#include "qemu/error-report.h"
#include "qapi/error.h"
#include "ram.h"
#include "migration.h"
#include "socket.h"
#include "tls.h"
#include "qemu-file.h"
#include "trace.h"
#include "multifd.h"
#include "qemu/yank.h"
#include "io/channel-socket.h"
#include "yank_functions.h"
/* Multiple fd's */
#define MULTIFD_MAGIC 0x11223344U
#define MULTIFD_VERSION 1
typedef struct {
uint32_t magic;
uint32_t version;
unsigned char uuid[16]; /* QemuUUID */
uint8_t id;
uint8_t unused1[7]; /* Reserved for future use */
uint64_t unused2[4]; /* Reserved for future use */
} __attribute__((packed)) MultiFDInit_t;
/* Multifd without compression */
/**
* nocomp_send_setup: setup send side
*
* For no compression this function does nothing.
*
* Returns 0 for success or -1 for error
*
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
static int nocomp_send_setup(MultiFDSendParams *p, Error **errp)
{
return 0;
}
/**
* nocomp_send_cleanup: cleanup send side
*
* For no compression this function does nothing.
*
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
static void nocomp_send_cleanup(MultiFDSendParams *p, Error **errp)
{
return;
}
/**
* nocomp_send_prepare: prepare date to be able to send
*
* For no compression we just have to calculate the size of the
* packet.
*
* Returns 0 for success or -1 for error
*
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)
{
p->next_packet_size = p->pages->num * qemu_target_page_size();
p->flags |= MULTIFD_FLAG_NOCOMP;
return 0;
}
/**
* nocomp_send_write: do the actual write of the data
*
* For no compression we just have to write the data.
*
* Returns 0 for success or -1 for error
*
* @p: Params for the channel that we are using
* @used: number of pages used
* @errp: pointer to an error
*/
static int nocomp_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
{
return qio_channel_writev_all(p->c, p->pages->iov, used, errp);
}
/**
* nocomp_recv_setup: setup receive side
*
* For no compression this function does nothing.
*
* Returns 0 for success or -1 for error
*
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
static int nocomp_recv_setup(MultiFDRecvParams *p, Error **errp)
{
return 0;
}
/**
* nocomp_recv_cleanup: setup receive side
*
* For no compression this function does nothing.
*
* @p: Params for the channel that we are using
*/
static void nocomp_recv_cleanup(MultiFDRecvParams *p)
{
}
/**
* nocomp_recv_pages: read the data from the channel into actual pages
*
* For no compression we just need to read things into the correct place.
*
* Returns 0 for success or -1 for error
*
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
static int nocomp_recv_pages(MultiFDRecvParams *p, Error **errp)
{
uint32_t flags = p->flags & MULTIFD_FLAG_COMPRESSION_MASK;
if (flags != MULTIFD_FLAG_NOCOMP) {
error_setg(errp, "multifd %d: flags received %x flags expected %x",
p->id, flags, MULTIFD_FLAG_NOCOMP);
return -1;
}
return qio_channel_readv_all(p->c, p->pages->iov, p->pages->num, errp);
}
static MultiFDMethods multifd_nocomp_ops = {
.send_setup = nocomp_send_setup,
.send_cleanup = nocomp_send_cleanup,
.send_prepare = nocomp_send_prepare,
.send_write = nocomp_send_write,
.recv_setup = nocomp_recv_setup,
.recv_cleanup = nocomp_recv_cleanup,
.recv_pages = nocomp_recv_pages
};
static MultiFDMethods *multifd_ops[MULTIFD_COMPRESSION__MAX] = {
[MULTIFD_COMPRESSION_NONE] = &multifd_nocomp_ops,
};
void multifd_register_ops(int method, MultiFDMethods *ops)
{
assert(0 < method && method < MULTIFD_COMPRESSION__MAX);
multifd_ops[method] = ops;
}
static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
{
MultiFDInit_t msg = {};
int ret;
