From: Peter Krempa Date: Mon, 23 Sep 2013 16:32:11 +0000 (+0200) Subject: qemu: Add support for paravirtual spinlocks in the guest X-Git-Tag: v1.2.0-rc1~109 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0dc851164d57f26ec10ceed022fe913f76ba24c;p=thirdparty%2Flibvirt.git qemu: Add support for paravirtual spinlocks in the guest The linux kernel recently added support for paravirtual spinlock handling to avoid performance regressions on overcomitted hosts. This feature needs to be turned in the hypervisor so that the guest OS is notified about the possible support. This patch adds a new feature "paravirt-spinlock" to the XML and supporting code to enable the "kvm_pv_unhalt" pseudo CPU feature in qemu. https://bugzilla.redhat.com/show_bug.cgi?id=1008989 --- diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index aa9070107b..096e2a3f33 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -1193,6 +1193,7 @@ <vapic state='on'/> <spinlocks state='on' retries='4096'/> </hyperv> + <pvspinlock/> </features> ... @@ -1264,6 +1265,13 @@ +
pvspinlock
+
Notify the guest that the host supports paravirtual spinlocks + for example by exposing the pvticketlocks mechanism. This feature + can be explicitly disabled by using state='off' + attribute. +
+

Time keeping

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 1f30161837..80848d2054 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -3561,7 +3561,7 @@ @@ -3607,6 +3607,14 @@ + + + + + + + + diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index d23e72410b..c1e0ea736a 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -142,7 +142,8 @@ VIR_ENUM_IMPL(virDomainFeature, VIR_DOMAIN_FEATURE_LAST, "hap", "viridian", "privnet", - "hyperv") + "hyperv", + "pvspinlock") VIR_ENUM_IMPL(virDomainFeatureState, VIR_DOMAIN_FEATURE_STATE_LAST, "default", @@ -11440,6 +11441,22 @@ virDomainDefParseXML(xmlDocPtr xml, def->features[val] = VIR_DOMAIN_FEATURE_STATE_ON; break; + case VIR_DOMAIN_FEATURE_PVSPINLOCK: + node = ctxt->node; + ctxt->node = nodes[i]; + if ((tmp = virXPathString("string(./@state)", ctxt))) { + if ((def->features[val] = virDomainFeatureStateTypeFromString(tmp)) == -1) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown state atribute '%s' of feature '%s'"), + tmp, virDomainFeatureTypeToString(val)); + goto error; + } + } else { + def->features[val] = VIR_DOMAIN_FEATURE_STATE_ON; + } + ctxt->node = node; + break; + case VIR_DOMAIN_FEATURE_LAST: break; } @@ -16807,6 +16824,23 @@ virDomainDefFormatInternal(virDomainDefPtr def, break; + case VIR_DOMAIN_FEATURE_PVSPINLOCK: + switch ((enum virDomainFeatureState) def->features[i]) { + case VIR_DOMAIN_FEATURE_STATE_LAST: + case VIR_DOMAIN_FEATURE_STATE_DEFAULT: + break; + + case VIR_DOMAIN_FEATURE_STATE_ON: + virBufferAsprintf(buf, " <%s state='on'/>\n", name); + break; + + case VIR_DOMAIN_FEATURE_STATE_OFF: + virBufferAsprintf(buf, " <%s state='off'/>\n", name); + break; + } + + break; + case VIR_DOMAIN_FEATURE_APIC: if (def->features[i] == VIR_DOMAIN_FEATURE_STATE_ON) { virBufferAddLit(buf, " features[VIR_DOMAIN_FEATURE_PVSPINLOCK]) { + char sign; + if (def->features[VIR_DOMAIN_FEATURE_PVSPINLOCK] == VIR_DOMAIN_FEATURE_STATE_ON) + sign = '+'; + else + sign = '-'; + + virBufferAsprintf(&buf, "%s,%ckvm_pv_unhalt", + have_cpu ? "" : default_model, + sign); + have_cpu = true; + } + if (def->features[VIR_DOMAIN_FEATURE_HYPERV] == VIR_DOMAIN_FEATURE_STATE_ON) { if (!have_cpu) { virBufferAdd(&buf, default_model, -1); diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.args b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.args new file mode 100644 index 0000000000..80047f9660 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.args @@ -0,0 +1,5 @@ +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \ +/usr/bin/qemu -S -M pc \ +-cpu qemu32,-kvm_pv_unhalt -m 214 -smp 6 -nographic -monitor \ +unix:/tmp/test-monitor,server,nowait -boot n -usb -net none -serial \ +none -parallel none diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.xml b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.xml new file mode 100644 index 0000000000..4820476b2b --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-disabled.xml @@ -0,0 +1,26 @@ + + QEMUGuest1 + c7a5fdbd-edaf-9455-926a-d65c16db1809 + 219100 + 219100 + 6 + + hvm + + + + + + + + + destroy + restart + destroy + + /usr/bin/qemu + + + + + diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.args b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.args new file mode 100644 index 0000000000..70db1730c5 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.args @@ -0,0 +1,5 @@ +LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test QEMU_AUDIO_DRV=none \ +/usr/bin/qemu -S -M pc \ +-cpu qemu32,+kvm_pv_unhalt -m 214 -smp 6 -nographic -monitor \ +unix:/tmp/test-monitor,server,nowait -boot n -usb -net none -serial \ +none -parallel none diff --git a/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.xml b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.xml new file mode 100644 index 0000000000..ac8781b558 --- /dev/null +++ b/tests/qemuxml2argvdata/qemuxml2argv-pv-spinlock-enabled.xml @@ -0,0 +1,26 @@ + + QEMUGuest1 + c7a5fdbd-edaf-9455-926a-d65c16db1809 + 219100 + 219100 + 6 + + hvm + + + + + + + + + destroy + restart + destroy + + /usr/bin/qemu + + + + + diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index a74ac2a597..0629e310ef 100644 --- a/tests/qemuxml2argvtest.c +++ b/tests/qemuxml2argvtest.c @@ -448,6 +448,8 @@ mymain(void) QEMU_CAPS_CHARDEV_SPICEVMC, QEMU_CAPS_SPICE, QEMU_CAPS_HDA_DUPLEX); DO_TEST("eoi-disabled", NONE); DO_TEST("eoi-enabled", NONE); + DO_TEST("pv-spinlock-disabled", NONE); + DO_TEST("pv-spinlock-enabled", NONE); DO_TEST("kvmclock+eoi-disabled", QEMU_CAPS_ENABLE_KVM); DO_TEST("hyperv", NONE); diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c index 4e308b406b..ffff3b5569 100644 --- a/tests/qemuxml2xmltest.c +++ b/tests/qemuxml2xmltest.c @@ -159,6 +159,8 @@ mymain(void) DO_TEST("cpu-eoi-enabled"); DO_TEST("eoi-disabled"); DO_TEST("eoi-enabled"); + DO_TEST("pv-spinlock-disabled"); + DO_TEST("pv-spinlock-enabled"); DO_TEST("hyperv"); DO_TEST("hyperv-off");