RE: [PATCH 13/13] bcm2835_cprman: put some peripherals of bcm2835 cprman into the 'misc' category

[ganqixin]

> -----Original Message-----
> From: Thomas Huth [mailto:thuth@redhat.com]
> Sent: Monday, November 16, 2020 10:30 PM
> To: Philippe Mathieu-Daudé <f4bug@amsat.org>; ganqixin
> <ganqixin@huawei.com>; qemu-devel@nongnu.org;
> qemu-trivial@nongnu.org
> Cc: Chenqun (kuhn) <kuhn.chenqun@huawei.com>; Zhanghailiang
> <zhang.zhanghailiang@huawei.com>; Markus Armbruster
> <armbru@redhat.com>
> Subject: Re: [PATCH 13/13] bcm2835_cprman: put some peripherals of
> bcm2835 cprman into the 'misc' category
> 
> On 16/11/2020 14.25, Philippe Mathieu-Daudé wrote:
> > Hi Gan,
> >
> > On 11/15/20 7:49 PM, Gan Qixin wrote:
> >> Some peripherals of bcm2835 cprman have no category, put them into the
> 'misc'
> >> category.
> >>
> >> Signed-off-by: Gan Qixin <ganqixin@huawei.com>
> >> ---
> >> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >> ---
> >>  hw/misc/bcm2835_cprman.c | 4 ++++
> >>  1 file changed, 4 insertions(+)
> >>
> >> diff --git a/hw/misc/bcm2835_cprman.c b/hw/misc/bcm2835_cprman.c
> >> index 7e415a017c..c62958a99e 100644
> >> --- a/hw/misc/bcm2835_cprman.c
> >> +++ b/hw/misc/bcm2835_cprman.c
> >> @@ -136,6 +136,7 @@ static void pll_class_init(ObjectClass *klass,
> >> void *data)
> >>
> >>      dc->reset = pll_reset;
> >>      dc->vmsd = &pll_vmstate;
> >> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> >
> > Well, this is not an usable device but a part of a bigger device, so
> > here we want the opposite: not list this device in any category.
> >
> > Maybe we could add a DEVICE_CATEGORY_COMPOSITE for all such QOM types
> > so management apps can filter them out? (And so we are sure all QOM is
> > classified).
> >
> > Thomas, you already dealt with categorizing devices in the past, what
> > do you think about this? Who else could help? Maybe add someone from
> > libvirt in the thread?
> 
> My 0.02 € : Mark the device as user_creatable = false if it can not really be 
> used
> by the user with the -device CLI parameter. Then it also does not need a
> category. I know Markus will likely have a different opinion, but in my eyes 
> it's
> just ugly if we present devices to the users that they can not use.
> (By the way, this device here seems to be a decendant of
> TYPE_SYS_BUS_DEVICE ... shouldn't these show up as user_creatable = false
> automatically?)

I agree, but marking user_creatable as false seems to make it deviate from its 
own meaning (like markus said).
Is there any other way to avoid presenting devices to the users in "-device 
help"?

Thanks,
Gan Qixin