From: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@xxxxxxxxxx>
In this commit we introduce 'poll_us' attribute which will be passed
then to the QEMU command line to enable support of busy polling. This
commit also take into account that attribute to generate the XML.
Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@xxxxxxxxxx>
---
Addressed comments:
- Moved the RNG and doc from patch3 to that one
- Added an xml2xml test
- Renamed var pollus to poll_us
docs/formatdomain.html.in | 12 +++++++-
docs/schemas/domaincommon.rng | 5 ++++
src/conf/domain_conf.c | 16 +++++++++++
src/conf/domain_conf.h | 1 +
.../qemuxml2argv-net-virtio-poll-us.xml | 23 +++++++++++++++
.../qemuxml2xmlout-net-virtio-poll-us.xml | 33 ++++++++++++++++++++++
tests/qemuxml2xmltest.c | 1 +
7 files changed, 90 insertions(+), 1 deletion(-)
create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-net-virtio-poll-us.xml
create mode 100644 tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-poll-us.xml
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index c12efcf..c0516e3 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -5071,7 +5071,7 @@ qemu-kvm -net nic,model=? /dev/null
<source network='default'/>
<target dev='vnet1'/>
<model type='virtio'/>
- <b><driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256'>
+ <b><driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256' poll_us='50'>
<host csum='off' gso='off' tso4='off' tso6='off' ecn='off' ufo='off' mrg_rxbuf='off'/>
<guest csum='off' tso4='off' tso6='off' ecn='off' ufo='off'/>
</driver>
@@ -5201,6 +5201,16 @@ qemu-kvm -net nic,model=? /dev/null
<b>In general you should leave this option alone, unless you
are very certain you know what you are doing.</b>
</dd>
+ <dd>
+ The optional <code>poll_us</code> attribute configure the
+ maximum number of microseconds that could be spent on busy
+ polling. It improves the performance, but requires more
+ CPU. This option is only available with vhost backend driver.
+ <span class="since">Since 2.7.0 (QEMU and KVM only)</span><br/><br/>
+
+ <b>In general you should leave this option alone, unless you
+ are very certain you know what you are doing.</b>
+ </dd>
<dt>virtio options</dt>
<dd>
For virtio interfaces,
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index fc1a40f..0cd2dc0 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -2723,6 +2723,11 @@
<optional>
<ref name="event_idx"/>
</optional>
+ <optional>
+ <attribute name='poll_us'>
+ <ref name='positiveInteger'/>
+ </attribute>
+ </optional>
</group>
</choice>
<ref name="virtioOptions"/>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 3feeccb..51735dc 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -9920,6 +9920,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
char *event_idx = NULL;
char *queues = NULL;
char *rx_queue_size = NULL;
+ char *poll_us = NULL;
char *str = NULL;
char *filter = NULL;
char *internal = NULL;
@@ -10093,6 +10094,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
event_idx = virXMLPropString(cur, "event_idx");
queues = virXMLPropString(cur, "queues");
rx_queue_size = virXMLPropString(cur, "rx_queue_size");
+ poll_us = virXMLPropString(cur, "poll_us");
} else if (xmlStrEqual(cur->name, BAD_CAST "filterref")) {
if (filter) {
virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -10490,6 +10492,17 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
}
def->driver.virtio.rx_queue_size = q;
}
+ if (poll_us) {
+ unsigned int us;
+ if (virStrToLong_uip(poll_us, NULL, 10, &us) < 0) {
+ virReportError(VIR_ERR_XML_DETAIL,
+ _("'poll_us' attribute must be positive: %s"),
+ poll_us);
+ goto error;
+ }
+ if (us > 1)
+ def->driver.virtio.poll_us = us;
+ }
if ((str = virXPathString("string(./driver/host/@csum)", ctxt))) {
if ((val = virTristateSwitchTypeFromString(str)) <= 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -10687,6 +10700,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
VIR_FREE(event_idx);
VIR_FREE(queues);
VIR_FREE(rx_queue_size);
+ VIR_FREE(poll_us);
VIR_FREE(str);
VIR_FREE(filter);
VIR_FREE(type);
@@ -22558,6 +22572,8 @@ virDomainVirtioNetDriverFormat(char **outstr,
if (def->driver.virtio.rx_queue_size)
virBufferAsprintf(&buf, " rx_queue_size='%u'",
def->driver.virtio.rx_queue_size);
+ if (def->driver.virtio.poll_us)
+ virBufferAsprintf(&buf, " poll_us='%u'", def->driver.virtio.poll_us);
virDomainVirtioOptionsFormat(&buf, def->virtio);
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index af15ee8..ae3616b 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -969,6 +969,7 @@ struct _virDomainNetDef {
virTristateSwitch event_idx;
unsigned int queues; /* Multiqueue virtio-net */
unsigned int rx_queue_size;
+ unsigned int poll_us; /* busy polling for tap */
struct {
virTristateSwitch csum;
virTristateSwitch gso;
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-poll-us.xml b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-poll-us.xml
new file mode 100644
index 0000000..46ef7d6
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-net-virtio-poll-us.xml
@@ -0,0 +1,23 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219100</memory>
+ <currentMemory unit='KiB'>219100</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-i686</emulator>
+ <interface type='ethernet'>
+ <mac address='52:54:00:23:bc:ba'/>
+ <model type='virtio'/>
+ <driver name="vhost" poll_us='50'/>
+ </interface>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-poll-us.xml b/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-poll-us.xml
new file mode 100644
index 0000000..7f81d15
--- /dev/null
+++ b/tests/qemuxml2xmloutdata/qemuxml2xmlout-net-virtio-poll-us.xml
@@ -0,0 +1,33 @@
+<domain type='qemu'>
+ <name>QEMUGuest1</name>
+ <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+ <memory unit='KiB'>219100</memory>
+ <currentMemory unit='KiB'>219100</currentMemory>
+ <vcpu placement='static'>1</vcpu>
+ <os>
+ <type arch='i686' machine='pc'>hvm</type>
+ <boot dev='hd'/>
+ </os>
+ <clock offset='utc'/>
+ <on_poweroff>destroy</on_poweroff>
+ <on_reboot>restart</on_reboot>
+ <on_crash>destroy</on_crash>
+ <devices>
+ <emulator>/usr/bin/qemu-system-i686</emulator>
+ <controller type='usb' index='0'>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
+ </controller>
+ <controller type='pci' index='0' model='pci-root'/>
+ <interface type='ethernet'>
+ <mac address='52:54:00:23:bc:ba'/>
+ <model type='virtio'/>
+ <driver name='vhost' poll_us='50'/>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
+ </interface>
+ <input type='mouse' bus='ps2'/>
+ <input type='keyboard' bus='ps2'/>
+ <memballoon model='virtio'>
+ <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
+ </memballoon>
+ </devices>
+</domain>
diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c
index 5e4b1d1..7abba30 100644
--- a/tests/qemuxml2xmltest.c
+++ b/tests/qemuxml2xmltest.c
@@ -538,6 +538,7 @@ mymain(void)
DO_TEST("net-eth-hostip", NONE);
DO_TEST("net-virtio-network-portgroup", NONE);
DO_TEST("net-virtio-rxqueuesize", NONE);
+ DO_TEST("net-virtio-poll-us", NONE);
DO_TEST("net-hostdev", NONE);
DO_TEST("net-hostdev-vfio", NONE);
DO_TEST("net-midonet", NONE);
--
2.9.4
--
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