Re: [libvirt] [PATCH REPOST 5/7] conf: Add support for virtio-scsi iothreads

On 05/03/2016 09:50 AM, Cole Robinson wrote: > On 05/02/2016 06:30 PM, John Ferlan wrote: >> Add the ability to add an 'iothread' to the controller which will be how >> virtio-scsi-pci and virtio-scsi-ccw iothreads have been implemented in qemu. >> >> Describe the new functionality and add tests to parse/validate that the >> new attribute can be added. >> >> Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; >> --- >> docs/formatdomain.html.in | 33 +++++++++++--- >> docs/schemas/domaincommon.rng | 3 ++ >> src/conf/domain_conf.c | 25 ++++++++++- >> src/conf/domain_conf.h | 1 + >> .../qemuxml2argv-iothreads-virtio-scsi-ccw.xml | 39 +++++++++++++++++ >> .../qemuxml2argv-iothreads-virtio-scsi-pci.xml | 47 ++++++++++++++++++++ >> .../qemuxml2xmlout-iothreads-virtio-scsi-ccw.xml | 40 +++++++++++++++++ >> .../qemuxml2xmlout-iothreads-virtio-scsi-pci.xml | 51 ++++++++++++++++++++++ >> tests/qemuxml2xmltest.c | 7 +++ >> 9 files changed, 240 insertions(+), 6 deletions(-) >> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-iothreads-virtio-scsi-ccw.xml >> create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-iothreads-virtio-scsi-pci.xml >> create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-iothreads-virtio-scsi-ccw.xml >> create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-iothreads-virtio-scsi-pci.xml >> >> diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in >> index 5781dba..5e27fca 100644 >> --- a/docs/formatdomain.html.in >> +++ b/docs/formatdomain.html.in >> @@ -565,11 +565,13 @@ >> <dt><code>iothreads</code></dt> >> <dd> >> The content of this optional element defines the number >> - of IOThreads to be assigned to the domain for use by >> - virtio-blk-pci and virtio-blk-ccw target storage devices. There >> - should be only 1 or 2 IOThreads per host CPU. There may be more >> - than one supported device assigned to each IOThread. >> - <span class="since">Since 1.2.8</span> >> + of IOThreads to be assigned to the domain for use by supported >> + storage disks or controllers. There should be only 1 or 2 IOThreads >> + per host CPU. There may be more than one supported device assigned >> + to each IOThread. Supported for virtio-blk-pci and virtio-blk-ccw >> + disk devices <span class="since">since 1.2.8 (QEMU 2.1)</span>. >> + Supported for virtio-scsi-pci and virtio-scsi-ccw controller >> + devices <span class="since">since 1.3.4 (QEMU 2.4)</span>. >> </dd> >> <dt><code>iothreadids</code></dt> >> <dd> > > This is the bit that should be made generic IMO > I'll remove this hunk... >> @@ -3004,6 +3006,10 @@ >> &lt;controller type='virtio-serial' index='1'&gt; >> &lt;address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/&gt; >> &lt;/controller&gt; >> + &lt;controller type='scsi' index='0' model='virtio-scsi'&gt; >> + &lt;driver iothread='4'&gt; >> + &lt;address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/&gt; >> + &lt;/controller&gt; >> ... >> &lt;/devices&gt; >> ...</pre> >> @@ -3084,6 +3090,23 @@ >> I/O asynchronous handling</a> or not. Accepted values are >> "on" and "off". <span class="since">Since 1.2.18</span> >> </dd> >> + <dt><code>iothread</code></dt> >> + <dd> >> + Supported for controller type <code>scsi</code> using model >> + <code>virtio-scsi</code> for <code>address</code> types >> + <code>pci</code> and <code>ccw</code> >> + <span class="since">since 1.3.4 (QEMU 2.4)</span>. >> + >> + The optional <code>iothread</code> attribute assigns the controller >> + to an IOThread as defined by the range for the domain >> + <a href="#elementsIOThreadsAllocation"><code>iothreads</code></a> >> + value. Each SCSI <code>disk</code> assigned to use the specified >> + <code>controller</code> will utilize the same IOThread. If a specific >> + IOThread is desired for a specific SCSI <code>disk</code>, then >> + multiple controllers must be defined each having a specific >> + <code>iothread</code> value. The <code>iothread</code> value >> + must be within the range 1 to the domain iothreads value. >> + </dd> >> </dl> >> <p> >> USB companion controllers have an optional >> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng >> index b82f8c8..ceced6b 100644 >> --- a/docs/schemas/domaincommon.rng >> +++ b/docs/schemas/domaincommon.rng >> @@ -1893,6 +1893,9 @@ >> <optional> >> <ref name="ioeventfd"/> >> </optional> >> + <optional> >> + <ref name="driverIOThread"/> >> + </optional> >> </element> >> </optional> >> </interleave> >> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c >> index 6375b2b..f571466 100644 >> --- a/src/conf/domain_conf.c >> +++ b/src/conf/domain_conf.c >> @@ -7853,6 +7853,7 @@ virDomainControllerDefParseXML(xmlNodePtr node, >> char *busNr = NULL; >> int numaNode = -1; >> char *ioeventfd = NULL; >> + char *iothread = NULL; >> xmlNodePtr saved = ctxt->node; >> int rc; >> >> @@ -7897,6 +7898,7 @@ virDomainControllerDefParseXML(xmlNodePtr node, >> cmd_per_lun = virXMLPropString(cur, "cmd_per_lun"); >> max_sectors = virXMLPropString(cur, "max_sectors"); >> ioeventfd = virXMLPropString(cur, "ioeventfd"); >> + iothread = virXMLPropString(cur, "iothread"); >> } else if (xmlStrEqual(cur->name, BAD_CAST "model")) { >> if (processedModel) { >> virReportError(VIR_ERR_XML_ERROR, "%s", >> @@ -7958,6 +7960,21 @@ virDomainControllerDefParseXML(xmlNodePtr node, >> goto error; >> } >> >> + if (iothread) { >> + if (def->model != VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI) { >> + virReportError(VIR_ERR_XML_ERROR, >> + _("'iothread' attribute only supported for " >> + "controller model '%s'"), >> + virDomainControllerModelSCSITypeToString(VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI)); >> + goto error; >> + } > > I think this particular check should be moved to one of the generic PostParse > validation functions, since it's not specific to parse time. > I guess I was under the impression that post parse callbacks were to be used when we didn't have all the information about a relationship between say a disk and controller.

In this case, the attribute is only supported on the controller that has been defined using "virtio-scsi" or "virtio-ccw". Since those weren't "discover-able" based on some other relationship, thus checking at parse time was better. IDC either way, but I think (without too much digging), that would mean a change to qemuDomainDeviceDefPostParse in the following if:

if (dev->type == VIR_DOMAIN_DEVICE_CONTROLLER) { in order to add a check such as if (cont->type == VIR_DOMAIN_CONTROLLER_TYPE_USB && cont->iothread && cont->model != VIR_DOMAIN_CONTROLLER_MODEL_SCSI_VIRTIO_SCSI) Is there anyone else that has a preference/thought where the check should go? Tks - John