Public bug reported: During VFIO/FLR recovery, the saved PCI Command register state may have Memory Space disabled. Restoring MSI-X messages in that state can issue MMIO writes to the MSI-X table while memory decoding is off, causing Unsupported Request completions and DPC containment on the root port.
The patch enables `PCI_COMMAND_MEMORY` before MSI-X restore and restores the original Command register value afterward. The patch is currently under review on LKML and is therefore taking as SAUCE: https://lore.kernel.org/all/[email protected]/ Note that the patch applied cleanly. As of now, this issue only impacts VR systems as GB is currently configured to treat UR as ANF. ## Validation - Verified backport is patch-id identical to the referenced LKML v20 patch. - `scripts/checkpatch.pl --strict --git HEAD` - `git diff --check HEAD~1 HEAD` ** Affects: linux-nvidia-6.17 (Ubuntu) Importance: Undecided Status: New ** Affects: linux-nvidia-bos (Ubuntu) Importance: Undecided Status: New ** Also affects: linux-nvidia-bos (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2158328 Title: Backport PCI/MSI: Enable memory decoding before restoring MSI-X messages To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-nvidia-6.17/+bug/2158328/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
