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docs/devel/writing-qmp-commands: Update for modular QAPI

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With modular code generation, putting stuff right into
qapi-schema.json is a bad idea.  Update writing-qmp-commands.txt
accordingly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-26-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This commit is contained in:
Markus Armbruster 2018-02-11 10:36:03 +01:00 committed by Eric Blake
parent 112ed241f5
commit bfe873e988
1 changed files with 7 additions and 7 deletions
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14
docs/devel/writing-qmp-commands.txt
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@ -15,8 +15,8 @@ start with docs/interop/qmp-intro.txt.
Generally speaking, the following steps should be taken in order to write a Generally speaking, the following steps should be taken in order to write a
new QMP command. new QMP command.
1. Write the command's and type(s) specification in the QAPI schema file 1. Define the command and any types it needs in the appropriate QAPI
(qapi-schema.json in the root source directory) schema module.
2. Write the QMP command itself, which is a regular C function. Preferably, 2. Write the QMP command itself, which is a regular C function. Preferably,
the command should be exported by some QEMU subsystem. But it can also be the command should be exported by some QEMU subsystem. But it can also be
@ -88,8 +88,9 @@ command carries some meaningful action in QEMU but here it will just print
Our command will be called "hello-world". It takes no arguments, nor does it Our command will be called "hello-world". It takes no arguments, nor does it
return any data. return any data.
The first step is to add the following line to the bottom of the The first step is defining the command in the appropriate QAPI schema
qapi-schema.json file: module. We pick module qapi/misc.json, and add the following line at
the bottom:
{ 'command': 'hello-world' } { 'command': 'hello-world' }
@ -245,7 +246,7 @@ This is very important. No QMP command will be accepted in QEMU without proper
documentation. documentation.
There are many examples of such documentation in the schema file already, but There are many examples of such documentation in the schema file already, but
here goes "hello-world"'s new entry for the qapi-schema.json file: here goes "hello-world"'s new entry for qapi/misc.json:
## ##
# @hello-world # @hello-world
@ -425,8 +426,7 @@ There are a number of things to be noticed:
allocated by the implementation. This is so because the QAPI also generates allocated by the implementation. This is so because the QAPI also generates
a function to free its types and it cannot distinguish between dynamically a function to free its types and it cannot distinguish between dynamically
or statically allocated strings or statically allocated strings
6. You have to include the "qmp-commands.h" header file in qemu-timer.c, 6. You have to include "qapi/qmp-commands-misc.h" in qemu-timer.c
otherwise qemu won't build
Time to test the new command. Build qemu, run it as described in the "Testing" Time to test the new command. Build qemu, run it as described in the "Testing"
section and try this: section and try this: