[Libguestfs] [PATCH v2] v2v: -i libvirt: If <vcpu> is missing, calculate it from CPU topology.

[Richard W.M. Jones]

On Fri, Mar 17, 2017 at 10:47:57AM +0100, Pino Toscano wrote:
> On Thursday, 16 March 2017 22:10:10 CET Richard W.M. Jones wrote:
> > ---
> >  v2v/parse_libvirt_xml.ml           | 18 ++++++++++++++++--
> >  v2v/test-v2v-print-source.expected |  2 +-
> >  2 files changed, 17 insertions(+), 3 deletions(-)
> > 
> > diff --git a/v2v/parse_libvirt_xml.ml b/v2v/parse_libvirt_xml.ml
> > index 6032c31..2dee274 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
> 
> Should there be a sockets * cores * threads <> vcpu check as well?

Yes, it's already included in v2v/v2v.ml in:

  [PATCH 4/4] v2v: Pass CPU vendor, model and topology from source to target.
  https://www.redhat.com/archives/libguestfs/2017-March/msg00185.html

However it's only a warning because we don't want to fail the
conversion if this metadata (which is basically informational) is
wrong.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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