[PATCH] iommu/vt-d: Fix bind svm with multiple devices

[PATCH] iommu/vt-d: Fix bind svm with multiple devices

[Jacob Pan]

If multiple devices try to bind to the same mm/PASID, we need to
set up first level PASID entries for all the devices. The current
code does not consider this case which results in failed DMA for
devices after the first bind.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reported-by: Mike Campin <mike.campin@intel.com>
---
 drivers/iommu/intel-svm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 3a4b09a..f3d59d1 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -357,6 +357,21 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 		}
 
 		list_add_tail(&svm->list, &global_svm_list);
+	} else {
+		/*
+		 * Binding a new device with existing PASID, need to setup
+		 * the PASID entry.
+		 */
+		spin_lock(&iommu->lock);
+		ret = intel_pasid_setup_first_level(iommu, dev,
+						mm ? mm->pgd : init_mm.pgd,
+						svm->pasid, FLPT_DEFAULT_DID,
+						mm ? 0 : PASID_FLAG_SUPERVISOR_MODE);
+		spin_unlock(&iommu->lock);
+		if (ret) {
+			kfree(sdev);
+			goto out;
+		}
 	}
 	list_add_rcu(&sdev->list, &svm->devs);
 
-- 
2.7.4

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Re: [PATCH] iommu/vt-d: Fix bind svm with multiple devices

[Jacob Pan]

Hi Joerg & David,

Any feedback on this one? Thanks.

On Wed,  8 May 2019 12:22:46 -0700
Jacob Pan <jacob.jun.pan@linux.intel.com> wrote:

> If multiple devices try to bind to the same mm/PASID, we need to
> set up first level PASID entries for all the devices. The current
> code does not consider this case which results in failed DMA for
> devices after the first bind.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Reported-by: Mike Campin <mike.campin@intel.com>
> ---
>  drivers/iommu/intel-svm.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
> index 3a4b09a..f3d59d1 100644
> --- a/drivers/iommu/intel-svm.c
> +++ b/drivers/iommu/intel-svm.c
> @@ -357,6 +357,21 @@ int intel_svm_bind_mm(struct device *dev, int
> *pasid, int flags, struct svm_dev_ }
>  
>  		list_add_tail(&svm->list, &global_svm_list);
> +	} else {
> +		/*
> +		 * Binding a new device with existing PASID, need to
> setup
> +		 * the PASID entry.
> +		 */
> +		spin_lock(&iommu->lock);
> +		ret = intel_pasid_setup_first_level(iommu, dev,
> +						mm ? mm->pgd :
> init_mm.pgd,
> +						svm->pasid,
> FLPT_DEFAULT_DID,
> +						mm ? 0 :
> PASID_FLAG_SUPERVISOR_MODE);
> +		spin_unlock(&iommu->lock);
> +		if (ret) {
> +			kfree(sdev);
> +			goto out;
> +		}
>  	}
>  	list_add_rcu(&sdev->list, &svm->devs);
>  

[Jacob Pan]
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Re: [PATCH] iommu/vt-d: Fix bind svm with multiple devices

[Joerg Roedel]

On Wed, May 08, 2019 at 12:22:46PM -0700, Jacob Pan wrote:
> If multiple devices try to bind to the same mm/PASID, we need to
> set up first level PASID entries for all the devices. The current
> code does not consider this case which results in failed DMA for
> devices after the first bind.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Reported-by: Mike Campin <mike.campin@intel.com>
> ---
>  drivers/iommu/intel-svm.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)

Applied for v5.3, thanks.

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