Re: [patch 21/32] NTB/msi: Convert to msi_on_each_desc()

On 2021-11-29 5:29 p.m., Thomas Gleixner wrote:

At the conceptual level these interrupts are in separate irq domains:

     |   _______________________
     |   |                      |
     |   | NTB                  |
     |   |                      |
     |   | PCI config space     |
     |   |     MSI-X space      | <- #1 Global or per IOMMU zone PCI/MSI domain
     |   |_____________________ |
     |---|                      |
         | Memory window A      |
         | Memory window ..     | <- #2 Per device NTB domain
         | Memory window N      |
         |______________________|

You surely can see the disctinction between #1 and #2, right?

I wouldn't say that's entirely obvious or even irrefutable. However, I'm
certainly open to this approach if it improves the code.

I'm way too tired to come up with a proper solution for that, but that
PCI_IRQ_VIRTUAL has to die ASAP.

I'm willing to volunteer a bit of my time to clean this up, but I'd need
a bit more direction on what a proper solution would look like. The MSI
domain code is far from well documented nor is it easy to understand.

Logan