RE: [RFC PATCH v2 1/3] vfio: Use capability chains to handle device specific irq

[Tian, Kevin]

> From: kraxel@xxxxxxxxxx
> Sent: Wednesday, June 5, 2019 6:10 PM
> 
>   Hi,
> 
> > > Really need to split for different planes? I'd like a
> > > VFIO_IRQ_SUBTYPE_GFX_DISPLAY_EVENT
> > > so user space can probe change for all.
> 
> > User space can choose to user different handlers according to the
> > specific event. For example, user space might not want to handle every
> > cursor event due to performance consideration. Besides, it can reduce
> > the probe times, as we don't need to probe twice to make sure if both
> > cursor plane and primary plane have been updated.
> 
> I'd suggest to use the value passed via eventfd for that, i.e. instead
> of sending "1" unconditionally send a mask of changed planes.
> 

sounds reasonable.