msg.magic = cpu_to_be32(MULTIFD_MAGIC);
msg.version = cpu_to_be32(MULTIFD_VERSION);
msg.id = p->id;
memcpy(msg.uuid, &qemu_uuid.data, sizeof(msg.uuid));
ret = qio_channel_write_all(p->c, (char *)&msg, sizeof(msg), errp);
if (ret != 0) {
return -1;
}
return 0;
}
static int multifd_recv_initial_packet(QIOChannel *c, Error **errp)
{
MultiFDInit_t msg;
int ret;
ret = qio_channel_read_all(c, (char *)&msg, sizeof(msg), errp);
if (ret != 0) {
return -1;
}
msg.magic = be32_to_cpu(msg.magic);
msg.version = be32_to_cpu(msg.version);
if (msg.magic != MULTIFD_MAGIC) {
error_setg(errp, "multifd: received packet magic %x "
"expected %x", msg.magic, MULTIFD_MAGIC);
return -1;
}
if (msg.version != MULTIFD_VERSION) {
error_setg(errp, "multifd: received packet version %d "
"expected %d", msg.version, MULTIFD_VERSION);
return -1;
}
if (memcmp(msg.uuid, &qemu_uuid, sizeof(qemu_uuid))) {
char *uuid = qemu_uuid_unparse_strdup(&qemu_uuid);
char *msg_uuid = qemu_uuid_unparse_strdup((const QemuUUID *)msg.uuid);
error_setg(errp, "multifd: received uuid '%s' and expected "
"uuid '%s' for channel %hhd", msg_uuid, uuid, msg.id);
g_free(uuid);
g_free(msg_uuid);
return -1;
}
if (msg.id > migrate_multifd_channels()) {
error_setg(errp, "multifd: received channel version %d "
"expected %d", msg.version, MULTIFD_VERSION);
return -1;
}
return msg.id;
}
static MultiFDPages_t *multifd_pages_init(size_t size)
{
MultiFDPages_t *pages = g_new0(MultiFDPages_t, 1);
pages->allocated = size;
pages->iov = g_new0(struct iovec, size);
pages->offset = g_new0(ram_addr_t, size);
return pages;
}
static void multifd_pages_clear(MultiFDPages_t *pages)
{
pages->num = 0;
pages->allocated = 0;
pages->packet_num = 0;
pages->block = NULL;
g_free(pages->iov);
pages->iov = NULL;
g_free(pages->offset);
pages->offset = NULL;
g_free(pages);
}
static void multifd_send_fill_packet(MultiFDSendParams *p)
{
MultiFDPacket_t *packet = p->packet;
int i;
packet->flags = cpu_to_be32(p->flags);
packet->pages_alloc = cpu_to_be32(p->pages->allocated);
packet->pages_used = cpu_to_be32(p->pages->num);
packet->next_packet_size = cpu_to_be32(p->next_packet_size);
packet->packet_num = cpu_to_be64(p->packet_num);
if (p->pages->block) {
strncpy(packet->ramblock, p->pages->block->idstr, 256);
}
for (i = 0; i < p->pages->num; i++) {
/* there are architectures where ram_addr_t is 32 bit */
uint64_t temp = p->pages->offset[i];
packet->offset[i] = cpu_to_be64(temp);
}
}
static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
{
MultiFDPacket_t *packet = p->packet;
size_t page_size = qemu_target_page_size();
uint32_t pages_max = MULTIFD_PACKET_SIZE / page_size;
RAMBlock *block;
int i;
packet->magic = be32_to_cpu(packet->magic);
if (packet->magic != MULTIFD_MAGIC) {
error_setg(errp, "multifd: received packet "
"magic %x and expected magic %x",
packet->magic, MULTIFD_MAGIC);
return -1;
}
packet->version = be32_to_cpu(packet->version);
if (packet->version != MULTIFD_VERSION) {
error_setg(errp, "multifd: received packet "
"version %d and expected version %d",
packet->version, MULTIFD_VERSION);
return -1;
}
p->flags = be32_to_cpu(packet->flags);
packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
/*
* If we received a packet that is 100 times bigger than expected
* just stop migration. It is a magic number.
*/
if (packet->pages_alloc > pages_max * 100) {
error_setg(errp, "multifd: received packet "
"with size %d and expected a maximum size of %d",
packet->pages_alloc, pages_max * 100) ;
return -1;
}
/*
* We received a packet that is bigger than expected but inside
* reasonable limits (see previous comment). Just reallocate.
