[Libguestfs] [v2v PATCH 4/9] create_libvirt_xml: eliminate childless <cpu match="minimum"/> element

Laszlo Ersek
2022-04-20T16:23:28Z

Commit 2a576b7cc5c3 ("v2v: -o libvirt: Don't write only <vendor>
without
<model> (RHBZ#1591789).", 2018-06-21) introduced a path in the code
where
we create a childless

  <cpu match="minimum"/>

element. Namely, after said commit, in case

  source.s_cpu_vendor <> None &&
  source.s_cpu_model = None &&
  source.s_cpu_topology = None

we no longer trigger a libvirt error; however, we do create the element

  <cpu match="minimum"/>

without any children. Surprisingly, libvirt doesn't complain; it silently
ignores and eliminates this element from the domain XML.

Remove this code path by restricting the outer condition, for creating the
<cpu> element, to:

  source.s_cpu_model <> None ||
  source.s_cpu_topology <> None

This reflects that "s_cpu_vendor" only plays a role if
"s_cpu_model" is
specified -- and the latter guarantees in itself that the <cpu> element
will be generated with at least one child element.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2076013
Signed-off-by: Laszlo Ersek <lersek at redhat.com>
---
 output/create_libvirt_xml.ml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/output/create_libvirt_xml.ml b/output/create_libvirt_xml.ml
index d2ca894d60bb..4a71f8bb27f5 100644
--- a/output/create_libvirt_xml.ml
+++ b/output/create_libvirt_xml.ml
@@ -157,53 +157,53 @@ let create_libvirt_xml ?pool source inspect

   (match source.s_genid with
    | None -> ()
    | Some genid -> List.push_back body (e "genid" [] [PCData
genid])
   );


   (match get_osinfo_id inspect with
    | None -> ()
    | Some osinfo_id ->
      List.push_back_list body [
        e "metadata" [] [
          e "libosinfo:libosinfo" ["xmlns:libosinfo",
"http://libosinfo.org/xmlns/libvirt/domain/1.0"] [
            e "libosinfo:os" ["id", osinfo_id] [];
          ];
        ];
      ];
   );

   let memory_k = source.s_memory /^ 1024L in
   List.push_back_list body [
     e "memory" ["unit", "KiB"] [PCData
(Int64.to_string memory_k)];
     e "currentMemory" ["unit", "KiB"] [PCData
(Int64.to_string memory_k)];
     e "vcpu" [] [PCData (string_of_int source.s_vcpu)]
   ];

-  if source.s_cpu_vendor <> None || source.s_cpu_model <> None ||
+  if source.s_cpu_model <> None ||
      source.s_cpu_topology <> None then (
     let cpu = ref [] in

     (match source.s_cpu_model with
      | None -> ()
      | Some model ->
          (match source.s_cpu_vendor with
           | None -> ()
           | Some vendor ->
               List.push_back cpu (e "vendor" [] [PCData vendor])
          );
          List.push_back cpu (e "model" ["fallback",
"allow"] [PCData model])
     );
     (match source.s_cpu_topology with
      | None -> ()
      | Some { s_cpu_sockets; s_cpu_cores; s_cpu_threads } ->
         let topology_attrs = [
           "sockets", string_of_int s_cpu_sockets;
           "cores", string_of_int s_cpu_cores;
           "threads", string_of_int s_cpu_threads;
         ] in
         List.push_back cpu (e "topology" topology_attrs [])
     );

     List.push_back_list body [ e "cpu" [ "match",
"minimum" ] !cpu ]
   );
--
2.19.1.3.g30247aa5d201