+#ifdef RTE_LIBRTE_VHOST_POSTCOPY
+static int
+vhost_user_postcopy_region_register(struct virtio_net *dev,
+ struct rte_vhost_mem_region *reg)
+{
+ struct uffdio_register reg_struct;
+
+ /*
+ * Let's register all the mmap'ed area to ensure
+ * alignment on page boundary.
+ */
+ reg_struct.range.start = (uint64_t)(uintptr_t)reg->mmap_addr;
+ reg_struct.range.len = reg->mmap_size;
+ reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
+
+ if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
+ ®_struct)) {
+ VHOST_LOG_CONFIG(ERR, "Failed to register ufd for region "
+ "%" PRIx64 " - %" PRIx64 " (ufd = %d) %s\n",
+ (uint64_t)reg_struct.range.start,
+ (uint64_t)reg_struct.range.start +
+ (uint64_t)reg_struct.range.len - 1,
+ dev->postcopy_ufd,
+ strerror(errno));
+ return -1;
+ }
+
+ VHOST_LOG_CONFIG(INFO, "\t userfaultfd registered for range : %" PRIx64 " - %" PRIx64 "\n",
+ (uint64_t)reg_struct.range.start,
+ (uint64_t)reg_struct.range.start +
+ (uint64_t)reg_struct.range.len - 1);
+
+ return 0;
+}
+#else
+static int
+vhost_user_postcopy_region_register(struct virtio_net *dev __rte_unused,
+ struct rte_vhost_mem_region *reg __rte_unused)
+{
+ return -1;
+}
+#endif
+