Messages in this thread | | | From | Ajay Garg <> | Date | Mon, 11 Oct 2021 23:43:29 +0530 | Subject | Re: [PATCH] iommu: intel: remove flooding of non-error logs, when new-DMA-PTE is the same as old-DMA-PTE. |
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Thanks Alex for your time.
I think I may have found the issue. Right now, when doing a dma-unmapping, we do a "soft-unmapping" only, as the pte-values themselves are not cleared in the unlinked pagetable-frame.
I have made the (simple) changes, and things are looking good as of now (almost an hour now). However, this time I will give it a day ;)
If there is not a single-flooding observed in the next 24 hours, I would float the v2 patch for review.
Thanks again for your time and patience.
Thanks and Regards, Ajay
> > Even this QEMU explanation doesn't make a lot of sense, vfio tracks > userspace mappings and will return an -EEXIST error for duplicate or > overlapping IOVA entries. We expect to have an entirely empty IOMMU > domain when a device is assigned, but it seems the only way userspace > can trigger duplicate PTEs would be if mappings already exist, or we > have a bug somewhere. > > If the most recent instance is purely on bare metal, then it seems the > host itself has conflicting mappings. I can only speculate with the > limited data presented, but I'm suspicious there's something happening > with RMRRs here (but that should also entirely preclude assignment). > dmesg, lspci -vvv, and VM configuration would be useful. Thanks, > > Alex >
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