11:06 a.m.
On 06/15/2017 10:17 AM, sferdjao(a)redhat.com wrote:
From: Sahid Orentino Ferdjaoui <sahid.ferdjaoui(a)redhat.com>
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(a)redhat.com>
---
src/conf/domain_conf.c | 16 ++++++++++++++++
src/conf/domain_conf.h | 1 +
2 files changed, 17 insertions(+)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 0507ec1..803f517 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -9748,6 +9748,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
char *event_idx = NULL;
char *queues = NULL;
char *rx_queue_size = NULL;
+ char *pollus = NULL;
since the option is "poll-us", but you can't have "-" in an
identifier
name, this should either be "poll_us", or "pollUS" (there is some
amount
of preference for camelCase in C and XML identifier names in libvirt,
but it is by no means universal, so probably best just to go along with
what's done for nearby identifiers in a similar class, e.g. event_idx).
(Of course some purists would say that we shouldn't include the type of
units in the name, but since this number is so specific to a particular
driver, I think it's reasonable to treat it as an opaque setting, named
"poll-us", with no units-type associated with it).
char *str = NULL;
char *filter = NULL;
char *internal = NULL;
@@ -9921,6 +9922,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
event_idx = virXMLPropString(cur, "event_idx");
queues = virXMLPropString(cur, "queues");
rx_queue_size = virXMLPropString(cur, "rx_queue_size");
+ pollus = virXMLPropString(cur, "poll_us");
} else if (xmlStrEqual(cur->name, BAD_CAST "filterref")) {
if (filter) {
virReportError(VIR_ERR_XML_ERROR, "%s",
@@ -10318,6 +10320,17 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
}
def->driver.virtio.rx_queue_size = q;
}
+ if (pollus) {
+ unsigned int us;
+ if (virStrToLong_uip(pollus, NULL, 10, &us) < 0) {
+ virReportError(VIR_ERR_XML_DETAIL,
+ _("'poll_us' attribute must be positive
number: %s"),
"...must be positive" or "...must be a positive integer"
+ pollus);
+ goto error;
+ }
+ if (us > 1)
+ def->driver.virtio.pollus = us;
+ }
if ((str = virXPathString("string(./driver/host/@csum)", ctxt))) {
if ((val = virTristateSwitchTypeFromString(str)) <= 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
@@ -10515,6 +10528,7 @@ virDomainNetDefParseXML(virDomainXMLOptionPtr xmlopt,
VIR_FREE(event_idx);
VIR_FREE(queues);
VIR_FREE(rx_queue_size);
+ VIR_FREE(pollus);
VIR_FREE(str);
VIR_FREE(filter);
VIR_FREE(type);
@@ -22308,6 +22322,8 @@ 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.pollus)
+ virBufferAsprintf(&buf, " poll_us='%u'",
def->driver.virtio.pollus);
virDomainVirtioOptionsFormat(&buf, def->virtio);
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index e67b6fd..d97d776 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -967,6 +967,7 @@ struct _virDomainNetDef {
virTristateSwitch event_idx;
unsigned int queues; /* Multiqueue virtio-net */
unsigned int rx_queue_size;
+ unsigned int pollus; /* busy polling for tap */
struct {
virTristateSwitch csum;
virTristateSwitch gso;
Generally I like to have the schema change (RNG file) and
formatdomain.html.in (documentation) change, along with xml2xml tests.
in the same commit as the change to the parser/formatter, but you've
included them in the commit that connects the parser/formatter change
into the qemu driver. Of course it all comes out the same in the end,
but separating it in the way I suggest makes each patch self documenting
and self-testing (xml2argv tests will still be added in the final patch).