[PATCH v1 05/20] iommu/amd: Implement test_dev callbacks to domain ops

Nicolin Chen
2025-10-13T00:07:53Z

Move sanity and compatibility tests from the attach_dev callbacks to the
new test_dev callback functions. The IOMMU core makes sure an attach_dev
call must be invoked after a successful test_dev call.

Correct the errno upon malloc failure. Also, drop the function prototype
of iommu_sva_set_dev_pasid() from the header and make it static, as only
pasid.c uses it.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/iommu/amd/amd_iommu.h | 3 ---
drivers/iommu/amd/iommu.c | 27 +++++++++++++++++++--------
drivers/iommu/amd/pasid.c | 29 +++++++++++++++++++----------
3 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h
index 9b4b589a54b57..f99fa4da34996 100644
--- a/drivers/iommu/amd/amd_iommu.h
+++ b/drivers/iommu/amd/amd_iommu.h
@@ -52,9 +52,6 @@ struct protection_domain *protection_domain_alloc(void);
struct iommu_domain *amd_iommu_domain_alloc_sva(struct device *dev,
struct mm_struct *mm);
void amd_iommu_domain_free(struct iommu_domain *dom);
-int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
- struct device *dev, ioasid_t pasid,
- struct iommu_domain *old);
void amd_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid,
struct iommu_domain *domain);

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index e16ad510c8c8a..dc0406427dcf8 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -70,6 +70,8 @@ int amd_iommu_max_glx_val = -1;
*/
DEFINE_IDA(pdom_ids);

+static int amd_iommu_test_device(struct iommu_domain *dom, struct device *dev,
+ ioasid_t pasid, struct iommu_domain *old);
static int amd_iommu_attach_device(struct iommu_domain *dom, struct device *dev,
struct iommu_domain *old);

@@ -2670,6 +2672,7 @@ static struct iommu_domain blocked_domain = {
static struct protection_domain identity_domain;

static const struct iommu_domain_ops identity_domain_ops = {
+ .test_dev = amd_iommu_test_device,
.attach_dev = amd_iommu_attach_device,
};

@@ -2686,12 +2689,26 @@ void amd_iommu_init_identity_domain(void)
protection_domain_init(&identity_domain);
}

+static int amd_iommu_test_device(struct iommu_domain *dom, struct device *dev,
+ ioasid_t pasid, struct iommu_domain *old)
+{
+ struct amd_iommu *iommu = get_amd_iommu_from_dev(dev);
+
+ /*
+ * Restrict to devices with compatible IOMMU hardware support
+ * when enforcement of dirty tracking is enabled.
+ */
+ if (dom->dirty_ops && !amd_iommu_hd_support(iommu))
+ return -EINVAL;
+
+ return 0;
+}
+
static int amd_iommu_attach_device(struct iommu_domain *dom, struct device *dev,
struct iommu_domain *old)
{
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
struct protection_domain *domain = to_pdomain(dom);
- struct amd_iommu *iommu = get_amd_iommu_from_dev(dev);
int ret;

/*
@@ -2703,13 +2720,6 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, struct device *dev,

dev_data->defer_attach = false;

- /*
- * Restrict to devices with compatible IOMMU hardware support
- * when enforcement of dirty tracking is enabled.
- */
- if (dom->dirty_ops && !amd_iommu_hd_support(iommu))
- return -EINVAL;
-
if (dev_data->domain)
detach_device(dev);

@@ -3047,6 +3057,7 @@ const struct iommu_ops amd_iommu_ops = {
.def_domain_type = amd_iommu_def_domain_type,
.page_response = amd_iommu_page_response,
.default_domain_ops = &(const struct iommu_domain_ops) {
+ .test_dev = amd_iommu_test_device,
.attach_dev = amd_iommu_attach_device,
.map_pages = amd_iommu_map_pages,
.unmap_pages = amd_iommu_unmap_pages,
diff --git a/drivers/iommu/amd/pasid.c b/drivers/iommu/amd/pasid.c
index 77c8e9a91cbca..474494a66dd40 100644
--- a/drivers/iommu/amd/pasid.c
+++ b/drivers/iommu/amd/pasid.c
@@ -99,31 +99,39 @@ static const struct mmu_notifier_ops sva_mn = {
.release = sva_mn_release,
};

-int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
- struct device *dev, ioasid_t pasid,
- struct iommu_domain *old)
+static int iommu_sva_test_dev(struct iommu_domain *domain, struct device *dev,
+ ioasid_t pasid, struct iommu_domain *old)
{
- struct pdom_dev_data *pdom_dev_data;
- struct protection_domain *sva_pdom = to_pdomain(domain);
struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
- unsigned long flags;
- int ret = -EINVAL;

if (old)
return -EOPNOTSUPP;

/* PASID zero is used for requests from the I/O device without PASID */
if (!is_pasid_valid(dev_data, pasid))
- return ret;
+ return -EINVAL;

/* Make sure PASID is enabled */
if (!is_pasid_enabled(dev_data))
- return ret;
+ return -EINVAL;
+
+ return 0;
+}
+
+static int iommu_sva_set_dev_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid,
+ struct iommu_domain *old)
+{
+ struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
+ struct protection_domain *sva_pdom = to_pdomain(domain);
+ struct pdom_dev_data *pdom_dev_data;
+ unsigned long flags;
+ int ret;

/* Add PASID to protection domain pasid list */
pdom_dev_data = kzalloc(sizeof(*pdom_dev_data), GFP_KERNEL);
if (pdom_dev_data == NULL)
- return ret;
+ return -ENOMEM;

pdom_dev_data->pasid = pasid;
pdom_dev_data->dev_data = dev_data;
@@ -175,6 +183,7 @@ static void iommu_sva_domain_free(struct iommu_domain *domain)
}

static const struct iommu_domain_ops amd_sva_domain_ops = {
+ .test_dev = iommu_sva_test_dev,
.set_dev_pasid = iommu_sva_set_dev_pasid,
.free = iommu_sva_domain_free
};
--
2.43.0