[PATCH 1/5] iommu/arm-smmu: Restrict domain attributes to UNMANAGED domains
From: robin.murphy@arm.com (Robin Murphy)
Date: 2017-01-19 18:41:34
Also in:
linux-iommu
On 19/01/17 18:19, Will Deacon wrote:
The ARM SMMU drivers provide a DOMAIN_ATTR_NESTING domain attribute,
which allows callers of the IOMMU API to request that the page table
for a domain is installed at stage-2, if supported by the hardware.
Since setting this attribute only makes sense for UNMANAGED domains,
this patch returns -ENODEV if the domain_{get,set}_attr operations are
called on other domain types.For the sake of discussion, would it make sense to enforce this in domain_set_attr() itself? The intersection of drivers providing these callbacks and drivers supporting anything other than unmanaged domains is currently these two below, so it clearly wouldn't break anything to put this check in core code today. Looking forward, is there likely to be any plausible situation where users of a managed domain would be legitimate in mucking about with its attrs, on any platform? Robin.
quoted hunk ↗ jump to hunk
Signed-off-by: Will Deacon <redacted> --- drivers/iommu/arm-smmu-v3.c | 6 ++++++ drivers/iommu/arm-smmu.c | 6 ++++++ 2 files changed, 12 insertions(+)diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 4d6ec444a9d6..c254325b0c7a 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c@@ -1839,6 +1839,9 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, { struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -ENODEV; + switch (attr) { case DOMAIN_ATTR_NESTING: *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);@@ -1854,6 +1857,9 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain, int ret = 0; struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -ENODEV; + mutex_lock(&smmu_domain->init_mutex); switch (attr) {diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index a60cded8a6ed..a328ffb75509 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c@@ -1497,6 +1497,9 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, { struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -ENODEV; + switch (attr) { case DOMAIN_ATTR_NESTING: *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);@@ -1512,6 +1515,9 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain, int ret = 0; struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + if (domain->type != IOMMU_DOMAIN_UNMANAGED) + return -ENODEV; + mutex_lock(&smmu_domain->init_mutex); switch (attr) {