[libvirt] [PATCH 2/2] qemuBuildMemPathStr: Forbid memoryBacking/access for non-numa case

[Michal Privoznik]

On 12/15/2017 08:48 PM, John Ferlan wrote:
> 
> 
> On 12/12/2017 08:36 AM, Michal Privoznik wrote:
>> https://bugzilla.redhat.com/show_bug.cgi?id=1448149
>>
>> If a domain has no numa nodes, that means we don't put any
>> memory-backend-file onto the qemu command line. That in turn
>> means we can't set access='shared'. Therefore, we should produce
>> an error instead of ignoring the setting silently.
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>>  src/qemu/qemu_command.c                         |  9 +++
>>  tests/qemuxml2argvdata/hugepages-memaccess3.xml | 87 +++++++++++++++++++++++++
>>  tests/qemuxml2argvtest.c                        |  3 +
>>  3 files changed, 99 insertions(+)
>>  create mode 100644 tests/qemuxml2argvdata/hugepages-memaccess3.xml
>>
>> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
>> index 2dd50a214..dfc17ce34 100644
>> --- a/src/qemu/qemu_command.c
>> +++ b/src/qemu/qemu_command.c
>> @@ -7682,6 +7682,15 @@ qemuBuildMemPathStr(virQEMUDriverConfigPtr cfg,
>>          return -1;
>>      }
>>  
>> +    if (def->mem.access != VIR_DOMAIN_MEMORY_ACCESS_DEFAULT &&
>> +        def->mem.access != VIR_DOMAIN_MEMORY_ACCESS_PRIVATE) {
>> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> +                       _("memory access mode '%s' not supported "
>> +                         "without guest numa node"),
>> +                       virDomainMemoryAccessTypeToString(def->mem.access));
>> +        return -1;
>> +    }
>> +
> 
> This works; however, why not move this and the virQEMUCapsGet check into
> a qemu_domain qemuDomainDef*Memory*Validate type function?  Thus
> removing failure checks from qemu_command...

I'm not quite sure which function you have in mind.

> 
> I suppose it's OK here, but I think better there.  Still for the concept,
> 
> Reviewed-by: John Ferlan <jferlan at redhat.com>

Thanks, I'll hold pushing these until we have clear consensus here.

Michal