gpu: nvgpu: unit: increase coverage of mm.vm

This patch brings a number of changes to the mm.vm unit test:
- test_map_buf: add steps to check for error cases and increase
  coverage.
- test_map_buf_gpu_va: add steps to check for error cases and
  increase coverage.
- test_init_error_paths: new test to target all possible error
  paths in the VM init code.
- test_map_buffer_error_cases: new test to target all possible
  error paths in the buffer mapping logic.
- test_nvgpu_vm_alloc_va: new test to target the nvgpu_vm_alloc_va
  API and also target error paths.
- test_vm_bind: new test to target the nvgpu_vm_bind_channel API
  and also target error paths.
- test_vm_aspace_id: new test to target the vm_aspace_id API
  and also target error paths.

JIRA NVGPU-909

Change-Id: I755c89a6de09376d2624130a98966c172d850bfe
Signed-off-by: Nicolas Benech <nbenech@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2217679
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/libnvgpu-drv_safe.export

@@ -106,6 +106,7 @@ nvgpu_allocator_init
 nvgpu_aperture_mask
 nvgpu_bar1_readl
 nvgpu_bar1_writel
+nvgpu_big_pages_possible
 nvgpu_bitmap_clear
 nvgpu_bitmap_set
 nvgpu_bsearch
@@ -393,14 +394,21 @@ nvgpu_udelay
 nvgpu_usermode_writel
 nvgpu_usleep_range
 nvgpu_vfree_impl
+nvgpu_vm_alloc_va
 nvgpu_vm_area_alloc
 nvgpu_vm_area_free
+nvgpu_vm_bind_channel
+nvgpu_vm_do_init
 nvgpu_vm_find_mapped_buf
+nvgpu_vm_find_mapped_buf_less_than
+nvgpu_vm_find_mapped_buf_range
+nvgpu_vm_get_buffers
 nvgpu_vm_init
 nvgpu_vm_map
 nvgpu_vm_mapping_batch_finish
 nvgpu_vm_mapping_batch_start
 nvgpu_vm_put
+nvgpu_vm_put_buffers
 nvgpu_vm_unmap
 nvgpu_vzalloc_impl
 nvgpu_writel

userspace/units/mm/vm/vm.h

@@ -20,6 +20,9 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#ifndef UNIT_VM_H
+#define UNIT_VM_H
+
 struct gk20a;
 struct unit_module;
 
