Re: [libvirt] [PATCH 2/3] qemu: add hypervisor feature cpu-pm support for kvm

From: Wim ten Have <wim.ten.have(a)oracle.com&gt; QEMU introduced a CPU power management feature with commit 6f131f13e68d ("kvm: support -overcommit cpu-pm=on|off"). This patch series adds support for controlling QEMU's "-overcommit" command line switch: "-overcommit cpu-pm=[on|off]". By default "cpu-pm" is off. To turn the CPU power management feature on, the following XML needs to be added to the guest's domain description: <features> <kvm> <cpu-pm state='on'/> </kvm> </features> Note that the "cpu-pm" element is only available if the CPU mode is set to "host-passthrough": <cpu mode='host-passthrough ... /> Signed-off-by: Wim ten Have <wim.ten.have(a)oracle.com&gt; Signed-off-by: Menno Lageman <menno.lageman(a)oracle.com&gt; --- docs/formatdomain.html.in | 7 +++++++ docs/schemas/domaincommon.rng | 5 +++++ src/conf/domain_conf.c | 4 ++++ src/conf/domain_conf.h | 1 + src/libvirt_private.syms | 1 + src/qemu/qemu_command.c | 16 +++++++++++++++- src/qemu/qemu_domain.c | 25 ++++++++++++++++++------- 7 files changed, 51 insertions(+), 8 deletions(-) diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in index a18119f9a08e..7ea819ef6fb2 100644 --- a/docs/formatdomain.html.in +++ b/docs/formatdomain.html.in @@ -2045,6 +2045,7 @@ &lt;kvm&gt; &lt;hidden state='on'/&gt; &lt;hint-dedicated state='on'/&gt; + &lt;cpu-pm state='on'/&gt; &lt;/kvm&gt; &lt;pvspinlock state='on'/&gt; &lt;gic version='2'/&gt; @@ -2224,6 +2225,12 @@ <td>on, off</td> <td><span class="since">5.7.0 (QEMU 2.12.1)</span></td> </tr>

