iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl

Add a mock_domain_hw_info function and an iommu_test_hw_info data
structure. This allows to test the IOMMU_GET_HW_INFO ioctl passing the
test_reg value for the mock_dev.

Link: https://lore.kernel.org/r/20230818101033.4100-5-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h
index 258de2253b61de1df35487fbd3d739c9636b8a57..3f3644375bf13c8fa78600f1f9e15d893195af65 100644 (file)
--- a/drivers/iommu/iommufd/iommufd_test.h
+++ b/drivers/iommu/iommufd/iommufd_test.h
@@ -100,4 +100,13 @@ struct iommu_test_cmd {
 };
 #define IOMMU_TEST_CMD _IO(IOMMUFD_TYPE, IOMMUFD_CMD_BASE + 32)
 
+/* Mock structs for IOMMU_DEVICE_GET_HW_INFO ioctl */
+#define IOMMU_HW_INFO_TYPE_SELFTEST    0xfeedbeef
+#define IOMMU_HW_INFO_SELFTEST_REGVAL  0xdeadbeef
+
+struct iommu_test_hw_info {
+       __u32 flags;
+       __u32 test_reg;
+};
+
 #endif

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 9223ff3f23f9dd18826cd814c8fa8a38f7043584..90e7c5400282603b140651c8db0e52647c82cc0d 100644 (file)
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -131,6 +131,21 @@ static struct iommu_domain mock_blocking_domain = {
        .ops = &mock_blocking_ops,
 };
 
+static void *mock_domain_hw_info(struct device *dev, u32 *length, u32 *type)
+{
+       struct iommu_test_hw_info *info;
+
+       info = kzalloc(sizeof(*info), GFP_KERNEL);
+       if (!info)
+               return ERR_PTR(-ENOMEM);
+
+       info->test_reg = IOMMU_HW_INFO_SELFTEST_REGVAL;
+       *length = sizeof(*info);
+       *type = IOMMU_HW_INFO_TYPE_SELFTEST;
+
+       return info;
+}
+
 static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
 {
        struct mock_iommu_domain *mock;
@@ -290,6 +305,7 @@ static struct iommu_device *mock_probe_device(struct device *dev)
 static const struct iommu_ops mock_ops = {
        .owner = THIS_MODULE,
        .pgsize_bitmap = MOCK_IO_PAGE_SIZE,
+       .hw_info = mock_domain_hw_info,
        .domain_alloc = mock_domain_alloc,
        .capable = mock_domain_capable,
        .set_platform_dma_ops = mock_domain_set_plaform_dma_ops,

diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index 8acd0af37aa5e8352c4b3f48867fd38619e29ac4..33d08600be13d6c23cf7b36ef6ef8ab6145b4ecc 100644 (file)
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -113,6 +113,7 @@ TEST_F(iommufd, cmd_length)
        }
 
        TEST_LENGTH(iommu_destroy, IOMMU_DESTROY);
+       TEST_LENGTH(iommu_hw_info, IOMMU_GET_HW_INFO);
        TEST_LENGTH(iommu_ioas_alloc, IOMMU_IOAS_ALLOC);
        TEST_LENGTH(iommu_ioas_iova_ranges, IOMMU_IOAS_IOVA_RANGES);
        TEST_LENGTH(iommu_ioas_allow_iovas, IOMMU_IOAS_ALLOW_IOVAS);
@@ -185,6 +186,7 @@ FIXTURE(iommufd_ioas)
        uint32_t ioas_id;
        uint32_t stdev_id;
        uint32_t hwpt_id;
+       uint32_t device_id;
        uint64_t base_iova;
 };
 
@@ -211,7 +213,7 @@ FIXTURE_SETUP(iommufd_ioas)
 
        for (i = 0; i != variant->mock_domains; i++) {
                test_cmd_mock_domain(self->ioas_id, &self->stdev_id,
-                                    &self->hwpt_id, NULL);
+                                    &self->hwpt_id, &self->device_id);
                self->base_iova = MOCK_APERTURE_START;
        }
 }
@@ -290,6 +292,40 @@ TEST_F(iommufd_ioas, ioas_area_auto_destroy)
        }
 }
 