@@ -45,12 +48,24 @@ struct unit_module;
  *   - Low hole size = 64MB
  *   - Address space size = 128GB
  *   - Kernel reserved space size = 4GB
+ * - Ensure that no buffers are already mapped.
+ * - Use nvgpu_big_pages_possible() to ensure big pages are possible in the
+ *   current condition, and check its error handling.
  * - Map a 4KB buffer into the VM
  *   - Check that the resulting GPU virtual address is aligned to 4KB
  *   - Unmap the buffer
  * - Map a 64KB buffer into the VM
  *   - Check that the resulting GPU virtual address is aligned to 64KB
  *   - Unmap the buffer
+ * - Check a few corner cases:
+ *   - If big pages explicitly disabled at gk20a level, mapping should still
+ *     succeed.
+ *   - If big pages explicitly disabled at the VM level, mapping should still
+ *     succeed.
+ *   - If VAs are not unified, mapping should still succeed.
+ *   - If IOMMU is disabled, mapping should still succeed.
+ *   - If the buffer to map is smaller than the big page size, mapping should
+ *     still succeed.
  * - Uninitialize the VM
  *
  * Output: Returns PASS if the steps above were executed successfully. FAIL
@@ -79,10 +94,20 @@ int test_map_buf(struct unit_module *m, struct gk20a *g, void *__args);
  *   - Check that the resulting GPU virtual address is aligned to 4KB
  *   - Check that the resulting GPU VA is the same as the requested GPU VA
  *   - Unmap the buffer
+ * - Ensure that requesting to map the same buffer at the same address still
+ *   reports success and does not result in an actual extra mapping.
  * - Map a 64KB buffer into the VM at a specific GPU virtual address
  *   - Check that the resulting GPU virtual address is aligned to 64KB
  *   - Check that the resulting GPU VA is the same as the requested GPU VA
  *   - Unmap the buffer
+ * - Check a few corner cases:
+ *   - If VA is not unified, mapping should still succeed.
+ *   - If VA is not unified, GPU_VA fixed below nvgpu_gmmu_va_small_page_limit,
+ *     mapping should still succeed.
+ *   - Do not allocate a VM area which will force an allocation with small
+ *     pages.
+ *   - Do not unmap the buffer so that nvgpu_vm_put can take care of the cleanup
+ *     of both the mapping and the VM area.
  * - Uninitialize the VM
  *
  * Output: Returns PASS if the steps above were executed successfully. FAIL
@@ -114,3 +139,173 @@ int test_map_buf_gpu_va(struct unit_module *m, struct gk20a *g, void *__args);
  * otherwise.
  */
 int test_batch(struct unit_module *m, struct gk20a *g, void *__args);
+
+/**
+ * Test specification for: test_init_error_paths
+ *
+ * Description: This test exercises the VM unit initialization code and covers
+ * a number of error paths.
+ *
+ * Test Type: Feature based, error injection
+ *
+ * Input: None
+ *
+ * Steps:
+ * - Create VM parameters with the following characteristics:
+ *   - 64KB large page support enabled
+ *   - Low hole size = 64MB
+ *   - Address space size = 128GB
+ *   - Kernel reserved space size = 4GB
+ * - Inject an error to make the allocation for struct vm_gk20a to fail and
+ *   check that nvgpu_vm_init returns NULL.
+ * - Set an invalid aperture size and ensure that nvgpu_vm_do_init asserts.
+ * - Try to initialize a guest managed VM with kernel space and ensure that
+ *   nvgpu_vm_do_init asserts.
+ * - Set gk20a to report a virtual GPU and ensure that nvgpu_vm_do_init returns
+ *   a failure when VM is guest managed.
+ * - Ensure that nvgpu_vm_do_init reports a failure if the vm_as_alloc_share HAL
+ *   fails.
+ * - Set invalid parameters (low hole above the small page limit) and ensure
+ *   that nvgpu_vm_do_init asserts.
+ * - Inject an error to cause a failure within nvgpu_allocator_init for the user
+ *   VMA and ensure that nvgpu_vm_do_init reports a failure.
+ * - Inject an error to cause a failure within nvgpu_allocator_init for the
+ *   kernel VMA and ensure that nvgpu_vm_do_init reports a failure.
+ * - Set invalid parameters (low hole is 0 with a non unified VA) and ensure
+ *   that nvgpu_vm_do_init reports a failure.
+ * - Ensure that nvgpu_vm_do_init succeeds with big pages enabled and a non
+ *   unified VA space.
+ * - Ensure that nvgpu_vm_do_init succeeds with big pages disabled.
+ * - Ensure that nvgpu_vm_do_init succeeds with no user VMA.
+ * - Uninitialize the VM
+ *
+ * Output: Returns PASS if the steps above were executed successfully. FAIL
+ * otherwise.
+ */
+int test_init_error_paths(struct unit_module *m, struct gk20a *g, void *__args);
