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From d7a1c9c0bb074d0e5c1878a38a6b6315d33be89c Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Mon, 12 Feb 2018 16:45:02 +0000
Subject: [PATCH] v2v: Add -o rhv-upload output mode (RHBZ#1557273).
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This adds a new output mode to virt-v2v.  virt-v2v -o rhv-upload
streams images directly to an oVirt or RHV >= 4 Data Domain using the
oVirt SDK v4.  It is more efficient than -o rhv because it does not
need to go via the Export Storage Domain, and is possible for humans
to use unlike -o vdsm.

The implementation uses the Python SDK (‘ovirtsdk4’ module).  An
nbdkit Python 3 plugin translates NBD calls from qemu into HTTPS
requests to oVirt via the SDK.

(cherry picked from commit cc04573927cca97de60d544d37467e67c25867a7)
---
 .gitignore                                |   3 +
 TODO                                      |  27 ++
 v2v/Makefile.am                           |  30 +-
 v2v/cmdline.ml                            |  41 ++
 v2v/embed.sh                              |  48 +++
 v2v/output_rhv_upload.ml                  | 401 +++++++++++++++++++
 v2v/output_rhv_upload.mli                 |  33 ++
 v2v/output_rhv_upload_createvm_source.mli |  19 +
 v2v/output_rhv_upload_plugin_source.mli   |  19 +
 v2v/output_rhv_upload_precheck_source.mli |  19 +
 v2v/rhv-upload-createvm.py                |  86 +++++
 v2v/rhv-upload-plugin.py                  | 445 ++++++++++++++++++++++
 v2v/rhv-upload-precheck.py                |  73 ++++
 v2v/test-v2v-o-rhv-upload-oo-query.sh     |  38 ++
 v2v/test-v2v-python-syntax.sh             |  45 +++
 v2v/virt-v2v.pod                          | 138 ++++++-
 16 files changed, 1447 insertions(+), 18 deletions(-)
 create mode 100755 v2v/embed.sh
 create mode 100644 v2v/output_rhv_upload.ml
 create mode 100644 v2v/output_rhv_upload.mli
 create mode 100644 v2v/output_rhv_upload_createvm_source.mli
 create mode 100644 v2v/output_rhv_upload_plugin_source.mli
 create mode 100644 v2v/output_rhv_upload_precheck_source.mli
 create mode 100644 v2v/rhv-upload-createvm.py
 create mode 100644 v2v/rhv-upload-plugin.py
 create mode 100644 v2v/rhv-upload-precheck.py
 create mode 100755 v2v/test-v2v-o-rhv-upload-oo-query.sh
 create mode 100755 v2v/test-v2v-python-syntax.sh

diff --git a/.gitignore b/.gitignore
index e67013478..ecdac6df3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -671,6 +671,9 @@ Makefile.in
 /utils/qemu-speed-test/qemu-speed-test
 /v2v/.depend
 /v2v/oUnit-*
+/v2v/output_rhv_upload_createvm_source.ml
+/v2v/output_rhv_upload_plugin_source.ml
+/v2v/output_rhv_upload_precheck_source.ml
 /v2v/real-*.d/
 /v2v/real-*.img
 /v2v/real-*.xml
diff --git a/TODO b/TODO
index 2e37ce67c..d196a3f6b 100644
--- a/TODO
+++ b/TODO
@@ -570,3 +570,30 @@ Subsecond handling in virt-diff, virt-ls
 
 Handle nanoseconds properly.  You should be able to specify them on
 the command line and display them.
+
+virt-v2v -o rhv-upload
+----------------------
+
+* Set or disable the ticket timeout.  The default is going to be
+  increased (from current 60 seconds), so maybe we won't have to
+  set it.  See also:
+  https://bugzilla.redhat.com/show_bug.cgi?id=1563278
+
+* qcow2 cannot be supported yet because there is not yet any
+  concept in imageio of read+write handles.
+  https://bugzilla.redhat.com/show_bug.cgi?id=1563299
+
+* preallocated cannot be supported yet because imageio doesn't
+  know how to zero the image efficiently, instead it runs an
+  fallocate process which writes to every block and that takes
+  many minutes.
+
+* Really check what insecure/rhv_cafile do and implement it correctly.
+
+* Measure and resolve performance problems.
+
+* Allocated image size is unknown for v2v uploads, but imageio needs
+  to know it.  We pass initial_size == provisioned_size == virtual size.
+  That can't be fixed from the v2v side.
+
+* There are unresolved issues about how to clean up disks on failure.
diff --git a/v2v/Makefile.am b/v2v/Makefile.am
index 5fcfeadba..affc00a8b 100644
--- a/v2v/Makefile.am
+++ b/v2v/Makefile.am
@@ -22,12 +22,19 @@ generator_built = \
 	uefi.mli
 
 BUILT_SOURCES = \
-	$(generator_built)
+	$(generator_built) \
+	output_rhv_upload_createvm_source.ml \
+	output_rhv_upload_plugin_source.ml \
+	output_rhv_upload_precheck_source.ml
 
 EXTRA_DIST = \
 	$(SOURCES_MLI) $(SOURCES_ML) $(SOURCES_C) \
 	copy_to_local.ml \
 	copy_to_local.mli \
+	embed-code.sh \
+	rhv-upload-createvm.py \
+	rhv-upload-plugin.py \
+	rhv-upload-precheck.py \
 	v2v_unit_tests.ml \
 	virt-v2v.pod \
 	virt-v2v-copy-to-local.pod
@@ -62,6 +69,10 @@ SOURCES_MLI = \
 	output_null.mli \
 	output_qemu.mli \
 	output_rhv.mli \
+	output_rhv_upload.mli \
+	output_rhv_upload_createvm_source.mli \
+	output_rhv_upload_plugin_source.mli \
+	output_rhv_upload_precheck_source.mli \
 	output_vdsm.mli \
 	parse_ova.mli \
 	parse_ovf_from_ova.mli \
@@ -116,6 +127,10 @@ SOURCES_ML = \
 	output_local.ml \
 	output_qemu.ml \
 	output_rhv.ml \
+	output_rhv_upload_createvm_source.ml \
+	output_rhv_upload_plugin_source.ml \
+	output_rhv_upload_precheck_source.ml \
+	output_rhv_upload.ml \
 	output_vdsm.ml \
 	inspect_source.ml \
 	target_bus_assignment.ml \
@@ -126,6 +141,15 @@ SOURCES_C = \
 	libvirt_utils-c.c \
 	qemuopts-c.c
 
+# These files are generated and contain rhv-upload-*.py embedded as an
+# OCaml string.
+output_rhv_upload_createvm_source.ml: rhv-upload-createvm.py
+	./embed.sh code $^ $@
+output_rhv_upload_plugin_source.ml: rhv-upload-plugin.py
+	./embed.sh code $^ $@
+output_rhv_upload_precheck_source.ml: rhv-upload-precheck.py
+	./embed.sh code $^ $@
+
 if HAVE_OCAML
 
 bin_PROGRAMS = virt-v2v virt-v2v-copy-to-local
@@ -295,6 +319,7 @@ TESTS_ENVIRONMENT = $(top_builddir)/run --test
 
 TESTS = \
 	test-v2v-docs.sh \
+	test-v2v-python-syntax.sh \
 	test-v2v-i-ova-bad-sha1.sh \
 	test-v2v-i-ova-bad-sha256.sh \
 	test-v2v-i-ova-formats.sh \
@@ -308,6 +333,7 @@ TESTS = \
 	test-v2v-i-ova-two-disks.sh \
 	test-v2v-i-vmx.sh \
 	test-v2v-it-vddk-io-query.sh \
+	test-v2v-o-rhv-upload-oo-query.sh \
 	test-v2v-o-vdsm-oo-query.sh \
 	test-v2v-bad-networks-and-bridges.sh
 
@@ -481,6 +507,7 @@ EXTRA_DIST += \
 	test-v2v-o-null.sh \
 	test-v2v-o-qemu.sh \
 	test-v2v-o-rhv.sh \
+	test-v2v-o-rhv-upload-oo-query.sh \
 	test-v2v-o-vdsm-oo-query.sh \
 	test-v2v-o-vdsm-options.sh \
 	test-v2v-oa-option.sh \
@@ -489,6 +516,7 @@ EXTRA_DIST += \
 	test-v2v-print-source.expected \
 	test-v2v-print-source.sh \
 	test-v2v-print-source.xml \
+	test-v2v-python-syntax.sh \
 	test-v2v-conversion-of.sh \
 	test-v2v-sound.sh \
 	test-v2v-sound.xml \
diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml
index c9b859dd6..6321eb656 100644
--- a/v2v/cmdline.ml
+++ b/v2v/cmdline.ml
@@ -133,6 +133,8 @@ let parse_cmdline () =
     | "disk" | "local" -> output_mode := `Local
     | "null" -> output_mode := `Null
     | "ovirt" | "rhv" | "rhev" -> output_mode := `RHV
+    | "ovirt-upload" | "ovirt_upload" | "rhv-upload" | "rhv_upload" ->
+       output_mode := `RHV_Upload
     | "qemu" -> output_mode := `QEmu
     | "vdsm" -> output_mode := `VDSM
     | s ->
@@ -389,6 +391,16 @@ read the man page virt-v2v(1).
     | `Null -> no_options (); `Null
     | `RHV -> no_options (); `RHV
     | `QEmu -> no_options (); `QEmu
+    | `RHV_Upload ->
+       if is_query then (
+         Output_rhv_upload.print_output_options ();
+         exit 0
+       )
+       else (
+         let rhv_options =
+           Output_rhv_upload.parse_output_options output_options in
+         `RHV_Upload rhv_options
+       )
     | `VDSM ->
        if is_query then (
          Output_vdsm.print_output_options ();
@@ -571,6 +583,35 @@ read the man page virt-v2v(1).
       Output_rhv.output_rhv os output_alloc,
       output_format, output_alloc
 
+    | `RHV_Upload rhv_options ->
+      let output_conn =
+        match output_conn with
+        | None ->
+           error (f_"-o rhv-upload: use ‘-oc’ to point to the oVirt or RHV server REST API URL, which is usually https://servername/ovirt-engine/api")
+        | Some oc -> oc in
+      (* Output format / sparse must currently be raw+sparse.  We can
+       * change this in future.  See TODO file for details. XXX
+       *)
+      if output_alloc <> Sparse || output_format <> Some "raw" then
+        error (f_"-o rhv-upload: currently you must use ‘-of raw’ and you cannot use ‘-oa preallocated’ with this output mode.  These restrictions will be loosened in a future version.");
+      (* In theory we could make the password optional in future. *)
+      let output_password =
+        match output_password with
+        | None ->
+           error (f_"-o rhv-upload: output password file was not specified, use ‘-op’ to point to a file which contains the password used to connect to the oVirt or RHV server")
+        | Some op -> op in
+      let os =
+        match output_storage with
+        | None ->
+           error (f_"-o rhv-upload: output storage was not specified, use ‘-os’");
+        | Some os -> os in
+      if qemu_boot then
+        error_option_cannot_be_used_in_output_mode "rhv-upload" "--qemu-boot";
+      Output_rhv_upload.output_rhv_upload output_alloc output_conn
+                                          output_password os
+                                          rhv_options,
+      output_format, output_alloc
+
     | `VDSM vdsm_options ->
       if output_password <> None then
         error_option_cannot_be_used_in_output_mode "vdsm" "-op";
diff --git a/v2v/embed.sh b/v2v/embed.sh
new file mode 100755
index 000000000..363d7e2b0
--- /dev/null
+++ b/v2v/embed.sh
@@ -0,0 +1,48 @@
+#!/bin/bash -
+# Embed code or other content into an OCaml file.
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+# Embed code or other content into an OCaml file.
+#
+# It is embedded into a string.  As OCaml string literals have virtually
+# no restrictions on length or content we only have to escape double
+# quotes for backslash characters.
+
+if [ $# -ne 3 ]; then
+    echo "embed.sh identifier input output"
+    exit 1
+fi
+
+set -e
+set -u
+
+ident="$1"
+input="$2"
+output="$3"
+
+rm -f "$output" "$output"-t
+
+exec >"$output"-t
+
+echo "(* Generated by embed.sh from $input *)"
+echo
+echo let "$ident" = '"'
+sed -e 's/\(["\]\)/\\\1/g' < "$input"
+echo '"'
+
+chmod -w "$output"-t
+mv "$output"-t "$output"
diff --git a/v2v/output_rhv_upload.ml b/v2v/output_rhv_upload.ml
new file mode 100644
index 000000000..129461242
--- /dev/null
+++ b/v2v/output_rhv_upload.ml
@@ -0,0 +1,401 @@
+(* virt-v2v
+ * Copyright (C) 2009-2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+open Printf
+open Unix
+
+open Std_utils
+open Tools_utils
+open Unix_utils
+open Common_gettext.Gettext
+
+open Types
+open Utils
+
+type rhv_options = {
+  rhv_cafile : string;
+  rhv_cluster : string option;
+  rhv_direct : bool;
+  rhv_verifypeer : bool;
+}
+
+let print_output_options () =
+  printf (f_"Output options (-oo) which can be used with -o rhv-upload:
+
+  -oo rhv-cafile=CA.PEM           Set ‘ca.pem’ certificate bundle filename.
+  -oo rhv-cluster=CLUSTERNAME     Set RHV cluster name.
+  -oo rhv-direct[=true|false]     Use direct transfer mode (default: false).
+  -oo rhv-verifypeer[=true|false] Verify server identity (default: false).
+")
+
+let parse_output_options options =
+  let rhv_cafile = ref None in
+  let rhv_cluster = ref None in
+  let rhv_direct = ref false in
+  let rhv_verifypeer = ref false in
+
+  List.iter (
+    function
+    | "rhv-cafile", v ->
+       if !rhv_cafile <> None then
+         error (f_"-o rhv-upload: -oo rhv-cafile set twice");
+       rhv_cafile := Some v
+    | "rhv-cluster", v ->
+       if !rhv_cluster <> None then
+         error (f_"-o rhv-upload: -oo rhv-cluster set twice");
+       rhv_cluster := Some v
+    | "rhv-direct", "" -> rhv_direct := true
+    | "rhv-direct", v -> rhv_direct := bool_of_string v
+    | "rhv-verifypeer", "" -> rhv_verifypeer := true
+    | "rhv-verifypeer", v -> rhv_verifypeer := bool_of_string v
+    | k, _ ->
+       error (f_"-o rhv-upload: unknown output option ‘-oo %s’") k
+  ) options;
+
+  let rhv_cafile =
+    match !rhv_cafile with
+    | Some s -> s
+    | None ->
+       error (f_"-o rhv-upload: must use ‘-oo rhv-cafile’ to supply the path to the oVirt or RHV user’s ‘ca.pem’ file") in
+  let rhv_cluster = !rhv_cluster in
+  let rhv_direct = !rhv_direct in
+  let rhv_verifypeer = !rhv_verifypeer in
+
+  { rhv_cafile; rhv_cluster; rhv_direct; rhv_verifypeer }
+
+let python3 = "python3" (* Defined by PEP 394 *)
+let pidfile_timeout = 30
+let finalization_timeout = 5*60
+
+class output_rhv_upload output_alloc output_conn
+                        output_password output_storage
+                        rhv_options =
+  (* Create a temporary directory which will be deleted on exit. *)
+  let tmpdir =
+    let base_dir = (open_guestfs ())#get_cachedir () in
+    let t = Mkdtemp.temp_dir ~base_dir "rhvupload." in
+    rmdir_on_exit t;
+    t in
+
+  let diskid_file_of_id id = tmpdir // sprintf "diskid.%d" id in
+
+  (* Write the Python precheck, plugin and create VM to a temporary file. *)
+  let precheck =
+    let precheck = tmpdir // "rhv-upload-precheck.py" in
+    with_open_out
+      precheck
+      (fun chan -> output_string chan Output_rhv_upload_precheck_source.code);
+    precheck in
+  let plugin =
+    let plugin = tmpdir // "rhv-upload-plugin.py" in
+    with_open_out
+      plugin
+      (fun chan -> output_string chan Output_rhv_upload_plugin_source.code);
+    plugin in
+  let createvm =
+    let createvm = tmpdir // "rhv-upload-createvm.py" in
+    with_open_out
+      createvm
+      (fun chan -> output_string chan Output_rhv_upload_createvm_source.code);
+    createvm in
+
+  (* Is SELinux enabled and enforcing on the host? *)
+  let have_selinux =
+    0 = Sys.command "getenforce 2>/dev/null | grep -isq Enforcing" in
+
+  (* Check that the Python binary is available. *)
+  let error_unless_python_binary_on_path () =
+    try ignore (which python3)
+    with Executable_not_found _ ->
+      error (f_"no python binary called ‘%s’ can be found on the $PATH")
+            python3
+  in
+
+  (* Check that nbdkit is available and new enough. *)
+  let error_unless_nbdkit_working () =
+    if 0 <> Sys.command "nbdkit --version >/dev/null" then
+      error (f_"nbdkit is not installed or not working.  It is required to use ‘-o rhv-upload’.  See \"OUTPUT TO RHV\" in the virt-v2v(1) manual.");
+
+    (* Check it's a new enough version.  The latest features we
+     * require are ‘--exit-with-parent’ and ‘--selinux-label’, both
+     * added in 1.1.14.  (We use 1.1.16 as the minimum here because
+     * it also adds the selinux=yes|no flag in --dump-config).
+     *)
+    let lines = external_command "nbdkit --help" in
+    let lines = String.concat " " lines in
+    if String.find lines "exit-with-parent" == -1 ||
+       String.find lines "selinux-label" == -1 then
+      error (f_"nbdkit is not new enough, you need to upgrade to nbdkit ≥ 1.1.16")
+  in
+
+  (* Check that the python3 plugin is installed and working
+   * and can load the plugin script.
+   *)
+  let error_unless_nbdkit_python3_working () =
+    let cmd = sprintf "nbdkit %s %s --dump-plugin >/dev/null"
+                      python3 (quote plugin) in
+    if Sys.command cmd <> 0 then
+      error (f_"nbdkit Python 3 plugin is not installed or not working.  It is required if you want to use ‘-o rhv-upload’.
+
+See also \"OUTPUT TO RHV\" in the virt-v2v(1) manual.")
+  in
+
+  (* Check that nbdkit was compiled with SELinux support (for the
+   * --selinux-label option).
+   *)
+  let error_unless_nbdkit_compiled_with_selinux () =
+    let lines = external_command "nbdkit --dump-config" in
+    (* In nbdkit <= 1.1.15 the selinux attribute was not present
+     * at all in --dump-config output so there was no way to tell.
+     * Ignore this case because there will be an error later when
+     * we try to use the --selinux-label parameter.
+     *)
+    if List.mem "selinux=no" (List.map String.trim lines) then
+      error (f_"nbdkit was compiled without SELinux support.  You will have to recompile nbdkit with libselinux-devel installed, or else set SELinux to Permissive mode while doing the conversion.")
+  in
+
+  (* JSON parameters which are invariant between disks. *)
+  let json_params = [
+    "verbose", JSON.Bool (verbose ());
+
+    "output_conn", JSON.String output_conn;
+    "output_password", JSON.String output_password;
+    "output_storage", JSON.String output_storage;
+    "output_sparse", JSON.Bool (match output_alloc with
+                                | Sparse -> true
+                                | Preallocated -> false);
+    "rhv_cafile", JSON.String rhv_options.rhv_cafile;
+    "rhv_cluster",
+      JSON.String (Option.default "Default" rhv_options.rhv_cluster);
+    "rhv_direct", JSON.Bool rhv_options.rhv_direct;
+
+    (* The 'Insecure' flag seems to be a number with various possible
+     * meanings, however we just set it to True/False.
+     *
+     * https://github.com/oVirt/ovirt-engine-sdk/blob/19aa7070b80e60a4cfd910448287aecf9083acbe/sdk/lib/ovirtsdk4/__init__.py#L395
+     *)
+    "insecure", JSON.Bool (not rhv_options.rhv_verifypeer);
+  ] in
+
+  (* nbdkit command line args which are invariant between disks. *)
+  let nbdkit_args =
+    let args = [
+      "nbdkit";
+
+      "--foreground";           (* run in foreground *)
+      "--exit-with-parent";     (* exit when virt-v2v exits *)
+      "--newstyle";             (* use newstyle NBD protocol *)
+      "--exportname"; "/";
+
+      "python3";                (* use the nbdkit Python 3 plugin *)
+      plugin;                   (* Python plugin script *)
+    ] in
