Re: [PATCH 0/6] MSI portability cleanups

This is the most straight forward and handles machines with really
weird msi setups, so I lean in this direction.

The question is there anything at all we can do generically?

I can't see a case where ppc_md would not wind up with the hooks
that decide if it is a hypervisor or not.  Even if we came up
with a better set of functions you need to hook.

Sure, but with Michael's approach, the only hook was get_msi_ops(pdev) 

Anyway, there isn't -that- much that can be done generically in the HV
case. Mostly some argument sanity checking, the logic for saving &
restoring pdev->irq for MSIs, that sort of thing.

Ok. I think I get the point of check.  I believe I need to look at your
code a little more and see what you are doing to see if there is anything
generic worth doing, that we can always do outside of architecture code
no matter how much of the job the Hypervisor wants to do for us.

I understand.

I'd hate to hit a different Hypervisor that did something close but
not quite the same and have the code fail then.  So definitely
avoiding touching pci config space at all in the calls seems to make a
lot of sense.  This includes avoiding pci_find_capability right?

Quite possibly yes. I'm pretty sure it will work on IBM HV but we aren't
really supposed to use it...

Off the top of my head the only things we can do generically are
some data structure things and flags like dev->msi_enabled or
dev->msix_enabled.

That and the saving & restoring of pdev->irq. That is not very much.

Anyway have a nice night and more in the morning.

Ben.