On Fri, Aug 14, 2015 at 09:26:21PM +0100, Bjorn Helgaas wrote:

On Fri, Aug 14, 2015 at 11:43 AM, Will Deacon [off-list ref] wrote:

quoted

On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:

quoted

Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.

If we can live without it, that would be nice.  It seems like a relic from
days when we couldn't reliably assign resources.  (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)

Kvmtool certainly uses it (and generates its own DT, hence why you don't
see it in mainline). Not sure about qemu, though.

Do you know why kvmtool wants probe-only?  Would something break if we
didn't support probe-only?  I guess we'd be looking for a case where
Linux assigns resources and that assignment doesn't work with kvmtool?

It's basically because the BARs aren't writable other than to find the
region size. It could fixed with a bit of pain, but it doesn't help older
kvmtools that do work with mainline today.

Will