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

[Anthony Liguori <aliguori@us.ibm.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> 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.

Another example is a converged network adapter.  It's a single device
with an ethernet port but it exposes two physical functions--one NIC and
one fibre channel device via FCoE.

The PIIX chipset and ICH9 are multifunction devices but we model them as
separate devices today.   It's quite likely that in the very near future
we'll fix that.

>> 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.

I was thinking the same thing.  Could also just cheat and make the sort
function a bit more complicated.

Regards,

Anthony Liguori

>
> Paolo