func: 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;
  
  }
  