When a kernel client uses intel_svm_bind_mm() and requests a supervisor PASID, IOMMU needs to track changes to these addresses. Otherwise the device tlb will be stale compared to what's on the cpu for kernel mappings. This is similar to what's done for user space registrations via mmu_notifier_register() api's.
To: [email protected] To: Joerg Roedel <[email protected]> Cc: Ashok Raj <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Huang Ying <[email protected]> Cc: CQ Tang <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Kees Cook <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Vegard Nossum <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: David Woodhouse <[email protected]> CC: Jean-Phillipe Brucker <[email protected]> Signed-off-by: Ashok Raj <[email protected]> --- drivers/iommu/intel-svm.c | 29 +++++++++++++++++++++++++++-- include/linux/intel-iommu.h | 5 ++++- 2 files changed, 31 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 0c9f077..1758814 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -292,6 +292,26 @@ static const struct mmu_notifier_ops intel_mmuops = { static DEFINE_MUTEX(pasid_mutex); +static int intel_init_mm_inval_range(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct kernel_mmu_address_range *range; + struct intel_svm *svm = container_of(nb, struct intel_svm, init_mm_nb); + unsigned long start, end; + struct intel_iommu *iommu; + + if (action == KERNEL_MMU_INVALIDATE_RANGE) { + range = data; + start = range->start; + end = range->end; + iommu = svm->iommu; + + intel_flush_svm_range(svm, start, + (end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0, 0); + } + return 0; +} + int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops) { struct intel_iommu *iommu = intel_svm_device_to_iommu(dev); @@ -391,12 +411,12 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ goto out; } svm->pasid = ret; - svm->notifier.ops = &intel_mmuops; svm->mm = mm; svm->flags = flags; INIT_LIST_HEAD_RCU(&svm->devs); ret = -ENOMEM; if (mm) { + svm->notifier.ops = &intel_mmuops; ret = mmu_notifier_register(&svm->notifier, mm); if (ret) { idr_remove(&svm->iommu->pasid_idr, svm->pasid); @@ -405,8 +425,11 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ goto out; } iommu->pasid_table[svm->pasid].val = (u64)__pa(mm->pgd) | 1; - } else + } else { + svm->init_mm_nb.notifier_call = intel_init_mm_inval_range; + kernel_mmu_notifier_register(&svm->init_mm_nb); iommu->pasid_table[svm->pasid].val = (u64)__pa(init_mm.pgd) | 1 | (1ULL << 11); + } wmb(); /* In caching mode, we still have to flush with PASID 0 when * a PASID table entry becomes present. Not entirely clear @@ -471,6 +494,8 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) idr_remove(&svm->iommu->pasid_idr, svm->pasid); if (svm->mm) mmu_notifier_unregister(&svm->notifier, svm->mm); + else + kernel_mmu_notifier_unregister(&svm->init_mm_nb); /* We mandate that no page faults may be outstanding * for the PASID when intel_svm_unbind_mm() is called. diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 485a5b4..d6019b4 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -477,7 +477,10 @@ struct intel_svm_dev { }; struct intel_svm { - struct mmu_notifier notifier; + union { + struct mmu_notifier notifier; + struct notifier_block init_mm_nb; + }; struct mm_struct *mm; struct intel_iommu *iommu; int flags; -- 2.7.4
