diff options
Diffstat (limited to 'migration/ram.c')
| -rw-r--r-- | migration/ram.c | 82 |
1 files changed, 60 insertions, 22 deletions
diff --git a/migration/ram.c b/migration/ram.c index 35bd621..d7f8fe4 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -583,20 +583,29 @@ exit: #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; @@ -643,6 +652,8 @@ typedef struct { 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 */ @@ -679,6 +690,8 @@ typedef struct { /* 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 */ @@ -776,13 +789,15 @@ static void multifd_pages_clear(MultiFDPages_t *pages) 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) { @@ -797,6 +812,7 @@ static void multifd_send_fill_packet(MultiFDSendParams *p) 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; @@ -818,22 +834,35 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) 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); + 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) { @@ -1073,6 +1102,7 @@ static void *multifd_send_thread(void *opaque) 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++; @@ -1080,7 +1110,8 @@ static void *multifd_send_thread(void *opaque) 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); @@ -1088,9 +1119,12 @@ static void *multifd_send_thread(void *opaque) 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); @@ -1148,7 +1182,7 @@ static void multifd_new_send_channel_async(QIOTask *task, gpointer opaque) 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()) { @@ -1312,14 +1346,18 @@ static void *multifd_recv_thread(void *opaque) 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) { @@ -1344,7 +1382,7 @@ static void *multifd_recv_thread(void *opaque) 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()) { |