[RHEL-9.2] iommu: amd: Updates for 9.2

Merge Request Required Information

Bugzilla: https://bugzilla.redhat.com/2097878

Bugzilla: https://bugzilla.redhat.com/2106596

Bugzilla: https://bugzilla.redhat.com/2117776

Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

Testing: Did test with fio, and forcing crash with kdump to verify kdump succeeds, and vmcore can be read. We only have AMD systems with 1 pci segment so could only verify that things are still working in that case. AMD will need to test with a multi-segment system. AMD will need to test and verify the change for USB4 as well, as we do not have the hw. The IOMMU portion of that is a really minor change, and the rest of the changes involving usb4/thunderbolt were backported in 9.1 with the usb/thunderbolt backports. I did testing both with this MR by itself, and on top of my main iommu backports.

Summary of Changes

This is a separate MR breaking out most of the AMD IOMMU changes for 9.2 as they require OtherQA from AMD, so I don't want it tying up the other IOMMU changes. It includes:

• Add support to indicate whether pre-boot DMA Remap support was enabled for usb4/thunderbolt trusted device support.
• Add support to AMD IOMMU driver for multiple PCI segments.
• Validate features across IOMMUs.
• Clean up Guest Virtual APIC enabling code.

Not included from 6.0 work:

• Secure Nested Paging changes (minus feature check). Nothing currently calls amd_iommu_snp_enable() so no means of testing the changes currently.

Signed-off-by: Jerry Snitselaar jsnitsel@redhat.com