* formatdomain.html.in: Document new clock options
---
docs/formatdomain.html.in | 34 +++++++++++++++++++++++++++++++---
1 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index ce49f7d..e47a6b7 100644
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -393,9 +393,37 @@
<dl>
<dt><code>clock</code></dt>
- <dd>The <code>offset</code> attribute takes either
"utc" or
- "localtime" to specify how the guest clock is initialized
- in relation to the host OS.
+ <dd>
+ <p>The <code>offset</code> attribute takes three possible
+ values, allowing fine grained control over how the guest
+ clock is synchronized to the host. NB, not all hypervisors
+ support all modes.</p>
+ <dl>
+ <dt><code>utc</code></dt>
+ <dd>
+ The guest clock will always be synchronized to UTC when
+ booted</dd>
+ <dt><code>localtime</code></dt>
+ <dd>
+ The guest clock will be synchronized to the host's configured
+ timezone when booted. It is possible to override the timezone
+ by using the <code>timezone</code> attribute.
+ </dd>
+ <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
+ in seconds, using the <code>adjustment</code> attribute.
+ The guest is free to adjust the RTC over time an expect
+ that it will be honoured at next reboot. This is in
+ contrast to 'utc' mode, where the RTC adjustments are
+ lost at each reboot.
+ </dd>
+ </dl>
+ <p>
+ NB, at time of writing, only QEMU supports the variable
+ clock mode, or custom timezones.
+ </p>
</dd>
</dl>
--
1.6.6