[Libguestfs] [PATCH] v2v: -i libvirt: If <vcpu> is missing, calculate it from CPU topology.

[Richard W.M. Jones]

---
 v2v/parse_libvirt_xml.ml | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/v2v/parse_libvirt_xml.ml b/v2v/parse_libvirt_xml.ml
index 6032c31..fb895e4 100644
--- a/v2v/parse_libvirt_xml.ml
+++ b/v2v/parse_libvirt_xml.ml
@@ -50,7 +50,7 @@ let parse_libvirt_xml ?conn xml =
   let xpathctx = Xml.xpath_new_context doc in
   let xpath_string = xpath_string xpathctx
   and xpath_int = xpath_int xpathctx
-  and xpath_int_default = xpath_int_default xpathctx
+  (*and xpath_int_default = xpath_int_default xpathctx*)
   and xpath_int64_default = xpath_int64_default xpathctx in
 
   let hypervisor =
@@ -65,7 +65,6 @@ let parse_libvirt_xml ?conn xml =
     | Some s -> s in
   let memory = xpath_int64_default "/domain/memory/text()" (1024L *^ 1024L) in
   let memory = memory *^ 1024L in
-  let vcpu = xpath_int_default "/domain/vcpu/text()" 1 in
 
   let cpu_vendor = xpath_string "/domain/cpu/vendor/text()" in
   let cpu_model = xpath_string "/domain/cpu/model/text()" in
@@ -73,6 +72,21 @@ let parse_libvirt_xml ?conn xml =
   let cpu_cores = xpath_int "/domain/cpu/topology/@cores" in
   let cpu_threads = xpath_int "/domain/cpu/topology/@threads" in
 
+  (* Get the <vcpu> field from the input XML.  If not set then
+   * try calculating it from the <cpu> <topology> node.  If that's
+   * not set either, then assume 1 vCPU.
+   *)
+  let vcpu = xpath_int "/domain/vcpu/text()" in
+  let vcpu =
+    match vcpu, cpu_sockets, cpu_cores, cpu_threads with
+    | Some vcpu, _,    _,    _ -> vcpu
+    | None,      None, None, None -> 1
+    | None,      _,    _,    _ ->
+       let sockets = match cpu_sockets with None -> 1 | Some v -> v in
+       let cores = match cpu_cores with None -> 1 | Some v -> v in
+       let threads = match cpu_threads with None -> 1 | Some v -> v in
+       sockets * cores * threads in
+
   let features =
     let features = ref [] in
     let obj = Xml.xpath_eval_expression xpathctx "/domain/features/*" in
-- 
2.10.2