[libvirt] [PATCHv4 1/3] Support clock=variable relative to localtime

Philipp Hahn hahn at univention.de
Mon Feb 6 13:59:16 UTC 2012


Since Xen 3.1 the clock=variable semantic is supported. In addition to
qemu/kvm Xen also knows about a variant where the offset is relative to
'localtime' instead of 'utc'.

Extends the libvirt structure with a flag 'basis' to specify, if the
offset is relative to 'localtime' or 'utc'.

Extends the libvirt structure with a flag 'reset' to force the reset
behaviour of 'localtime' and 'utc'; this is needed for backward
compatibility with previous versions of libvirt, since they report
incorrect XML.

Adapt the only user 'qemu' to the new name.
Extend the RelaxNG schema accordingly.
Document the new 'basis' attribute in the HTML documentation.
Adapt test for the new attribute.

Signed-off-by: Philipp Hahn <hahn at univention.de>
---
 docs/formatdomain.html.in                          |   18 +++++-
 docs/schemas/domaincommon.rng                      |   30 ++++++++--
 src/conf/domain_conf.c                             |   61 ++++++++++++++++++-
 src/conf/domain_conf.h                             |   17 +++++-
 src/libvirt_private.syms                           |    1 +
 src/qemu/qemu_command.c                            |    8 ++-
 src/qemu/qemu_process.c                            |    2 +-
 .../qemuxml2argv-clock-variable.xml                |    2 +-
 8 files changed, 121 insertions(+), 18 deletions(-)

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 5305f82..b2104cb 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -920,11 +920,20 @@
           <dt><code>utc</code></dt>
           <dd>
             The guest clock will always be synchronized to UTC when
-            booted</dd>
+            booted.
+            <span class="since">Since 0.9.11</span> 'utc' mode can be converted
+            to 'variable' mode, which can be controlled by using the
+            <code>adjustment</code> attribute. If the value is 'reset', the
+            conversion is never done and an error is returned. A numeric value
+            forces the conversion to 'variable' mode using the value as the
+            initial adjustment. The default is hypervisor specific.
+          </dd>
           <dt><code>localtime</code></dt>
           <dd>
             The guest clock will be synchronized to the host's configured
             timezone when booted, if any.
+            <span class="since">Since 0.9.11</span> <code>adjustment</code>
+            attribute (see 'utc' mode).
           </dd>
           <dt><code>timezone</code></dt>
           <dd>
@@ -935,12 +944,15 @@
           <dt><code>variable</code></dt>
           <dd>
             The guest clock will have an arbitrary offset applied
-            relative to UTC. The delta relative to UTC is specified
+            relative to UTC or localtime, depending on the <code>basis</code>
+            attribute. The delta relative to UTC (or localtime) is specified
             in seconds, using the <code>adjustment</code> attribute.
             The guest is free to adjust the RTC over time and expect
             that it will be honoured at next reboot. This is in
-            contrast to 'utc' mode, where the RTC adjustments are
+            contrast to 'utc' and 'localtime' mode, where the RTC adjustments are
             lost at each reboot. <span class="since">Since 0.7.7</span>
+            <span class="since">Since 0.9.11</span> the <code>basis</code>
+            attribute can be either 'utc' (default) or 'localtime'.
           </dd>
         </dl>
         <p>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index e276a92..35d048f 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -557,12 +557,22 @@
     <optional>
       <element name="clock">
         <choice>
-          <attribute name="offset">
-            <value>localtime</value>
-          </attribute>
-          <attribute name="offset">
-            <value>utc</value>
-          </attribute>
+          <group>
+            <attribute name="offset">
+              <choice>
+                <value>localtime</value>
+                <value>utc</value>
+              </choice>
+            </attribute>
+            <optional>
+              <attribute name='adjustment'>
+                <choice>
+                  <ref name='timeDelta'/>
+                  <value>reset</value>
+                </choice>
+              </attribute>
+            </optional>
+          </group>
           <group>
             <attribute name="offset">
               <value>timezone</value>
@@ -582,6 +592,14 @@
                 <ref name="timeDelta"/>
               </attribute>
             </optional>
+            <optional>
+              <attribute name="basis">
+                <choice>
+                  <value>utc</value>
+                  <value>localtime</value>
+                </choice>
+              </attribute>
+            </optional>
           </group>
         </choice>
         <zeroOrMore>
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index f8d0a4c..b34e148 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -573,6 +573,10 @@ VIR_ENUM_IMPL(virDomainClockOffset, VIR_DOMAIN_CLOCK_OFFSET_LAST,
               "variable",
               "timezone");
 
