The colo-compare option documentation has some formatting issues: it
uses a "@var{...}" syntax which is not used elsewhere and which is
rendered literally into the HTML documentation. The bare "@" sign
also results in an unintended 'mailto:' hyperlink.
Rewrite this into the style we seem to use most in the rest of
the command line options, where an option which takes an argument
is written as "my-option=<thing>".
We take the opportunity to make the documentation a little clearer
by splitting up the long paragraph and using preformatted-text
markup for the names of the suboptions.
Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Alex Bennée <[email protected]>
Reviewed-by: Zhang Chen <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-id: [email protected]
---
qemu-options.hx | 41 +++++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 16 deletions(-)
diff --git a/qemu-options.hx b/qemu-options.hx
index 862b6c7661..bd014a3244 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -5972,22 +5972,31 @@ SRST
stored. The file format is libpcap, so it can be analyzed with
tools such as tcpdump or Wireshark.
- ``-object
colo-compare,id=id,primary_in=chardevid,secondary_in=chardevid,outdev=chardevid,iothread=id[,vnet_hdr_support][,notify_dev=id][,compare_timeout=@var{ms}][,expired_scan_cycle=@var{ms}][,max_queue_size=@var{size}]``
- Colo-compare gets packet from primary\_in chardevid and
- secondary\_in, then compare whether the payload of primary packet
- and secondary packet are the same. If same, it will output
- primary packet to out\_dev, else it will notify COLO-framework to do
- checkpoint and send primary packet to out\_dev. In order to
- improve efficiency, we need to put the task of comparison in
- another iothread. If it has the vnet\_hdr\_support flag,
- colo compare will send/recv packet with vnet\_hdr\_len.
- The compare\_timeout=@var{ms} determines the maximum time of the
- colo-compare hold the packet. The expired\_scan\_cycle=@var{ms}
- is to set the period of scanning expired primary node network packets.
- The max\_queue\_size=@var{size} is to set the max compare queue
- size depend on user environment.
- If user want to use Xen COLO, need to add the notify\_dev to
- notify Xen colo-frame to do checkpoint.
+ ``-object
colo-compare,id=<id>,primary_in=<chardevid>,secondary_in=<chardevid>,outdev=<chardevid>,iothread=<id>[,vnet_hdr_support][,notify_dev=<id>][,compare_timeout=<time_ms>][,expired_scan_cycle=<time_ms>][,max_queue_size=<maxsize>]``
+ Colo-compare gets packets from the chardev backends specified by
+ ``primary_in`` and ``secondary_in``, and compares whether the payloads
+ of the primary packet and the secondary packet are the same.
+ If they match, it will output the primary packet to the chardev
+ backend specified by ``outdev``; otherwise it will notify
COLO-framework
+ to do a checkpoint and send the primary packet to ``outdev``.
+
+ In order to improve efficiency, we need to put the task of comparison
in
+ another iothread; the ``iothread`` option specifies that iothread
object
+ (which your commandline should create).
+
+ The ``vnet_hdr_support`` flag tells
+ colo compare to pass the vnet header length when it sends and receives
packets.
+
+ The ``compare_timeout`` option sets the maximum time that
+ colo-compare will hold the packet for, in ms.
+
+ The ``expired_scan_cycle`` option sets the period of scanning expired
+ primary node network packets, in ms.
+
+ The ``max_queue_size`` option sets the max compare queue size.
+
+ If you want to use Xen COLO, you need to specify ``notify_dev`` to
+ tell colo-compare how to notify Xen colo-frame to do a checkpoint.
COLO-compare must be used with the help of filter-mirror,
filter-redirector and filter-rewriter.
--
2.47.3
