Re: [PATCH v2 08/20] qemu-storage-daemon: Add --object option

[Coiby Xu]

Hi Kevin,

I tried to start vhost-user block device backend server with the
following command,
  $ qemu-storage-daemon --blockdev 
driver=file,node-name=disk,filename=file.img,read-only=off \
                  --object 
vhost-user-blk-server,id=disk,unix-socket=/tmp/vu_blk.socket,node-name=disk,writable=off

but the following error occurred,

  qemu-storage-daemon: Invalid parameter type for 'writable', expected: boolean

I notice qmp_object_add is used. Should we use user_creatable_add_opts
instead?

diff --git a/qemu-storage-daemon.c b/qemu-storage-daemon.c
index dd128978cc..9d21aaaf54 100644
--- a/qemu-storage-daemon.c
+++ b/qemu-storage-daemon.c
@@ -277,8 +277,6 @@ static void process_options(int argc, char *argv[])
             {
                 QemuOpts *opts;
                 const char *type;
-                QDict *args;
-                QObject *ret_data = NULL;

                 /* FIXME The keyval parser rejects 'help' arguments, so we must
                  * unconditionall try QemuOpts first. */
@@ -288,12 +286,11 @@ static void process_options(int argc, char *argv[])
                 if (type && user_creatable_print_help(type, opts)) {
                     exit(EXIT_SUCCESS);
                 }
+
+
+                user_creatable_add_opts(opts, &error_fatal);
                 qemu_opts_del(opts);

-                args = keyval_parse(optarg, "qom-type", &error_fatal);
-                qmp_object_add(args, &ret_data, &error_fatal);
-                qobject_unref(args);
-                qobject_unref(ret_data);
                 break;
             }
         default:

On Mon, Feb 24, 2020 at 03:29:56PM +0100, Kevin Wolf wrote:
> Add a command line option to create user-creatable QOM objects.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
> qemu-storage-daemon.c | 47 +++++++++++++++++++++++++++++++++++++++++++
> Makefile.objs         |  2 +-
> qom/Makefile.objs     |  1 +
> 3 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/qemu-storage-daemon.c b/qemu-storage-daemon.c
> index c30caaf59e..0cd8144c81 100644
> --- a/qemu-storage-daemon.c
> +++ b/qemu-storage-daemon.c
> @@ -33,15 +33,19 @@
> #include "qapi/error.h"
> #include "qapi/qapi-visit-block-core.h"
> #include "qapi/qapi-commands-block-core.h"
> +#include "qapi/qmp/qdict.h"
> #include "qapi/qobject-input-visitor.h"
>
> #include "qemu-common.h"
> #include "qemu-version.h"
> #include "qemu/config-file.h"
> #include "qemu/error-report.h"
> +#include "qemu/help_option.h"
> #include "qemu/log.h"
> #include "qemu/main-loop.h"
> #include "qemu/module.h"
> +#include "qemu/option.h"
> +#include "qom/object_interfaces.h"
>
> #include "trace/control.h"
>
> @@ -63,12 +67,31 @@ static void help(void)
> "             [,driver specific parameters...]\n"
> "                         configure a block backend\n"
> "\n"
> +"  --object help          list object types that can be added\n"
> +"  --object <type>,help   list properties for the given object type\n"
> +"  --object <type>[,<property>=<value>...]\n"
> +"                         create a new object of type <type>, setting\n"
> +"                         properties in the order they are specified. Note\n"
> +"                         that the 'id' property must be set.\n"
> +"                         See the qemu(1) man page for documentation of the\n"
> +"                         objects that can be added.\n"
> +"\n"
> QEMU_HELP_BOTTOM "\n",
>     error_get_progname());
> }
>
> enum {
>     OPTION_BLOCKDEV = 256,
> +    OPTION_OBJECT,
> +};
> +
> +static QemuOptsList qemu_object_opts = {
> +    .name = "object",
> +    .implied_opt_name = "qom-type",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_object_opts.head),
> +    .desc = {
> +        { }
> +    },
> };
>
> static void process_options(int argc, char *argv[])
> @@ -78,6 +101,7 @@ static void process_options(int argc, char *argv[])
>     static const struct option long_options[] = {
>         {"blockdev", required_argument, NULL, OPTION_BLOCKDEV},
>         {"help", no_argument, NULL, 'h'},
> +        {"object", required_argument, NULL, OPTION_OBJECT},
>         {"trace", required_argument, NULL, 'T'},
>         {"version", no_argument, NULL, 'V'},
>         {0, 0, 0, 0}
> @@ -121,6 +145,29 @@ static void process_options(int argc, char *argv[])
>                 qapi_free_BlockdevOptions(options);
>                 break;
>             }
> +        case OPTION_OBJECT:
> +            {
> +                QemuOpts *opts;
> +                const char *type;
> +                QDict *args;
> +                QObject *ret_data = NULL;
> +
> +                /* FIXME The keyval parser rejects 'help' arguments, so we must
> +                 * unconditionall try QemuOpts first. */
> +                opts = qemu_opts_parse(&qemu_object_opts,
> +                                       optarg, true, &error_fatal);
> +                type = qemu_opt_get(opts, "qom-type");
> +                if (type && user_creatable_print_help(type, opts)) {
> +                    exit(EXIT_SUCCESS);
> +                }
> +                qemu_opts_del(opts);
> +
> +                args = keyval_parse(optarg, "qom-type", &error_fatal);
> +                qmp_object_add(args, &ret_data, &error_fatal);
> +                qobject_unref(args);
> +                qobject_unref(ret_data);
> +                break;
> +            }
>         default:
>             g_assert_not_reached();
>         }
> diff --git a/Makefile.objs b/Makefile.objs
> index c7e1b36130..fa92b00427 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -31,7 +31,7 @@ endif # CONFIG_SOFTMMU or CONFIG_TOOLS
> # storage-daemon-obj-y is code used by qemu-storage-daemon (these objects are
> # used for system emulation, too, but specified separately there)
>
> -storage-daemon-obj-y = block/
> +storage-daemon-obj-y = block/ qom/
> storage-daemon-obj-y += blockdev.o iothread.o
>
> ######################################################################
> diff --git a/qom/Makefile.objs b/qom/Makefile.objs
> index f9d77350ac..1b45d104ba 100644
> --- a/qom/Makefile.objs
> +++ b/qom/Makefile.objs
> @@ -2,3 +2,4 @@ qom-obj-y = object.o container.o qom-qobject.o
> qom-obj-y += object_interfaces.o
>
> common-obj-$(CONFIG_SOFTMMU) += qom-hmp-cmds.o qom-qmp-cmds.o
> +storage-daemon-obj-y += qom-qmp-cmds.o
> --
> 2.20.1