Re: [Qemu-devel] [PATCH v3 2/3] qemu-help: Sort devices by logical functionality

[Michael S. Tsirkin]

On Mon, Jul 29, 2013 at 03:36:24PM +0300, Marcel Apfelbaum wrote:
> On Mon, 2013-07-29 at 15:28 +0300, Michael S. Tsirkin wrote:
> > On Mon, Jul 29, 2013 at 03:11:42PM +0300, Marcel Apfelbaum wrote:
> > > Categorize devices that appear as output to "-device ?" command
> > > by logical functionality. Sort the devices by logical categories
> > > before showing them to user.
> > > 
> > > The sort is done by functionality rather than alphabetical.
> > > 
> > > Signed-off-by: Marcel Apfelbaum <address@hidden>
> > > ---
> > > Changes from v2:
> > >     Addressed Michael Tsirkin's review:
> > >     - Explicit connection between the categories
> > >       and their names
> > >     - Refactoring of unsafe code
> > >     Addressed Paolo Bonzini's review
> > >     - Replaced Management category by USB 
> > > 
> > > Changes from v1:
> > >     Addressed Michael Tsirkin's review:
> > >     - Used bitmap operations on categories
> > >     - Moved category names into the header file
> > > 
> > > include/hw/qdev-core.h | 29 ++++++++++++++++++++++++++++
> > >  qdev-monitor.c         | 52 
> > > +++++++++++++++++++++++++++++++++++++++++---------
> > >  2 files changed, 72 insertions(+), 9 deletions(-)
> > > 
> > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> > > index e8b89b1..111ad06 100644
> > > --- a/include/hw/qdev-core.h
> > > +++ b/include/hw/qdev-core.h
> > > @@ -18,6 +18,34 @@ enum {
> > >  #define DEVICE_CLASS(klass) OBJECT_CLASS_CHECK(DeviceClass, (klass), 
> > > TYPE_DEVICE)
> > >  #define DEVICE_GET_CLASS(obj) OBJECT_GET_CLASS(DeviceClass, (obj), 
> > > TYPE_DEVICE)
> > >  
> > > +typedef enum DeviceCategory {
> > > +    DEVICE_CATEGORY_ASSEMBLY,
> > > +    DEVICE_CATEGORY_USB,
> > > +    DEVICE_CATEGORY_STORAGE,
> > > +    DEVICE_CATEGORY_NETWORK,
> > > +    DEVICE_CATEGORY_INPUT,
> > > +    DEVICE_CATEGORY_DISPLAY,
> > > +    DEVICE_CATEGORY_SOUND,
> > > +    DEVICE_CATEGORY_MISC,
> > > +    DEVICE_CATEGORY_MAX
> > > +} DeviceCategory;
> > > +
> > > +static inline const char *qdev_category_get_name(DeviceCategory category)
> > > +{
> > > +    static const char *category_names[DEVICE_CATEGORY_MAX] = {
> > > +        [DEVICE_CATEGORY_ASSEMBLY] = "Assembly",
> > > +        [DEVICE_CATEGORY_USB]      = "USB",
> > > +        [DEVICE_CATEGORY_STORAGE]  = "Storage",
> > > +        [DEVICE_CATEGORY_NETWORK]  = "Network",
> > > +        [DEVICE_CATEGORY_INPUT]    = "Input",
> > > +        [DEVICE_CATEGORY_DISPLAY]  = "Display",
> > > +        [DEVICE_CATEGORY_SOUND]    = "Sound",
> > > +        [DEVICE_CATEGORY_MISC]     = "Misc",
> > > +    };
> > > +
> > > +    return category_names[category];
> > > +};
> > > +
> > >  typedef int (*qdev_initfn)(DeviceState *dev);
> > >  typedef int (*qdev_event)(DeviceState *dev);
> > >  typedef void (*qdev_resetfn)(DeviceState *dev);
> > > @@ -81,6 +109,7 @@ typedef struct DeviceClass {
> > >      ObjectClass parent_class;
> > >      /*< public >*/
> > >  
> > > +    DECLARE_BITMAP(categories, DEVICE_CATEGORY_MAX);
> > >      const char *fw_name;
> > >      const char *desc;
> > >      Property *props;
> > > diff --git a/qdev-monitor.c b/qdev-monitor.c
> > > index e54dbc2..536e246 100644
> > > --- a/qdev-monitor.c
> > > +++ b/qdev-monitor.c
> > > @@ -75,24 +75,27 @@ static bool qdev_class_has_alias(DeviceClass *dc)
> > >      return (qdev_class_get_alias(dc) != NULL);
> > >  }
> > >  
> > > -static void qdev_print_devinfo(ObjectClass *klass, void *opaque)
> > > +static void qdev_print_class_devinfo(DeviceClass *dc)
> > >  {
> > > -    DeviceClass *dc;
> > > -    bool *show_no_user = opaque;
> > > -
> > > -    dc = (DeviceClass *)object_class_dynamic_cast(klass, TYPE_DEVICE);
> > > +    DeviceCategory category;
> > >  
> > > -    if (!dc || (show_no_user && !*show_no_user && dc->no_user)) {
> > > +    if (!dc || dc->no_user) {
> > >          return;
> > >      }
> > >  
> > > -    error_printf("name \"%s\"", object_class_get_name(klass));
> > > +    error_printf("name \"%s\"", object_class_get_name(OBJECT_CLASS(dc)));
> > >      if (dc->bus_type) {
> > >          error_printf(", bus %s", dc->bus_type);
> > >      }
> > >      if (qdev_class_has_alias(dc)) {
> > >          error_printf(", alias \"%s\"", qdev_class_get_alias(dc));
> > >      }
> > > +    error_printf(", categories");
> > > +    for (category = 0; category < DEVICE_CATEGORY_MAX; ++category) {
> > > +        if (test_bit(category, dc->categories)) {
> > > +            error_printf(" \"%s\"", qdev_category_get_name(category));
> > > +        }
> > > +    }
> > >      if (dc->desc) {
> > >          error_printf(", desc \"%s\"", dc->desc);
> > >      }
> > > @@ -102,6 +105,20 @@ static void qdev_print_devinfo(ObjectClass *klass, 
> > > void *opaque)
> > >      error_printf("\n");
> > >  }
> > >  
> > > +static void qdev_print_devinfo(ObjectClass *klass, void *opaque)
> > > +{
> > > +    DeviceClass *dc;
> > > +    bool *show_no_user = opaque;
> > > +
> > > +    dc = (DeviceClass *)object_class_dynamic_cast(klass, TYPE_DEVICE);
> > > +
> > > +    if (!dc || (show_no_user && !*show_no_user && dc->no_user)) {
> > > +        return;
> > > +    }
> > > +
> > 
> > Looks like the only user of this function is passing in NULL opaque now,
> > so this is equivalent to if (!dc)? The rest is dead code?
> > I'm not sure dc is ever NULL BTW, but maybe for some devices it is.
> Yes, I saw that.... , but
>  - maybe the cleaning shall be done by a separate patch and not in this 
> series.