+    let args = if verbose () then args @ ["--verbose"] else args in
+    let args =
+      (* label the socket so qemu can open it *)
+      if have_selinux then
+        args @ ["--selinux-label"; "system_u:object_r:svirt_t:s0"]
+      else args in
+    args in
+
+object
+  inherit output
+
+  method precheck () =
+    error_unless_python_binary_on_path ();
+    error_unless_nbdkit_working ();
+    error_unless_nbdkit_python3_working ();
+    if have_selinux then
+      error_unless_nbdkit_compiled_with_selinux ()
+
+  method as_options =
+    "-o rhv-upload" ^
+    (match output_alloc with
+     | Sparse -> "" (* default, don't need to print it *)
+     | Preallocated -> " -oa preallocated") ^
+    sprintf " -oc %s -op %s -os %s"
+            output_conn output_password output_storage
+
+  method supported_firmware = [ TargetBIOS ]
+
+  method prepare_targets source targets =
+    let output_name = source.s_name in
+    let json_params =
+      ("output_name", JSON.String output_name) :: json_params in
+
+    (* Python code prechecks.  These can't run in #precheck because
+     * we need to know the name of the virtual machine.
+     *)
+    let json_param_file = tmpdir // "params.json" in
+    with_open_out
+      json_param_file
+      (fun chan -> output_string chan (JSON.string_of_doc json_params));
+    if run_command [ python3; precheck; json_param_file ] <> 0 then
+      error (f_"failed server prechecks, see earlier errors");
+
+    (* Create an nbdkit instance for each disk and set the
+     * target URI to point to the NBD socket.
+     *)
+    List.map (
+      fun t ->
+        let id = t.target_overlay.ov_source.s_disk_id in
+        let disk_name = sprintf "%s-%03d" output_name id in
+        let json_params =
+          ("disk_name", JSON.String disk_name) :: json_params in
+
+        let disk_format =
+          match t.target_format with
+          | ("raw" | "qcow2") as fmt -> fmt
+          | _ ->
+             error (f_"rhv-upload: -of %s: Only output format ‘raw’ or ‘qcow2’ is supported.  If the input is in a different format then force one of these output formats by adding either ‘-of raw’ or ‘-of qcow2’ on the command line.")
+                   t.target_format in
+        let json_params =
+          ("disk_format", JSON.String disk_format) :: json_params in
+
+        let disk_size = t.target_overlay.ov_virtual_size in
+        let json_params =
+          ("disk_size", JSON.Int64 disk_size) :: json_params in
+
+        (* Ask the plugin to write the disk ID to a special file. *)
+        let diskid_file = diskid_file_of_id id in
+        let json_params =
+          ("diskid_file", JSON.String diskid_file) :: json_params in
+
+        (* Write the JSON parameters to a file. *)
+        let json_param_file = tmpdir // sprintf "params%d.json" id in
+        with_open_out
+          json_param_file
+          (fun chan -> output_string chan (JSON.string_of_doc json_params));
+
+        let sock = tmpdir // sprintf "nbdkit%d.sock" id in
+        let pidfile = tmpdir // sprintf "nbdkit%d.pid" id in
+
+        (* Add common arguments to per-target arguments. *)
+        let args =
+          nbdkit_args @ [ "--pidfile"; pidfile;
+                          "--unix"; sock;
+                          sprintf "params=%s" json_param_file ] in
+
+        (* Print the full command we are about to run when debugging. *)
+        if verbose () then (
+          eprintf "running nbdkit:\n";
+          List.iter (fun arg -> eprintf " %s" (quote arg)) args;
+          prerr_newline ()
+        );
+
+        (* Start an nbdkit instance in the background.  By using
+         * --exit-with-parent we don't have to worry about clean-up.
+         *)
+        let args = Array.of_list args in
+        let pid = fork () in
+        if pid = 0 then (
+          (* Child process (nbdkit). *)
+          execvp "nbdkit" args
+        );
+
+        (* Wait for the pidfile to appear so we know that nbdkit
+         * is listening for requests.
+         *)
+        if not (wait_for_file pidfile pidfile_timeout) then (
+          if verbose () then
+            error (f_"nbdkit did not start up.  See previous debugging messages for problems.")
+          else
+            error (f_"nbdkit did not start up.  There may be errors printed by nbdkit above.
+
+If the messages above are not sufficient to diagnose the problem then add the ‘virt-v2v -v -x’ options and examine the debugging output carefully.")
+        );
+
+        if have_selinux then (
+          (* Note that Unix domain sockets have both a file label and
+           * a socket/process label.  Using --selinux-label above
+           * only set the socket label, but we must also set the file
+           * label.
+           *)
+          ignore (
+              run_command ["chcon"; "system_u:object_r:svirt_image_t:s0";
+                           sock]
+          );
+        );
+        (* ... and the regular Unix permissions, in case qemu is
+         * running as another user.
+         *)
+        chmod sock 0o777;
+
+        (* Tell ‘qemu-img convert’ to write to the nbd socket which is
+         * connected to nbdkit.
+         *)
+        let json_params = [
+          "file.driver", JSON.String "nbd";
+          "file.path", JSON.String sock;
+          "file.export", JSON.String "/";
+        ] in
+        let target_file =
+          TargetURI ("json:" ^ JSON.string_of_doc json_params) in
+        { t with target_file }
+    ) targets
+
+  method create_metadata source targets _ guestcaps inspect target_firmware =
+    (* Get the UUIDs of each disk image.  These files are written
+     * out by the nbdkit plugins on successful finalization of the
+     * transfer.
+     *)
+    let nr_disks = List.length targets in
+    let image_uuids =
+      List.map (
+        fun t ->
+          let id = t.target_overlay.ov_source.s_disk_id in
+          let diskid_file = diskid_file_of_id id in
+          if not (wait_for_file diskid_file finalization_timeout) then
+            error (f_"transfer of disk %d/%d failed, see earlier error messages")
+                  (id+1) nr_disks;
+          let diskid = read_whole_file diskid_file in
+          diskid
+      ) targets in
+
+    (* We don't have the storage domain UUID, but instead we write
+     * in a magic value which the Python code (which can get it)
+     * will substitute.
+     *)
+    let sd_uuid = "@SD_UUID@" in
+
+    (* The volume and VM UUIDs are made up. *)
+    let vol_uuids = List.map (fun _ -> uuidgen ()) targets
+    and vm_uuid = uuidgen () in
+
+    (* Create the metadata. *)
+    let ovf =
+      Create_ovf.create_ovf source targets guestcaps inspect
+                            output_alloc
+                            sd_uuid image_uuids vol_uuids vm_uuid
+                            OVirt in
+    let ovf = DOM.doc_to_string ovf in
+
+    let json_param_file = tmpdir // "params.json" in
+    with_open_out
+      json_param_file
+      (fun chan -> output_string chan (JSON.string_of_doc json_params));
+
+    let ovf_file = tmpdir // "vm.ovf" in
+    with_open_out ovf_file (fun chan -> output_string chan ovf);
+    if run_command [ python3; createvm; json_param_file; ovf_file ] <> 0 then
+      error (f_"failed to create virtual machine, see earlier errors")
+
+end
+
+let output_rhv_upload = new output_rhv_upload
+let () = Modules_list.register_output_module "rhv-upload"
diff --git a/v2v/output_rhv_upload.mli b/v2v/output_rhv_upload.mli
new file mode 100644
index 000000000..f6cd69a61
--- /dev/null
+++ b/v2v/output_rhv_upload.mli
@@ -0,0 +1,33 @@
+(* virt-v2v
+ * Copyright (C) 2009-2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+(** [-o rhv-upload] target. *)
+
+type rhv_options
+(** Miscellaneous extra command line parameters used by rhv-upload. *)
+
+val print_output_options : unit -> unit
+val parse_output_options : (string * string) list -> rhv_options
+(** Print and parse rhv-upload -oo options. *)
+
+val output_rhv_upload : Types.output_allocation -> string -> string ->
+                        string -> rhv_options -> Types.output
+(** [output_rhv_upload output_alloc output_conn output_password output_storage
+     rhv_options]
+    creates and returns a new {!Types.output} object specialized for writing
+    output to oVirt or RHV directly via RHV APIs. *)
diff --git a/v2v/output_rhv_upload_createvm_source.mli b/v2v/output_rhv_upload_createvm_source.mli
new file mode 100644
index 000000000..c1bafa15b
--- /dev/null
+++ b/v2v/output_rhv_upload_createvm_source.mli
@@ -0,0 +1,19 @@
+(* virt-v2v
+ * Copyright (C) 2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+val code : string
diff --git a/v2v/output_rhv_upload_plugin_source.mli b/v2v/output_rhv_upload_plugin_source.mli
new file mode 100644
index 000000000..c1bafa15b
--- /dev/null
+++ b/v2v/output_rhv_upload_plugin_source.mli
@@ -0,0 +1,19 @@
+(* virt-v2v
+ * Copyright (C) 2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+val code : string
diff --git a/v2v/output_rhv_upload_precheck_source.mli b/v2v/output_rhv_upload_precheck_source.mli
new file mode 100644
index 000000000..c1bafa15b
--- /dev/null
+++ b/v2v/output_rhv_upload_precheck_source.mli
@@ -0,0 +1,19 @@
+(* virt-v2v
+ * Copyright (C) 2018 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *)
+
+val code : string
diff --git a/v2v/rhv-upload-createvm.py b/v2v/rhv-upload-createvm.py
new file mode 100644
index 000000000..a34627ec8
--- /dev/null
+++ b/v2v/rhv-upload-createvm.py
@@ -0,0 +1,86 @@
+# -*- python -*-
+# oVirt or RHV upload create VM used by ‘virt-v2v -o rhv-upload’
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import json
+import logging
+import sys
+import time
+
+from http.client import HTTPSConnection
+from urllib.parse import urlparse
+
+import ovirtsdk4 as sdk
+import ovirtsdk4.types as types
+
+# Parameters are passed in via a JSON doc from the OCaml code.
+# Because this Python code ships embedded inside virt-v2v there
+# is no formal API here.
+params = None
+ovf = None                      # OVF file
+
+if len(sys.argv) != 3:
+    raise RuntimeError("incorrect number of parameters")
+
+# Parameters are passed in via a JSON document.
+with open(sys.argv[1], 'r') as fp:
+    params = json.load(fp)
+
+# What is passed in is a password file, read the actual password.
+with open(params['output_password'], 'r') as fp:
+    output_password = fp.read()
+output_password = output_password.rstrip()
+
+# Read the OVF document.
+with open(sys.argv[2], 'r') as fp:
+    ovf = fp.read()
+
+# Parse out the username from the output_conn URL.
+parsed = urlparse(params['output_conn'])
+username = parsed.username or "admin@internal"
+
+# Connect to the server.
+connection = sdk.Connection(
+    url = params['output_conn'],
+    username = username,
+    password = output_password,
+    ca_file = params['rhv_cafile'],
+    log = logging.getLogger(),
+    insecure = params['insecure'],
+)
+
+system_service = connection.system_service()
+
+# Get the storage domain UUID and substitute it into the OVF doc.
+sds_service = system_service.storage_domains_service()
+sd = sds_service.list(search=("name=%s" % params['output_storage']))[0]
+sd_uuid = sd.id
+
+ovf.replace("@SD_UUID@", sd_uuid)
+
+vms_service = system_service.vms_service()
+vm = vms_service.add(
+    types.Vm(
+        cluster=types.Cluster(name = params['rhv_cluster']),
+        initialization=types.Initialization(
+            configuration = types.Configuration(
+                type = types.ConfigurationType.OVA,
+                data = ovf,
+            )
+        )
+    )
+)
diff --git a/v2v/rhv-upload-plugin.py b/v2v/rhv-upload-plugin.py
new file mode 100644
index 000000000..791c9e7d2
--- /dev/null
+++ b/v2v/rhv-upload-plugin.py
@@ -0,0 +1,445 @@
+# -*- python -*-
+# oVirt or RHV upload nbdkit plugin used by ‘virt-v2v -o rhv-upload’
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import builtins
+import json
+import logging
+import ssl
+import sys
+import time
+
+from http.client import HTTPSConnection
+from urllib.parse import urlparse
+
+import ovirtsdk4 as sdk
+import ovirtsdk4.types as types
+
+# Timeout to wait for oVirt disks to change status, or the transfer
+# object to finish initializing [seconds].
+timeout = 5*60
+
+# Parameters are passed in via a JSON doc from the OCaml code.
+# Because this Python code ships embedded inside virt-v2v there
+# is no formal API here.
+params = None
+
+def config(key, value):
+    global params
+
+    if key == "params":
+        with builtins.open(value, 'r') as fp:
+            params = json.load(fp)
+    else:
+        raise RuntimeError("unknown configuration key '%s'" % key)
+
+def config_complete():
+    if params is None:
+        raise RuntimeError("missing configuration parameters")
+
+def debug(s):
+    if params['verbose']:
+        print(s, file=sys.stderr)
+        sys.stderr.flush()
+
+def open(readonly):
+    # Parse out the username from the output_conn URL.
+    parsed = urlparse(params['output_conn'])
+    username = parsed.username or "admin@internal"
+
+    # Read the password from file.
+    with builtins.open(params['output_password'], 'r') as fp:
+        password = fp.read()
+    password = password.rstrip()
+
+    # Connect to the server.
+    connection = sdk.Connection(
+        url = params['output_conn'],
+        username = username,
+        password = password,
+        ca_file = params['rhv_cafile'],
+        log = logging.getLogger(),
+        insecure = params['insecure'],
+    )
+
+    system_service = connection.system_service()
+
+    # Create the disk.
+    disks_service = system_service.disks_service()
+    if params['disk_format'] == "raw":
+        disk_format = types.DiskFormat.RAW
+    else:
+        disk_format = types.DiskFormat.COW
+    disk = disks_service.add(
+        disk = types.Disk(
+            name = params['disk_name'],
+            description = "Uploaded by virt-v2v",
+            format = disk_format,
+            initial_size = params['disk_size'],
+            provisioned_size = params['disk_size'],
+            # XXX Ignores params['output_sparse'].
+            # Handling this properly will be complex, see:
+            # https://www.redhat.com/archives/libguestfs/2018-March/msg00177.html
+            sparse = True,
+            storage_domains = [
+                types.StorageDomain(
+                    name = params['output_storage'],
+                )
+            ],
+        )
+    )
+
+    # Wait till the disk is up, as the transfer can't start if the
+    # disk is locked:
+    disk_service = disks_service.disk_service(disk.id)
+    debug("disk.id = %r" % disk.id)
+
+    endt = time.time() + timeout
+    while True:
+        time.sleep(5)
+        disk = disk_service.get()
+        if disk.status == types.DiskStatus.OK:
+            break
+        if time.time() > endt:
+            raise RuntimeError("timed out waiting for disk to become unlocked")
+
+    # Get a reference to the transfer service.
+    transfers_service = system_service.image_transfers_service()
+
+    # Create a new image transfer.
+    transfer = transfers_service.add(
+        types.ImageTransfer(
+            image = types.Image(
+                id = disk.id
+            )
+        )
+    )
+    debug("transfer.id = %r" % transfer.id)
+
+    # Get a reference to the created transfer service.
+    transfer_service = transfers_service.image_transfer_service(transfer.id)
+
+    # After adding a new transfer for the disk, the transfer's status
+    # will be INITIALIZING.  Wait until the init phase is over. The
+    # actual transfer can start when its status is "Transferring".
+    endt = time.time() + timeout
+    while True:
+        time.sleep(5)
+        transfer = transfer_service.get()
+        if transfer.phase != types.ImageTransferPhase.INITIALIZING:
+            break
+        if time.time() > endt:
+            raise RuntimeError("timed out waiting for transfer status " +
+                               "!= INITIALIZING")
+
+    # Now we have permission to start the transfer.
+    if params['rhv_direct']:
+        if transfer.transfer_url is None:
+            raise RuntimeError("direct upload to host not supported, " +
+                               "requires ovirt-engine >= 4.2 and only works " +
+                               "when virt-v2v is run within the oVirt/RHV " +
+                               "environment, eg. on an oVirt node.")
+        destination_url = urlparse(transfer.transfer_url)
+    else:
+        destination_url = urlparse(transfer.proxy_url)
+
+    context = ssl.create_default_context()
+    context.load_verify_locations(cafile = params['rhv_cafile'])
+
+    http = HTTPSConnection(
+        destination_url.hostname,
+        destination_url.port,
+        context = context
+    )
+
+    # Save everything we need to make requests in the handle.
+    return {
+        'can_flush': False,
+        'can_trim': False,
+        'can_zero': False,
+        'connection': connection,
+        'disk': disk,
+        'disk_service': disk_service,
+        'failed': False,
+        'got_options': False,
+        'highestwrite': 0,
+        'http': http,
+        'needs_auth': not params['rhv_direct'],
+        'path': destination_url.path,
+        'transfer': transfer,
+        'transfer_service': transfer_service,
+    }
+
+# Can we issue zero, trim or flush requests?
+def get_options(h):
+    if h['got_options']:
+        return
+    h['got_options'] = True
+
+    http = h['http']
+    transfer = h['transfer']
+
+    http.putrequest("OPTIONS", h['path'])
+    http.putheader("Authorization", transfer.signed_ticket)
+    http.endheaders()
+
+    r = http.getresponse()
+    if r.status == 200:
+        # New imageio never needs authentication.
+        h['needs_auth'] = False
+
+        j = json.loads(r.read())
+        h['can_zero'] = "zero" in j['features']
+        h['can_trim'] = "trim" in j['features']
+        h['can_flush'] = "flush" in j['features']
+
+    # Old imageio servers returned either 405 Method Not Allowed or
+    # 204 No Content (with an empty body).  If we see that we leave
+    # all the features as False and they will be emulated.
+    elif r.status == 405 or r.status == 204:
+        pass
+
+    else:
+        raise RuntimeError("could not use OPTIONS request: %d: %s" %
+                           (r.status, r.reason))
+
+def can_trim(h):
+    get_options(h)
+    return h['can_trim']
+
+def can_flush(h):
+    get_options(h)
+    return h['can_flush']
+
+def get_size(h):
+    return params['disk_size']
+
+# For documentation see:
+# https://github.com/oVirt/ovirt-imageio/blob/master/docs/random-io.md
+# For examples of working code to read/write from the server, see:
+# https://github.com/oVirt/ovirt-imageio/blob/master/daemon/test/server_test.py
+
+def pread(h, count, offset):
+    http = h['http']
+    transfer = h['transfer']
+    transfer_service = h['transfer_service']
+
+    http.putrequest("GET", h['path'])
+    # Authorization is only needed for old imageio.
+    if h['needs_auth']:
+        http.putheader("Authorization", transfer.signed_ticket)
+    http.putheader("Range", "bytes=%d-%d" % (offset, offset+count-1))
+    http.endheaders()
+
+    r = http.getresponse()
+    # 206 = HTTP Partial Content.
+    if r.status != 206:
+        h['transfer_service'].pause()
+        h['failed'] = True
+        raise RuntimeError("could not read sector (%d, %d): %d: %s" %
+                           (offset, count, r.status, r.reason))
+    return r.read()
+
+def pwrite(h, buf, offset):
+    http = h['http']
+    transfer = h['transfer']
+    transfer_service = h['transfer_service']
+
+    count = len(buf)
+    h['highestwrite'] = max(h['highestwrite'], offset+count)
+
+    http.putrequest("PUT", h['path'] + "?flush=n")
+    # Authorization is only needed for old imageio.
+    if h['needs_auth']:
+        http.putheader("Authorization", transfer.signed_ticket)
