Re: [PATCH RFC v2 02/18] irq/dev-msi: Add support for a new DEV_MSI irq domain

From: Dey, Megha
Date: Fri Aug 07 2020 - 16:32:04 EST



On 8/7/2020 11:39 AM, Jason Gunthorpe wrote:
On Fri, Aug 07, 2020 at 10:54:51AM -0700, Dey, Megha wrote:

So from the hierarchical domain standpoint, we will have:
- For DSA device: vector->intel-IR->IDXD
- For Jason's device: root domain-> domain A-> Jason's device's IRQ domain
- For any other intel IMS device in the future which
    does not require interrupt remapping: vector->new device IRQ domain
    requires interrupt remapping: vector->intel-IR->new device IRQ domain
I think you need a better classification than Jason's device or
Intel's device :)
hehe yeah, for sure, just wanted to get my point across :)

Shouldn't the two cases be either you take the parent domain from the
IOMMU or you take the parent domain from the pci device?

Hmm yeah this makes sense..

Although in the case of DSA, we find the iommu corresponding to the parent PCI device.


What other choices could a PCI driver make?
Currently I think based on the devices we have, I don't think there are any others

Jason