From: "Maciej S. Szmigiero" <maciej.szmigi...@oracle.com>
A new function multifd_queue_device_state() is provided for device to queue
its state for transmission via a multifd channel.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigi...@oracle.com>
---
include/migration/misc.h | 4 +
migration/multifd-zlib.c | 2 +-
migration/multifd-zstd.c | 2 +-
migration/multifd.c | 244 ++++++++++++++++++++++++++++++++++-----
migration/multifd.h | 30 +++--
5 files changed, 244 insertions(+), 38 deletions(-)
diff --git a/include/migration/misc.h b/include/migration/misc.h
index c9e200f4eb8f..25968e31247b 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -117,4 +117,8 @@ bool migration_in_bg_snapshot(void);
/* migration/block-dirty-bitmap.c */
void dirty_bitmap_mig_init(void);
+/* migration/multifd.c */
+int multifd_queue_device_state(char *idstr, uint32_t instance_id,
+ char *data, size_t len);
+
#endif
diff --git a/migration/multifd-zlib.c b/migration/multifd-zlib.c
index 99821cd4d5ef..e20c1de6033d 100644
--- a/migration/multifd-zlib.c
+++ b/migration/multifd-zlib.c
@@ -177,7 +177,7 @@ static int zlib_send_prepare(MultiFDSendParams *p, Error
**errp)
out:
p->flags |= MULTIFD_FLAG_ZLIB;
- multifd_send_fill_packet(p);
+ multifd_send_fill_packet_ram(p);
return 0;
}
diff --git a/migration/multifd-zstd.c b/migration/multifd-zstd.c
index 02112255adcc..37cebd006921 100644
--- a/migration/multifd-zstd.c
+++ b/migration/multifd-zstd.c
@@ -166,7 +166,7 @@ static int zstd_send_prepare(MultiFDSendParams *p, Error
**errp)
out:
p->flags |= MULTIFD_FLAG_ZSTD;
- multifd_send_fill_packet(p);
+ multifd_send_fill_packet_ram(p);
return 0;
}
diff --git a/migration/multifd.c b/migration/multifd.c
index 878ff7d9f9f0..d8ce01539a05 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -12,6 +12,7 @@
#include "qemu/osdep.h"
#include "qemu/cutils.h"
+#include "qemu/iov.h"
#include "qemu/rcu.h"
#include "exec/target_page.h"
#include "sysemu/sysemu.h"
@@ -20,6 +21,7 @@
#include "qapi/error.h"
#include "channel.h"
#include "file.h"
+#include "migration/misc.h"
#include "migration.h"
#include "migration-stats.h"
#include "savevm.h"
@@ -50,9 +52,17 @@ typedef struct {
} __attribute__((packed)) MultiFDInit_t;
struct {
+ /*
+ * Are there some device state dedicated channels (true) or
+ * should device state be sent via any available channel (false)?
+ */
+ bool device_state_dedicated_channels;
+ GMutex queue_job_mutex;
+
MultiFDSendParams *params;
- /* array of pages to sent */
+ /* array of pages or device state to be sent */
MultiFDPages_t *pages;
+ MultiFDDeviceState_t *device_state;
/*
* Global number of generated multifd packets.
*
@@ -169,7 +179,7 @@ static void multifd_send_prepare_iovs(MultiFDSendParams *p)
}
/**
- * nocomp_send_prepare: prepare date to be able to send
+ * nocomp_send_prepare_ram: prepare RAM data for sending
*
* For no compression we just have to calculate the size of the
* packet.
@@ -179,7 +189,7 @@ static void multifd_send_prepare_iovs(MultiFDSendParams *p)
* @p: Params for the channel that we are using
* @errp: pointer to an error
*/
-static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)
+static int nocomp_send_prepare_ram(MultiFDSendParams *p, Error **errp)
{
bool use_zero_copy_send = migrate_zero_copy_send();
int ret;
@@ -198,13 +208,13 @@ static int nocomp_send_prepare(MultiFDSendParams *p,
Error **errp)
* Only !zerocopy needs the header in IOV; zerocopy will
* send it separately.