+
+/**
+ * Test specification for: test_map_buffer_error_cases
+ *
+ * Description: This test targets error handling within the nvgpu_vm_map API.
+ *
+ * Test Type: Error injection
+ *
+ * Input: None
+ *
+ * Steps:
+ * - Initialize a VM with the following characteristics:
+ *   - 64KB large page support enabled
+ *   - Low hole size = 64MB
+ *   - Address space size = 128GB
+ *   - Kernel reserved space size = 4GB
+ * - Ensure that if a non-fixed offset with userspace managed VM is in use,
+ *   the nvgpu_vm_map API reports a failure.
+ * - Ensure that if an invalid buffer size is provided,the nvgpu_vm_map API
+ *   reports a failure.
+ * - Inject a memory allocation error at allocation 0 and ensure that
+ *   nvgpu_vm_map reports a failure of type ENOMEM. (This makes mapped_buffer
+ *   memory allocation to fail.)
+ * - Try to map an oversized buffer of 1GB and ensure that nvgpu_vm_map reports
+ *   a failure of type EINVAL.
+ * - Inject a memory allocation error at allocation 40 and ensure that
+ *   nvgpu_vm_map reports a failure of type ENOMEM. (This makes the call to
+ *   g->ops.mm.gmmu.map to fail.)
+ * - Uninitialize the VM
+ *
+ * Output: Returns PASS if the steps above were executed successfully. FAIL
+ * otherwise.
+ */
+int test_map_buffer_error_cases(struct unit_module *m, struct gk20a *g,
+	void *__args);
+
+/**
+ * Test specification for: test_nvgpu_vm_alloc_va
+ *
+ * Description: This test targets the nvgpu_vm_alloc_va API.
+ *
+ * Test Type: Feature based, Error injection
+ *
+ * Input: None
+ *
+ * Steps:
+ * - Initialize a VM with the following characteristics:
+ *   - 64KB large page support enabled
+ *   - Low hole size = 64MB
+ *   - Address space size = 128GB
+ *   - Kernel reserved space size = 4GB
+ * - Set the VM as guest managed and call nvgpu_vm_alloc_va and ensure that it
+ *   fails (returns NULL) as a guest managed VM cannot allocate VA spaces.
+ * - Call nvgpu_vm_alloc_va with an invalid page size and ensure that it fails
+ *   (returns NULL).
+ * - Call nvgpu_vm_alloc_va with an unsupported page size index
+ *   (GMMU_PAGE_SIZE_BIG) and ensure that it fails (returns NULL).
+ * - Inject a memory allocation error at allocation 0 and ensure that
+ *   nvgpu_vm_alloc_va reports a failure (returns NULL). (This makes the PTE
+ *   memory allocation to fail.)
+ * - Call nvgpu_vm_alloc_va with valid parameters and ensure that it succeeds
+ *   (returns a non-NULL address.)
+ * - Uninitialize the VM
+ *
+ * Output: Returns PASS if the steps above were executed successfully. FAIL
+ * otherwise.
+ */
+int test_nvgpu_vm_alloc_va(struct unit_module *m, struct gk20a *g,
+	void *__args);
+
+/**
+ * Test specification for: test_vm_bind
+ *
+ * Description: This test targets the nvgpu_vm_bind_channel API.
+ *
+ * Test Type: Feature based
+ *
+ * Input: None
+ *
+ * Steps:
+ * - Initialize a VM with the following characteristics:
+ *   - 64KB large page support enabled
+ *   - Low hole size = 64MB
+ *   - Address space size = 128GB
+ *   - Kernel reserved space size = 4GB
+ * - Create an empty nvgpu_channel instance.
+ * - Call the nvgpu_vm_bind_channel API with the empty channel instance.
+ * - Ensure that after the call, the VM pointer in the nvgpu_channel structure
+ *   points to the VM in use in the test.
+ * - Uninitialize the VM
+ *
+ * Output: Returns PASS if the steps above were executed successfully. FAIL
+ * otherwise.
+ */
+int test_vm_bind(struct unit_module *m, struct gk20a *g, void *__args);
+
+/**
+ * Test specification for: test_vm_aspace_id
+ *
+ * Description: This test targets the vm_aspace_id API.
+ *
+ * Test Type: Feature based
+ *
+ * Input: None
+ *
+ * Steps:
+ * - Initialize a VM with the following characteristics:
+ *   - 64KB large page support enabled
+ *   - Low hole size = 64MB
+ *   - Address space size = 128GB
+ *   - Kernel reserved space size = 4GB
+ * - Call vm_aspace_id on the test VM and ensure it reports an invalid value
+ *   (-1) since the AS share is not set.
+ * - Create an AS share structure and set its id to 0. Assign the AS share to
+ *   the test VM.
+ * - Call vm_aspace_id on the test VM and ensure it reports a value of 0.
+ * - Uninitialize the VM
+ *
+ * Output: Returns PASS if the steps above were executed successfully. FAIL
+ * otherwise.
+ */
+int test_vm_aspace_id(struct unit_module *m, struct gk20a *g, void *__args);
+
+
+/** }@ */
+#endif /* UNIT_VM_H */