On 11/13/2018 04:56 PM, Keith Busch wrote:

On Tue, Nov 13, 2018 at 10:39:15PM +0000, Alex_Gagniuc@Dellteam.com wrote:

quoted

On 11/12/2018 11:02 PM, Bjorn Helgaas wrote:

quoted

The whole issue of firmware-first, the mechanism by which firmware
gets control, the System Error enables in Root Port Root Control
registers, etc., is very murky to me.  Jon has a sort of similar issue
with VMD where he needs to leave System Errors enabled instead of
disabling them as we currently do.

Well, OS gets control via _OSC method, and based on that it should
touch/not touch the AER bits. The bits that get set/cleared come from
_HPX method, and there's a more about the FFS described in ACPI spec. It
seems that if platform, wants to enable VMD, it should pass the correct
bits via _HPX. I'm curious to know in what new twisted way FFS doesn't
work as intended.

When VMD is enabled, the platform sees a VMD endpoint. It doesn't see
any of the root ports on that domain, so ACPI can't provide policies for
them nor AER registers for the platform to consider controlling.

I'm not understanding the interdependency between RP AER settings and 
VMD. My understanding of VMD is quite rudimentary though, so I'll take 
your word for it.

Alex