#define MULTIFD_FLAG_SYNC (1 << 0)
+/* This value needs to be a multiple of qemu_target_page_size() */
+#define MULTIFD_PACKET_SIZE (512 * 1024)
+
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;
typedef struct {
uint32_t magic;
uint32_t version;
uint32_t flags;
- uint32_t size;
- uint32_t used;
+ /* maximum number of allocated pages */
+ uint32_t pages_alloc;
+ uint32_t pages_used;
+ /* size of the next packet that contains pages */
+ uint32_t next_packet_size;
uint64_t packet_num;
+ uint64_t unused[4]; /* Reserved for future use */
char ramblock[256];
uint64_t offset[];
} __attribute__((packed)) MultiFDPacket_t;
MultiFDPacket_t *packet;
/* multifd flags for each packet */
uint32_t flags;
+ /* size of the next packet that contains pages */
+ uint32_t next_packet_size;
/* global number of generated multifd packets */
uint64_t packet_num;
/* thread local variables */
/* global number of generated multifd packets */
uint64_t packet_num;
/* thread local variables */
+ /* size of the next packet that contains pages */
+ uint32_t next_packet_size;
/* packets sent through this channel */
uint64_t num_packets;
/* pages sent through this channel */
static void multifd_send_fill_packet(MultiFDSendParams *p)
{
MultiFDPacket_t *packet = p->packet;
+ uint32_t page_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
int i;
packet->magic = cpu_to_be32(MULTIFD_MAGIC);
packet->version = cpu_to_be32(MULTIFD_VERSION);
packet->flags = cpu_to_be32(p->flags);
- packet->size = cpu_to_be32(migrate_multifd_page_count());
- packet->used = cpu_to_be32(p->pages->used);
+ packet->pages_alloc = cpu_to_be32(page_max);
+ packet->pages_used = cpu_to_be32(p->pages->used);
+ packet->next_packet_size = cpu_to_be32(p->next_packet_size);
packet->packet_num = cpu_to_be64(p->packet_num);
if (p->pages->block) {
static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp)
{
MultiFDPacket_t *packet = p->packet;
+ uint32_t pages_max = MULTIFD_PACKET_SIZE / qemu_target_page_size();
RAMBlock *block;
int i;
p->flags = be32_to_cpu(packet->flags);
- packet->size = be32_to_cpu(packet->size);
- if (packet->size > migrate_multifd_page_count()) {
+ packet->pages_alloc = be32_to_cpu(packet->pages_alloc);
+ /*
+ * If we recevied 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 maximum size %d",
- packet->size, migrate_multifd_page_count()) ;
+ "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->used = be32_to_cpu(packet->used);
- if (p->pages->used > packet->size) {
+ p->pages->used = be32_to_cpu(packet->pages_used);
+ if (p->pages->used > packet->pages_alloc) {
error_setg(errp, "multifd: received packet "
- "with size %d and expected maximum size %d",
- p->pages->used, packet->size) ;
+ "with %d pages and expected maximum pages are %d",
+ p->pages->used, 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->used) {
* - 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 loocking. It belongs to the migration thread
+ * 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
uint64_t packet_num = p->packet_num;
uint32_t flags = p->flags;
+ p->next_packet_size = used * qemu_target_page_size();
multifd_send_fill_packet(p);
p->flags = 0;
p->num_packets++;
p->pages->used = 0;
qemu_mutex_unlock(&p->mutex);
- trace_multifd_send(p->id, packet_num, used, flags);
+ 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);
break;
}
- ret = qio_channel_writev_all(p->c, p->pages->iov, used, &local_err);
- if (ret != 0) {
- break;
+ if (used) {
+ ret = qio_channel_writev_all(p->c, p->pages->iov,
+ used, &local_err);
+ if (ret != 0) {
+ break;
+ }
}
qemu_mutex_lock(&p->mutex);
int multifd_save_setup(void)
{
int thread_count;
- uint32_t page_count = migrate_multifd_page_count();
+ uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
uint8_t i;
if (!migrate_use_multifd()) {
used = p->pages->used;
flags = p->flags;
- trace_multifd_recv(p->id, p->packet_num, used, flags);
+ 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);
- ret = qio_channel_readv_all(p->c, p->pages->iov, used, &local_err);
- if (ret != 0) {
- break;
+ if (used) {
+ ret = qio_channel_readv_all(p->c, p->pages->iov,
+ used, &local_err);
+ if (ret != 0) {
+ break;
+ }
}
if (flags & MULTIFD_FLAG_SYNC) {
int multifd_load_setup(void)
{
int thread_count;
- uint32_t page_count = migrate_multifd_page_count();
+ uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size();
uint8_t i;
if (!migrate_use_multifd()) {
/**
* migration_bitmap_find_dirty: find the next dirty page from start
*
- * Called with rcu_read_lock() to protect migration_bitmap
- *
- * Returns the byte offset within memory region of the start of a dirty page
+ * Returns the page offset within memory region of the start of a dirty page
*
* @rs: current RAM state
* @rb: RAMBlock where to search for dirty pages
}
static void migration_bitmap_sync_range(RAMState *rs, RAMBlock *rb,
- ram_addr_t start, ram_addr_t length)
+ ram_addr_t length)
{
rs->migration_dirty_pages +=
- cpu_physical_memory_sync_dirty_bitmap(rb, start, length,
+ cpu_physical_memory_sync_dirty_bitmap(rb, 0, length,
&rs->num_dirty_pages_period);
}
qemu_mutex_lock(&rs->bitmap_mutex);
rcu_read_lock();
RAMBLOCK_FOREACH_NOT_IGNORED(block) {
- migration_bitmap_sync_range(rs, block, 0, block->used_length);
+ migration_bitmap_sync_range(rs, block, block->used_length);
}
ram_counters.remaining = ram_bytes_remaining();
rcu_read_unlock();
* find_dirty_block: find the next dirty page and update any state
* associated with the search process.
*
- * Returns if a page is found
+ * Returns true if a page is found
*
* @rs: current RAM state
* @pss: data about the state of the current dirty page scan
*
* Skips pages that are already sent (!dirty)
*
- * Returns if a queued page is found
+ * Returns true if a queued page is found
*
* @rs: current RAM state
* @pss: data about the state of the current dirty page scan
RAMBlock *block;
/* caller have hold iothread lock or is in a bh, so there is
- * no writing race against this migration_bitmap
+ * no writing race against the migration bitmap
*/
memory_global_dirty_log_stop();
/* we want to check in the 1st loop, just in case it was the 1st time
and we had to sync the dirty bitmap.
- qemu_get_clock_ns() is a bit expensive, so we only check each some
+ qemu_clock_get_ns() is a bit expensive, so we only check each some
iterations
*/
if ((i & 63) == 0) {
}
ram_state = g_new0(RAMState, 1);
ram_state->migration_dirty_pages = 0;
+ qemu_mutex_init(&ram_state->bitmap_mutex);
memory_global_dirty_log_start();
return 0;
}
rcu_read_unlock();
+ qemu_mutex_destroy(&ram_state->bitmap_mutex);
g_free(ram_state);
ram_state = NULL;
}
memory_global_dirty_log_sync();
rcu_read_lock();
RAMBLOCK_FOREACH_NOT_IGNORED(block) {
- migration_bitmap_sync_range(ram_state, block, 0, block->used_length);
+ migration_bitmap_sync_range(ram_state, block, block->used_length);
}
rcu_read_unlock();
projects / qemu.git / blobdiff