*/
if (packet->pages_alloc > p->pages->allocated) {
multifd_pages_clear(p->pages);
p->pages = multifd_pages_init(packet->pages_alloc);
}
p->pages->num = be32_to_cpu(packet->pages_used);
if (p->pages->num > packet->pages_alloc) {
error_setg(errp, "multifd: received packet "
"with %d pages and expected maximum pages are %d",
p->pages->num, packet->pages_alloc) ;
return -1;
}
p->next_packet_size = be32_to_cpu(packet->next_packet_size);
p->packet_num = be64_to_cpu(packet->packet_num);
if (p->pages->num == 0) {
return 0;
}
/* make sure that ramblock is 0 terminated */
packet->ramblock[255] = 0;
block = qemu_ram_block_by_name(packet->ramblock);
if (!block) {
error_setg(errp, "multifd: unknown ram block %s",
packet->ramblock);
return -1;
}
p->pages->block = block;
for (i = 0; i < p->pages->num; i++) {
uint64_t offset = be64_to_cpu(packet->offset[i]);
if (offset > (block->used_length - page_size)) {
error_setg(errp, "multifd: offset too long %" PRIu64
" (max " RAM_ADDR_FMT ")",
offset, block->used_length);
return -1;
}
p->pages->offset[i] = offset;
p->pages->iov[i].iov_base = block->host + offset;
p->pages->iov[i].iov_len = page_size;
}
return 0;
}
struct {
MultiFDSendParams *params;
/* array of pages to sent */
MultiFDPages_t *pages;
/* global number of generated multifd packets */
uint64_t packet_num;
/* send channels ready */
QemuSemaphore channels_ready;
/*
* Have we already run terminate threads. There is a race when it
* happens that we got one error while we are exiting.
* We will use atomic operations. Only valid values are 0 and 1.
*/
int exiting;
/* multifd ops */
MultiFDMethods *ops;
} *multifd_send_state;
/*
* How we use multifd_send_state->pages and channel->pages?
*
* We create a pages for each channel, and a main one. Each time that
* we need to send a batch of pages we interchange the ones between
* multifd_send_state and the channel that is sending it. There are
* two reasons for that:
* - to not have to do so many mallocs during migration
* - to make easier to know what to free at the end of migration
*
* This way we always know who is the owner of each "pages" struct,
* and we don't need any locking. It belongs to the migration thread
* or to the channel thread. Switching is safe because the migration
* thread is using the channel mutex when changing it, and the channel
* have to had finish with its own, otherwise pending_job can't be
* false.
*/
static int multifd_send_pages(QEMUFile *f)
{
int i;
static int next_channel;
MultiFDSendParams *p = NULL; /* make happy gcc */
MultiFDPages_t *pages = multifd_send_state->pages;
uint64_t transferred;
if (qatomic_read(&multifd_send_state->exiting)) {
return -1;
}
qemu_sem_wait(&multifd_send_state->channels_ready);
/*
* next_channel can remain from a previous migration that was
* using more channels, so ensure it doesn't overflow if the
* limit is lower now.
