[libvirt] [PATCH 1/2] Add mrg_rxbuf option to virtio interfaces

Add an XML attribute to allow disabling merge of rx buffers on the host: <interface ...> ... <model type='virtio'/> <driver ...> <host mrg_rxbuf='off'/> </driver> </interface> https://bugzilla.redhat.com/show_bug.cgi?id=1186886 --- docs/formatdomain.html.in | 6 +++++- docs/schemas/domaincommon.rng | 5 +++++ src/conf/domain_conf.c | 14 ++++++++++++++ src/conf/domain_conf.h | 1 + 4 files changed, 25 insertions(+), 1 deletion(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index 679194f..96fb8de 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -3998,7 +3998,7 @@ qemu-kvm -net nic,model=? /dev/null &lt;target dev='vnet1'/&gt; &lt;model type='virtio'/&gt; <b>&lt;driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5'&gt; - &lt;host csum='off' gso='off' tso4='off' tso6='off' ecn='off' ufo='off'/&gt; + &lt;host csum='off' gso='off' tso4='off' tso6='off' ecn='off' ufo='off' mrg_rxbuf='off'/&gt; &lt;guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/&gt; &lt;/driver&gt; </b> @@ -4113,6 +4113,10 @@ qemu-kvm -net nic,model=? /dev/null and <code>off</code> can be used to turn off host offloading options. By default, the supported offloads are enabled by QEMU. <span class="since">Since 1.2.9 (QEMU only)</span> + The <code>mrg_rxbuf</code> attribute can be used to control + mergeable rx buffers on the host side. Possible values are + <code>on</code> (default) and <code>off</code>. + <span class="since">Since 1.2.13 (QEMU only)</span> </dd> <dt><code>guest</code> offloading options</dt> <dd> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index d467dce..bc4b088 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -2425,6 +2425,11 @@ <ref name="virOnOff"/> </attribute> </optional> + <optional> + <attribute name='mrg_rxbuf'> + <ref name="virOnOff"/> + </attribute> + </optional> </element> </optional> <optional> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index f0b715d..ef0eb3a 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7944,6 +7944,16 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt, def->driver.virtio.host.ufo = val; } VIR_FREE(str); + if ((str = virXPathString("string(./driver/host/@mrg_rxbuf)", ctxt))) { + if ((val = virTristateSwitchTypeFromString(str)) <= 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown host mrg_rxbuf mode '%s'"), + str); + goto error; + } + def->driver.virtio.host.mrg_rxbuf = val; + } + VIR_FREE(str); if ((str = virXPathString("string(./driver/guest/@csum)", ctxt))) { if ((val = virTristateSwitchTypeFromString(str)) <= 0) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, @@ -17585,6 +17595,10 @@ virDomainVirtioNetHostOptsFormat(char **outstr, virBufferAsprintf(&buf, "ufo='%s' ", virTristateSwitchTypeToString(def->driver.virtio.host.ufo)); } + if (def->driver.virtio.host.mrg_rxbuf) { + virBufferAsprintf(&buf, "mrg_rxbuf='%s' ", + virTristateSwitchTypeToString(def->driver.virtio.host.mrg_rxbuf)); + } virBufferTrim(&buf, " ", -1); if (virBufferCheckError(&buf) < 0) diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 93f2314..626901b 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -938,6 +938,7 @@ struct _virDomainNetDef { virTristateSwitch tso6; virTristateSwitch ecn; virTristateSwitch ufo; + virTristateSwitch mrg_rxbuf; } host; struct { virTristateSwitch csum; -- 2.0.5