*/
- multifd_send_prepare_header(p);
+ multifd_send_prepare_header_ram(p);
}
multifd_send_prepare_iovs(p);
p->flags |= MULTIFD_FLAG_NOCOMP;
- multifd_send_fill_packet(p);
+ multifd_send_fill_packet_ram(p);
if (use_zero_copy_send) {
/* Send header first, without zerocopy */
@@ -218,6 +228,59 @@ static int nocomp_send_prepare(MultiFDSendParams *p, Error
**errp)
return 0;
}
+static void multifd_send_fill_packet_device_state(MultiFDSendParams *p)
+{
+ MultiFDPacketDeviceState_t *packet = p->packet_device_state;
+
+ packet->hdr.flags = cpu_to_be32(p->flags);
+ strncpy(packet->idstr, p->device_state->idstr, sizeof(packet->idstr));
+ packet->instance_id = cpu_to_be32(p->device_state->instance_id);
+ packet->next_packet_size = cpu_to_be32(p->next_packet_size);
+}
+
+/**
+ * nocomp_send_prepare_device_state: prepare device state data for sending
+ *
+ * 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_device_state(MultiFDSendParams *p,
+ Error **errp)
+{
+ assert(!multifd_send_state->device_state_dedicated_channels ||
+ p->is_device_state_dedicated);
+
+ multifd_send_prepare_header_device_state(p);
+
+ assert(!(p->flags & MULTIFD_FLAG_SYNC));
+
+ p->next_packet_size = p->device_state->buf_len;
+ if (p->next_packet_size > 0) {
+ p->iov[p->iovs_num].iov_base = p->device_state->buf;
+ p->iov[p->iovs_num].iov_len = p->next_packet_size;
+ p->iovs_num++;
+ }
+
+ p->flags |= MULTIFD_FLAG_NOCOMP | MULTIFD_FLAG_DEVICE_STATE;
+
+ multifd_send_fill_packet_device_state(p);
+
+ return 0;
+}
+
+static int nocomp_send_prepare(MultiFDSendParams *p, Error **errp)
+{
+ if (p->is_device_state_job) {
+ return nocomp_send_prepare_device_state(p, errp);
+ } else {
+ return nocomp_send_prepare_ram(p, errp);
+ }
+
+ g_assert_not_reached();
+}
+
/**
* nocomp_recv_setup: setup receive side
*
@@ -397,7 +460,18 @@ static void multifd_pages_clear(MultiFDPages_t *pages)
g_free(pages);
}
-void multifd_send_fill_packet(MultiFDSendParams *p)
+static void multifd_device_state_free(MultiFDDeviceState_t *device_state)
+{
+ if (!device_state) {
+ return;
+ }
+
+ g_clear_pointer(&device_state->idstr, g_free);
+ g_clear_pointer(&device_state->buf, g_free);
+ g_free(device_state);
+}
+
+void multifd_send_fill_packet_ram(MultiFDSendParams *p)
{
MultiFDPacket_t *packet = p->packet;
MultiFDPages_t *pages = p->pages;
@@ -585,7 +659,8 @@ static void multifd_send_kick_main(MultiFDSendParams *p)
}
/*
- * How we use multifd_send_state->pages and channel->pages?
+ * How we use multifd_send_state->pages + channel->pages
+ * and multifd_send_state->device_state + channel->device_state?
*
* 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
@@ -601,14 +676,15 @@ static void multifd_send_kick_main(MultiFDSendParams *p)
* have to had finish with its own, otherwise pending_job can't be
* false.
*
+ * 'device_state' struct has similar handling.
+ *
* Returns true if succeed, false otherwise.
*/
-static bool multifd_send_pages(void)
+static bool multifd_send_queue_job(bool is_device_state)
{
int i;
static int next_channel;
MultiFDSendParams *p = NULL; /* make happy gcc */
- MultiFDPages_t *pages = multifd_send_state->pages;
if (multifd_send_should_exit()) {
return false;
@@ -632,7 +708,9 @@ static bool multifd_send_pages(void)
* Lockless read to p->pending_job is safe, because only multifd
* sender thread can clear it.
*/
- if (qatomic_read(&p->pending_job) == false) {
+ if ((!multifd_send_state->device_state_dedicated_channels ||
+ p->is_device_state_dedicated == is_device_state) &&
+ qatomic_read(&p->pending_job) == false) {
qatomic_store_release(&next_channel,
(i + 1) % migrate_multifd_channels());
break;
@@ -644,12 +722,30 @@ static bool multifd_send_pages(void)
* qatomic_store_release() in multifd_send_thread().
*/
smp_mb_acquire();
- assert(!p->pages->num);
- multifd_send_state->pages = p->pages;
- p->pages = pages;
+
+ if (!is_device_state) {
+ assert(!p->pages->num);
+ } else {
+ assert(!p->device_state->buf);
+ }
+
+ p->is_device_state_job = is_device_state;
+
+ if (!is_device_state) {
+ MultiFDPages_t *pages = multifd_send_state->pages;
+
+ multifd_send_state->pages = p->pages;
+ p->pages = pages;
+ } else {
+ MultiFDDeviceState_t *device_state = multifd_send_state->device_state;
+
+ multifd_send_state->device_state = p->device_state;
+ p->device_state = device_state;
+ }
+
/*
- * Making sure p->pages is setup before marking pending_job=true. Pairs
- * with the qatomic_load_acquire() in multifd_send_thread().