*/
next_channel %= migrate_multifd_channels();
for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) {
p = &multifd_send_state->params[i];
qemu_mutex_lock(&p->mutex);
if (p->quit) {
error_report("%s: channel %d has already quit!", __func__, i);
qemu_mutex_unlock(&p->mutex);
return -1;
}
if (!p->pending_job) {
p->pending_job++;
next_channel = (i + 1) % migrate_multifd_channels();
break;
}
qemu_mutex_unlock(&p->mutex);
}
assert(!p->pages->num);
assert(!p->pages->block);
p->packet_num = multifd_send_state->packet_num++;
multifd_send_state->pages = p->pages;
p->pages = pages;
transferred = ((uint64_t) pages->num) * qemu_target_page_size()
+ p->packet_len;
qemu_file_update_transfer(f, transferred);
ram_counters.multifd_bytes += transferred;
ram_counters.transferred += transferred;
qemu_mutex_unlock(&p->mutex);
qemu_sem_post(&p->sem);
return 1;
}
int multifd_queue_page(QEMUFile *f, RAMBlock *block, ram_addr_t offset)
{
MultiFDPages_t *pages = multifd_send_state->pages;
if (!pages->block) {
pages->block = block;
}
if (pages->block == block) {
pages->offset[pages->num] = offset;
pages->iov[pages->num].iov_base = block->host + offset;
pages->iov[pages->num].iov_len = qemu_target_page_size();
pages->num++;
if (pages->num < pages->allocated) {
return 1;
}
}
if (multifd_send_pages(f) < 0) {
return -1;
}
if (pages->block != block) {
return multifd_queue_page(f, block, offset);
}
return 1;
}
static void multifd_send_terminate_threads(Error *err)
{
int i;
trace_multifd_send_terminate_threads(err != NULL);
if (err) {
MigrationState *s = migrate_get_current();
migrate_set_error(s, err);
if (s->state == MIGRATION_STATUS_SETUP ||
s->state == MIGRATION_STATUS_PRE_SWITCHOVER ||
s->state == MIGRATION_STATUS_DEVICE ||
s->state == MIGRATION_STATUS_ACTIVE) {
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_FAILED);
}
}
/*
* We don't want to exit each threads twice. Depending on where
* we get the error, or if there are two independent errors in two
* threads at the same time, we can end calling this function
* twice.
*/
if (qatomic_xchg(&multifd_send_state->exiting, 1)) {
return;
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
qemu_mutex_lock(&p->mutex);
p->quit = true;
qemu_sem_post(&p->sem);
if (p->c) {
qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
}
qemu_mutex_unlock(&p->mutex);
}
}
void multifd_save_cleanup(void)
{
int i;
if (!migrate_use_multifd() || !migrate_multifd_is_allowed()) {
return;
}
multifd_send_terminate_threads(NULL);
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
if (p->running) {
qemu_thread_join(&p->thread);
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
Error *local_err = NULL;
if (p->registered_yank) {
migration_ioc_unregister_yank(p->c);
}
socket_send_channel_destroy(p->c);
p->c = NULL;
qemu_mutex_destroy(&p->mutex);
qemu_sem_destroy(&p->sem);
qemu_sem_destroy(&p->sem_sync);
g_free(p->name);
p->name = NULL;
g_free(p->tls_hostname);
p->tls_hostname = NULL;
multifd_pages_clear(p->pages);
p->pages = NULL;
p->packet_len = 0;
g_free(p->packet);
p->packet = NULL;
multifd_send_state->ops->send_cleanup(p, &local_err);
if (local_err) {
migrate_set_error(migrate_get_current(), local_err);
error_free(local_err);
}
}
qemu_sem_destroy(&multifd_send_state->channels_ready);
g_free(multifd_send_state->params);
multifd_send_state->params = NULL;
multifd_pages_clear(multifd_send_state->pages);
multifd_send_state->pages = NULL;
g_free(multifd_send_state);
multifd_send_state = NULL;
}
void multifd_send_sync_main(QEMUFile *f)