+    # The oVirt server only uses the first part of the range, and the
+    # content-length.
+    http.putheader("Content-Range", "bytes %d-%d/*" % (offset, offset+count-1))
+    http.putheader("Content-Length", str(count))
+    http.endheaders()
+    http.send(buf)
+
+    r = http.getresponse()
+    if r.status != 200:
+        transfer_service.pause()
+        h['failed'] = True
+        raise RuntimeError("could not write sector (%d, %d): %d: %s" %
+                           (offset, count, r.status, r.reason))
+
+def zero(h, count, offset, may_trim):
+    http = h['http']
+    transfer = h['transfer']
+    transfer_service = h['transfer_service']
+
+    # Unlike the trim and flush calls, there is no 'can_zero' method
+    # so nbdkit could call this even if the server doesn't support
+    # zeroing.  If this is the case we must emulate.
+    if not h['can_zero']:
+        emulate_zero(h, count, offset)
+        return
+
+    # Construct the JSON request for zeroing.
+    buf = json.dumps({'op': "zero",
+                      'offset': offset,
+                      'size': count,
+                      'flush': False}).encode()
+
+    http.putrequest("PATCH", h['path'])
+    http.putheader("Content-Type", "application/json")
+    http.putheader("Content-Length", len(buf))
+    http.endheaders()
+    http.send(buf)
+
+    r = http.getresponse()
+    if r.status != 200:
+        transfer_service.pause()
+        h['failed'] = True
+        raise RuntimeError("could not zero sector (%d, %d): %d: %s" %
+                           (offset, count, r.status, r.reason))
+
+def emulate_zero(h, count, offset):
+    # qemu-img convert starts by trying to zero/trim the whole device.
+    # Since we've just created a new disk it's safe to ignore these
+    # requests as long as they are smaller than the highest write seen.
+    # After that we must emulate them with writes.
+    if offset+count < h['highestwrite']:
+        http.putrequest("PUT", h['path'])
+        # Authorization is only needed for old imageio.
+        if h['needs_auth']:
+            http.putheader("Authorization", transfer.signed_ticket)
+        http.putheader("Content-Range",
+                       "bytes %d-%d/*" % (offset, offset+count-1))
+        http.putheader("Content-Length", str(count))
+        http.endheaders()
+
+        buf = bytearray(128*1024)
+        while count > len(buf):
+            http.send(buf)
+            count -= len(buf)
+        http.send(buffer(buf, 0, count))
+
+        r = http.getresponse()
+        if r.status != 200:
+            transfer_service.pause()
+            h['failed'] = True
+            raise RuntimeError("could not write zeroes (%d, %d): %d: %s" %
+                               (offset, count, r.status, r.reason))
+
+def trim(h, count, offset):
+    http = h['http']
+    transfer = h['transfer']
+    transfer_service = h['transfer_service']
+
+    # Construct the JSON request for trimming.
+    buf = json.dumps({'op': "trim",
+                      'offset': offset,
+                      'size': count,
+                      'flush': False}).encode()
+
+    http.putrequest("PATCH", h['path'])
+    http.putheader("Content-Type", "application/json")
+    http.putheader("Content-Length", len(buf))
+    http.endheaders()
+    http.send(buf)
+
+    r = http.getresponse()
+    if r.status != 200:
+        transfer_service.pause()
+        h['failed'] = True
+        raise RuntimeError("could not trim sector (%d, %d): %d: %s" %
+                           (offset, count, r.status, r.reason))
+
+def flush(h):
+    http = h['http']
+    transfer = h['transfer']
+    transfer_service = h['transfer_service']
+
+    # Construct the JSON request for flushing.
+    buf = json.dumps({'op': "flush"}).encode()
+
+    http.putrequest("PATCH", h['path'])
+    http.putheader("Content-Type", "application/json")
+    http.putheader("Content-Length", len(buf))
+    http.endheaders()
+    http.send(buf)
+
+    r = http.getresponse()
+    if r.status != 200:
+        transfer_service.pause()
+        h['failed'] = True
+        raise RuntimeError("could not flush: %d: %s" % (r.status, r.reason))
+
+def delete_disk_on_failure(h):
+    disk_service = h['disk_service']
+    disk_service.remove()
+
+def close(h):
+    http = h['http']
+    connection = h['connection']
+
+    # This is sometimes necessary because python doesn't set up
+    # sys.stderr to be line buffered and so debug, errors or
+    # exceptions printed previously might not be emitted before the
+    # plugin exits.
+    sys.stderr.flush()
+
+    # If the connection failed earlier ensure we clean up the disk.
+    if h['failed']:
+        delete_disk_on_failure(h)
+        connection.close()
+        return
+
+    try:
+        # Issue a flush request on close so that the data is written to
+        # persistent store before we create the VM.
+        if h['can_flush']:
+            flush(h)
+
+        http.close()
+
+        disk = h['disk']
+        transfer_service = h['transfer_service']
+
+        transfer_service.finalize()
+
+        # Wait until the transfer disk job is completed since
+        # only then we can be sure the disk is unlocked.  As this
+        # code is not very clear, what's happening is that we are
+        # waiting for the transfer object to cease to exist, which
+        # falls through to the exception case and then we can
+        # continue.
+        endt = time.time() + timeout
+        try:
+            while True:
+                time.sleep(1)
+                tmp = transfer_service.get()
+                if time.time() > endt:
+                    raise RuntimeError("timed out waiting for transfer " +
+                                       "to finalize")
+        except sdk.NotFoundError:
+            pass
+
+        # Write the disk ID file.  Only do this on successful completion.
+        with builtins.open(params['diskid_file'], 'w') as fp:
+            fp.write(disk.id)
+
+    except:
+        # Otherwise on any failure we must clean up the disk.
+        delete_disk_on_failure(h)
+        raise
+
+    connection.close()
diff --git a/v2v/rhv-upload-precheck.py b/v2v/rhv-upload-precheck.py
new file mode 100644
index 000000000..2798a29dd
--- /dev/null
+++ b/v2v/rhv-upload-precheck.py
@@ -0,0 +1,73 @@
+# -*- python -*-
+# oVirt or RHV pre-upload checks used by ‘virt-v2v -o rhv-upload’
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import json
+import logging
+import sys
+import time
+
+from http.client import HTTPSConnection
+from urllib.parse import urlparse
+
+import ovirtsdk4 as sdk
+import ovirtsdk4.types as types
+
+# Parameters are passed in via a JSON doc from the OCaml code.
+# Because this Python code ships embedded inside virt-v2v there
+# is no formal API here.
+params = None
+
+if len(sys.argv) != 2:
+    raise RuntimeError("incorrect number of parameters")
+
+# Parameters are passed in via a JSON document.
+with open(sys.argv[1], 'r') as fp:
+    params = json.load(fp)
+
+# What is passed in is a password file, read the actual password.
+with open(params['output_password'], 'r') as fp:
+    output_password = fp.read()
+output_password = output_password.rstrip()
+
+# Parse out the username from the output_conn URL.
+parsed = urlparse(params['output_conn'])
+username = parsed.username or "admin@internal"
+
+# Connect to the server.
+connection = sdk.Connection(
+    url = params['output_conn'],
+    username = username,
+    password = output_password,
+    ca_file = params['rhv_cafile'],
+    log = logging.getLogger(),
+    insecure = params['insecure'],
+)
+
+system_service = connection.system_service()
+
+# Find if a virtual machine already exists with that name.
+vms_service = system_service.vms_service()
+vms = vms_service.list(
+    search = ("name=%s" % params['output_name']),
+)
+if len(vms) > 0:
+    vm = vms[0]
+    raise RuntimeError("VM already exists with name ‘%s’, id ‘%s’" %
+                       (params['output_name'], vm.id))
+
+# Otherwise everything is OK, exit with no error.
diff --git a/v2v/test-v2v-o-rhv-upload-oo-query.sh b/v2v/test-v2v-o-rhv-upload-oo-query.sh
new file mode 100755
index 000000000..29d69e1c1
--- /dev/null
+++ b/v2v/test-v2v-o-rhv-upload-oo-query.sh
@@ -0,0 +1,38 @@
+#!/bin/bash -
+# libguestfs virt-v2v test script
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+# Test -oo "?" option.
+
+set -e
+
+$TEST_FUNCTIONS
+skip_if_skipped
+
+export VIRT_TOOLS_DATA_DIR="$top_srcdir/test-data/fake-virt-tools"
+export VIRTIO_WIN="$top_srcdir/test-data/fake-virtio-win"
+
+f=test-v2v-o-rhv-upload-oo-query.actual
+rm -f $f
+
+$VG virt-v2v --debug-gc \
+    -o rhv-upload -oo "?" > $f
+
+grep -- "-oo rhv-cafile" $f
+grep -- "-oo rhv-verifypeer" $f
+
+rm $f
diff --git a/v2v/test-v2v-python-syntax.sh b/v2v/test-v2v-python-syntax.sh
new file mode 100755
index 000000000..b167f4610
--- /dev/null
+++ b/v2v/test-v2v-python-syntax.sh
@@ -0,0 +1,45 @@
+#!/bin/bash -
+# libguestfs
+# Copyright (C) 2018 Red Hat Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+set -e
+
+$TEST_FUNCTIONS
+skip_if_skipped
+
+# Files to check.
+files="rhv-upload-createvm.py rhv-upload-plugin.py rhv-upload-precheck.py"
+
+# Base version of Python.
+python=python3
+
+# Checks the files are syntactically correct, but not very much else.
+for f in $files; do
+    $python -m py_compile $f
+done
+
+# Checks the files correspond to PEP8 coding style.
+# https://www.python.org/dev/peps/pep-0008/
+if $python-pep8 --version >/dev/null 2>&1; then
+    for f in $files; do
+        # Ignore:
+        # E226 missing whitespace around arithmetic operator
+        # E251 unexpected spaces around keyword / parameter equals
+        # E302 expected 2 blank lines, found 1
+        $python-pep8 --ignore=E226,E251,E302 $f
+    done
+fi
diff --git a/v2v/virt-v2v.pod b/v2v/virt-v2v.pod
index 5dd888e77..62b726b8f 100644
--- a/v2v/virt-v2v.pod
+++ b/v2v/virt-v2v.pod
@@ -6,15 +6,18 @@ virt-v2v - Convert a guest to use KVM
 
  virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest
 
- virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest \
-   -o rhv -os rhv.nfs:/export_domain --bridge ovirtmgmt
-
  virt-v2v -i libvirtxml guest-domain.xml -o local -os /var/tmp
 
  virt-v2v -i disk disk.img -o local -os /var/tmp
 
  virt-v2v -i disk disk.img -o glance
 
+ virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest \
+   -o rhv-upload -oc https://ovirt-engine.example.com/ovirt-engine/api \
+   -os ovirt-data -op /tmp/ovirt-admin-password -of raw \
+   -oo rhv-cafile=/tmp/ca.pem -oo rhv-direct \
+   --bridge ovirtmgmt
+
 =head1 DESCRIPTION
 
 Virt-v2v converts guests from a foreign hypervisor to run on KVM.  It
@@ -50,20 +53,18 @@ For more information see L</INPUT FROM VMWARE VCENTER SERVER> below.
 =head2 Convert from VMware to RHV/oVirt
 
 This is the same as the previous example, except you want to send the
-guest to a RHV-M Export Storage Domain which is located remotely
-(over NFS) at C<rhv.nfs:/export_domain>.  If you are unclear about
-the location of the Export Storage Domain you should check the
-settings on your RHV-M management console.  Guest network
+guest to a RHV Data Domain using the RHV REST API.  Guest network
 interface(s) are connected to the target network called C<ovirtmgmt>.
 
  virt-v2v -ic vpx://vcenter.example.com/Datacenter/esxi vmware_guest \
-   -o rhv -os rhv.nfs:/export_domain --bridge ovirtmgmt
+   -o rhv-upload -oc https://ovirt-engine.example.com/ovirt-engine/api \
+   -os ovirt-data -op /tmp/ovirt-admin-password -of raw \
+   -oo rhv-cafile=/tmp/ca.pem -oo rhv-direct \
+   --bridge ovirtmgmt
 
 In this case the host running virt-v2v acts as a B<conversion server>.
 
