iommu/arm-smmu-v3: Fix incorrect return in arm_smmu_attach_dev

After commit 48e7b8e284e5 ("iommu/arm-smmu-v3: Remove
arm_smmu_domain_finalise() during attach"), an error code is not
returned on the attach path when the smmu does not match with the
domain. This causes problems with VFIO because
vfio_iommu_type1_attach_group() relies on this check to determine domain
compatability.

Re-instate the -EINVAL return value when the SMMU doesn't match on the
device attach path.

Fixes: 48e7b8e284e5 ("iommu/arm-smmu-v3: Remove arm_smmu_domain_finalise() during attach")
Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
Link: https://lore.kernel.org/r/20250422112951.2027969-1-xiaqinxin@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index b4c21aaed1266a025167e03a7e616c6bdc7a6c66..f50c26596416877786d5ea1f099223a9b60907c1 100644 (file)
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2953,7 +2953,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
        smmu = master->smmu;
 
        if (smmu_domain->smmu != smmu)
-               return ret;
+               return -EINVAL;
 
        if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
                cdptr = arm_smmu_alloc_cd_ptr(master, IOMMU_NO_PASID);