Bjorn, On 1/29/2024 11:49 AM, Ethan Zhao wrote:
This patchset is used to fix vt-d hard lockup reported when surprise unplug ATS capable endpoint device connects to system via PCIe switch as following topology. +-[0000:15]-+-00.0 Intel Corporation Ice Lake Memory Map/VT-d | +-00.1 Intel Corporation Ice Lake Mesh 2 PCIe | +-00.2 Intel Corporation Ice Lake RAS | +-00.4 Intel Corporation Device 0b23 | \-01.0-[16-1b]----00.0-[17-1b]--+-00.0-[18]----00.0 NVIDIA Corporation Device 2324 | +-01.0-[19]----00.0 Mellanox Technologies MT2910 Family [ConnectX-7] User brought endpoint device 19:00.0's link down by flapping it's hotplug capable slot 17:01.0 link control register, as sequence DLLSC response, pciehp_ist() will unload device driver and power it off, durning device driver is unloading an iommu device-TLB invalidation (Intel VT-d spec, or 'ATS Invalidation' in PCIe spec) request issued to that link down device, thus a long time completion/timeout waiting in interrupt context causes continuous hard lockup warnning and system hang. Other detail, see every patch commit log. patch [1&2] were tested by yehaorong@xxxxxxxxxxxxx on stable v6.7-rc4. patch [1-5] passed compiling on stable v6.8-rc2. change log: v12: - use base-commit tag to format patch. - fix building issue on v6.8-rc2 repported by lkp@xxxxxxxxx. v11: - update per latest comment and suggestion from Baolu and YiLiu. - split refactoring patch into two patches, [3/5] for simplify parameters and [4/5] for pdev parameter passing. - re-order patches. - fold target device presence check into qi_check_fault(). - combine patch[2][5] in v10 into one patch[5]. - some commit description correctness. - add fixes tag to patch[2/5]. - rebased on 6.8rc1 v10: - refactor qi_submit_sync() and its callers to get pci_dev instance, as Kevin pointed out add target_flush_dev to iommu is not right. v9: - unify all spelling of ATS Invalidation adhere to PCIe spec per Bjorn's suggestion. v8: - add a patch to break the loop for timeout device-TLB invalidation, as Bjorn said there is possibility device just no response but not gone. v7: - reorder patches and revise commit log per Bjorn's guide. - other code and commit log revise per Lukas' suggestion. - rebased to stable v6.7-rc6. v6: - add two patches to break out device-TLB invalidation if device is gone. v5: - add a patch try to fix the rare case (surprise remove a device in safe removal process). not work because surprise removal handling can't re-enter when another safe removal is in process. v4: - move the PCI device state checking after ATS per Baolu's suggestion. v3: - fix commit description typo. v2: - revise commit[1] description part according to Lukas' suggestion. - revise commit[2] description to clarify the issue's impact. v1: - https://lore.kernel.org/lkml/20231213034637.2603013-1-haifeng.zhao@ linux.intel.com/T/ Thanks, EthanEthan Zhao (5): PCI: make pci_dev_is_disconnected() helper public for other drivers iommu/vt-d: don't issue ATS Invalidation request when device is disconnected iommu/vt-d: simplify parameters of qi_submit_sync() ATS invalidation callers iommu/vt-d: pass pdev parameter for qi_check_fault() and refactor callers iommu/vt-d: improve ITE fault handling if target device isn't present drivers/iommu/intel/dmar.c | 71 +++++++++++++++++++++++------ drivers/iommu/intel/iommu.c | 29 +++--------- drivers/iommu/intel/iommu.h | 20 ++++---- drivers/iommu/intel/irq_remapping.c | 2 +- drivers/iommu/intel/nested.c | 9 +--- drivers/iommu/intel/pasid.c | 12 ++--- drivers/iommu/intel/svm.c | 23 +++++----- drivers/pci/pci.h | 5 -- include/linux/pci.h | 5 ++ 9 files changed, 98 insertions(+), 78 deletions(-) base-commit: 41bccc98fb7931d63d03f326a746ac4d429c1dd3
I got mail delivery failure message from Gmail for "unsolicited mail", I don't
know if you could read it by linux-pci mail list. the vt-d maintainer is going
to pick up this patchset, may I ask your 'ack' for the pci change if no more
comment from you ? Thanks, Ethan
