Hi Alex, Lu. Posted v2 patch, as per https://lists.linuxfoundation.org/pipermail/iommu/2021-October/059955.html Kindly review, and let's continue on that thread now. Thanks and Regards, Ajay On Mon, Oct 11, 2021 at 11:43 PM Ajay Garg <ajaygargnsit@xxxxxxxxx> wrote: > > 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 > >