+ * Making sure p->pages or p->device state is setup before marking
+ * pending_job=true. Pairs with the qatomic_load_acquire() in
multifd_send_thread().
*/
qatomic_store_release(&p->pending_job, true);
qemu_sem_post(&p->sem);
@@ -673,7 +769,7 @@ static inline void multifd_enqueue(MultiFDPages_t *pages,
ram_addr_t offset)
}
/* Returns true if enqueue successful, false otherwise */
-bool multifd_queue_page(RAMBlock *block, ram_addr_t offset)
+static bool multifd_queue_page_locked(RAMBlock *block, ram_addr_t offset)
{
MultiFDPages_t *pages;
@@ -696,7 +792,7 @@ retry:
* After flush, always retry.
*/
if (pages->block != block || multifd_queue_full(pages)) {
- if (!multifd_send_pages()) {
+ if (!multifd_send_queue_job(false)) {
return false;
}
goto retry;
@@ -707,6 +803,45 @@ retry:
return true;
}
+bool multifd_queue_page(RAMBlock *block, ram_addr_t offset)
+{
+ g_autoptr(GMutexLocker) locker = NULL;
+
+ /*
+ * Device state submissions for shared channels can come
+ * from multiple threads and conflict with page submissions
+ * with respect to multifd_send_state access.
+ */
+ if (!multifd_send_state->device_state_dedicated_channels) {
+ locker = g_mutex_locker_new(&multifd_send_state->queue_job_mutex);
+ }
+
+ return multifd_queue_page_locked(block, offset);
+}
+
+int multifd_queue_device_state(char *idstr, uint32_t instance_id,
+ char *data, size_t len)
+{
+ /* Device state submissions can came from multiple threads */
+ g_autoptr(GMutexLocker) locker =
+ g_mutex_locker_new(&multifd_send_state->queue_job_mutex);
+ MultiFDDeviceState_t *device_state = multifd_send_state->device_state;
+
+ assert(!device_state->buf);
+ device_state->idstr = g_strdup(idstr);
+ device_state->instance_id = instance_id;
+ device_state->buf = g_memdup2(data, len);
+ device_state->buf_len = len;
+
+ if (!multifd_send_queue_job(true)) {
+ g_clear_pointer(&device_state->idstr, g_free);
+ g_clear_pointer(&device_state->buf, g_free);
+ return -1;
+ }
+
+ return 0;
+}
+
/* Multifd send side hit an error; remember it and prepare to quit */
static void multifd_send_set_error(Error *err)
{
@@ -811,10 +946,12 @@ static bool
multifd_send_cleanup_channel(MultiFDSendParams *p, Error **errp)
multifd_pages_clear(p->pages);
p->pages = NULL;
p->packet_len = 0;
+ g_clear_pointer(&p->packet_device_state, g_free);
g_free(p->packet);
p->packet = NULL;
g_free(p->iov);
p->iov = NULL;
+ g_clear_pointer(&p->device_state, multifd_device_state_free);
multifd_send_state->ops->send_cleanup(p, errp);
return *errp == NULL;
@@ -829,7 +966,9 @@ static void multifd_send_cleanup_state(void)
g_free(multifd_send_state->params);
multifd_send_state->params = NULL;
multifd_pages_clear(multifd_send_state->pages);
+ g_clear_pointer(&multifd_send_state->device_state,
multifd_device_state_free);
multifd_send_state->pages = NULL;
+ g_mutex_clear(&multifd_send_state->queue_job_mutex);
g_free(multifd_send_state);
multifd_send_state = NULL;
}
@@ -876,17 +1015,28 @@ static int multifd_zero_copy_flush(QIOChannel *c)
int multifd_send_sync_main(void)
{
+ g_autoptr(GMutexLocker) locker = NULL;
int i;
bool flush_zero_copy;
if (!migrate_multifd()) {
return 0;
}
+
+ /*
+ * Page SYNC can conflict with device state submissions for shared channels
+ * with respect to multifd_send_state access.
