Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 20 Jan 2023 13:50:25 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 1/4] iommu/amd: Introduce Protection-domain flag VFIO |
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On Fri, Jan 20, 2023 at 11:01:21AM -0600, Kalra, Ashish wrote:
> We basically get the RMP #PF from the IOMMU because there is a page size > mismatch between the RMP table and the IOMMU page table. The RMP table's > large page entry has been smashed to 4K PTEs to handle page state change to > shared on 4K mappings, so this change has to be synced up with the IOMMU > page table, otherwise there is now a page size mismatch between RMP table > and IOMMU page table which causes the RMP #PF.
I understand that, you haven't answered my question:
Why is the IOMMU being programmed with pages it cannot access in the first place?
Don't do that is the obvious solution there, and preserves huge page IO performance.
Jason
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