Re: [Qemu-devel] [RFC PATCH v3 1/3] vGPU Core driver

[Tian, Kevin]

> From: Alex Williamson
> Sent: Wednesday, May 04, 2016 6:44 AM
> 
> > diff --git a/drivers/vgpu/Kconfig b/drivers/vgpu/Kconfig
> > new file mode 100644
> > index 0000000..792eb48
> > --- /dev/null
> > +++ b/drivers/vgpu/Kconfig
> > @@ -0,0 +1,21 @@
> > +
> > +menuconfig VGPU
> > +    tristate "VGPU driver framework"
> > +    depends on VFIO
> > +    select VGPU_VFIO
> > +    help
> > +        VGPU provides a framework to virtualize GPU without SR-IOV cap
> > +        See Documentation/vgpu.txt for more details.
> > +
> > +        If you don't know what do here, say N.
> > +
> > +config VGPU
> > +    tristate
> > +    depends on VFIO
> > +    default n
> > +
> > +config VGPU_VFIO
> > +    tristate
> > +    depends on VGPU
> > +    default n
> > +
> 
> This is a little bit convoluted, it seems like everything added in this
> patch is vfio agnostic, it doesn't necessarily care what the consumer
> is.  That makes me think we should only be adding CONFIG_VGPU here and
> it should not depend on CONFIG_VFIO or be enabling CONFIG_VGPU_VFIO.
> The middle config entry is also redundant to the first, just move the
> default line up to the first and remove the rest.

Agree. Removing such dependency also benefits other hypervisor if
VFIO is not used.

Alex, there is one idea which I'd like to hear your comment. When looking at
the whole series, we can see the majority logic (maybe I cannot say 100%)
is GPU agnostic. Same frameworks in VFIO and vGPU core are actually neutral
to underlying device type, which e.g. can be easily applied to a NIC card too
if a similar technology is developed there.

Do you think whether we'd better make framework not GPU specific now
(mostly naming change), or continue current style and change later only 
when there is a real implementation on a different device? 

Thanks
Kevin