+ <tr> + <td>cpu-pm</td> + <td>Enable guest management of the host CPU's power state. Note that enabling this will increase latency for other processes running on the same host CPU.</td> + <td>on, off</td> + <td><span class="since">5.7.0 (QEMU 2.12.1)</span></td> + </tr> </table> </dd> <dt><code>pmu</code></dt> diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng index 08853f9d9e92..51c9e434aa35 100644 --- a/docs/schemas/domaincommon.rng +++ b/docs/schemas/domaincommon.rng @@ -5970,6 +5970,11 @@ <ref name="featurestate"/> </element> </optional> + <optional> + <element name="cpu-pm"> + <ref name="featurestate"/> + </element> + </optional> </interleave> </element> </define> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 8642927d6bf3..e348aa0bcb5f 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -203,6 +203,7 @@ VIR_ENUM_IMPL(virDomainKVM, VIR_DOMAIN_KVM_LAST, "hidden", "hint-dedicated", + "cpu-pm", ); VIR_ENUM_IMPL(virDomainMsrsUnknown, @@ -20412,6 +20413,7 @@ virDomainDefParseXML(xmlDocPtr xml, switch ((virDomainKVM) feature) { case VIR_DOMAIN_KVM_HIDDEN: case VIR_DOMAIN_KVM_DEDICATED: + case VIR_DOMAIN_KVM_CPU_PM: if (!(tmp = virXMLPropString(nodes[i], "state"))) { virReportError(VIR_ERR_XML_ERROR, _("missing 'state' attribute for " @@ -22625,6 +22627,7 @@ virDomainDefFeaturesCheckABIStability(virDomainDefPtr src, switch ((virDomainKVM) i) { case VIR_DOMAIN_KVM_HIDDEN: case VIR_DOMAIN_KVM_DEDICATED: + case VIR_DOMAIN_KVM_CPU_PM: if (src->kvm_features[i] != dst->kvm_features[i]) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("State of KVM feature '%s' differs: " @@ -28126,6 +28129,7 @@ virDomainDefFormatFeatures(virBufferPtr buf, switch ((virDomainKVM) j) { case VIR_DOMAIN_KVM_HIDDEN: case VIR_DOMAIN_KVM_DEDICATED: + case VIR_DOMAIN_KVM_CPU_PM: if (def->kvm_features[j]) virBufferAsprintf(&childBuf, "<%s state='%s'/>\n", virDomainKVMTypeToString(j), diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index f7423b1b6f89..b5a4cee46c1e 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1766,6 +1766,7 @@ typedef enum { typedef enum { VIR_DOMAIN_KVM_HIDDEN = 0, VIR_DOMAIN_KVM_DEDICATED, + VIR_DOMAIN_KVM_CPU_PM, VIR_DOMAIN_KVM_LAST } virDomainKVM; diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 9db4ac7933e5..67a3a14c9b36 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -446,6 +446,7 @@ virDomainIOThreadIDDel; virDomainIOThreadIDFind; virDomainKeyWrapCipherNameTypeFromString; virDomainKeyWrapCipherNameTypeToString; +virDomainKVMTypeToString; virDomainLeaseDefFree; virDomainLeaseIndex; virDomainLeaseInsert; diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 922456ec679e..163c98bc7d0f 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -7217,6 +7217,8 @@ qemuBuildCpuCommandLine(virCommandPtr cmd, virBufferAddLit(&buf, ",kvm-hint-dedicated=on"); break; + /* Not a -cpu option */ + case VIR_DOMAIN_KVM_CPU_PM: /* coverity[dead_error_begin] */ case VIR_DOMAIN_KVM_LAST: break; @@ -7852,8 +7854,20 @@ qemuBuildOvercommitCommandLine(virCommandPtr cmd, virQEMUCapsPtr qemuCaps) { if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_OVERCOMMIT)) { + virBuffer buf = VIR_BUFFER_INITIALIZER; + char *overcommit; + + virBufferAsprintf(&buf, "mem-lock=%s", def->mem.locked ? "on" : "off"); + + if (def->features[VIR_DOMAIN_FEATURE_KVM] == VIR_TRISTATE_SWITCH_ON) + virBufferAsprintf(&buf, ",cpu-pm=%s", + def->kvm_features[VIR_DOMAIN_KVM_CPU_PM] == VIR_TRISTATE_SWITCH_ON ? "on" : "off");

+ + overcommit = virBufferContentAndReset(&buf); virCommandAddArg(cmd, "-overcommit"); - virCommandAddArgFormat(cmd, "mem-lock=%s", def->mem.locked ? "on" : "off"); + virCommandAddArgFormat(cmd, "%s", overcommit);

+ + VIR_FREE(overcommit); } return 0; } diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index a06672333cf7..5571f52fec47 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -4442,7 +4442,7 @@ static int qemuDomainDefValidateFeatures(const virDomainDef *def, virQEMUCapsPtr qemuCaps) { - size_t i; + size_t i, j; for (i = 0; i < VIR_DOMAIN_FEATURE_LAST; i++) { const char *featureName = virDomainFeatureTypeToString(i); @@ -4499,12 +4499,23 @@ qemuDomainDefValidateFeatures(const virDomainDef *def, break; case VIR_DOMAIN_FEATURE_KVM: - if (def->kvm_features[VIR_DOMAIN_KVM_DEDICATED] == VIR_TRISTATE_SWITCH_ON && - (!def->cpu || def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", - _("kvm-hint-dedicated=on is only applicable " - "for cpu host-passthrough")); - return -1; + for (j = 0; j < VIR_DOMAIN_KVM_LAST; j++) { + switch ((virDomainKVM) j) { + case VIR_DOMAIN_KVM_DEDICATED: + case VIR_DOMAIN_KVM_CPU_PM: + if (def->kvm_features[j] == VIR_TRISTATE_SWITCH_ON && + (!def->cpu || def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("%s=on is only applicable for cpu host-passthrough"), + virDomainKVMTypeToString(j)); + return -1; + }

+ break; + + case VIR_DOMAIN_KVM_HIDDEN: + case VIR_DOMAIN_KVM_LAST: + break; + } } break; -- 2.21.0 -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list