+TEST_F(iommufd_ioas, get_hw_info)
+{
+       struct iommu_test_hw_info buffer_exact;
+       struct iommu_test_hw_info_buffer_larger {
+               struct iommu_test_hw_info info;
+               uint64_t trailing_bytes;
+       } buffer_larger;
+       struct iommu_test_hw_info_buffer_smaller {
+               __u32 flags;
+       } buffer_smaller;
+
+       if (self->device_id) {
+               /* Provide a zero-size user_buffer */
+               test_cmd_get_hw_info(self->device_id, NULL, 0);
+               /* Provide a user_buffer with exact size */
+               test_cmd_get_hw_info(self->device_id, &buffer_exact, sizeof(buffer_exact));
+               /*
+                * Provide a user_buffer with size larger than the exact size to check if
+                * kernel zero the trailing bytes.
+                */
+               test_cmd_get_hw_info(self->device_id, &buffer_larger, sizeof(buffer_larger));
+               /*
+                * Provide a user_buffer with size smaller than the exact size to check if
+                * the fields within the size range still gets updated.
+                */
+               test_cmd_get_hw_info(self->device_id, &buffer_smaller, sizeof(buffer_smaller));
+       } else {
+               test_err_get_hw_info(ENOENT, self->device_id,
+                                    &buffer_exact, sizeof(buffer_exact));
+               test_err_get_hw_info(ENOENT, self->device_id,
+                                    &buffer_larger, sizeof(buffer_larger));
+       }
+}
+
 TEST_F(iommufd_ioas, area)
 {
        int i;

diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c
index d4c552e5694812e991e4f950e89d83ffc500d4c5..a220ca2a689d160c95129d0bc281ed63dfb38c73 100644 (file)
--- a/tools/testing/selftests/iommu/iommufd_fail_nth.c
+++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c
@@ -576,6 +576,7 @@ TEST_FAIL_NTH(basic_fail_nth, access_pin_domain)
 /* device.c */
 TEST_FAIL_NTH(basic_fail_nth, device)
 {
+       struct iommu_test_hw_info info;
        uint32_t ioas_id;
        uint32_t ioas_id2;
        uint32_t stdev_id;
@@ -611,6 +612,9 @@ TEST_FAIL_NTH(basic_fail_nth, device)
                                  &idev_id))
                return -1;
 
+       if (_test_cmd_get_hw_info(self->fd, idev_id, &info, sizeof(info)))
+               return -1;
+
        if (_test_cmd_hwpt_alloc(self->fd, idev_id, ioas_id, &hwpt_id))
                return -1;
 

diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 70353e68e5997fafbf693e1fc68e2f329c311501..e0753d03ecaa8576005120cf86dd47a529df1f94 100644 (file)
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -21,6 +21,10 @@ static unsigned long BUFFER_SIZE;
 
 static unsigned long PAGE_SIZE;
 
+#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
+#define offsetofend(TYPE, MEMBER) \
+       (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
+
 /*
  * Have the kernel check the refcount on pages. I don't know why a freshly
  * mmap'd anon non-compound page starts out with a ref of 3
@@ -348,3 +352,61 @@ static void teardown_iommufd(int fd, struct __test_metadata *_metadata)
        })
 
 #endif
+
+/* @data can be NULL */
+static int _test_cmd_get_hw_info(int fd, __u32 device_id,
+                                void *data, size_t data_len)
+{
+       struct iommu_test_hw_info *info = (struct iommu_test_hw_info *)data;
+       struct iommu_hw_info cmd = {
+               .size = sizeof(cmd),
+               .dev_id = device_id,
+               .data_len = data_len,
+               .data_uptr = (uint64_t)data,
+       };
+       int ret;
+
+       ret = ioctl(fd, IOMMU_GET_HW_INFO, &cmd);
+       if (ret)
+               return ret;
+
+       assert(cmd.out_data_type == IOMMU_HW_INFO_TYPE_SELFTEST);
+
+       /*
+        * The struct iommu_test_hw_info should be the one defined
+        * by the current kernel.
+        */
+       assert(cmd.data_len == sizeof(struct iommu_test_hw_info));
+
+       /*
+        * Trailing bytes should be 0 if user buffer is larger than
+        * the data that kernel reports.
+        */
+       if (data_len > cmd.data_len) {
+               char *ptr = (char *)(data + cmd.data_len);
+               int idx = 0;
+
+               while (idx < data_len - cmd.data_len) {
+                       assert(!*(ptr + idx));
+                       idx++;
+               }
+       }
+
+       if (info) {
+               if (data_len >= offsetofend(struct iommu_test_hw_info, test_reg))
+                       assert(info->test_reg == IOMMU_HW_INFO_SELFTEST_REGVAL);
+               if (data_len >= offsetofend(struct iommu_test_hw_info, flags))
+                       assert(!info->flags);
+       }
+
+       return 0;
+}
+
+#define test_cmd_get_hw_info(device_id, data, data_len)         \
+       ASSERT_EQ(0, _test_cmd_get_hw_info(self->fd, device_id, \
+                                          data, data_len))
+
+#define test_err_get_hw_info(_errno, device_id, data, data_len) \
+       EXPECT_ERRNO(_errno,                                    \
+                    _test_cmd_get_hw_info(self->fd, device_id, \
+                                          data, data_len))