diff --git a/migration/ram.c b/migration/ram.c index 454d3eb539bba4206b5644f02c2341433969b511..77c18782921e69fa1918a06acc7a081f0687493d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -786,13 +786,13 @@ static void multifd_pages_clear(MultiFDPages_t *pages) static void multifd_send_fill_packet(MultiFDSendParams *p) { MultiFDPacket_t *packet = p->packet; - uint32_t page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); + 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->pages_alloc = cpu_to_be32(page_count); + 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); @@ -809,7 +809,7 @@ 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 page_count = MULTIFD_PACKET_SIZE / qemu_target_page_size(); + uint32_t pages_max = MULTIFD_PACKET_SIZE / qemu_target_page_size(); RAMBlock *block; int i; @@ -832,12 +832,24 @@ static int multifd_recv_unfill_packet(MultiFDRecvParams *p, Error **errp) p->flags = be32_to_cpu(packet->flags); packet->pages_alloc = be32_to_cpu(packet->pages_alloc); - if (packet->pages_alloc > page_count) { + /* + * 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->pages_alloc, 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->pages_used); if (p->pages->used > packet->pages_alloc) {