Re: [Qemu-devel] [resend] fix/re-do query-command-line-options

[Amos Kong <akong@redhat.com>]

Hi QEMU/Libvirt list,

When I worked on query-command-line-options, I first used some marcos [1] to
generate two config & option tables. This will cover all the options,
but it returns a string, it's difficult for libvirt to parse and use
it.

| {"execute": "query-config", "arguments" : {"name": "boot"}}
| {"return": {"config": "-boot [order=drives][,once=drives][,menu=on|off]\n
|   ....
|   'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n"}}


Finally I got a suggestion to read info from new interface (QemuOpts),
We add opts info to vm_config_groups[], query-command-line-options
will visit the array. It doesn't conver all the options, but the
latest options are covered, so this implementation is acceptable.

Problem:
* QemuOpts was designed just for options _have parameter_, some new option
  without parameters is lost in query output (eg: -enable-fips)
* block drive uses three QemuOpts, it's legacy issue. it's fixed by 968854c8.
* QemuOpts of some options aren't updated, it might be difficult to
  updated when we add some new parameters
* other

We discussed to reimplement this command, but it seems DEF maroc is the
only point to cover all the options, all the options are described in
qemu-options.hx

I'm considering to reuse the DEF marocs to generate a table, try to
return the crude info if QemuOpts doesn't cover it.
Or maintain a split array (like vm_config_groups[]), it only contains
the option without parameter (option name & help info).

If you touched some problem of the query-command-line-options, welcome
to reply it, I will try to satisfy your requests.


Thanks, Amos

[1] http://www.redhat.com/archives/libvir-list/2013-January/msg01656.html


|#elif defined(QEMU_OPTIONS_GENERATE_CONFIG)
|
|#define DEF(option, opt_arg, opt_enum, opt_help, arch_mask)    \
|      opt_help,
|
|#define DEFHEADING(text)
|#define ARCHHEADING(text, arch_mask)
|
|#elif defined(QEMU_OPTIONS_GENERATE_NAME)
|
|#define DEF(option, opt_arg, opt_enum, opt_help, arch_mask)    \
|      option,
|
|#define DEFHEADING(text)
|#define ARCHHEADING(text, arch_mask)

    char const *optionstr[] = {
#define QEMU_OPTIONS_GENERATE_NAME
#include "qemu-options-wrapper.h"
    };

    char const *configstr[] = {
#define QEMU_OPTIONS_GENERATE_CONFIG
#include "qemu-options-wrapper.h"
    };