3:07 p.m.
Added "rss" and "rss_hash_report" configuration that should be used
with
qemu virtio RSS.
Both options are triswitches. Used as "driver" options and affects only NIC
with model type "virtio".
In other patches - options should turn on virtio-net RSS and hash properties.
Signed-off-by: Andrew Melnychenko <andrew(a)daynix.com>
---
docs/formatdomain.rst | 18 ++++++++++++++++++
docs/schemas/domaincommon.rng | 10 ++++++++++
src/conf/domain_conf.c | 31 ++++++++++++++++++++++++++++++-
src/conf/domain_conf.h | 2 ++
4 files changed, 60 insertions(+), 1 deletion(-)
diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
index d4f30bb8af..ce3e8a5dbf 100644
--- a/docs/formatdomain.rst
+++ b/docs/formatdomain.rst
@@ -5305,6 +5305,24 @@ following attributes are available for the ``"virtio"``
NIC driver:
only for ``vhostuser`` type. :since:`Since 3.7.0 (QEMU and KVM only)`
**In general you should leave this option alone, unless you are very certain
you know what you are doing.**
+``rss``
+ The ``rss`` option enables in-qemu/ebpf RSS for virtio NIC. RSS works with
+ virtio and tap backends only. Virtio NIC will be launched with "rss"
+ property. For now "in-qemu" RSS is supported by libvirt.
+ QEMU may load eBPF RSS if it has CAP_SYS_ADMIN permissions, which is
+ not supported by default in libvirt.
+ **In general you should leave this option alone, unless you are very certain
+ you know what you are doing. Proper RSS configuration depends from vcpu,
+ tap, and vhost settings.**
+``rss_hash_report``
+ The ``rss_hash_report`` option enables in-qemu RSS hash report for virtio
+ NIC. Virtio NIC will be launched with a "hash" property. Network packets
provided
+ to VM will contain a hash of the packet in the virt header. Usually enabled
+ alongside with ``rss``. Without ``rss`` option, the hash report doesn't affect
+ steering itself but provides vnet header with a calculated hash.
+ **In general you should leave this option alone, unless you are very certain
+ you know what you are doing. Proper RSS configuration depends from vcpu,
+ tap, and vhost settings.**
virtio options
For virtio interfaces, `Virtio-specific options <#elementsVirtio>`__ can also
be set. ( :since:`Since 3.5.0` )
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 7fa5c2b8b5..9b5b94fc6c 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -3595,6 +3595,16 @@
</optional>
</element>
</optional>
+ <optional>
+ <attribute name="rss">
+ <ref name="virOnOff"/>
+ </attribute>
+ </optional>
+ <optional>
+ <attribute name="rss_hash_report">
+ <ref name="virOnOff"/>
+ </attribute>
+ </optional>
</interleave>
</element>
</optional>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 716c6d2240..762987e8a9 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -10271,6 +10271,8 @@ virDomainNetDefParseXML(virDomainXMLOption *xmlopt,
g_autofree char *vhost_path = NULL;
g_autofree char *tap = NULL;
g_autofree char *vhost = NULL;
+ g_autofree char *virtio_rss = NULL;
+ g_autofree char *virtio_rss_hash_report = NULL;
const char *prefix = xmlopt ? xmlopt->config.netPrefix : NULL;
if (!(def = virDomainNetDefNew(xmlopt)))
@@ -10412,6 +10414,8 @@ virDomainNetDefParseXML(virDomainXMLOption *xmlopt,
queues = virXMLPropString(driver_node, "queues");
rx_queue_size = virXMLPropString(driver_node, "rx_queue_size");
tx_queue_size = virXMLPropString(driver_node, "tx_queue_size");
+ virtio_rss = virXMLPropString(driver_node, "rss");
+ virtio_rss_hash_report = virXMLPropString(driver_node, "rss_hash_report");
if ((filterref_node = virXPathNode("./filterref", ctxt))) {
filter = virXMLPropString(filterref_node, "filter");
@@ -10822,7 +10826,24 @@ virDomainNetDefParseXML(virDomainXMLOption *xmlopt,
}
def->driver.virtio.tx_queue_size = q;
}
-
+ if (virtio_rss) {
+ if ((val = virTristateSwitchTypeFromString(virtio_rss)) <= 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("'rss' attribute must be
'on'/'off'/'default': %s"),
+ virtio_rss);
+ goto error;
+ }
+ def->driver.virtio.rss = val;
+ }
+ if (virtio_rss_hash_report) {
+ if ((val = virTristateSwitchTypeFromString(virtio_rss_hash_report)) <= 0)
{
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("'rss_hash_report' attribute must be
'on'/'off'/'default': %s"),
+ virtio_rss_hash_report);
+ goto error;
+ }
+ def->driver.virtio.rss_hash_report = val;
+ }
if ((tmpNode = virXPathNode("./driver/host", ctxt))) {
if (virXMLPropTristateSwitch(tmpNode, "csum", VIR_XML_PROP_NONE,
&def->driver.virtio.host.csum) < 0)
@@ -24751,6 +24772,14 @@ virDomainVirtioNetDriverFormat(virBuffer *buf,
if (def->driver.virtio.tx_queue_size)
virBufferAsprintf(buf, " tx_queue_size='%u'",
def->driver.virtio.tx_queue_size);
+ if (def->driver.virtio.rss != VIR_TRISTATE_SWITCH_ABSENT) {
+ virBufferAsprintf(buf, " rss='%s'",
+ virTristateSwitchTypeToString(def->driver.virtio.rss));
+ }
+ if (def->driver.virtio.rss_hash_report != VIR_TRISTATE_SWITCH_ABSENT) {
+ virBufferAsprintf(buf, " rss_hash_report='%s'",
+
virTristateSwitchTypeToString(def->driver.virtio.rss_hash_report));
+ }
virDomainVirtioOptionsFormat(buf, def->virtio);
}
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 144ba4dd12..64ebff012e 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1055,6 +1055,8 @@ struct _virDomainNetDef {
virTristateSwitch ecn;
virTristateSwitch ufo;
} guest;
+ virTristateSwitch rss;
+ virTristateSwitch rss_hash_report;
} virtio;
} driver;
struct {
--
2.34.1