[PATCH 1/3] conf: Add a new xenbus controller option for event channels

Event channels are like PV interrupts and in conjuction with grant frames form a data transfer mechanism for PV drivers. They are also used for inter-processor interrupts. Guests with a large number of vcpus and/or many PV devices many need to increase the maximum default value of 1023. For this reason the native Xen config format supports the 'max_event_channels' setting. See xl.cfg(5) man page for more details. Similar to the existing maxGrantFrames option, add a new xenbus controller option 'maxEventChannels', allowing to adjust the maximum value via libvirt. Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; --- docs/formatdomain.html.in | 8 ++++++-- docs/schemas/domaincommon.rng | 5 +++++ src/conf/domain_conf.c | 15 +++++++++++++++ src/conf/domain_conf.h | 1 + 4 files changed, 27 insertions(+), 2 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index d56600dc18..eabb7b6ece 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -4454,7 +4454,7 @@ &lt;driver iothread='4'/&gt; &lt;address type='pci' domain='0x0000' bus='0x00' slot='0x0b' function='0x0'/&gt; &lt;/controller&gt; - &lt;controller type='xenbus' maxGrantFrames='64'/&gt; + &lt;controller type='xenbus' maxGrantFrames='64' maxEventChannels='2047'/&gt; ... &lt;/devices&gt; ...</pre> @@ -4514,7 +4514,11 @@ <dd><span class="since">Since 5.2.0</span>, the <code>xenbus</code> controller has an optional attribute <code>maxGrantFrames</code>, which specifies the maximum number of grant frames the controller - makes available for connected devices.</dd> + makes available for connected devices. + <span class="since">Since 6.3.0</span>, the xenbus controller + supports the optional <code>maxEventChannels</code> attribute, + which specifies maximum number of event channels (PV interrupts) + that can be used by the guest.</dd> </dl> <p> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index dcf2e09db8..d0dcab9059 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2548,6 +2548,11 @@ <ref name="unsignedInt"/> </attribute> </optional> + <optional> + <attribute name="maxEventChannels"> + <ref name="unsignedInt"/> + </attribute> + </optional> </group> </choice> <optional> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 6ad7552bde..0a2aa53264 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -2252,6 +2252,7 @@ virDomainControllerDefNew(virDomainControllerType type) break; case VIR_DOMAIN_CONTROLLER_TYPE_XENBUS: def->opts.xenbusopts.maxGrantFrames = -1; + def->opts.xenbusopts.maxEventChannels = -1; break; case VIR_DOMAIN_CONTROLLER_TYPE_IDE: case VIR_DOMAIN_CONTROLLER_TYPE_FDC: @@ -11344,6 +11345,7 @@ virDomainControllerDefParseXML(virDomainXMLOptionPtr xmlopt, break; case VIR_DOMAIN_CONTROLLER_TYPE_XENBUS: { g_autofree char *gntframes = virXMLPropString(node, "maxGrantFrames"); + g_autofree char *eventchannels = virXMLPropString(node, "maxEventChannels"); if (gntframes) { int r = virStrToLong_i(gntframes, NULL, 10, @@ -11354,6 +11356,15 @@ virDomainControllerDefParseXML(virDomainXMLOptionPtr xmlopt, goto error; } } + if (eventchannels) { + int r = virStrToLong_i(eventchannels, NULL, 10, + &def->opts.xenbusopts.maxEventChannels); + if (r != 0 || def->opts.xenbusopts.maxEventChannels < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Invalid maxEventChannels: %s"), eventchannels); + goto error; + } + } break; } @@ -25286,6 +25297,10 @@ virDomainControllerDefFormat(virBufferPtr buf, virBufferAsprintf(&attrBuf, " maxGrantFrames='%d'", def->opts.xenbusopts.maxGrantFrames); } + if (def->opts.xenbusopts.maxEventChannels != -1) { + virBufferAsprintf(&attrBuf, " maxEventChannels='%d'", + def->opts.xenbusopts.maxEventChannels); + } break; default: diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 024f692053..089d600061 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -730,6 +730,7 @@ struct _virDomainUSBControllerOpts { struct _virDomainXenbusControllerOpts { int maxGrantFrames; /* -1 == undef */ + int maxEventChannels; /* -1 == undef */ }; /* Stores the virtual disk controller configuration */ -- 2.26.0