I don't see how.  Before your patch there are two callers so
show_no_user is not always NULL.

>  - maybe someone will use this flag?

It's a static function, not part of interface.

> > 
> > > +    qdev_print_class_devinfo(dc);

Wait a second, if device has no_user flag set,
qdev_print_class_devinfo will not print anything,
this is a bug: we want to be able to see
properties of builtin devices.


> > > +}
> > > +
> > >  static int set_property(const char *name, const char *value, void 
> > > *opaque)
> > >  {
> > >      DeviceState *dev = opaque;
> > > @@ -139,6 +156,20 @@ static const char *find_typename_by_alias(const char 
> > > *alias)
> > >      return NULL;
> > >  }
> > >  
> > > +static void qdev_print_category_devices(DeviceCategory category)
> > > +{
> > > +    DeviceClass *dc;
> > > +    GSList *list, *curr;
> > > +
> > > +    list = object_class_get_list(TYPE_DEVICE, false);
> > > +    for (curr = list; curr; curr = g_slist_next(curr)) {
> > > +        dc = (DeviceClass *)object_class_dynamic_cast(curr->data, 
> > > TYPE_DEVICE);
> > 
> > So here don't we need if (dc->no_user)) { continue; } ?
> > Otherwise we'll get a list of internal devices which
> > can not be instanciated with -device.
> qdev_print_class_devinfo() handles this check


That's a bug, qdev_print_class_devinfo is called from 
qdev_print_devinfo which should be able to dump info
about an abstract class.

> > 
> > > +        if (test_bit(category, dc->categories)) {
> > > +            qdev_print_class_devinfo(dc);
> > > +        }
> > > +    }
> > > +}
> > > +
> > >  int qdev_device_help(QemuOpts *opts)
> > >  {
> > >      const char *driver;
> > > @@ -147,8 +178,11 @@ int qdev_device_help(QemuOpts *opts)
> > >  
> > >      driver = qemu_opt_get(opts, "driver");
> > >      if (driver && is_help_option(driver)) {
> > > -        bool show_no_user = false;
> > > -        object_class_foreach(qdev_print_devinfo, TYPE_DEVICE, false, 
> > > &show_no_user);
> > > +        DeviceCategory category;
> > > +        for (category = 0; category < DEVICE_CATEGORY_MAX; ++category) {
> > > +            qdev_print_category_devices(category);
> > > +        }
> > > +
> > >          return 1;
> > >      }
> > >  
> > > -- 
> > > 1.8.3.1
>