Re: [RFC PATCH v3 5/6] kvm/ppc/mpic: in-kernel MPIC emulation

[Gleb Natapov <gleb@redhat.com>]

On Thu, Apr 04, 2013 at 06:33:38PM -0500, Scott Wood wrote:
> On 04/04/2013 12:59:02 AM, Gleb Natapov wrote:
> >On Wed, Apr 03, 2013 at 03:58:04PM -0500, Scott Wood wrote:
> >> KVM_DEV_MPIC_* could go elsewhere if you want to avoid cluttering
> >> the main kvm.h.  The arch header would be OK, since the non-arch
> >> header includes the arch header, and thus it wouldn't be visible to
> >> userspace where it is -- if there later is a need for MPIC (or
> >> whatever other device follows MPIC's example) on another
> >> architecture, it could be moved without breaking anything.  Or, we
> >> could just have a header for each device type.
> >>
> >If device will be used by more then one arch it will move into
> >virt/kvm
> >and will have its own header, like ioapic.
> 
> virt/kvm/ioapic.h is not uapi.  The ioapic uapi component (e.g.
> struct kvm_ioapic_state) is duplicated between x86 and ia64, which
> is the sort of thing I'd like to avoid.  I'm OK with putting it in
> the PPC header if, upon a later need for multi-architecture support,
> it could move into either the main uapi header or a separate uapi
> header that the main uapi header includes (i.e. no userspace-visible
> change in which header needs to be included).
> 
Agree, it make sense to have separate uapi header for a device that is
used by more then one arch.

--
			Gleb.