+VIR_ENUM_IMPL(virDomainClockBasis, VIR_DOMAIN_CLOCK_BASIS_LAST,
+              "utc",
+              "localtime");
+
 VIR_ENUM_IMPL(virDomainTimerName, VIR_DOMAIN_TIMER_NAME_LAST,
               "platform",
               "pit",
@@ -7503,10 +7507,53 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         def->clock.offset = VIR_DOMAIN_CLOCK_OFFSET_UTC;
     }
     switch (def->clock.offset) {
+    case VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME:
+    case VIR_DOMAIN_CLOCK_OFFSET_UTC:
+        tmp = virXPathString("string(./clock/@adjustment)", ctxt);
+        if (tmp) {
+            if (STREQ(tmp, "reset")) {
+                def->clock.data.utc_reset = true;
+            } else {
+                char *conv = NULL;
+                unsigned long long val;
+                val = strtoll(tmp, &conv, 10);
+                if (conv == tmp || *conv != '\0') {
+                    virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                                         _("unknown clock adjustment '%s'"), tmp);
+                    goto error;
+                }
+                switch (def->clock.offset) {
+                case VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME:
+                    def->clock.data.variable.basis = VIR_DOMAIN_CLOCK_BASIS_LOCALTIME;
+                    break;
+                case VIR_DOMAIN_CLOCK_OFFSET_UTC:
+                    def->clock.data.variable.basis = VIR_DOMAIN_CLOCK_BASIS_UTC;
+                    break;
+                }
+                def->clock.offset = VIR_DOMAIN_CLOCK_OFFSET_VARIABLE;
+                def->clock.data.variable.adjustment = val;
+            }
+            VIR_FREE(tmp);
+        } else {
+            def->clock.data.utc_reset = false;
+        }
+        break;
+
     case VIR_DOMAIN_CLOCK_OFFSET_VARIABLE:
         if (virXPathLongLong("number(./clock/@adjustment)", ctxt,
-                             &def->clock.data.adjustment) < 0)
-            def->clock.data.adjustment = 0;
+                             &def->clock.data.variable.adjustment) < 0)
+            def->clock.data.variable.adjustment = 0;
+        tmp = virXPathString("string(./clock/@basis)", ctxt);
+        if (tmp) {
+            if ((def->clock.data.variable.basis = virDomainClockBasisTypeFromString(tmp)) < 0) {
+                virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                                     _("unknown clock basis '%s'"), tmp);
+                goto error;
+            }
+            VIR_FREE(tmp);
+        } else {
+            def->clock.data.variable.basis = VIR_DOMAIN_CLOCK_BASIS_UTC;
+        }
         break;
 
     case VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE:
@@ -11830,9 +11877,15 @@ virDomainDefFormatInternal(virDomainDefPtr def,
     virBufferAsprintf(buf, "  <clock offset='%s'",
                       virDomainClockOffsetTypeToString(def->clock.offset));
     switch (def->clock.offset) {
+    case VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME:
+    case VIR_DOMAIN_CLOCK_OFFSET_UTC:
+        if (def->clock.data.utc_reset)
+            virBufferAddLit(buf, " adjustment='reset'");
+        break;
     case VIR_DOMAIN_CLOCK_OFFSET_VARIABLE:
-        virBufferAsprintf(buf, " adjustment='%lld'",
-                          def->clock.data.adjustment);
+        virBufferAsprintf(buf, " adjustment='%lld' basis='%s'",
+                          def->clock.data.variable.adjustment,
+                          virDomainClockBasisTypeToString(def->clock.data.variable.basis));
         break;
     case VIR_DOMAIN_CLOCK_OFFSET_TIMEZONE:
         virBufferEscapeString(buf, " timezone='%s'", def->clock.data.timezone);
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 59aff0d..e77b7f7 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1366,15 +1366,27 @@ enum virDomainClockOffsetType {
     VIR_DOMAIN_CLOCK_OFFSET_LAST,
 };
 
