Commit 942fd543 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu: Remove SVM_FLAG_SUPERVISOR_MODE support 

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: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Tested-by: default avatarZhangfei Gao <zhangfei.gao@linaro.org>
Tested-by: default avatarTony Zhu <tony.zhu@intel.com>
Link: https://lore.kernel.org/r/20221031005917.45690-4-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 22d2c7af

drivers/dma/idxd/cdev.c

+1 −2
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
#include <linux/pci.h>

#include <linux/device.h>

#include <linux/sched/task.h>

#include <linux/intel-svm.h>

#include <linux/io-64-nonatomic-lo-hi.h>

#include <linux/cdev.h>

#include <linux/fs.h>
@@ -100,7 +99,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) 
	filp->private_data = ctx;



	if (device_user_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);

drivers/dma/idxd/init.c

+1 −24
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#include <linux/io-64-nonatomic-lo-hi.h>

#include <linux/device.h>

#include <linux/idr.h>

#include <linux/intel-svm.h>

#include <linux/iommu.h>

#include <uapi/linux/idxd.h>

#include <linux/dmaengine.h>
@@ -502,29 +501,7 @@ 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)

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c

+1 −2
Original line number Diff line number Diff line
@@ -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);

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

+2 −3
Original line number Diff line number Diff line
@@ -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);

}

drivers/iommu/intel/iommu.h

+1 −2
Original line number Diff line number Diff line
@@ -748,8 +748,7 @@ 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,