Re: [libvirt] [Qemu-devel] [RFC] introduce a general query-config cmd

On Wed, Jan 23, 2013 at 06:41:44PM +0800, Amos Kong wrote: > On Tue, Jan 22, 2013 at 12:26:03PM -0600, Anthony Liguori wrote: > > Eric Blake <eblake(a)redhat.com&gt; writes: > > > On 01/22/2013 08:52 AM, Amos Kong wrote: > > >>>> > > >>>> Libvirt will need to expose an attribute that lets the user control > > >>>> whether to use this new option; how do we probe via QMP whether the > > >>>> new > > >>>> -boot strict=on command-line option is available? > > >>> > > >>> Hi all, > > >>> > > >>> How about add new info/query command? > > >>> > > >>> (hmp) info strict-boot > > >>> on > > >>> > > >>> (qmp) {"execute": "query-strict-boot"} > > >>> {"return": {"state": true}} > > >> > > >> It might be not a good solution, I already updated qemu-options.hx, > > >> we can check help message to know if this new option is added or not. > > > > > > Having libvirt probe the -help output is out of the question. We > > > already declared that for qemu 1.3 and beyond, ALL command line behavior > > > must ALSO be probe-able via QMP. I think Anthony had a trick for > > > testing for existence of various command line options without needing to > > > add a new query-strict-boot command, but I don't remember what that > > > trick was. > > > > We need a generic query-config-schema command. > > > Hi all, > > The config info is included in qemu-options.def, current > help() defines QEMU_OPTIONS_GENERATE_HELP, and includes > qemu-options-wrapper.h, DEF macro will output the help > message of options to the stdio. > > I tried to add two branches in qemu-options-wrapper.h, which > are used to generate two string arraies (one for option name, > one for help message) > > Thy help message is too long, it's failed to output all message to > hmp monitor, always got a segfault, the max limitation maybe reached. > It's more clear to only output help message of one option, > > eg: {"execute": "query-config", "arguments" : {"name": "boot"}} > > {"return": {"config": "-boot [order=drives][,once=drives][,menu=on|off]\n > [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n > 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n > 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n > 'sp_time': the period that splash picture last if menu=on, unit is ms\n > 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n"}} > > But info command of hmp doesn't support parameter > (eg: (hmp) info config boot) Hi Anthony, As we talked in IRC, you will send a patch to resolve the query issue. Can you post patch out when you have time? I will review it.

Thanks, Amos > Q1) Is my patch ok for resolve the issue in last email (libvirt can check > the help message of each option)? > > Q2) Can we only added a command for qmp monitor? > > Q3) Is it ok to output all help message for hmp (info config)? > > Q4) query-config or query-config-schema ? > > > diff --git a/hmp-commands.hx b/hmp-commands.hx > index 010b8c9..13d1840 100644 > --- a/hmp-commands.hx > +++ b/hmp-commands.hx > @@ -1552,6 +1552,8 @@ show the vnc server status > show the current VM name > @item info uuid > show the current VM UUID > +@item info config > +show config > @item info cpustats > show CPU statistics > @item info usernet > diff --git a/hmp.c b/hmp.c > index 9e9e624..c0d84d1 100644 > --- a/hmp.c > +++ b/hmp.c > @@ -98,6 +98,17 @@ void hmp_info_uuid(Monitor *mon) > qapi_free_UuidInfo(info); > } > > +void hmp_info_config(Monitor *mon) > +{ > + ConfigInfo *info; > + > + /* Fixed ME: hmp info command doesn't support parameter */ > + > + info = qmp_query_config("boot", NULL); > + monitor_printf(mon, "%s\n", info->config); > + qapi_free_ConfigInfo(info); > +} > + > void hmp_info_chardev(Monitor *mon) > { > ChardevInfoList *char_info, *info; > diff --git a/hmp.h b/hmp.h > index 21f3e05..f217a8c 100644 > --- a/hmp.h > +++ b/hmp.h > @@ -23,6 +23,7 @@ void hmp_info_version(Monitor *mon); > void hmp_info_kvm(Monitor *mon); > void hmp_info_status(Monitor *mon); > void hmp_info_uuid(Monitor *mon); > +void hmp_info_config(Monitor *mon); > void hmp_info_chardev(Monitor *mon); > void hmp_info_mice(Monitor *mon); > void hmp_info_migrate(Monitor *mon); > diff --git a/monitor.c b/monitor.c > index 9cf419b..6f331fa 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -2661,6 +2661,13 @@ static mon_cmd_t info_cmds[] = { > .help = "show the current VM UUID", > .mhandler.info = hmp_info_uuid, > }, > + { > + .name = "config", > + .args_type = "", > + .params = "", > + .help = "show the config", > + .mhandler.info = hmp_info_config, > + }, > #if defined(TARGET_PPC) > { > .name = "cpustats", > diff --git a/qapi-schema.json b/qapi-schema.json > index 5dfa052..8c46d57 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -3017,3 +3017,23 @@ > # Since: 1.3.0 > ## > { 'command': 'nbd-server-stop' } > + > +## > +# @ConfigInfo: > +# > +# Commandline configration information. > +# > +## > +{ 'type': 'ConfigInfo', 'data': {'config': 'str'} } > + > +## > +# @query-config > +# > +# Query configuration information of one option > +# > +# @name: option name > +# > +# Returns: configuration information. > +# > +## > +{'command': 'query-config', 'data': {'name': 'str'}, 'returns': 'ConfigInfo'} > diff --git a/qemu-options-wrapper.h b/qemu-options-wrapper.h > index 13bfea0..97b44fb 100644 > --- a/qemu-options-wrapper.h > +++ b/qemu-options-wrapper.h > @@ -18,6 +18,22 @@ > > #define DEFHEADING(text) ARCHHEADING(text, QEMU_ARCH_ALL) > > +#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) > + > #elif defined(QEMU_OPTIONS_GENERATE_OPTIONS) > > #define DEF(option, opt_arg, opt_enum, opt_help, arch_mask) \ > diff --git a/qmp-commands.hx b/qmp-commands.hx > index 5c692d0..ed42525 100644 > --- a/qmp-commands.hx > +++ b/qmp-commands.hx > @@ -2339,7 +2339,30 @@ EQMP > .args_type = "", > .mhandler.cmd_new = qmp_marshal_input_query_uuid, > }, > +SQMP > +query-config > +------------ > + > +Show config. > + > +- "Config": config > + > +Example: > +-> {"execute": "query-config", "arguments" : {"name": "boot"}} > +<- {"return": {"config": "-boot [order=drives][,once=drives][,menu=on|off]\n > + [,splash=sp_name][,splash-time=sp_time][,reboot-timeout=rb_time][,strict=on|off]\n > + 'drives': floppy (a), hard disk (c), CD-ROM (d), network (n)\n > + 'sp_name': the file's name that would be passed to bios as logo picture, if menu=on\n > + 'sp_time': the period that splash picture last if menu=on, unit is ms\n > + 'rb_timeout': the timeout before guest reboot when boot failed, unit is ms\n"}} > + > +EQMP > > + { > + .name = "query-config", > + .args_type = "name:s", > + .mhandler.cmd_new = qmp_marshal_input_query_config, > + }, > SQMP > query-migrate > ------------- > diff --git a/qmp.c b/qmp.c > index 55b056b..6a3a13a 100644 > --- a/qmp.c > +++ b/qmp.c > @@ -24,6 +24,7 @@ > #include "hw/qdev.h" > #include "sysemu/blockdev.h" > #include "qom/qom-qobject.h" > +#include "qemu-options.h" > > NameInfo *qmp_query_name(Error **errp) > { > @@ -78,6 +79,31 @@ UuidInfo *qmp_query_uuid(Error **errp) > return info; > } > > +ConfigInfo *qmp_query_config(const char *name, Error **errp) > +{ > + ConfigInfo *info = g_malloc0(sizeof(*info)); > + > + 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" > + }; > + > + int i; > + for (i=0; i < sizeof(optionstr) / sizeof(char *); i++) { > + if (!strcmp(name, optionstr[i])) { > + info->config = g_strdup(configstr[i]); > + break; > + } > + } > + > + return info; > +} > + > void qmp_quit(Error **err) > { > no_shutdown = 0;