-Note that after conversion, the guest will appear in the RHV-M Export
-Storage Domain, from where you will need to import it using the RHV-M
-user interface.  (See L</OUTPUT TO RHV>).
+For more information see L</OUTPUT TO RHV> below.
 
 =head2 Convert from ESXi hypervisor over SSH to local libvirt
 
@@ -122,9 +123,9 @@ command line.
  Xen ───▶│ -i libvirt ──▶ │            │     │  (default) │
  ... ───▶│  (default) │   │            │ ──┐ └────────────┘
          └────────────┘   │            │ ─┐└──────▶ -o glance
- -i libvirtxml ─────────▶ │            │ ┐└─────────▶ -o rhv
- -i vmx ────────────────▶ │            │ └──────────▶ -o vdsm
-                          └────────────┘
+ -i libvirtxml ─────────▶ │            │ ┐├─────────▶ -o rhv
+ -i vmx ────────────────▶ │            │ │└─────────▶ -o vdsm
+                          └────────────┘ └──────────▶ -o rhv-upload
 
 Virt-v2v has a number of possible input and output modes, selected
 using the I<-i> and I<-o> options.  Only one input and output mode can
@@ -157,8 +158,9 @@ libvirt configuration file (mainly for testing).
 I<-o qemu> writes to a local disk image with a shell script for
 booting the guest directly in qemu (mainly for testing).
 
-I<-o rhv> is used to write to a RHV / oVirt target.  I<-o vdsm>
-is only used when virt-v2v runs under VDSM control.
+I<-o rhv-upload> is used to write to a RHV / oVirt target.  I<-o rhv>
+is a legacy method to write to RHV / oVirt E<lt> 4.2.  I<-o vdsm> is
+only used when virt-v2v runs under VDSM control.
 
 =head1 OPTIONS
 
@@ -426,6 +428,10 @@ written.
 
 This is the same as I<-o rhv>.
 
+=item B<-o> B<ovirt-upload>
+
+This is the same as I<-o rhv-upload>.
+
 =item B<-o> B<qemu>
 
 Set the output method to I<qemu>.
@@ -447,6 +453,16 @@ I<-os> parameter must also be used to specify the location of the
 Export Storage Domain.  Note this does not actually import the guest
 into RHV.  You have to do that manually later using the UI.
 
+See L</OUTPUT TO RHV (OLD METHOD)> below.
+
+=item B<-o> B<rhv-upload>
+
+Set the output method to I<rhv-upload>.
+
+The converted guest is written directly to a RHV Data Domain.
+This is a faster method than I<-o rhv>, but requires oVirt
+or RHV E<ge> 4.2.
+
 See L</OUTPUT TO RHV> below.
 
 =item B<-o> B<vdsm>
@@ -488,7 +504,33 @@ the output name is the same as the input name.
 Set output option(s) related to the current output mode.
 To display short help on what options are available you can use:
 
- virt-v2v -o vdsm -oo "?"
+ virt-v2v -o rhv-upload -oo "?"
+
+=item B<-oo rhv-cafile=>F<ca.pem>
+
+For I<-o rhv-upload> (L</OUTPUT TO RHV>) only, the F<ca.pem> file
+(Certificate Authority), copied from F</etc/pki/ovirt-engine/ca.pem>
+on the oVirt engine.
+
+=item B<-oo rhv-cluster=>C<CLUSTERNAME>
+
+For I<-o rhv-upload> (L</OUTPUT TO RHV>) only, set the RHV Cluster
+Name.  If not given it uses C<Default>.
+
+=item B<-oo rhv-direct>
+
+For I<-o rhv-upload> (L</OUTPUT TO RHV>) only, if this option is given
+then virt-v2v will attempt to directly upload the disk to the oVirt
+node, otherwise it will proxy the upload through the oVirt engine.
+Direct upload requires that you have network access to the oVirt
+nodes.  Non-direct upload is slightly slower but should work in all
+situations.
+
+=item B<-oo rhv-verifypeer>
+
+For I<-o rhv-upload> (L</OUTPUT TO RHV>) only, verify the oVirt/RHV
+server’s identity by checking the server‘s certificate against the
+Certificate Authority.
 
 =item B<-oo vdsm-compat=0.10>
 
@@ -1749,6 +1791,68 @@ Define the final guest in libvirt:
 
 =head1 OUTPUT TO RHV
 
+This new method to upload guests to oVirt or RHV directly via the REST
+API requires oVirt/RHV E<ge> 4.2.
+
+You need to specify I<-o rhv-upload> as well as the following extra
+parameters:
+
+=over 4
+
+=item I<-oc> C<https://ovirt-engine.example.com/ovirt-engine/api>
+
+The URL of the REST API which is usually the server name with
+C</ovirt-engine/api> appended, but might be different if you installed
+oVirt Engine on a different path.
+
+You can optionally add a username and port number to the URL.  If the
+username is not specified then virt-v2v defaults to using
+C<admin@internal> which is the typical superuser account for oVirt
+instances.
+
+=item I<-of raw>
+
+Currently you must use I<-of raw> and you cannot use I<-oa preallocated>.
+
+These restrictions will be loosened in a future version.
+
+=item I<-op> F<password-file>
+
+A file containing a password to be used when connecting to the oVirt
+engine.  Note the file should contain the whole password, B<without
+any trailing newline>, and for security the file should have mode
+C<0600> so that others cannot read it.
+
+=item I<-os> C<ovirt-data>
+
+The storage domain.
+
+=item I<-oo rhv-cafile=>F<ca.pem>
+
+The F<ca.pem> file (Certificate Authority), copied from
+F</etc/pki/ovirt-engine/ca.pem> on the oVirt engine.
+
+=item I<-oo rhv-cluster=>C<CLUSTERNAME>
+
+Set the RHV Cluster Name.  If not given it uses C<Default>.
+
+=item I<-oo rhv-direct>
+
+If this option is given then virt-v2v will attempt to directly upload
+the disk to the oVirt node, otherwise it will proxy the upload through
+the oVirt engine.  Direct upload requires that you have network access
+to the oVirt nodes.  Non-direct upload is slightly slower but should
+work in all situations.
+
+=item I<-oo rhv-verifypeer>
+
+Verify the oVirt/RHV server’s identity by checking the server‘s
+certificate against the Certificate Authority.
+
+=back
+
+=head1 OUTPUT TO RHV (OLD METHOD)
+
 This section only applies to the I<-o rhv> output mode.  If you use
 virt-v2v from the RHV-M user interface, then behind the scenes the
 import is managed by VDSM using the I<-o vdsm> output mode (which end
-- 
2.20.1