Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 1 Dec 2022 16:36:26 +0800 | From | Baolu Lu <> | Subject | Re: [PATCH 1/4] iommu/vt-d: Add a fix for devices need extra dtlb flush |
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On 2022/12/1 12:01, Lu Baolu wrote: > From: Jacob Pan<jacob.jun.pan@linux.intel.com> > > QAT devices on Intel Sapphire Rapids and Emerald Rapids have a defect in > address translation service (ATS). These devices may inadvertently issue > ATS invalidation completion before posted writes initiated with > translated address that utilized translations matching the invalidation > address range, violating the invalidation completion ordering. > > This patch adds an extra device TLB invalidation for the affected devices, > it is needed to ensure no more posted writes with translated address > following the invalidation completion. Therefore, the ordering is > preserved and data-corruption is prevented. > > Device TLBs are invalidated under the following six conditions: > 1. Device driver does DMA API unmap IOVA > 2. Device driver unbind a PASID from a process, sva_unbind_device() > 3. PASID is torn down, after PASID cache is flushed. e.g. process > exit_mmap() due to crash > 4. Under SVA usage, called by mmu_notifier.invalidate_range() where > VM has to free pages that were unmapped > 5. userspace driver unmaps a DMA buffer > 6. Cache invalidation in vSVA usage (upcoming) > > For #1 and #2, device drivers are responsible for stopping DMA traffic > before unmap/unbind. For #3, iommu driver gets mmu_notifier to > invalidate TLB the same way as normal user unmap which will do an extra > invalidation. The dTLB invalidation after PASID cache flush does not > need an extra invalidation. > > Therefore, we only need to deal with #4 and #5 in this patch. #1 is also > covered by this patch due to common code path with #5. > > Tested-by: Yuzhang Luo<yuzhang.luo@intel.com> > Reviewed-by: Ashok Raj<ashok.raj@intel.com> > Reviewed-by: Kevin Tian<kevin.tian@intel.com>
This missed cc stable tag.
Cc: stable@vger.kernel.org # v5.15+
Sorry for the inconvenience.
> Signed-off-by: Jacob Pan<jacob.jun.pan@linux.intel.com> > Link:https://lore.kernel.org/r/20221130062449.1360063-1-jacob.jun.pan@linux.intel.com > Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com> > --- > drivers/iommu/intel/iommu.h | 4 +++ > drivers/iommu/intel/iommu.c | 69 +++++++++++++++++++++++++++++++++++-- > drivers/iommu/intel/svm.c | 5 ++- > 3 files changed, 75 insertions(+), 3 deletions(-)
Best regards, baolu
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