[libvirt] [PATCH 1/2] bhyve: add CPU topology support

[Peter Krempa]

On Mon, May 28, 2018 at 20:27:50 +0400, Roman Bogorodskiy wrote:
> Recently, bhyve started supporting specifying guest CPU topology.
> It looks this way:
> 
>   bhyve -c cpus=C,sockets=S,cores=C,threads=T ...
> 
> The old behaviour with bhyve -c C, where C is a number of vCPUs, is
> still supported.
> 
> So if we have CPU topology in the domain XML, use the new syntax,
> otherwise keeps the old behaviour.
> 
> Signed-off-by: Roman Bogorodskiy <bogorodskiy at gmail.com>
> ---
>  src/bhyve/bhyve_capabilities.c                |  7 +++--
>  src/bhyve/bhyve_capabilities.h                |  1 +
>  src/bhyve/bhyve_command.c                     | 17 +++++++++++-
>  .../bhyvexml2argv-cputopology.args            |  9 +++++++
>  .../bhyvexml2argv-cputopology.ldargs          |  3 +++
>  .../bhyvexml2argv-cputopology.xml             | 26 +++++++++++++++++++
>  tests/bhyvexml2argvtest.c                     |  7 ++++-
>  7 files changed, 66 insertions(+), 4 deletions(-)
>  create mode 100644 tests/bhyvexml2argvdata/bhyvexml2argv-cputopology.args
>  create mode 100644 tests/bhyvexml2argvdata/bhyvexml2argv-cputopology.ldargs
>  create mode 100644 tests/bhyvexml2argvdata/bhyvexml2argv-cputopology.xml

[...]

> diff --git a/src/bhyve/bhyve_command.c b/src/bhyve/bhyve_command.c
> index e3f7ded7db..b319518520 100644
> --- a/src/bhyve/bhyve_command.c
> +++ b/src/bhyve/bhyve_command.c
> @@ -467,7 +467,22 @@ virBhyveProcessBuildBhyveCmd(virConnectPtr conn,
>  
>      /* CPUs */
>      virCommandAddArg(cmd, "-c");
> -    virCommandAddArgFormat(cmd, "%d", virDomainDefGetVcpus(def));
> +    if (def->cpu && def->cpu->sockets) {
> +        if ((bhyveDriverGetCaps(conn) & BHYVE_CAP_CPUTOPOLOGY) != 0) {
> +            virCommandAddArgFormat(cmd, "cpus=%d,sockets=%d,cores=%d,threads=%d",
> +                                   virDomainDefGetVcpus(def),
> +                                   def->cpu->sockets,
> +                                   def->cpu->cores,
> +                                   def->cpu->threads);

Note that libvirt XML->def conversion does not validate that def->nvcpus
equals to def->cpu->sockets * def->cpu->cores * def->cpu->threads.

This is a historic artefact since qemu did not do it either. They
started doing it just recently. It might be worth adding that check to
be sure in the future.

> +        } else {
> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                           _("Installed bhyve binary does not support "
> +                             "defining CPU topology"));
> +            goto error;
> +        }

The rest looks good to me, so ACK if you don't think the check for the
topology<->vcpu count is important enough.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20180529/9552bcfb/attachment-0001.sig>