[libvirt] [PATCH 10/12] vcpu: improve vcpu support in qemu command line

[Daniel Veillard]

On Wed, Sep 29, 2010 at 06:02:14PM -0600, Eric Blake wrote:
> * src/qemu/qemu_conf.c (qemuParseCommandLineSmp): Distinguish
> between vcpus and maxvcpus, for new enough qemu.
> * tests/qemuargv2xmltest.c (mymain): Add new test.
> * tests/qemuxml2argvtest.c (mymain): Likewise.
> * tests/qemuxml2xmltest.c (mymain): Likewise.
> * tests/qemuxml2argvdata/qemuxml2argv-smp.args: New file.
> ---
> 
> This manages just the command-line aspects needed for qemu 0.12+;
> so far, I haven't done anything about 0.11 or earlier (on those
> versions of qemu, maxvcpus and vcpus must always be equal).
> 
>  src/qemu/qemu_conf.c                         |   13 +++++++++----
>  tests/qemuargv2xmltest.c                     |    2 ++
>  tests/qemuxml2argvdata/qemuxml2argv-smp.args |    1 +
>  tests/qemuxml2argvtest.c                     |    2 ++
>  tests/qemuxml2xmltest.c                      |    2 ++
>  5 files changed, 16 insertions(+), 4 deletions(-)
>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-smp.args
> 
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index 5169e3c..f387a5d 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
> @@ -3616,6 +3616,8 @@ qemuBuildSmpArgStr(const virDomainDefPtr def,
>      virBufferVSprintf(&buf, "%u", def->vcpus);
> 
>      if ((qemuCmdFlags & QEMUD_CMD_FLAG_SMP_TOPOLOGY)) {

 ohhh, we were already loking for this option at run time ... 

> +        if (def->vcpus != def->maxvcpus)
> +            virBufferVSprintf(&buf, ",maxcpus=%u", def->maxvcpus);
>          /* sockets, cores, and threads are either all zero
>           * or all non-zero, thus checking one of them is enough */
>          if (def->cpu && def->cpu->sockets) {
> @@ -3628,12 +3630,12 @@ qemuBuildSmpArgStr(const virDomainDefPtr def,
>              virBufferVSprintf(&buf, ",cores=%u", 1);
>              virBufferVSprintf(&buf, ",threads=%u", 1);
>          }
> -    }
> -    if (def->vcpus != def->maxvcpus) {
> +    } else if (def->vcpus != def->maxvcpus) {
>          virBufferFreeAndReset(&buf);
> +        // FIXME - consider hot-unplugging cpus after boot

Please no C++ like comments :-)

>          qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                          _("setting current vcpu count less than maximum is "
> -                          "not supported yet"));
> +                          "not supported with this QEMU binary"));
>          return NULL;
>      }
> 

ACK,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/