static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp) { RAMBlock *block; RAMBlock *last_block = NULL; ram_addr_t old_ram_size, new_ram_size; old_ram_size = last_ram_offset() >> TARGET_PAGE_BITS; qemu_mutex_lock_ramlist(); new_block->offset = find_ram_offset(new_block->max_length); if (!new_block->host) { if (xen_enabled()) { xen_ram_alloc(new_block->offset, new_block->max_length, new_block->mr); } else { new_block->host = phys_mem_alloc(new_block->max_length, &new_block->mr->align); if (!new_block->host) { error_setg_errno(errp, errno, "cannot set up guest memory '%s'", memory_region_name(new_block->mr)); qemu_mutex_unlock_ramlist(); return -1; memory_try_enable_merging(new_block->host, new_block->max_length); /* Keep the list sorted from biggest to smallest block. Unlike QTAILQ, * QLIST (which has an RCU-friendly variant) does not have insertion at * tail, so save the last element in last_block. */ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { last_block = block; if (block->max_length < new_block->max_length) { break; if (block) { QLIST_INSERT_BEFORE_RCU(block, new_block, next); } else if (last_block) { QLIST_INSERT_AFTER_RCU(last_block, new_block, next); } else { /* list is empty */ QLIST_INSERT_HEAD_RCU(&ram_list.blocks, new_block, next); ram_list.mru_block = NULL; /* Write list before version */ smp_wmb(); ram_list.version++; qemu_mutex_unlock_ramlist(); new_ram_size = last_ram_offset() >> TARGET_PAGE_BITS; int i; /* ram_list.dirty_memory[] is protected by the iothread lock. */ for (i = 0; i < DIRTY_MEMORY_NUM; i++) { ram_list.dirty_memory[i] = bitmap_zero_extend(ram_list.dirty_memory[i], old_ram_size, new_ram_size); cpu_physical_memory_set_dirty_range(new_block->offset, new_block->used_length, DIRTY_CLIENTS_ALL); if (new_block->host) { qemu_ram_setup_dump(new_block->host, new_block->max_length); qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_HUGEPAGE); qemu_madvise(new_block->host, new_block->max_length, QEMU_MADV_DONTFORK); if (kvm_enabled()) { kvm_setup_guest_memory(new_block->host, new_block->max_length); return new_block->offset;