Re: [PATCH v4 17/17] virt: acrn: Introduce an interface for Service VM to control vCPU

[Shuo A Liu]

On Mon 28.Sep'20 at  7:23:05 +0200, Greg Kroah-Hartman wrote:
> On Mon, Sep 28, 2020 at 12:10:07PM +0800, Shuo A Liu wrote:
> > > You just raced with userspace and lost.  If you want to add attribute
> > > files to a device, use the default attribute group list, and it will be
> > > managed properly for you by the driver core.
> > >
> > > Huge hint, if a driver every has to touch a kobject, or call sysfs_*,
> > > then it is probably doing something wrong.
> >
> > Do you mean use .groups of struct miscdevice directly ?
> >
> > If yes, let me follow drivers/char/hw_random/s390-trng.c to do this.
> > BTW, few driver use the .groups directly. :)
>
> Drivers should almost never be messing with individual sysfs files.  And
> this ability to use .groups is a "new" one, conversions of existing code
> that do not use them is always welcome.

OK. Thanks for the explanation. I will follow the 'new' way :)

Thanks
shuo