+enum virDomainClockBasis {
+    VIR_DOMAIN_CLOCK_BASIS_UTC = 0,
+    VIR_DOMAIN_CLOCK_BASIS_LOCALTIME = 1,
+
+    VIR_DOMAIN_CLOCK_BASIS_LAST,
+};
+
 typedef struct _virDomainClockDef virDomainClockDef;
 typedef virDomainClockDef *virDomainClockDefPtr;
 struct _virDomainClockDef {
     int offset;
 
     union {
-        /* Adjustment in seconds, relative to UTC, when
+        /* Bug-compatibility-mode for Xen utc|localtime */
+        int utc_reset;
+        /* Adjustment in seconds, relative to UTC or LOCALTIME, when
          * offset == VIR_DOMAIN_CLOCK_OFFSET_VARIABLE */
-        long long adjustment;
+        struct {
+            long long adjustment;
+            int basis;
+        } variable;
 
         /* Timezone name, when
          * offset == VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME */
@@ -2069,6 +2081,7 @@ int virDomainStateReasonFromString(virDomainState state, const char *reason);
 
 VIR_ENUM_DECL(virDomainSeclabel)
 VIR_ENUM_DECL(virDomainClockOffset)
+VIR_ENUM_DECL(virDomainClockBasis)
 
 VIR_ENUM_DECL(virDomainTimerName)
 VIR_ENUM_DECL(virDomainTimerTrack)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 0c22dec..d36da53 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -258,6 +258,7 @@ virDomainChrTcpProtocolTypeFromString;
 virDomainChrTcpProtocolTypeToString;
 virDomainChrTypeFromString;
 virDomainChrTypeToString;
+virDomainClockBasisTypeToString;
 virDomainClockOffsetTypeFromString;
 virDomainClockOffsetTypeToString;
 virDomainConfigFile;
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 99d7129..43f5614 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -3411,7 +3411,13 @@ qemuBuildClockArgStr(virDomainClockDefPtr def)
         time_t now = time(NULL);
         struct tm nowbits;
 
-        now += def->data.adjustment;
+        if (def->data.variable.basis != VIR_DOMAIN_CLOCK_BASIS_UTC) {
+            qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                            _("unsupported clock basis '%s'"),
+                            virDomainClockBasisTypeToString(def->data.variable.basis));
+            goto error;
+        }
+        now += def->data.variable.adjustment;
         gmtime_r(&now, &nowbits);
 
         virBufferAsprintf(&buf, "base=%d-%02d-%02dT%02d:%02d:%02d",
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 2d92d66..2f6f068 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -734,7 +734,7 @@ qemuProcessHandleRTCChange(qemuMonitorPtr mon ATTRIBUTE_UNUSED,
     event = virDomainEventRTCChangeNewFromObj(vm, offset);
 
     if (vm->def->clock.offset == VIR_DOMAIN_CLOCK_OFFSET_VARIABLE)
-        vm->def->clock.data.adjustment = offset;
+        vm->def->clock.data.variable.adjustment = offset;
 
     if (virDomainSaveStatus(driver->caps, driver->stateDir, vm) < 0)
         VIR_WARN("unable to save domain status with RTC change");
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml b/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
index eea6ce4..6a70a92 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-clock-variable.xml
@@ -8,7 +8,7 @@
     <type arch='i686' machine='pc'>hvm</type>
     <boot dev='hd'/>
   </os>
-  <clock offset='variable' adjustment='123456'/>
+  <clock offset='variable' adjustment='123456' basis='utc'/>
   <on_poweroff>destroy</on_poweroff>
   <on_reboot>restart</on_reboot>
   <on_crash>destroy</on_crash>
-- 
1.7.1




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