[PATCH 6.6 281/638] iommu/arm-smmu-v3: Check that the RID domain is S1 in SVA

Sasha Levin
2024-03-24T23:05:53Z

From: Jason Gunthorpe <jgg@nvidia.com>

[ Upstream commit ae91f6552c301e5e8569667e9d5440d5f75a90c4 ]

The SVA code only works if the RID domain is a S1 domain and has already
installed the cdtable.

Originally the check for this was in arm_smmu_sva_bind() but when the op
was removed the test didn't get copied over to the new
arm_smmu_sva_set_dev_pasid().

Without the test wrong usage usually will hit a WARN_ON() in
arm_smmu_write_ctx_desc() due to a missing ctx table.

However, the next patches wil change things so that an IDENTITY domain is
not a struct arm_smmu_domain and this will get into memory corruption if
the struct is wrongly casted.

Fail in arm_smmu_sva_set_dev_pasid() if the STE does not have a S1, which
is a proxy for the STE having a pointer to the CD table. Write it in a way
that will be compatible with the next patches.

Fixes: 386fa64fd52b ("arm-smmu-v3/sva: Add SVA domain support")
Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Closes: https://lore.kernel.org/linux-iommu/2a828e481416405fb3a4cceb9e075a59@huawei.com/
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/11-v6-96275f25c39d+2d4-smmuv3_newapi_p1_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

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 8a16cd3ef487c..cc33e8297b8d0 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
@@ -352,7 +352,13 @@ __arm_smmu_sva_bind(struct device *dev, struct mm_struct *mm)
struct arm_smmu_bond *bond;
struct arm_smmu_master *master = dev_iommu_priv_get(dev);
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+ struct arm_smmu_domain *smmu_domain;
+
+ if (!(domain->type & __IOMMU_DOMAIN_PAGING))
+ return -ENODEV;
+ smmu_domain = to_smmu_domain(domain);
+ if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1)
+ return -ENODEV;

if (!master || !master->sva_enabled)
return ERR_PTR(-ENODEV);
--
2.43.0