{
int i;
if (!migrate_use_multifd()) {
return;
}
if (multifd_send_state->pages->num) {
if (multifd_send_pages(f) < 0) {
error_report("%s: multifd_send_pages fail", __func__);
return;
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
trace_multifd_send_sync_main_signal(p->id);
qemu_mutex_lock(&p->mutex);
if (p->quit) {
error_report("%s: channel %d has already quit", __func__, i);
qemu_mutex_unlock(&p->mutex);
return;
}
p->packet_num = multifd_send_state->packet_num++;
p->flags |= MULTIFD_FLAG_SYNC;
p->pending_job++;
qemu_file_update_transfer(f, p->packet_len);
ram_counters.multifd_bytes += p->packet_len;
ram_counters.transferred += p->packet_len;
qemu_mutex_unlock(&p->mutex);
qemu_sem_post(&p->sem);
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
trace_multifd_send_sync_main_wait(p->id);
qemu_sem_wait(&p->sem_sync);
}
trace_multifd_send_sync_main(multifd_send_state->packet_num);
}
static void *multifd_send_thread(void *opaque)
{
MultiFDSendParams *p = opaque;
Error *local_err = NULL;
int ret = 0;
trace_multifd_send_thread_start(p->id);
rcu_register_thread();
if (multifd_send_initial_packet(p, &local_err) < 0) {
ret = -1;
goto out;
}
/* initial packet */
p->num_packets = 1;
while (true) {
qemu_sem_wait(&p->sem);
if (qatomic_read(&multifd_send_state->exiting)) {
break;
}
qemu_mutex_lock(&p->mutex);
if (p->pending_job) {
uint32_t used = p->pages->num;
uint64_t packet_num = p->packet_num;
uint32_t flags = p->flags;
if (used) {
ret = multifd_send_state->ops->send_prepare(p, &local_err);
if (ret != 0) {
qemu_mutex_unlock(&p->mutex);
break;
}
}
multifd_send_fill_packet(p);
p->flags = 0;
p->num_packets++;
p->num_pages += used;
p->pages->num = 0;
p->pages->block = NULL;
qemu_mutex_unlock(&p->mutex);
trace_multifd_send(p->id, packet_num, used, flags,
p->next_packet_size);
ret = qio_channel_write_all(p->c, (void *)p->packet,
p->packet_len, &local_err);
if (ret != 0) {
break;
}
if (used) {
ret = multifd_send_state->ops->send_write(p, used, &local_err);
if (ret != 0) {
break;
}
}
qemu_mutex_lock(&p->mutex);
p->pending_job--;
qemu_mutex_unlock(&p->mutex);
if (flags & MULTIFD_FLAG_SYNC) {
qemu_sem_post(&p->sem_sync);
}
qemu_sem_post(&multifd_send_state->channels_ready);
} else if (p->quit) {
qemu_mutex_unlock(&p->mutex);
break;
} else {
qemu_mutex_unlock(&p->mutex);
/* sometimes there are spurious wakeups */
}
}
out:
if (local_err) {
trace_multifd_send_error(p->id);
multifd_send_terminate_threads(local_err);
error_free(local_err);
}
/*
* Error happen, I will exit, but I can't just leave, tell
* who pay attention to me.
*/
if (ret != 0) {
qemu_sem_post(&p->sem_sync);
qemu_sem_post(&multifd_send_state->channels_ready);
}
qemu_mutex_lock(&p->mutex);
p->running = false;
qemu_mutex_unlock(&p->mutex);
rcu_unregister_thread();
trace_multifd_send_thread_end(p->id, p->num_packets, p->num_pages);
return NULL;
}
static bool multifd_channel_connect(MultiFDSendParams *p,
QIOChannel *ioc,
Error *error);
static void multifd_tls_outgoing_handshake(QIOTask *task,
gpointer opaque)
{
MultiFDSendParams *p = opaque;
QIOChannel *ioc = QIO_CHANNEL(qio_task_get_source(task));
Error *err = NULL;
if (qio_task_propagate_error(task, &err)) {
trace_multifd_tls_outgoing_handshake_error(ioc, error_get_pretty(err));
} else {
trace_multifd_tls_outgoing_handshake_complete(ioc);
}
if (!multifd_channel_connect(p, ioc, err)) {
/*
* Error happen, mark multifd_send_thread status as 'quit' although it
* is not created, and then tell who pay attention to me.
