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authorLuiz Capitulino <lcapitulino@redhat.com>2013-09-11 13:52:51 -0400
committerLuiz Capitulino <lcapitulino@redhat.com>2013-09-18 08:57:02 -0400
commit715c18600ca770a8ada65d9fd77ad6423ab5fce9 (patch)
treef1770616bae9403b3e27db93ff912492c50381df /docs/qmp
parent52bbff77c4d1c26b5d9f56e1f140523ec931c471 (diff)
QMP: Update qmp-spec.txt
Simplify the text, fix some of the examples. Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'docs/qmp')
-rw-r--r--docs/qmp/qmp-spec.txt65
1 files changed, 28 insertions, 37 deletions
diff --git a/docs/qmp/qmp-spec.txt b/docs/qmp/qmp-spec.txt
index a27789692b..22568c644e 100644
--- a/docs/qmp/qmp-spec.txt
+++ b/docs/qmp/qmp-spec.txt
@@ -1,21 +1,17 @@
- QEMU Monitor Protocol Specification - Version 0.1
+ QEMU Machine Protocol Specification
1. Introduction
===============
-This document specifies the QEMU Monitor Protocol (QMP), a JSON-based protocol
-which is available for applications to control QEMU at the machine-level.
-
-To enable QMP support, QEMU has to be run in "control mode". This is done by
-starting QEMU with the appropriate command-line options. Please, refer to the
-QEMU manual page for more information.
+This document specifies the QEMU Machine Protocol (QMP), a JSON-based protocol
+which is available for applications to operate QEMU at the machine-level.
2. Protocol Specification
=========================
This section details the protocol format. For the purpose of this document
-"Client" is any application which is communicating with QEMU in control mode,
-and "Server" is QEMU itself.
+"Client" is any application which is using QMP to communicate with QEMU and
+"Server" is QEMU itself.
JSON data structures, when mentioned in this document, are always in the
following format:
@@ -47,14 +43,14 @@ that the connection has been successfully established and that the Server is
ready for capabilities negotiation (for more information refer to section
'4. Capabilities Negotiation').
-The format is:
+The greeting message format is:
{ "QMP": { "version": json-object, "capabilities": json-array } }
Where,
- The "version" member contains the Server's version information (the format
- is the same of the 'query-version' command)
+ is the same of the query-version command)
- The "capabilities" member specify the availability of features beyond the
baseline specification
@@ -83,10 +79,7 @@ of a command execution: success or error.
2.4.1 success
-------------
-The success response is issued when the command execution has finished
-without errors.
-
-The format is:
+The format of a success response is:
{ "return": json-object, "id": json-value }
@@ -96,15 +89,12 @@ The format is:
in a per-command basis or an empty json-object if the command does not
return data
- The "id" member contains the transaction identification associated
- with the command execution (if issued by the Client)
+ with the command execution if issued by the Client
2.4.2 error
-----------
-The error response is issued when the command execution could not be
-completed because of an error condition.
-
-The format is:
+The format of an error response is:
{ "error": { "class": json-string, "desc": json-string }, "id": json-value }
@@ -114,7 +104,7 @@ The format is:
- The "desc" member is a human-readable error message. Clients should
not attempt to parse this message.
- The "id" member contains the transaction identification associated with
- the command execution (if issued by the Client)
+ the command execution if issued by the Client
NOTE: Some errors can occur before the Server is able to read the "id" member,
in these cases the "id" member will not be part of the error response, even
@@ -124,9 +114,9 @@ if provided by the client.
-----------------------
As a result of state changes, the Server may send messages unilaterally
-to the Client at any time. They are called 'asynchronous events'.
+to the Client at any time. They are called "asynchronous events".
-The format is:
+The format of asynchronous events is:
{ "event": json-string, "data": json-object,
"timestamp": { "seconds": json-number, "microseconds": json-number } }
@@ -147,36 +137,37 @@ qmp-events.txt file.
===============
This section provides some examples of real QMP usage, in all of them
-'C' stands for 'Client' and 'S' stands for 'Server'.
+"C" stands for "Client" and "S" stands for "Server".
3.1 Server greeting
-------------------
-S: {"QMP": {"version": {"qemu": "0.12.50", "package": ""}, "capabilities": []}}
+S: { "QMP": { "version": { "qemu": { "micro": 50, "minor": 6, "major": 1 },
+ "package": ""}, "capabilities": []}}
3.2 Simple 'stop' execution
---------------------------
C: { "execute": "stop" }
-S: {"return": {}}
+S: { "return": {} }
3.3 KVM information
-------------------
C: { "execute": "query-kvm", "id": "example" }
-S: {"return": {"enabled": true, "present": true}, "id": "example"}
+S: { "return": { "enabled": true, "present": true }, "id": "example"}
3.4 Parsing error
------------------
C: { "execute": }
-S: {"error": {"class": "GenericError", "desc": "Invalid JSON syntax" } }
+S: { "error": { "class": "GenericError", "desc": "Invalid JSON syntax" } }
3.5 Powerdown event
-------------------
-S: {"timestamp": {"seconds": 1258551470, "microseconds": 802384}, "event":
-"POWERDOWN"}
+S: { "timestamp": { "seconds": 1258551470, "microseconds": 802384 },
+ "event": "POWERDOWN" }
4. Capabilities Negotiation
----------------------------
@@ -184,17 +175,17 @@ S: {"timestamp": {"seconds": 1258551470, "microseconds": 802384}, "event":
When a Client successfully establishes a connection, the Server is in
Capabilities Negotiation mode.
-In this mode only the 'qmp_capabilities' command is allowed to run, all
-other commands will return the CommandNotFound error. Asynchronous messages
-are not delivered either.
+In this mode only the qmp_capabilities command is allowed to run, all
+other commands will return the CommandNotFound error. Asynchronous
+messages are not delivered either.
-Clients should use the 'qmp_capabilities' command to enable capabilities
+Clients should use the qmp_capabilities command to enable capabilities
advertised in the Server's greeting (section '2.2 Server Greeting') they
support.
-When the 'qmp_capabilities' command is issued, and if it does not return an
+When the qmp_capabilities command is issued, and if it does not return an
error, the Server enters in Command mode where capabilities changes take
-effect, all commands (except 'qmp_capabilities') are allowed and asynchronous
+effect, all commands (except qmp_capabilities) are allowed and asynchronous
messages are delivered.
5 Compatibility Considerations
@@ -245,7 +236,7 @@ arguments, errors, asynchronous events, and so forth.
Any new names downstream wishes to add must begin with '__'. To
ensure compatibility with other downstreams, it is strongly
-recommended that you prefix your downstram names with '__RFQDN_' where
+recommended that you prefix your downstream names with '__RFQDN_' where
RFQDN is a valid, reverse fully qualified domain name which you
control. For example, a qemu-kvm specific monitor command would be: