Messages in this thread Patch in this message | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH v7 02/10] iommu: Remove SVM_FLAG_SUPERVISOR_MODE support | Date | Tue, 24 May 2022 09:27:48 +0000 |
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> From: Lu Baolu <baolu.lu@linux.intel.com> > Sent: Thursday, May 19, 2022 3:21 PM > > The current kernel DMA with PASID support is based on the SVA with a flag > SVM_FLAG_SUPERVISOR_MODE. The IOMMU driver binds the kernel > memory address > space to a PASID of the device. The device driver programs the device with > kernel virtual address (KVA) for DMA access. There have been security and > functional issues with this approach: > > - The lack of IOTLB synchronization upon kernel page table updates. > (vmalloc, module/BPF loading, CONFIG_DEBUG_PAGEALLOC etc.) > - Other than slight more protection, using kernel virtual address (KVA) > has little advantage over physical address. There are also no use > cases yet where DMA engines need kernel virtual addresses for in-kernel > DMA. > > This removes SVM_FLAG_SUPERVISOR_MODE support from the IOMMU > interface. > The device drivers are suggested to handle kernel DMA with PASID through > the kernel DMA APIs. > > The drvdata parameter in iommu_sva_bind_device() and all callbacks is not > needed anymore. Cleanup them as well. > > Link: https://lore.kernel.org/linux- > iommu/20210511194726.GP1002214@nvidia.com/ > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> --- > include/linux/intel-iommu.h | 3 +- > include/linux/intel-svm.h | 13 ----- > include/linux/iommu.h | 8 +-- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 5 +- > drivers/dma/idxd/cdev.c | 2 +- > drivers/dma/idxd/init.c | 24 +------- > .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 3 +- > drivers/iommu/intel/svm.c | 57 +++++-------------- > drivers/iommu/iommu.c | 5 +- > drivers/misc/uacce/uacce.c | 2 +- > 10 files changed, 26 insertions(+), 96 deletions(-) > > diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h > index 4f29139bbfc3..df23300cfa88 100644 > --- a/include/linux/intel-iommu.h > +++ b/include/linux/intel-iommu.h > @@ -739,8 +739,7 @@ struct intel_iommu *device_to_iommu(struct device > *dev, u8 *bus, u8 *devfn); > extern void intel_svm_check(struct intel_iommu *iommu); > extern int intel_svm_enable_prq(struct intel_iommu *iommu); > extern int intel_svm_finish_prq(struct intel_iommu *iommu); > -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct > *mm, > - void *drvdata); > +struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct > *mm); > void intel_svm_unbind(struct iommu_sva *handle); > u32 intel_svm_get_pasid(struct iommu_sva *handle); > int intel_svm_page_response(struct device *dev, struct iommu_fault_event > *evt, > diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h > index 207ef06ba3e1..f9a0d44f6fdb 100644 > --- a/include/linux/intel-svm.h > +++ b/include/linux/intel-svm.h > @@ -13,17 +13,4 @@ > #define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x20) > #define PRQ_DEPTH ((0x1000 << PRQ_ORDER) >> 5) > > -/* > - * The SVM_FLAG_SUPERVISOR_MODE flag requests a PASID which can be > used only > - * for access to kernel addresses. No IOTLB flushes are automatically done > - * for kernel mappings; it is valid only for access to the kernel's static > - * 1:1 mapping of physical memory — not to vmalloc or even module > mappings. > - * A future API addition may permit the use of such ranges, by means of an > - * explicit IOTLB flush call (akin to the DMA API's unmap method). > - * > - * It is unlikely that we will ever hook into flush_tlb_kernel_range() to > - * do such IOTLB flushes automatically. > - */ > -#define SVM_FLAG_SUPERVISOR_MODE BIT(0) > - > #endif /* __INTEL_SVM_H__ */ > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index da423e87f248..0c358b7c583b 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -243,8 +243,7 @@ struct iommu_ops { > int (*dev_enable_feat)(struct device *dev, enum > iommu_dev_features f); > int (*dev_disable_feat)(struct device *dev, enum > iommu_dev_features f); > > - struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct > *mm, > - void *drvdata); > + struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct > *mm); > void (*sva_unbind)(struct iommu_sva *handle); > u32 (*sva_get_pasid)(struct iommu_sva *handle); > > @@ -667,8 +666,7 @@ int iommu_dev_disable_feature(struct device *dev, > enum iommu_dev_features f); > bool iommu_dev_feature_enabled(struct device *dev, enum > iommu_dev_features f); > > struct iommu_sva *iommu_sva_bind_device(struct device *dev, > - struct mm_struct *mm, > - void *drvdata); > + struct mm_struct *mm); > void iommu_sva_unbind_device(struct iommu_sva *handle); > u32 iommu_sva_get_pasid(struct iommu_sva *handle); > > @@ -1010,7 +1008,7 @@ iommu_dev_disable_feature(struct device *dev, > enum iommu_dev_features feat) > } > > static inline struct iommu_sva * > -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void > *drvdata) > +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) > { > return NULL; > } > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h > b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h > index cd48590ada30..d2ba86470c42 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h > @@ -754,8 +754,7 @@ bool arm_smmu_master_sva_enabled(struct > arm_smmu_master *master); > int arm_smmu_master_enable_sva(struct arm_smmu_master *master); > int arm_smmu_master_disable_sva(struct arm_smmu_master *master); > bool arm_smmu_master_iopf_supported(struct arm_smmu_master > *master); > -struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct > mm_struct *mm, > - void *drvdata); > +struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct > mm_struct *mm); > void arm_smmu_sva_unbind(struct iommu_sva *handle); > u32 arm_smmu_sva_get_pasid(struct iommu_sva *handle); > void arm_smmu_sva_notifier_synchronize(void); > @@ -791,7 +790,7 @@ static inline bool > arm_smmu_master_iopf_supported(struct arm_smmu_master *master > } > > static inline struct iommu_sva * > -arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void > *drvdata) > +arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm) > { > return ERR_PTR(-ENODEV); > } > diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c > index b9b2b4a4124e..312ec37ebf91 100644 > --- a/drivers/dma/idxd/cdev.c > +++ b/drivers/dma/idxd/cdev.c > @@ -100,7 +100,7 @@ static int idxd_cdev_open(struct inode *inode, struct > file *filp) > filp->private_data = ctx; > > if (device_pasid_enabled(idxd)) { > - sva = iommu_sva_bind_device(dev, current->mm, NULL); > + sva = iommu_sva_bind_device(dev, current->mm); > if (IS_ERR(sva)) { > rc = PTR_ERR(sva); > dev_err(dev, "pasid allocation failed: %d\n", rc); > diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c > index 993a5dcca24f..1fd80c63248a 100644 > --- a/drivers/dma/idxd/init.c > +++ b/drivers/dma/idxd/init.c > @@ -466,29 +466,7 @@ static struct idxd_device *idxd_alloc(struct pci_dev > *pdev, struct idxd_driver_d > > static int idxd_enable_system_pasid(struct idxd_device *idxd) > { > - int flags; > - unsigned int pasid; > - struct iommu_sva *sva; > - > - flags = SVM_FLAG_SUPERVISOR_MODE; > - > - sva = iommu_sva_bind_device(&idxd->pdev->dev, NULL, &flags); > - if (IS_ERR(sva)) { > - dev_warn(&idxd->pdev->dev, > - "iommu sva bind failed: %ld\n", PTR_ERR(sva)); > - return PTR_ERR(sva); > - } > - > - pasid = iommu_sva_get_pasid(sva); > - if (pasid == IOMMU_PASID_INVALID) { > - iommu_sva_unbind_device(sva); > - return -ENODEV; > - } > - > - idxd->sva = sva; > - idxd->pasid = pasid; > - dev_dbg(&idxd->pdev->dev, "system pasid: %u\n", pasid); > - return 0; > + return -EOPNOTSUPP; > } > > static void idxd_disable_system_pasid(struct idxd_device *idxd) > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c > b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c > index 1ef7bbb4acf3..f155d406c5d5 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c > @@ -367,8 +367,7 @@ __arm_smmu_sva_bind(struct device *dev, struct > mm_struct *mm) > return ERR_PTR(ret); > } > > -struct iommu_sva * > -arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm, void > *drvdata) > +struct iommu_sva *arm_smmu_sva_bind(struct device *dev, struct > mm_struct *mm) > { > struct iommu_sva *handle; > struct iommu_domain *domain = iommu_get_domain_for_dev(dev); > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c > index 7ee37d996e15..d04880a291c3 100644 > --- a/drivers/iommu/intel/svm.c > +++ b/drivers/iommu/intel/svm.c > @@ -313,8 +313,7 @@ static int pasid_to_svm_sdev(struct device *dev, > unsigned int pasid, > return 0; > } > > -static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm, > - unsigned int flags) > +static int intel_svm_alloc_pasid(struct device *dev, struct mm_struct *mm) > { > ioasid_t max_pasid = dev_is_pci(dev) ? > pci_max_pasids(to_pci_dev(dev)) : > intel_pasid_max_id; > @@ -324,8 +323,7 @@ static int intel_svm_alloc_pasid(struct device *dev, > struct mm_struct *mm, > > static struct iommu_sva *intel_svm_bind_mm(struct intel_iommu *iommu, > struct device *dev, > - struct mm_struct *mm, > - unsigned int flags) > + struct mm_struct *mm) > { > struct device_domain_info *info = dev_iommu_priv_get(dev); > unsigned long iflags, sflags; > @@ -341,22 +339,18 @@ static struct iommu_sva > *intel_svm_bind_mm(struct intel_iommu *iommu, > > svm->pasid = mm->pasid; > svm->mm = mm; > - svm->flags = flags; > INIT_LIST_HEAD_RCU(&svm->devs); > > - if (!(flags & SVM_FLAG_SUPERVISOR_MODE)) { > - svm->notifier.ops = &intel_mmuops; > - ret = mmu_notifier_register(&svm->notifier, mm); > - if (ret) { > - kfree(svm); > - return ERR_PTR(ret); > - } > + svm->notifier.ops = &intel_mmuops; > + ret = mmu_notifier_register(&svm->notifier, mm); > + if (ret) { > + kfree(svm); > + return ERR_PTR(ret); > } > > ret = pasid_private_add(svm->pasid, svm); > if (ret) { > - if (svm->notifier.ops) > - mmu_notifier_unregister(&svm->notifier, > mm); > + mmu_notifier_unregister(&svm->notifier, mm); > kfree(svm); > return ERR_PTR(ret); > } > @@ -391,9 +385,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct > intel_iommu *iommu, > } > > /* Setup the pasid table: */ > - sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ? > - PASID_FLAG_SUPERVISOR_MODE : 0; > - sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? > PASID_FLAG_FL5LP : 0; > + sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? > PASID_FLAG_FL5LP : 0; > spin_lock_irqsave(&iommu->lock, iflags); > ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm- > >pasid, > FLPT_DEFAULT_DID, sflags); > @@ -410,8 +402,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct > intel_iommu *iommu, > kfree(sdev); > free_svm: > if (list_empty(&svm->devs)) { > - if (svm->notifier.ops) > - mmu_notifier_unregister(&svm->notifier, mm); > + mmu_notifier_unregister(&svm->notifier, mm); > pasid_private_remove(mm->pasid); > kfree(svm); > } > @@ -767,7 +758,7 @@ static irqreturn_t prq_event_thread(int irq, void *d) > * to unbind the mm while any page faults are > outstanding. > */ > svm = pasid_private_find(req->pasid); > - if (IS_ERR_OR_NULL(svm) || (svm->flags & > SVM_FLAG_SUPERVISOR_MODE)) > + if (IS_ERR_OR_NULL(svm)) > goto bad_req; > } > > @@ -818,40 +809,20 @@ static irqreturn_t prq_event_thread(int irq, void *d) > return IRQ_RETVAL(handled); > } > > -struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct > *mm, void *drvdata) > +struct iommu_sva *intel_svm_bind(struct device *dev, struct mm_struct > *mm) > { > struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL); > - unsigned int flags = 0; > struct iommu_sva *sva; > int ret; > > - if (drvdata) > - flags = *(unsigned int *)drvdata; > - > - if (flags & SVM_FLAG_SUPERVISOR_MODE) { > - if (!ecap_srs(iommu->ecap)) { > - dev_err(dev, "%s: Supervisor PASID not supported\n", > - iommu->name); > - return ERR_PTR(-EOPNOTSUPP); > - } > - > - if (mm) { > - dev_err(dev, "%s: Supervisor PASID with user > provided mm\n", > - iommu->name); > - return ERR_PTR(-EINVAL); > - } > - > - mm = &init_mm; > - } > - > mutex_lock(&pasid_mutex); > - ret = intel_svm_alloc_pasid(dev, mm, flags); > + ret = intel_svm_alloc_pasid(dev, mm); > if (ret) { > mutex_unlock(&pasid_mutex); > return ERR_PTR(ret); > } > > - sva = intel_svm_bind_mm(iommu, dev, mm, flags); > + sva = intel_svm_bind_mm(iommu, dev, mm); > mutex_unlock(&pasid_mutex); > > return sva; > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 847ad47a2dfd..9955f58bd08c 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -2768,7 +2768,6 @@ > EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); > * iommu_sva_bind_device() - Bind a process address space to a device > * @dev: the device > * @mm: the mm to bind, caller must hold a reference to it > - * @drvdata: opaque data pointer to pass to bind callback > * > * Create a bond between device and address space, allowing the device to > access > * the mm using the returned PASID. If a bond already exists between > @device and > @@ -2781,7 +2780,7 @@ > EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); > * On error, returns an ERR_PTR value. > */ > struct iommu_sva * > -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void > *drvdata) > +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) > { > struct iommu_group *group; > struct iommu_sva *handle = ERR_PTR(-EINVAL); > @@ -2806,7 +2805,7 @@ iommu_sva_bind_device(struct device *dev, struct > mm_struct *mm, void *drvdata) > if (iommu_group_device_count(group) != 1) > goto out_unlock; > > - handle = ops->sva_bind(dev, mm, drvdata); > + handle = ops->sva_bind(dev, mm); > > out_unlock: > mutex_unlock(&group->mutex); > diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c > index 281c54003edc..3238a867ea51 100644 > --- a/drivers/misc/uacce/uacce.c > +++ b/drivers/misc/uacce/uacce.c > @@ -99,7 +99,7 @@ static int uacce_bind_queue(struct uacce_device *uacce, > struct uacce_queue *q) > if (!(uacce->flags & UACCE_DEV_SVA)) > return 0; > > - handle = iommu_sva_bind_device(uacce->parent, current->mm, > NULL); > + handle = iommu_sva_bind_device(uacce->parent, current->mm); > if (IS_ERR(handle)) > return PTR_ERR(handle); > > -- > 2.25.1
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