[PATCH 2/3] docs, schema, conf: Add support for setting scheduler parameters of guest threads

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



In order for QEMU vCPU (and other) threads to run with RT scheduler,
libvirt needs to take care of that so QEMU doesn't have to run privileged.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1178986

Signed-off-by: Martin Kletzander <mkletzan@xxxxxxxxxx>
---
 docs/formatdomain.html.in                       |  13 +++
 docs/schemas/domaincommon.rng                   |  33 ++++++
 src/conf/domain_conf.c                          | 137 +++++++++++++++++++++++-
 src/conf/domain_conf.h                          |  24 +++++
 tests/qemuxml2argvdata/qemuxml2argv-cputune.xml |   4 +
 5 files changed, 210 insertions(+), 1 deletion(-)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index d8c31e0..60dad76 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -550,6 +550,8 @@
     &lt;quota&gt;-1&lt;/quota&gt;
     &lt;emulator_period&gt;1000000&lt;/emulator_period&gt;
     &lt;emulator_quota&gt;-1&lt;/emulator_quota&gt;
+    &lt;vcpusched scheduler='fifo' priority='1'/&gt;
+    &lt;iothreadsched scheduler='idle'/&gt;
   &lt;/cputune&gt;
   ...
 &lt;/domain&gt;
@@ -656,6 +658,17 @@
         <span class="since">Only QEMU driver support since 0.10.0</span>
       </dd>

+      <dt><code>vcpusched</code> and <code>iothreadsched</code></dt>
+      <dd>
+        The optional <code>vcpusched</code> element specifies the scheduler
+        (values <code>batch</code>, <code>idle</code>, <code>fifo</code>,
+        <code>rr</code> and <code>other</code>, which is default and ignored)
+        for all vCPU/IOThread threads.  For real-time schedulers
+        (<code>fifo</code>, <code>rr</code>), priority can be specified as
+        well. The value range for the priority depends on the host kernel.
+        <span class="since">Since 1.2.12</span>
+      </dd>
+
     </dl>


diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index d250e6f..6653737 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -815,10 +815,43 @@
             </attribute>
           </element>
         </zeroOrMore>
+        <zeroOrMore>
+          <element name="vcpusched">
+            <attribute name="vcpu">
+              <ref name="vcpuid"/>
+            </attribute>
+            <ref name="schedparam"/>
+          </element>
+        </zeroOrMore>
+        <zeroOrMore>
+          <element name="iothreadsched">
+            <attribute name="iothread">
+              <ref name="unsignedInt"/>
+            </attribute>
+            <ref name="schedparam"/>
+          </element>
+        </zeroOrMore>
       </interleave>
     </element>
   </define>

+  <define name="schedparam">
+    <attribute name="scheduler">
+      <choice>
+        <value>other</value>
+        <value>batch</value>
+        <value>idle</value>
+        <value>fifo</value>
+        <value>rr</value>
+      </choice>
+    </attribute>
+    <optional>
+      <attribute name="priority">
+        <ref name="unsignedShort"/>
+      </attribute>
+    </optional>
+  </define>
+
   <!-- All the NUMA related tunables would go in the numatune -->
   <define name="numatune">
     <element name="numatune">
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 96d80a9..16adbf1 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -795,6 +795,13 @@ VIR_ENUM_IMPL(virDomainLoader,
               "rom",
               "pflash")

+VIR_ENUM_IMPL(virDomainThreadSched, VIR_DOMAIN_THREAD_SCHED_LAST,
+              "other", /* default */
+              "batch",
+              "idle",
+              "fifo",
+              "rr")
+
 /* Internal mapping: subset of block job types that can be present in
  * <mirror> XML (remaining types are not two-phase). */
 VIR_ENUM_DECL(virDomainBlockJob)
@@ -2260,6 +2267,9 @@ void virDomainDefFree(virDomainDefPtr def)
     virDomainVcpuPinDefArrayFree(def->cputune.iothreadspin,
                                  def->cputune.niothreadspin);

+    VIR_FREE(def->cputune.vcpusched);
+    VIR_FREE(def->cputune.iothreadsched);
+
     virDomainNumatuneFree(def->numatune);

     virSysinfoDefFree(def->sysinfo);
@@ -12653,6 +12663,65 @@ virDomainLoaderDefParseXML(xmlNodePtr node,
     return ret;
 }