*/
p->quit = true;
qemu_sem_post(&multifd_send_state->channels_ready);
qemu_sem_post(&p->sem_sync);
}
}
static void *multifd_tls_handshake_thread(void *opaque)
{
MultiFDSendParams *p = opaque;
QIOChannelTLS *tioc = QIO_CHANNEL_TLS(p->c);
qio_channel_tls_handshake(tioc,
multifd_tls_outgoing_handshake,
p,
NULL,
NULL);
return NULL;
}
static void multifd_tls_channel_connect(MultiFDSendParams *p,
QIOChannel *ioc,
Error **errp)
{
MigrationState *s = migrate_get_current();
const char *hostname = p->tls_hostname;
QIOChannelTLS *tioc;
tioc = migration_tls_client_create(s, ioc, hostname, errp);
if (!tioc) {
return;
}
object_unref(OBJECT(ioc));
trace_multifd_tls_outgoing_handshake_start(ioc, tioc, hostname);
qio_channel_set_name(QIO_CHANNEL(tioc), "multifd-tls-outgoing");
p->c = QIO_CHANNEL(tioc);
qemu_thread_create(&p->thread, "multifd-tls-handshake-worker",
multifd_tls_handshake_thread, p,
QEMU_THREAD_JOINABLE);
}
static bool multifd_channel_connect(MultiFDSendParams *p,
QIOChannel *ioc,
Error *error)
{
MigrationState *s = migrate_get_current();
trace_multifd_set_outgoing_channel(
ioc, object_get_typename(OBJECT(ioc)), p->tls_hostname, error);
if (!error) {
if (s->parameters.tls_creds &&
*s->parameters.tls_creds &&
!object_dynamic_cast(OBJECT(ioc),
TYPE_QIO_CHANNEL_TLS)) {
multifd_tls_channel_connect(p, ioc, &error);
if (!error) {
/*
* tls_channel_connect will call back to this
* function after the TLS handshake,
* so we mustn't call multifd_send_thread until then
*/
return true;
} else {
return false;
}
} else {
migration_ioc_register_yank(ioc);
p->registered_yank = true;
p->c = ioc;
qemu_thread_create(&p->thread, p->name, multifd_send_thread, p,
QEMU_THREAD_JOINABLE);
}
return true;
}
return false;
}
static void multifd_new_send_channel_cleanup(MultiFDSendParams *p,
QIOChannel *ioc, Error *err)
{
migrate_set_error(migrate_get_current(), err);
/* Error happen, we need to tell who pay attention to me */
qemu_sem_post(&multifd_send_state->channels_ready);
qemu_sem_post(&p->sem_sync);
/*
* Although multifd_send_thread is not created, but main migration
* thread neet to judge whether it is running, so we need to mark
* its status.
*/
p->quit = true;
object_unref(OBJECT(ioc));
error_free(err);
}
static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque)
{
MultiFDSendParams *p = opaque;
QIOChannel *sioc = QIO_CHANNEL(qio_task_get_source(task));
Error *local_err = NULL;
trace_multifd_new_send_channel_async(p->id);
if (qio_task_propagate_error(task, &local_err)) {
goto cleanup;
} else {
p->c = QIO_CHANNEL(sioc);
qio_channel_set_delay(p->c, false);
p->running = true;
if (!multifd_channel_connect(p, sioc, local_err)) {
goto cleanup;
}
return;
}
cleanup:
multifd_new_send_channel_cleanup(p, sioc, local_err);
}
static bool migrate_allow_multifd = true;
void migrate_protocol_allow_multifd(bool allow)
{
migrate_allow_multifd = allow;
}
bool migrate_multifd_is_allowed(void)
{
return migrate_allow_multifd;
}
int multifd_save_setup(Error **errp)
{
int thread_count;
uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
uint8_t i;
MigrationState *s;
if (!migrate_use_multifd()) {
return 0;
}
if (!migrate_multifd_is_allowed()) {
error_setg(errp, "multifd is not supported by current protocol");
return -1;
}
s = migrate_get_current();
thread_count = migrate_multifd_channels();
multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
multifd_send_state->params = g_new0(MultiFDSendParams, thread_count);
multifd_send_state->pages = multifd_pages_init(page_count);
qemu_sem_init(&multifd_send_state->channels_ready, 0);
qatomic_set(&multifd_send_state->exiting, 0);
multifd_send_state->ops = multifd_ops[migrate_multifd_compression()];
for (i = 0; i < thread_count; i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
