Re: [Qemu-devel] [RFC,PATCH 08/11] qdev: Add usb_bus_dev_info

[Markus Armbruster]

Nathan Baum <address@hidden> writes:

> On Fri, 2010-01-15 at 19:14 +0100, Markus Armbruster wrote:
>> Nathan Baum <address@hidden> writes:
>> 
>> > Returns a QObject with information about a USB device.
>> >
>> > Signed-off-by: Nathan Baum <address@hidden>
>> > ---
>> >  hw/usb-bus.c |   13 +++++++++++++
>> >  1 files changed, 13 insertions(+), 0 deletions(-)
>> >
>> > diff --git a/hw/usb-bus.c b/hw/usb-bus.c
>> > index 54027df..6d02807 100644
>> > --- a/hw/usb-bus.c
>> > +++ b/hw/usb-bus.c
>> > @@ -3,6 +3,7 @@
>> >  #include "qdev.h"
>> >  #include "sysemu.h"
>> >  #include "monitor.h"
>> > +#include "qjson.h"
>> >  
>> >  static void usb_bus_dev_print(Monitor *mon, DeviceState *qdev, int 
>> > indent);
>> >  
>> > @@ -232,6 +233,18 @@ static void usb_bus_dev_print(Monitor *mon, 
>> > DeviceState *qdev, int indent)
>> >                     dev->attached ? ", attached" : "");
>> >  }
>> >  
>> > +static QObject *usb_bus_dev_info(Monitor *mon, DeviceState *qdev)
>> > +{
>> > +    USBDevice *dev = DO_UPCAST(USBDevice, qdev, qdev);
>> > +    USBBus *bus = usb_bus_from_device(dev);
>> > +    return qobject_from_jsonf("{'busnr': %d, 'addr':%d, 'speed': %s, 
>> > 'desc': %s, 'attached': %i}",
>> > +                              bus->busnr,
>> 
>> As for PCI, 'busnr' belongs to the bus, not the device.
>
> Hmm. In cases like this, is it appropriate to modify the output of the
> existing "info qtree" when it is modified to use the QObject data?
>
> Would it be sensible to go the (probably small amount of) effort to
> change the print functions to print exactly they do now, and put changes
> to their output in different patches so they can easily be dropped if
> necessary?

We might want to change info qtree output anyway if we show bus
information separately there...

>> Hmm, we don't have the infrastructure to return bus information, yet.
>> "info qtree" hardcodes printing of name and type.  Gerd, what do you
>> think?

... as I implied here.

Regardless, I think we should first decide what data we want to transmit
over QMP, and how to structure it, then figure out if and how to change
its human readable presentation.

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