From b7a00e7b473add0fa94776292be45a25b31c1407 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 30 Nov 2016 16:52:42 +0000
Subject: [PATCH] v2v: -o vdsm: Add --vdsm-compat flag. -o rhev: Drop support
 for RHV < 4.1 (RHBZ#1400205).

Support for RHEV with RHEL 6 nodes required us to output the old style
qcow2 compat=0.10 images.  Since RHEV 3.6 GA, RHEL 6 has not been
supported as a RHEV node type.  Since RHV 4.1, compat=1.1 is
supported.  (Support for compat=1.1 is uncertain in RHV 4.0 even on
RHEL 7 nodes.)

There are significant downsides to using qcow2 compat=0.10 instead of
the modern default (compat=1.1).

Therefore this patch does two things:

For -o rhev, it drops support for compat=0.10 completely.  You must
use RHV 4.1.

For -o vdsm, it adds an interim flag (--vdsm-compat=0.10 or
--vdsm-compat=1.1) which controls the compat level of the qcow2 output
file.  VDSM should use --vdsm-compat=1.1 when it is known that modern
qemu is available.  We can make this the default later when all RHV
instances have moved to 4.1.

It also adds:

  vdsm-compat-option

to the `virt-v2v --machine-readable' output to indicate that this flag
can be used.

Thanks: Yaniv Kaul, Michal Skrivanek.
(cherry picked from commit bdaeeb4e606f3828887da87ad5acb4f7b49cfed5)
---
 v2v/cmdline.ml                 |  8 ++++++++
 v2v/output_rhev.ml             |  4 ----
 v2v/output_vdsm.ml             | 11 ++++++++---
 v2v/output_vdsm.mli            |  1 +
 v2v/test-v2v-o-vdsm-options.sh |  9 ++++++++-
 v2v/virt-v2v.pod               | 19 +++++++++++++++++++
 6 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml
index b9992eb..f5fb3b3 100644
--- a/v2v/cmdline.ml
+++ b/v2v/cmdline.ml
@@ -66,6 +66,10 @@ let parse_cmdline () =
   let vdsm_vm_uuid = ref None in
   let vdsm_ovf_output = ref None in (* default "." *)
   let vmtype = ref None in
+
+  let vdsm_compat = ref "0.10" in
+  let set_vdsm_compat s = vdsm_compat := s in
+
   let set_string_option_once optname optref arg =
     match !optref with
     | Some _ ->
@@ -215,6 +219,7 @@ let parse_cmdline () =
                                             "file " ^ s_"Use password from file";
     "--print-source", Arg.Set print_source, " " ^ s_"Print source and stop";
     "--root",    Arg.String set_root_choice,"ask|... " ^ s_"How to choose root filesystem";
+    "--vdsm-compat", Arg.Symbol (["0.10"; "1.1"], set_vdsm_compat), " " ^ s_"Write qcow2 with compat=0.10|1.1";
     "--vdsm-image-uuid", Arg.String add_vdsm_image_uuid, "uuid " ^ s_"Output image UUID(s)";
     "--vdsm-vol-uuid", Arg.String add_vdsm_vol_uuid, "uuid " ^ s_"Output vol UUID(s)";
     "--vdsm-vm-uuid", Arg.String (set_string_option_once "--vdsm-vm-uuid" vdsm_vm_uuid),
@@ -277,6 +282,7 @@ read the man page virt-v2v(1).
   let print_source = !print_source in
   let qemu_boot = !qemu_boot in
   let root_choice = !root_choice in
+  let vdsm_compat = !vdsm_compat in
   let vdsm_image_uuids = List.rev !vdsm_image_uuids in
   let vdsm_vol_uuids = List.rev !vdsm_vol_uuids in
   let vdsm_vm_uuid = !vdsm_vm_uuid in
@@ -297,6 +303,7 @@ read the man page virt-v2v(1).
     printf "virt-v2v\n";
     printf "libguestfs-rewrite\n";
     printf "colours-option\n";
+    printf "vdsm-compat-option\n";
     List.iter (printf "input:%s\n") (Modules_list.input_modules ());
     List.iter (printf "output:%s\n") (Modules_list.output_modules ());
     List.iter (printf "convert:%s\n") (Modules_list.convert_modules ());
@@ -454,6 +461,7 @@ read the man page virt-v2v(1).
         vol_uuids = vdsm_vol_uuids;
         vm_uuid = vdsm_vm_uuid;
         ovf_output = vdsm_ovf_output;
+        compat = vdsm_compat;
       } in
       Output_vdsm.output_vdsm os vdsm_params vmtype output_alloc in
 
diff --git a/v2v/output_rhev.ml b/v2v/output_rhev.ml
index ae37a3f..7bd94df 100644
--- a/v2v/output_rhev.ml
+++ b/v2v/output_rhev.ml
@@ -253,10 +253,6 @@ object
     Changeuid.func changeuid_t (
       fun () ->
         let g = open_guestfs ~identifier:"rhev_disk_create" () in
-        (* For qcow2, override v2v-supplied compat option, because RHEL 6
-         * nodes cannot handle qcow2 v3 (RHBZ#1145582).
-         *)
-        let compat = if format <> "qcow2" then compat else Some "0.10" in
         g#disk_create ?backingfile ?backingformat ?preallocation ?compat
           ?clustersize path format size;
         (* Make it sufficiently writable so that possibly root, or
diff --git a/v2v/output_vdsm.ml b/v2v/output_vdsm.ml
index 7bb28a9..57b5352 100644
--- a/v2v/output_vdsm.ml
+++ b/v2v/output_vdsm.ml
@@ -30,6 +30,7 @@ type vdsm_params = {
   vol_uuids : string list;
   vm_uuid : string;
   ovf_output : string;
+  compat : string;
 }
 