+static int
+virDomainThreadSchedParse(xmlNodePtr node,
+                          unsigned int maxid,
+                          const char *name,
+                          virDomainThreadSchedParamPtr sp)
+{
+    char *tmp = NULL;
+    int sched = 0;
+
+    tmp = virXMLPropString(node, name);
+    if (!tmp) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("invalid value for attribute %s"), name);
+        goto error;
+    }
+
+    if (virStrToLong_uip(tmp, NULL, 10, &sp->id) < 0 ||
+        sp->id >= maxid) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("vcpu must be positive integer smaller than "
+                         "maximum of vcpus, not '%s'"),
+                       tmp);
+        goto error;
+    }
+    VIR_FREE(tmp);
+
+    tmp = virXMLPropString(node, "scheduler");
+    if (tmp) {
+        if ((sched = virDomainThreadSchedTypeFromString(tmp)) < 0) {
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("invalid vcpu scheduler: '%s'"), tmp);
+            goto error;
+        }
+        sp->scheduler = sched;
+
+        VIR_FREE(tmp);
+        if (sp->scheduler >= VIR_DOMAIN_THREAD_SCHED_FIFO) {
+            tmp = virXMLPropString(node, "priority");
+            if (!tmp) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("missing scheduler priority"));
+                goto error;
+            }
+            if (virStrToLong_i(tmp, NULL, 10, &sp->priority) < 0) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("invalid value for element priority"));
+                goto error;
+            }
+            VIR_FREE(tmp);
+        }
+    }
+
+    return 0;
+
+ error:
+    VIR_FREE(tmp);
+    return -1;
+}
+
 static virDomainDefPtr
 virDomainDefParseXML(xmlDocPtr xml,
                      xmlNodePtr root,
@@ -13201,6 +13270,51 @@ virDomainDefParseXML(xmlDocPtr xml,
     }
     VIR_FREE(nodes);

+    if ((n = virXPathNodeSet("./cputune/vcpusched", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("cannot extract vcpusched nodes"));
+        goto error;
+    }
+    if (n) {
+        if (n > def->maxvcpus) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("too many vcpusched nodes in cputune"));
+            goto error;
+        }
+
+        if (VIR_ALLOC_N(def->cputune.vcpusched, n) < 0)
+            goto error;
+        def->cputune.nvcpusched = n;
+
+        for (i = 0; i < def->cputune.nvcpusched; i++) {
+            if (virDomainThreadSchedParse(nodes[i], def->maxvcpus, "vcpu",
+                                          &def->cputune.vcpusched[i]) < 0)
+                goto error;
+        }
+    }
+
+    if ((n = virXPathNodeSet("./cputune/iothreadsched", ctxt, &nodes)) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("cannot extract iothreadsched nodes"));
+        goto error;
+    }
+    if (n) {
+        if (n > def->iothreads) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("too many iothreadsched nodes in cputune"));
+            goto error;
+        }
+
+        if (VIR_ALLOC_N(def->cputune.iothreadsched, n) < 0)
+            goto error;
+        def->cputune.niothreadsched = n;
+
+        for (i = 0; i < def->cputune.niothreadsched; i++) {
+            if (virDomainThreadSchedParse(nodes[i], def->iothreads + 1, "iothread",
+                                          &def->cputune.iothreadsched[i]) < 0)
+                goto error;
+        }
+    }

     /* analysis of cpu handling */
     if ((node = virXPathNode("./cpu[1]", ctxt)) != NULL) {
@@ -19519,7 +19633,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
         def->cputune.period || def->cputune.quota ||
         def->cputune.emulatorpin ||
         def->cputune.emulator_period || def->cputune.emulator_quota ||
-        def->cputune.niothreadspin) {
+        def->cputune.niothreadspin ||
+        def->cputune.vcpusched || def->cputune.iothreadsched) {
         virBufferAddLit(buf, "<cputune>\n");
         cputune = true;
     }
@@ -19592,6 +19707,26 @@ virDomainDefFormatInternal(virDomainDefPtr def,
         VIR_FREE(cpumask);
     }

