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

[Michael S. Tsirkin]

On Thu, Jul 18, 2013 at 09:58:59AM -0500, Anthony Liguori wrote:
> Paolo Bonzini <address@hidden> 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 <address@hidden> 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 <address@hidden>
> >>>> Reviewed-by: Kevin Wolf <address@hidden>
> >>>> ---
> >>>>  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

No, I think a multi-purpose device should appear in multiple
places, not be lumped with one randomly selected category.
E.g. storage/network controller should appear
under both storage and network. Otherwise how will users
find it?






> >
> > Paolo
>