 class output_vdsm os vdsm_params vmtype output_alloc =
@@ -37,7 +38,7 @@ object
   inherit output
 
   method as_options =
-    sprintf "-o vdsm -os %s%s%s --vdsm-vm-uuid %s --vdsm-ovf-output %s%s" os
+    sprintf "-o vdsm -os %s%s%s --vdsm-vm-uuid %s --vdsm-ovf-output %s%s%s" os
       (String.concat ""
          (List.map (sprintf " --vdsm-image-uuid %s") vdsm_params.image_uuids))
       (String.concat ""
@@ -48,6 +49,9 @@ object
       | None -> ""
       | Some Server -> " --vmtype server"
       | Some Desktop -> " --vmtype desktop")
+      (match vdsm_params.compat with
+       | "0.10" -> "" (* currently this is the default, so don't print it *)
+       | s -> sprintf " --vdsm-compat=%s" s)
 
   method supported_firmware = [ TargetBIOS ]
 
@@ -153,9 +157,10 @@ object
     ?clustersize path format size =
     let g = open_guestfs ~identifier:"vdsm_disk_create" () in
     (* For qcow2, override v2v-supplied compat option, because RHEL 6
-     * nodes cannot handle qcow2 v3 (RHBZ#1145582).
+     * nodes cannot handle qcow2 v3 (RHBZ#1145582, RHBZ#1400205).
      *)
-    let compat = if format <> "qcow2" then compat else Some "0.10" in
+    let compat =
+      if format <> "qcow2" then compat else Some vdsm_params.compat in
     g#disk_create ?backingfile ?backingformat ?preallocation ?compat
       ?clustersize path format size
 
diff --git a/v2v/output_vdsm.mli b/v2v/output_vdsm.mli
index 1a88eaa..40eceee 100644
--- a/v2v/output_vdsm.mli
+++ b/v2v/output_vdsm.mli
@@ -23,6 +23,7 @@ type vdsm_params = {
   vol_uuids : string list;            (* --vdsm-vol-uuid (multiple) *)
   vm_uuid : string;                   (* --vdsm-vm-uuid *)
   ovf_output : string;                (* --vdsm-ovf-output *)
+  compat : string;                    (* --vdsm-compat=0.10|1.1 *)
 }
 (** Miscellaneous extra command line parameters used by VDSM. *)
 
diff --git a/v2v/test-v2v-o-vdsm-options.sh b/v2v/test-v2v-o-vdsm-options.sh
index 6ae5d56..de07b9c 100755
--- a/v2v/test-v2v-o-vdsm-options.sh
+++ b/v2v/test-v2v-o-vdsm-options.sh
@@ -1,6 +1,6 @@
 #!/bin/bash -
 # libguestfs virt-v2v test script
-# Copyright (C) 2014 Red Hat Inc.
+# Copyright (C) 2014-2016 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
@@ -21,6 +21,7 @@
 unset CDPATH
 export LANG=C
 set -e
+set -x
 
 if [ -n "$SKIP_TEST_V2V_O_VDSM_OPTIONS_SH" ]; then
     echo "$0: test skipped because environment variable is set"
@@ -62,10 +63,12 @@ $VG virt-v2v --debug-gc \
     -i libvirt -ic "$libvirt_uri" windows \
     -o vdsm -os $d/12345678-1234-1234-1234-123456789abc \
     --vmtype desktop \
+    -of qcow2 \
     --vdsm-image-uuid IMAGE \
     --vdsm-vol-uuid VOL \
     --vdsm-vm-uuid VM \
     --vdsm-ovf-output $d/12345678-1234-1234-1234-123456789abc/master/vms/VM \
+    --vdsm-compat=1.1
 
 # Test the OVF metadata was created.
 test -f $d/12345678-1234-1234-1234-123456789abc/master/vms/VM/VM.ovf
@@ -82,6 +85,10 @@ test -f VOL.meta
 # Test the disk file was created.
 test -f VOL
 
+# Test that a qcow2 file with compat=1.1 was generated.
+test "$(guestfish disk-format VOL)" = "qcow2"
+qemu-img info VOL | grep 'compat: 1.1'
+
 popd
 
 rm -r $d
diff --git a/v2v/virt-v2v.pod b/v2v/virt-v2v.pod
index 32085c1..fb00e82 100644
--- a/v2v/virt-v2v.pod
+++ b/v2v/virt-v2v.pod
@@ -495,6 +495,25 @@ boot an operating system from the first VirtIO disk.  Specifically,
 F</boot> must be on the first VirtIO disk, and it cannot chainload an
 OS which is not in the first VirtIO disk.
 
+=item B<--vdsm-compat=0.10>
+
+=item B<--vdsm-compat=1.1>
+
+If I<-o vdsm> and the output format is qcow2, then we add the qcow2
+I<compat=0.10> option to the output file for compatibility with RHEL 6
+(see L<https://bugzilla.redhat.com/1145582>).
+
+If I<--vdsm-compat=1.1> is used then modern qcow2 (I<compat=1.1>)
+files are generated instead.
+
+Currently I<--vdsm-compat=0.10> is the default, but this will change
+to I<--vdsm-compat=1.1> in a future version of virt-v2v (when we can
+assume that everyone is using a modern version of qemu).
+
+B<Note this option only affects I<-o vdsm> output>.  All other output
+modes (including I<-o rhev>) generate modern qcow2 I<compat=1.1>
+files, always.
+
 =item B<--vdsm-image-uuid> UUID
 
 =item B<--vdsm-vol-uuid> UUID
-- 
1.8.3.1