[PATCH v3 08/11] iommufd/selftest: Add IOMMU_VIOMMU_TYPE_SELFTEST

[Nicolin Chen]

Implement the viommu alloc/free functions to increase/reduce refcount of
its dependent mock iommu device. User space can verify this loop via the
IOMMU_VIOMMU_TYPE_SELFTEST.

Signed-off-by: Nicolin Chen <nicol...@nvidia.com>
---
 drivers/iommu/iommufd/iommufd_test.h |  2 ++
 drivers/iommu/iommufd/selftest.c     | 45 ++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/drivers/iommu/iommufd/iommufd_test.h 
b/drivers/iommu/iommufd/iommufd_test.h
index f4bc23a92f9a..edced4ac7cd3 100644
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -180,4 +180,6 @@ struct iommu_hwpt_invalidate_selftest {
        __u32 iotlb_id;
 };
 
+#define IOMMU_VIOMMU_TYPE_SELFTEST 0xdeadbeef
+
 #endif
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index a89a865617db..4fcf475facb1 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -132,6 +132,10 @@ struct mock_iommu_domain_nested {
        u32 iotlb[MOCK_NESTED_DOMAIN_IOTLB_NUM];
 };
 
+struct mock_viommu {
+       struct iommufd_viommu core;
+};
+
 enum selftest_obj_type {
        TYPE_IDEV,
 };
@@ -544,6 +548,46 @@ static int mock_dev_disable_feat(struct device *dev, enum 
iommu_dev_features fea
        return 0;
 }
 
+static void mock_viommu_free(struct iommufd_viommu *viommu)
+{
+       struct mock_iommu_device *mock_iommu =
+               container_of(viommu->iommu_dev, struct mock_iommu_device,
+                            iommu_dev);
+
+       if (refcount_dec_and_test(&mock_iommu->users))
+               wake_up_interruptible_all(&mock_iommu->wait);
+
+       /* iommufd core frees mock_viommu and viommu */
+}
+
+static struct iommufd_viommu_ops mock_viommu_ops = {
+       .free = mock_viommu_free,
+};
+
+static struct iommufd_viommu *
+mock_viommu_alloc(struct iommu_device *iommu_dev, struct iommu_domain *domain,
+                 struct iommufd_ctx *ictx, unsigned int viommu_type)
+{
+       struct mock_iommu_device *mock_iommu =
+               container_of(iommu_dev, struct mock_iommu_device, iommu_dev);
+       struct mock_viommu *mock_viommu;
+
+       if (viommu_type != IOMMU_VIOMMU_TYPE_SELFTEST)
+               return ERR_PTR(-EOPNOTSUPP);
+
+       mock_viommu = iommufd_viommu_alloc(ictx, mock_viommu, core,
+                                          &mock_viommu_ops);
+       if (IS_ERR(mock_viommu))
+               return ERR_CAST(mock_viommu);
+
+       if (!refcount_inc_not_zero(&mock_iommu->users)) {
+               kfree(mock_viommu);
+               return ERR_PTR(-ENXIO);
+       }
+
+       return &mock_viommu->core;
+}
+
 static const struct iommu_ops mock_ops = {
        /*
         * IOMMU_DOMAIN_BLOCKED cannot be returned from def_domain_type()
@@ -563,6 +607,7 @@ static const struct iommu_ops mock_ops = {
        .dev_enable_feat = mock_dev_enable_feat,
        .dev_disable_feat = mock_dev_disable_feat,
        .user_pasid_table = true,
+       .viommu_alloc = mock_viommu_alloc,
        .default_domain_ops =
                &(struct iommu_domain_ops){
                        .free = mock_domain_free,
-- 
2.43.0