+ */
+ if (!multifd_send_state->device_state_dedicated_channels) {
+ locker = g_mutex_locker_new(&multifd_send_state->queue_job_mutex);
+ }
+
if (multifd_send_state->pages->num) {
- if (!multifd_send_pages()) {
+ if (!multifd_send_queue_job(false)) {
error_report("%s: multifd_send_pages fail", __func__);
return -1;
}
+ assert(!multifd_send_state->pages->num);
}
flush_zero_copy = migrate_zero_copy_send();
@@ -898,6 +1048,11 @@ int multifd_send_sync_main(void)
return -1;
}
+ if (p->is_device_state_dedicated) {
+ assert(multifd_send_state->device_state_dedicated_channels);
+ continue;
+ }
+
trace_multifd_send_sync_main_signal(p->id);
/*
@@ -915,6 +1070,10 @@ int multifd_send_sync_main(void)
return -1;
}
+ if (p->is_device_state_dedicated) {
+ continue;
+ }
+
qemu_sem_wait(&multifd_send_state->channels_ready);
trace_multifd_send_sync_main_wait(p->id);
qemu_sem_wait(&p->sem_sync);
@@ -962,17 +1121,22 @@ static void *multifd_send_thread(void *opaque)
*/
if (qatomic_load_acquire(&p->pending_job)) {
MultiFDPages_t *pages = p->pages;
+ bool is_device_state = p->is_device_state_job;
+ size_t total_size;
p->flags = 0;
p->iovs_num = 0;
- assert(pages->num);
+ assert(is_device_state || pages->num);
ret = multifd_send_state->ops->send_prepare(p, &local_err);
if (ret != 0) {
break;
}
+ total_size = iov_size(p->iov, p->iovs_num);
if (migrate_mapped_ram()) {
+ assert(!is_device_state);
+
ret = file_write_ramblock_iov(p->c, p->iov, p->iovs_num,
p->pages->block, &local_err);
} else {
@@ -985,12 +1149,18 @@ static void *multifd_send_thread(void *opaque)
break;
}
- stat64_add(&mig_stats.multifd_bytes,
- p->next_packet_size + p->packet_len);
- stat64_add(&mig_stats.normal_pages, pages->normal_num);
- stat64_add(&mig_stats.zero_pages, pages->num - pages->normal_num);
+ stat64_add(&mig_stats.multifd_bytes, total_size);
+ if (!is_device_state) {
+ stat64_add(&mig_stats.normal_pages, pages->normal_num);
+ stat64_add(&mig_stats.zero_pages, pages->num -
pages->normal_num);
+ }
- multifd_pages_reset(p->pages);
+ if (is_device_state) {
+ g_clear_pointer(&p->device_state->idstr, g_free);
+ g_clear_pointer(&p->device_state->buf, g_free);
+ } else {
+ multifd_pages_reset(p->pages);
+ }
p->next_packet_size = 0;
/*
@@ -1009,7 +1179,7 @@ static void *multifd_send_thread(void *opaque)
if (use_packets) {
p->flags = MULTIFD_FLAG_SYNC;
- multifd_send_fill_packet(p);
+ multifd_send_fill_packet_ram(p);
ret = qio_channel_write_all(p->c, (void *)p->packet,
p->packet_len, &local_err);
if (ret != 0) {
@@ -1223,7 +1393,12 @@ static bool
multifd_new_send_channel_create(MultiFDSendParams *p, Error **errp)
g_autoptr(MFDSendChannelConnectData) data = NULL;
MigChannelHeader header = {};
- header.channel_type = MIG_CHANNEL_TYPE_MULTIFD;
+ if (!p->is_device_state_dedicated) {
+ header.channel_type = MIG_CHANNEL_TYPE_MULTIFD;
+ } else {
+ header.channel_type = MIG_CHANNEL_TYPE_MULTIFD_DEVICE_STATE;
+ }
+
data = mfd_send_channel_connect_data_new(p, &header);
if (!multifd_use_packets()) {
@@ -1239,7 +1414,7 @@ bool multifd_send_setup(void)
{
MigrationState *s = migrate_get_current();
Error *local_err = NULL;
- int thread_count, ret = 0;
+ int thread_count, device_state_thread_count, ret = 0;
uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
bool use_packets = multifd_use_packets();
uint8_t i;
@@ -1249,10 +1424,16 @@ bool multifd_send_setup(void)
}
thread_count = migrate_multifd_channels();
+ device_state_thread_count = migrate_multifd_channels_device_state();
+ assert(device_state_thread_count < thread_count);
+
multifd_send_state = g_malloc0(sizeof(*multifd_send_state));
+ multifd_send_state->device_state_dedicated_channels =
device_state_thread_count >= 1;
+ g_mutex_init(&multifd_send_state->queue_job_mutex);
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_created, 0);
