[libvirt] [PATCH v2 01/12] Introduce /domain/devices/interface/driver/@queues attribute

[Michal Privoznik]

On 13.05.2013 22:38, Laine Stump wrote:
> On 05/13/2013 01:22 PM, Michal Privoznik wrote:
>> This attribute is going to represent number of queues for
>> multique vhost network interface. This commit implements XML
>> extension part of the feature and add one test as well. For now,
>> we can only do xml2xml test as qemu command line generation code
>> is not adapted yet.
>> ---
>>  docs/formatdomain.html.in                          | 11 ++++-
>>  docs/schemas/domaincommon.rng                      |  5 +++
>>  src/conf/domain_conf.c                             | 15 +++++++
>>  src/conf/domain_conf.h                             |  1 +
>>  src/qemu/qemu_domain.c                             | 27 +++++++-----
>>  tests/qemuxml2argvdata/qemuxml2argv-event_idx.xml  |  2 +-
>>  .../qemuxml2argv-net-virtio-device.xml             |  2 +-
>>  .../qemuxml2argvdata/qemuxml2argv-vhost_queues.xml | 51 ++++++++++++++++++++++
>>  tests/qemuxml2argvdata/qemuxml2argv-virtio-lun.xml |  2 +-
>>  tests/qemuxml2xmltest.c                            |  1 +
>>  10 files changed, 103 insertions(+), 14 deletions(-)
>>  create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-vhost_queues.xml
>>

>> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
>> index 8004428..d671491 100644
>> --- a/docs/schemas/domaincommon.rng
>> +++ b/docs/schemas/domaincommon.rng
>> @@ -1990,6 +1990,11 @@
>>                  </attribute>
>>                </optional>
>>                <optional>
>> +                <attribute name='queues'>
>> +                  <ref name="positiveInteger"/>
> 
> 
> Should a lower limit be put on it in the RNG? (does qemu have a
> documented limit?)

I don't think so. QEMU doesn't have anything documented, but they are
using uint16_t to store the max_queues internally. However, when setting
it in virtio_net_device_init they use:

n->max_queues = MAX(n->nic_conf.queues, 1);

where n->nic_conf.queues is int32_t. Maybe we should ask on the qemu list.

> 
> 
>> +                </attribute>
>> +              </optional>
>> +              <optional>
>>                  <attribute name="txmode">
>>                    <choice>
>>                      <value>iothread</value>