qemu_mutex_init(&p->mutex);
qemu_sem_init(&p->sem, 0);
qemu_sem_init(&p->sem_sync, 0);
p->quit = false;
p->pending_job = 0;
p->id = i;
p->pages = multifd_pages_init(page_count);
p->packet_len = sizeof(MultiFDPacket_t)
+ sizeof(uint64_t) * page_count;
p->packet = g_malloc0(p->packet_len);
p->packet->magic = cpu_to_be32(MULTIFD_MAGIC);
p->packet->version = cpu_to_be32(MULTIFD_VERSION);
p->name = g_strdup_printf("multifdsend_%d", i);
p->tls_hostname = g_strdup(s->hostname);
socket_send_channel_create(multifd_new_send_channel_async, p);
}
for (i = 0; i < thread_count; i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
Error *local_err = NULL;
int ret;
ret = multifd_send_state->ops->send_setup(p, &local_err);
if (ret) {
error_propagate(errp, local_err);
return ret;
}
}
return 0;
}
struct {
MultiFDRecvParams *params;
/* number of created threads */
int count;
/* syncs main thread and channels */
QemuSemaphore sem_sync;
/* global number of generated multifd packets */
uint64_t packet_num;
/* multifd ops */
MultiFDMethods *ops;
} *multifd_recv_state;
static void multifd_recv_terminate_threads(Error *err)
{
int i;
trace_multifd_recv_terminate_threads(err != NULL);
if (err) {
MigrationState *s = migrate_get_current();
migrate_set_error(s, err);
if (s->state == MIGRATION_STATUS_SETUP ||
s->state == MIGRATION_STATUS_ACTIVE) {
migrate_set_state(&s->state, s->state,
MIGRATION_STATUS_FAILED);
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
qemu_mutex_lock(&p->mutex);
p->quit = true;
/*
* We could arrive here for two reasons:
* - normal quit, i.e. everything went fine, just finished
* - error quit: We close the channels so the channel threads
* finish the qio_channel_read_all_eof()
*/
if (p->c) {
qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
}
qemu_mutex_unlock(&p->mutex);
}
}
int multifd_load_cleanup(Error **errp)
{
int i;
if (!migrate_use_multifd() || !migrate_multifd_is_allowed()) {
return 0;
}
multifd_recv_terminate_threads(NULL);
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
if (p->running) {
p->quit = true;
/*
* multifd_recv_thread may hung at MULTIFD_FLAG_SYNC handle code,
* however try to wakeup it without harm in cleanup phase.
*/
qemu_sem_post(&p->sem_sync);
qemu_thread_join(&p->thread);
}
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
migration_ioc_unregister_yank(p->c);
object_unref(OBJECT(p->c));
p->c = NULL;
qemu_mutex_destroy(&p->mutex);
qemu_sem_destroy(&p->sem_sync);
g_free(p->name);
p->name = NULL;
multifd_pages_clear(p->pages);
p->pages = NULL;
p->packet_len = 0;
g_free(p->packet);
p->packet = NULL;
multifd_recv_state->ops->recv_cleanup(p);
}
qemu_sem_destroy(&multifd_recv_state->sem_sync);
g_free(multifd_recv_state->params);
multifd_recv_state->params = NULL;
g_free(multifd_recv_state);
multifd_recv_state = NULL;
return 0;
}
void multifd_recv_sync_main(void)
{
int i;
if (!migrate_use_multifd()) {
return;
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
trace_multifd_recv_sync_main_wait(p->id);
qemu_sem_wait(&multifd_recv_state->sem_sync);
}
for (i = 0; i < migrate_multifd_channels(); i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
WITH_QEMU_LOCK_GUARD(&p->mutex) {
if (multifd_recv_state->packet_num < p->packet_num) {
multifd_recv_state->packet_num = p->packet_num;
}
}
trace_multifd_recv_sync_main_signal(p->id);
qemu_sem_post(&p->sem_sync);
}
trace_multifd_recv_sync_main(multifd_recv_state->packet_num);
}
static void *multifd_recv_thread(void *opaque)
{
MultiFDRecvParams *p = opaque;
Error *local_err = NULL;
int ret;
trace_multifd_recv_thread_start(p->id);
rcu_register_thread();
while (true) {
uint32_t used;
uint32_t flags;
if (p->quit) {
break;
}
ret = qio_channel_read_all_eof(p->c, (void *)p->packet,
p->packet_len, &local_err);
