static int vhost_user_set_mem_table(struct vhost_dev *dev, struct vhost_memory *mem) { int fds[VHOST_MEMORY_MAX_NREGIONS]; int i, fd; size_t fd_num = 0; bool reply_supported = virtio_has_feature(dev->protocol_features, VHOST_USER_PROTOCOL_F_REPLY_ACK); VhostUserMsg msg = { .hdr.request = VHOST_USER_SET_MEM_TABLE, .hdr.flags = VHOST_USER_VERSION, }; if (reply_supported) { msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK; } for (i = 0; i < dev->mem->nregions; ++i) { struct vhost_memory_region *reg = dev->mem->regions + i; ram_addr_t offset; MemoryRegion *mr; assert((uintptr_t)reg->userspace_addr == reg->userspace_addr); mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr, &offset); fd = memory_region_get_fd(mr); if (fd > 0) { msg.payload.memory.regions[fd_num].userspace_addr = reg->userspace_addr; msg.payload.memory.regions[fd_num].memory_size = reg->memory_size; msg.payload.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr; msg.payload.memory.regions[fd_num].mmap_offset = offset; assert(fd_num < VHOST_MEMORY_MAX_NREGIONS); fds[fd_num++] = fd; } } msg.payload.memory.nregions = fd_num; if (!fd_num) { error_report("Failed initializing vhost-user memory map, " "consider using -object memory-backend-file share=on"); return -1; } msg.hdr.size = sizeof(msg.payload.memory.nregions); msg.hdr.size += sizeof(msg.payload.memory.padding); msg.hdr.size += fd_num * sizeof(VhostUserMemoryRegion); if (vhost_user_write(dev, &msg, fds, fd_num) < 0) { return -1; } if (reply_supported) { return process_message_reply(dev, &msg); } return 0; }