Re: kvm PCI assignment & VFIO ramblings

On Fri, Aug 26, 2011 at 12:04:22PM -0600, Alex Williamson wrote:

On Thu, 2011-08-25 at 20:05 +0200, Joerg Roedel wrote:

quoted

If we really expect segment numbers that need the full 16 bit then this
would be the way to go. Otherwise I would prefer returning the group-id
directly and partition the group-id space for the error values (s32 with
negative numbers being errors).

It's unlikely to have segments using the top bit, but it would be broken
for an iommu driver to define it's group numbers using pci s:b:d.f if we
don't have that bit available.  Ben/David, do PEs have an identifier of
a convenient size?  I'd guess any hardware based identifier is going to
use a full unsigned bit width.

Okay, if we want to go the secure way I am fine with the "int *group"
parameter. Another option is to just return u64 and use the extended
number space for errors. But that is even worse as an interface, I
think.

	Joerg