+    for (i = 0; i < def->cputune.nvcpusched; i++) {
+        virDomainThreadSchedParamPtr sp = &def->cputune.vcpusched[i];
+        virBufferAsprintf(buf, "<vcpusched vcpu='%d' scheduler='%s'",
+                          sp->id,
+                          virDomainThreadSchedTypeToString(sp->scheduler));
+        if (sp->priority)
+            virBufferAsprintf(buf, " priority='%d'", sp->priority);
+        virBufferAddLit(buf, "/>\n");
+    }
+
+    for (i = 0; i < def->cputune.niothreadsched; i++) {
+        virDomainThreadSchedParamPtr sp = &def->cputune.iothreadsched[i];
+        virBufferAsprintf(buf, "<iothreadsched iothread='%d' scheduler='%s'",
+                          sp->id,
+                          virDomainThreadSchedTypeToString(sp->scheduler));
+        if (sp->priority)
+            virBufferAsprintf(buf, " priority='%d'", sp->priority);
+        virBufferAddLit(buf, "/>\n");
+    }
+
     virBufferAdjustIndent(buf, -2);
     if (cputune)
         virBufferAddLit(buf, "</cputune>\n");
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 5cc42d1..636e2d1 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1815,6 +1815,24 @@ typedef enum {
     VIR_DOMAIN_CPU_PLACEMENT_MODE_LAST
 } virDomainCpuPlacementMode;

+typedef enum {
+    VIR_DOMAIN_THREAD_SCHED_OTHER = 0,
+    VIR_DOMAIN_THREAD_SCHED_BATCH,
+    VIR_DOMAIN_THREAD_SCHED_IDLE,
+    VIR_DOMAIN_THREAD_SCHED_FIFO,
+    VIR_DOMAIN_THREAD_SCHED_RR,
+
+    VIR_DOMAIN_THREAD_SCHED_LAST
+} virDomainThreadSched;
+
+typedef struct _virDomainThreadSchedParam virDomainThreadSchedParam;
+typedef virDomainThreadSchedParam *virDomainThreadSchedParamPtr;
+struct _virDomainThreadSchedParam {
+    unsigned int id;
+    virDomainThreadSched scheduler;
+    int priority;
+};
+
 typedef struct _virDomainTimerCatchupDef virDomainTimerCatchupDef;
 typedef virDomainTimerCatchupDef *virDomainTimerCatchupDefPtr;
 struct _virDomainTimerCatchupDef {
@@ -2002,6 +2020,11 @@ struct _virDomainCputune {
     virDomainVcpuPinDefPtr emulatorpin;
     size_t niothreadspin;
     virDomainVcpuPinDefPtr *iothreadspin;
+
+    size_t nvcpusched;
+    virDomainThreadSchedParamPtr vcpusched;
+    size_t niothreadsched;
+    virDomainThreadSchedParamPtr iothreadsched;
 };

 typedef struct _virDomainBlkiotune virDomainBlkiotune;
@@ -2807,6 +2830,7 @@ VIR_ENUM_DECL(virDomainRNGModel)
 VIR_ENUM_DECL(virDomainRNGBackend)
 VIR_ENUM_DECL(virDomainTPMModel)
 VIR_ENUM_DECL(virDomainTPMBackend)
+VIR_ENUM_DECL(virDomainThreadSched)
 /* from libvirt.h */
 VIR_ENUM_DECL(virDomainState)
 VIR_ENUM_DECL(virDomainNostateReason)
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-cputune.xml b/tests/qemuxml2argvdata/qemuxml2argv-cputune.xml
index 813d201..243092b 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-cputune.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-cputune.xml
@@ -4,6 +4,7 @@
   <memory unit='KiB'>219136</memory>
   <currentMemory unit='KiB'>219136</currentMemory>
   <vcpu placement='static'>2</vcpu>
+  <iothreads>1</iothreads>
   <cputune>
     <shares>2048</shares>
     <period>1000000</period>
@@ -11,6 +12,9 @@
     <vcpupin vcpu='0' cpuset='0'/>
     <vcpupin vcpu='1' cpuset='1'/>
     <emulatorpin cpuset='1'/>
+    <vcpusched vcpu='0' scheduler='fifo' priority='1'/>
+    <vcpusched vcpu='1' scheduler='batch'/>
+    <iothreadsched iothread='0' scheduler='idle'/>
   </cputune>
   <os>
     <type arch='i686' machine='pc'>hvm</type>
-- 
2.2.1

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list



[Index of Archives]     [Virt Tools]     [Libvirt Users]     [Lib OS Info]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [KDE Users]     [Fedora Tools]