if (ret == 0) { /* EOF */
break;
}
if (ret == -1) { /* Error */
break;
}
qemu_mutex_lock(&p->mutex);
ret = multifd_recv_unfill_packet(p, &local_err);
if (ret) {
qemu_mutex_unlock(&p->mutex);
break;
}
used = p->pages->num;
flags = p->flags;
/* recv methods don't know how to handle the SYNC flag */
p->flags &= ~MULTIFD_FLAG_SYNC;
trace_multifd_recv(p->id, p->packet_num, used, flags,
p->next_packet_size);
p->num_packets++;
p->num_pages += used;
qemu_mutex_unlock(&p->mutex);
if (used) {
ret = multifd_recv_state->ops->recv_pages(p, &local_err);
if (ret != 0) {
break;
}
}
if (flags & MULTIFD_FLAG_SYNC) {
qemu_sem_post(&multifd_recv_state->sem_sync);
qemu_sem_wait(&p->sem_sync);
}
}
if (local_err) {
multifd_recv_terminate_threads(local_err);
error_free(local_err);
}
qemu_mutex_lock(&p->mutex);
p->running = false;
qemu_mutex_unlock(&p->mutex);
rcu_unregister_thread();
trace_multifd_recv_thread_end(p->id, p->num_packets, p->num_pages);
return NULL;
}
int multifd_load_setup(Error **errp)
{
int thread_count;
uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
uint8_t i;
if (!migrate_use_multifd()) {
return 0;
}
if (!migrate_multifd_is_allowed()) {
error_setg(errp, "multifd is not supported by current protocol");
return -1;
}
thread_count = migrate_multifd_channels();
multifd_recv_state = g_malloc0(sizeof(*multifd_recv_state));
multifd_recv_state->params = g_new0(MultiFDRecvParams, thread_count);
qatomic_set(&multifd_recv_state->count, 0);
qemu_sem_init(&multifd_recv_state->sem_sync, 0);
multifd_recv_state->ops = multifd_ops[migrate_multifd_compression()];
for (i = 0; i < thread_count; i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
qemu_mutex_init(&p->mutex);
qemu_sem_init(&p->sem_sync, 0);
p->quit = false;
p->id = i;
p->pages = multifd_pages_init(page_count);
p->packet_len = sizeof(MultiFDPacket_t)
+ sizeof(uint64_t) * page_count;
p->packet = g_malloc0(p->packet_len);
p->name = g_strdup_printf("multifdrecv_%d", i);
}
for (i = 0; i < thread_count; i++) {
MultiFDRecvParams *p = &multifd_recv_state->params[i];
Error *local_err = NULL;
int ret;
ret = multifd_recv_state->ops->recv_setup(p, &local_err);
if (ret) {
error_propagate(errp, local_err);
return ret;
}
}
return 0;
}
bool multifd_recv_all_channels_created(void)
{
int thread_count = migrate_multifd_channels();
if (!migrate_use_multifd()) {
return true;
}
if (!multifd_recv_state) {
/* Called before any connections created */
return false;
}
return thread_count == qatomic_read(&multifd_recv_state->count);
}
/*
* Try to receive all multifd channels to get ready for the migration.
* - Return true and do not set @errp when correctly receiving all channels;
* - Return false and do not set @errp when correctly receiving the current one;
* - Return false and set @errp when failing to receive the current channel.
*/
bool multifd_recv_new_channel(QIOChannel *ioc, Error **errp)
{
MultiFDRecvParams *p;
Error *local_err = NULL;
int id;
id = multifd_recv_initial_packet(ioc, &local_err);
if (id < 0) {
multifd_recv_terminate_threads(local_err);
error_propagate_prepend(errp, local_err,
"failed to receive packet"
" via multifd channel %d: ",
qatomic_read(&multifd_recv_state->count));
return false;
}
trace_multifd_recv_new_channel(id);
p = &multifd_recv_state->params[id];
if (p->c != NULL) {
error_setg(&local_err, "multifd: received id '%d' already setup'",
id);
multifd_recv_terminate_threads(local_err);
error_propagate(errp, local_err);
return false;
}
p->c = ioc;
object_ref(OBJECT(ioc));
/* initial packet */
p->num_packets = 1;
p->running = true;
qemu_thread_create(&p->thread, p->name, multifd_recv_thread, p,
QEMU_THREAD_JOINABLE);
qatomic_inc(&multifd_recv_state->count);
return qatomic_read(&multifd_recv_state->count) ==
migrate_multifd_channels();
}