+ multifd_send_state->device_state =
g_malloc0(sizeof(*multifd_send_state->device_state));
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()];
@@ -1260,21 +1441,28 @@ bool multifd_send_setup(void)
for (i = 0; i < thread_count; i++) {
MultiFDSendParams *p = &multifd_send_state->params[i];
+ p->is_device_state_dedicated = i >= thread_count -
device_state_thread_count;
qemu_sem_init(&p->sem, 0);
qemu_sem_init(&p->sem_sync, 0);
p->id = i;
p->pages = multifd_pages_init(page_count);
if (use_packets) {
+ p->device_state = g_malloc0(sizeof(*p->device_state));
+
p->packet_len = sizeof(MultiFDPacket_t)
+ sizeof(uint64_t) * page_count;
p->packet = g_malloc0(p->packet_len);
p->packet->hdr.magic = cpu_to_be32(MULTIFD_MAGIC);
p->packet->hdr.version = cpu_to_be32(MULTIFD_VERSION);
+ p->packet_device_state =
g_malloc0(sizeof(*p->packet_device_state));
+ p->packet_device_state->hdr = p->packet->hdr;
/* We need one extra place for the packet header */
p->iov = g_new0(struct iovec, page_count + 1);
} else {
+ assert(!p->is_device_state_dedicated);
+
p->iov = g_new0(struct iovec, page_count);
}
p->name = g_strdup_printf("multifdsend_%d", i);
@@ -1858,7 +2046,7 @@ bool multifd_send_prepare_common(MultiFDSendParams *p)
return false;
}
- multifd_send_prepare_header(p);
+ multifd_send_prepare_header_ram(p);
return true;
}
diff --git a/migration/multifd.h b/migration/multifd.h
index b5fa56b791af..53cf80c66f98 100644
--- a/migration/multifd.h
+++ b/migration/multifd.h
@@ -138,6 +138,7 @@ typedef struct {
uint32_t page_count;
/* multifd flags for sending ram */
int write_flags;
+ bool is_device_state_dedicated;
/* sem where to wait for more work */
QemuSemaphore sem;
@@ -157,17 +158,23 @@ typedef struct {
*/
bool pending_job;
bool pending_sync;
- /* array of pages to sent.
- * The owner of 'pages' depends of 'pending_job' value:
+
+ /* Whether the pending job is pages (false) or device state (true) */
+ bool is_device_state_job;
+
+ /* Array of pages or device state to be sent (depending on the flag above).
+ * The owner of these depends of 'pending_job' value:
* pending_job == 0 -> migration_thread can use it.
* pending_job != 0 -> multifd_channel can use it.
*/
MultiFDPages_t *pages;
+ MultiFDDeviceState_t *device_state;
/* thread local variables. No locking required */
- /* pointer to the packet */
+ /* pointers to the possible packet types */
MultiFDPacket_t *packet;
+ MultiFDPacketDeviceState_t *packet_device_state;
/* size of the next packet that contains pages */
uint32_t next_packet_size;
/* packets sent through this channel */
@@ -268,20 +275,27 @@ typedef struct {
} MultiFDMethods;
void multifd_register_ops(int method, MultiFDMethods *ops);
-void multifd_send_fill_packet(MultiFDSendParams *p);
+void multifd_send_fill_packet_ram(MultiFDSendParams *p);
bool multifd_send_prepare_common(MultiFDSendParams *p);
void multifd_send_zero_page_detect(MultiFDSendParams *p);
void multifd_recv_zero_page_process(MultiFDRecvParams *p);
-static inline void multifd_send_prepare_header(MultiFDSendParams *p)
+struct MFDSendChannelConnectData;
+typedef struct MFDSendChannelConnectData MFDSendChannelConnectData;
+bool multifd_channel_connect(MFDSendChannelConnectData *data, QIOChannel *ioc,
Error **errp);
+
+static inline void multifd_send_prepare_header_ram(MultiFDSendParams *p)
{
p->iov[0].iov_len = p->packet_len;
p->iov[0].iov_base = p->packet;
p->iovs_num++;
}
-struct MFDSendChannelConnectData;
-typedef struct MFDSendChannelConnectData MFDSendChannelConnectData;
-bool multifd_channel_connect(MFDSendChannelConnectData *data, QIOChannel *ioc,
Error **errp);
+static inline void multifd_send_prepare_header_device_state(MultiFDSendParams
*p)
+{
+ p->iov[0].iov_len = sizeof(*p->packet_device_state);
+ p->iov[0].iov_base = p->packet_device_state;
+ p->iovs_num++;
+}
#endif
