On 05/29/2014 07:58 AM, Benjamin Herrenschmidt wrote: > On Wed, 2014-05-28 at 22:49 +1000, Gavin Shan wrote: >> >> I will remove those "address" related macros in next revision because it's >> user-level bussiness, not related to host kernel any more. >> >> If the user is QEMU + guest, we need the address to identify the PE though PHB >> BUID could be used as same purpose to get PHB, which is one-to-one mapping with >> IOMMU group on sPAPR platform. However, once the PE address is built and returned >> to guest, guest will use the PE address as input parameter in subsequent RTAS >> calls. >> >> If the user is some kind of application who just uses the ioctl() without supporting >> RTAS calls. We don't need care about PE address. > > I am a bit reluctant with that PE==PHB equation we seem to be introducing. > > This isn't the case in HW. It is pseries, not real HW. Does phyp allow multiple real host PEs on the same virtual PHB? > It's possible that this is how we handle VFIO *today* > in qemu but it doesn't have to be does it ? > > It also paints us into a corner if we want to start implementing some kind of > emulated EEH for selected emulated devices and/or virtio. -- Alexey -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html