On 11/22/2017 04:45 AM, Michal Privoznik wrote:
> On 11/22/2017 01:04 AM, John Ferlan wrote:
>>
>>
>> On 11/14/2017 09:47 AM, Michal Privoznik wrote:
>>> Since we already have such support for libxl all we need is qemu
>>> driver adjustment. And a test case.
>>>
>>> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
>>> ---
>>> src/qemu/qemu_command.c | 36 +++++++++++-
>>> .../qemuxml2argv-numatune-distances.args | 63 +++++++++++++++++++++
>>> .../qemuxml2argv-numatune-distances.xml | 65 ++++++++++++++++++++++
>>> tests/qemuxml2argvtest.c | 2 +
>>> 4 files changed, 165 insertions(+), 1 deletion(-)
>>> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-numatune-distances.args
>>> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-numatune-distances.xml
>>>
>>> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
>>> index eb72db33b..8b9daaea3 100644
>>> --- a/src/qemu/qemu_command.c
>>> +++ b/src/qemu/qemu_command.c
>>> @@ -7675,7 +7675,7 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
>>> virCommandPtr cmd,
>>> qemuDomainObjPrivatePtr priv)
>>> {
>>> - size_t i;
>>> + size_t i, j;
>>> virQEMUCapsPtr qemuCaps = priv->qemuCaps;
>>> virBuffer buf = VIR_BUFFER_INITIALIZER;
>>> char *cpumask = NULL, *tmpmask = NULL, *next = NULL;
>>> @@ -7685,6 +7685,7 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
>>> int ret = -1;
>>> size_t ncells = virDomainNumaGetNodeCount(def->numa);
>>> const long system_page_size = virGetSystemPageSizeKB();
>>> + bool numa_distances = false;
>>>
>>> if (virDomainNumatuneHasPerNodeBinding(def->numa) &&
>>> !(virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_MEMORY_RAM) ||
>>> @@ -7793,6 +7794,39 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg,
>>>
>>> virCommandAddArgBuffer(cmd, &buf);
>>> }
>>> +
>>> + /* If NUMA node distance is specified for at least one pair
>>> + * of nodes, we have to specify all the distances. Even
>>> + * though they might be the default ones. */
>>> + for (i = 0; i < ncells; i++) {
>>> + for (j = 0; j < ncells; j++) {
>>> + if (!virDomainNumaNodeDistanceSpecified(def->numa, i, j))
>>> + continue;
>>> +
>>> + numa_distances = true;
>>> +
>>> + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_NUMA_DIST)) {
>>> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>>> + _("setting NUMA distances is not "
>>> + "supported with this qemu"));
>>> + goto cleanup;
>>> + }
>>> + }
>>> + }
>>
>> Not sure I understand the need for the above double loop.... Even with
>> your adjustment...
>>
>> It would seem that all that's necessary is
>>
>> for (i < 0; i < ncells; i++) {
>> if (numa->mem_nodes[i].ndistances > 0)
>
> It things only were so simple. Thing is, numa is a private struct. We
> need accessors for getting any value. I can't just dereference numa
> struct from qemu code.
Oh right... Could have another accessor too, but your need is a bit more
specific especially since as you point out next qemu will default to 10
and 20...
Still I think with the different name this will make more sense in v2.
>
> That's why I'm introducing an accessor in 2/5. Moreover, in case all
> values are defaults I wanted to not put them onto the cmd line. The
> advantage would be that it would work even with older qemu which doesn't
> have the capability. I mean, qemu does follow the spec and if no
> distances are provided it uses the ones from the spec (10 and 20).
>
Nothing is ever so simple, but I did ask if I was in the weeds too
basically because I've learned over time that simplicity and numa are
not synonymous!
John
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