Re: [Qemu-devel] [RFC PATCH 1/2] qemu-help: Sort devices by logical functionality

[Paolo Bonzini <pbonzini@redhat.com>]

Il 18/07/2013 16:42, Marcel Apfelbaum ha scritto:
> On Thu, 2013-07-18 at 09:28 -0500, Anthony Liguori wrote:
>> Marcel Apfelbaum <marcel.a@redhat.com> writes:
>>
>>> Categorize devices that appear as output to "-device ?" command
>>> by logical functionality. Sort the devices by logical categories
>>> before showing them to user.
>>>
>>> Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
>>> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
>>> ---
>>>  include/hw/qdev-core.h |  7 +++++++
>>>  qdev-monitor.c         | 23 ++++++++++++++++++++++-
>>>  2 files changed, 29 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
>>> index 7fbffcb..4f7a9b8 100644
>>> --- a/include/hw/qdev-core.h
>>> +++ b/include/hw/qdev-core.h
>>> @@ -17,6 +17,12 @@ enum {
>>>  #define DEVICE_CLASS(klass) OBJECT_CLASS_CHECK(DeviceClass, (klass), TYPE_DEVICE)
>>>  #define DEVICE_GET_CLASS(obj) OBJECT_GET_CLASS(DeviceClass, (obj), TYPE_DEVICE)
>>>  
>>> +#define DEVICE_CATEGORY_STORAGE "storage"
>>> +#define DEVICE_CATEGORY_NETWORK "network"
>>> +#define DEVICE_CATEGORY_INPUT "input"
>>> +#define DEVICE_CATEGORY_DISPLAY "display"
>>> +#define DEVICE_CATEGORY_SOUND "sound"
>>> +
>>
>> Looks reasonable, but please make this a bitmap.  There are cases,
>> particularly if we start modeling multifunction PCI cards as a single
>> device, where a single device can support multiple types of
>> functionality.
> 
> Antony, thanks for your review!
> The whole point was to find a way to differentiate them by
> functionality so they can be sorted...
> Is it possible that a multifunction pci card will be used
> for more then one category mentioned above?

Yes, for example your laptop's GPU probably has an audio function too.

> I agree the list may not be exhaustive, but I really hope
> I'll find a way to sort them in such a way that a
> device will not fall under more than one category

If you sort the bit definitions in alphabetic order (audio=bit 30,
display=bit 29, etc. for example), the resulting integer sort should
also yield alphabetic order.  But perhaps it's not a smart idea if we
take into account future localization of the help text.

Paolo