10:08 a.m.
On 02/06/2012 06:59 AM, Philipp Hahn wrote:
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.
+++ b/docs/formatdomain.html.in
@@ -985,11 +985,20 @@
<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.
An error is not mandatory on 'reset' unless the hypervisor doesn't
support resetting the time back to utc on each reboot.
@@ -1000,12 +1009,15 @@
<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
As long as we're touching this, we can favor US spelling.
- 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'.
ACK, and I'm squashing the following tweak in:
diff --git i/docs/formatdomain.html.in w/docs/formatdomain.html.in
index 3ff9c28..a382d30 100644
--- i/docs/formatdomain.html.in
+++ w/docs/formatdomain.html.in
@@ -989,16 +989,19 @@
<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
+ conversion is never done (not all hypervisors can
+ synchronize to UTC on each boot; use of 'reset' will cause
+ an error on those hypervisors). A numeric value
forces the conversion to 'variable' mode using the value as the
- initial adjustment. The default is hypervisor specific.
+ initial adjustment. The default <code>adjustment</code> 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).
+ <span class="since">Since 0.9.11,</span> the
<code>adjustment</code>
+ attribute behaves the same as in 'utc' mode.
</dd>
<dt><code>timezone</code></dt>
<dd>
@@ -1013,8 +1016,9 @@
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' and 'localtime' mode, where the RTC
adjustments are
+ that it will be honored at next reboot. This is in
+ contrast to 'utc' and 'localtime' mode (with the optional
+ attribute adjustment='reset'), 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'.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org