iommu/arm-smmu-v3: Do not allow a SVA domain to be set on the wrong P…

…ASID

The SVA code is wired to assume that the SVA is programmed onto the
mm->pasid. The current core code always does this, so it is fine.

Add a check for clarity.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v6-228e7adf25eb+4155-smmuv3_newapi_p2_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>

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

@@ -569,6 +569,9 @@ static int arm_smmu_sva_set_dev_pasid(struct iommu_domain *domain,
 	int ret = 0;
 	struct mm_struct *mm = domain->mm;
 
+	if (mm_get_enqcmd_pasid(mm) != id)
+		return -EINVAL;
+
 	mutex_lock(&sva_lock);
 	ret = __arm_smmu_sva_bind(dev, id, mm);
 	mutex_unlock(&sva_lock);