Messages in this thread | | | Date | Tue, 5 Jan 2021 19:03:58 +0000 | From | Will Deacon <> | Subject | Re: [PATCH 2/5] iommu/vt-d: Fix unaligned addresses for intel_flush_svm_range_dev() |
| |
On Thu, Dec 31, 2020 at 08:53:20AM +0800, Lu Baolu wrote: > The VT-d hardware will ignore those Addr bits which have been masked by > the AM field in the PASID-based-IOTLB invalidation descriptor. As the > result, if the starting address in the descriptor is not aligned with > the address mask, some IOTLB caches might not invalidate. Hence people > will see below errors. > > [ 1093.704661] dmar_fault: 29 callbacks suppressed > [ 1093.704664] DMAR: DRHD: handling fault status reg 3 > [ 1093.712738] DMAR: [DMA Read] Request device [7a:02.0] PASID 2 > fault addr 7f81c968d000 [fault reason 113] > SM: Present bit in first-level paging entry is clear > > Fix this by using aligned address for PASID-based-IOTLB invalidation. > > Fixes: 1c4f88b7f1f92 ("iommu/vt-d: Shared virtual address in scalable mode") > Reported-and-tested-by: Guo Kaijie <Kaijie.Guo@intel.com> > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > --- > drivers/iommu/intel/svm.c | 22 ++++++++++++++++++++-- > 1 file changed, 20 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c > index 69566695d032..b16a4791acfb 100644 > --- a/drivers/iommu/intel/svm.c > +++ b/drivers/iommu/intel/svm.c > @@ -118,8 +118,10 @@ void intel_svm_check(struct intel_iommu *iommu) > iommu->flags |= VTD_FLAG_SVM_CAPABLE; > } > > -static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev, > - unsigned long address, unsigned long pages, int ih) > +static void __flush_svm_range_dev(struct intel_svm *svm, > + struct intel_svm_dev *sdev, > + unsigned long address, > + unsigned long pages, int ih) > { > struct qi_desc desc; > > @@ -170,6 +172,22 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d > } > } > > +static void intel_flush_svm_range_dev(struct intel_svm *svm, > + struct intel_svm_dev *sdev, > + unsigned long address, > + unsigned long pages, int ih) > +{ > + unsigned long shift = ilog2(__roundup_pow_of_two(pages)); > + unsigned long align = (1ULL << (VTD_PAGE_SHIFT + shift)); > + unsigned long start = ALIGN_DOWN(address, align); > + unsigned long end = ALIGN(address + (pages << VTD_PAGE_SHIFT), align); > + > + while (start < end) { > + __flush_svm_range_dev(svm, sdev, start, align >> VTD_PAGE_SHIFT, ih); > + start += align; > + } > +}
Given that this only seems to be called from intel_invalidate_range(), which has to compute 'pages' only to have it pulled apart again here, perhaps it would be cleaner for intel_flush_svm_range() to take something like an 'order' argument instead?
What do you think?
Will
| |