Re: [libvirt] [PATCH 1/4] domain_conf: Introduce iothreads XML

On Mon, Aug 25, 2014 at 08:38:06PM -0400, John Ferlan wrote: > Introduce XML to allowing adding iothreads to the domain. These can be > used by virtio-blk-pci devices in order to assign a specific thread to > handle the workload for the device. The iothreads are the official > implementation of the virtio-blk Data Plane that's been in tech preview > for QEMU. > > Signed-off-by: John Ferlan <jferlan(a)redhat.com&gt; > --- > docs/formatdomain.html.in | 26 ++++++++++++++++++++++++++ > docs/schemas/domaincommon.rng | 12 ++++++++++++ > src/conf/domain_conf.c | 28 ++++++++++++++++++++++++++++ > src/conf/domain_conf.h | 2 ++ > 4 files changed, 68 insertions(+) > [...] > diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng > index 9a89dd8..b4ac483 100644 > --- a/docs/schemas/domaincommon.rng > +++ b/docs/schemas/domaincommon.rng > @@ -632,6 +632,12 @@ > </optional> > > <optional> > + <element name="iothreads"> > + <ref name="countIOThreads"/> What's the difference between this and using ref name="unsignedInt" directly?

> + </element> > + </optional> > + > + <optional> > <ref name="blkiotune"/> > </optional> > > @@ -4747,6 +4753,12 @@ > <param name="minInclusive">1</param> > </data> > </define> > + <define name="countIOThreads"> > + <data type="unsignedInt"> > + <param name="pattern">[0-9]+</param> > + <param name="minInclusive">0</param> > + </data> > + </define> > <define name="vcpuid"> > <data type="unsignedShort"> > <param name="pattern">[0-9]+</param> > diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c > index 22a7f7e..671c41c 100644 > --- a/src/conf/domain_conf.c > +++ b/src/conf/domain_conf.c > @@ -11953,6 +11953,23 @@ virDomainDefParseXML(xmlDocPtr xml, > } > } > > + /* Optional - iothreads */ > + n = virXPathULong("string(./iothreads[1])", ctxt, &count); > + if (n == -2) { > + virReportError(VIR_ERR_XML_ERROR, "%s", > + _("iothreads count must be an integer")); > + goto error; > + } else if (n < 0) { > + def->iothreads = 0; > + } else { > + if ((unsigned int) count != count) { Instead of this machinery, it would be more straightforward to just do (example written by hand, not tested): tmp = virXPathString("string(./iothreads[1])", ctxt); if (tmp && virStrToLong_uip(tmp, NULL, 0, &def->iothreads) < 0) virReportError(VIR_ERR_XML_ERROR, _("invalid iothreads count '%s'"), tmp);