[PATCH i-g-t v3 09/10] tests/intel/xe_svm: Add svm-mprotect test to verify SVM functionality with read-only memory access

[Bommu Krishnaiah]

svm-mprotect test ensures that the driver correctly handles invalid
GPU write attempts to read-only memory regions in the context of SVM scenarios.

Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
Cc: Oak Zeng <oak.zeng at intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 tests/intel/xe_svm.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tests/intel/xe_svm.c b/tests/intel/xe_svm.c
index 072a602b1..86c9e86b8 100644
--- a/tests/intel/xe_svm.c
+++ b/tests/intel/xe_svm.c
@@ -42,6 +42,9 @@
  *
  * SUBTEST: svm-benchmark
  * Description: Verify SVM performance with a simple benchmark test.
+ *
+ * SUBTEST: svm-mprotect
+ * Description: verify SVM functionality while accessing read only memory
  */
 
 #include <fcntl.h>
@@ -345,6 +348,38 @@ static void svm_benchmark(int fd, uint32_t vm, struct drm_xe_engine_class_instan
 	igt_info("engine class %d, engine id %d memset E2E bandwidth(include sync overhead) %.3f MiB/s\n", eci->engine_class, eci->engine_instance, bandwidth);
 }
 
+/**
+ * Use mprotect to mark a chunk of memory to be read only and submit
+ * GPU command to write to this read only memory. GPU write should
+ * fail and driver should detect an invalid access error.
+ */
+static void svm_mprotect(int fd, uint32_t vm, struct drm_xe_engine_class_instance *eci)
+{
+	uint64_t gpu_va = 0x1a0000;
+	size_t bo_size = xe_bb_size(fd, PAGE_ALIGN_UFENCE);
+	uint32_t *dst;
+	uint32_t size = 65536;
+
+	struct xe_buffer cmd_buf = {
+			.fd = fd,
+			.gpu_addr = (void *)(uintptr_t)gpu_va,
+			.vm = vm,
+			.size = bo_size,
+			.placement = vram_if_possible(fd, eci->gt_id),
+			.flag = DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+	};
+
+	dst = aligned_alloc(size, size);
+	mprotect(dst, size, PROT_READ);
+
+	xe_create_cmdbuf(&cmd_buf, insert_store, (uint64_t)dst, 0xc0ffee, eci);
+
+	igt_assert_eq(__xe_submit_cmd(&cmd_buf), -EIO);
+
+	xe_destroy_cmdbuf(&cmd_buf);
+	free(dst);
+}
+
 igt_main
 {
 	int fd;
@@ -389,6 +424,10 @@ igt_main
 		xe_for_each_engine(fd, hwe)
 			svm_benchmark(fd, vm, hwe);
 
+	igt_subtest_f("svm-mprotect")
+		xe_for_each_engine(fd, hwe)
+			svm_mprotect(fd, vm, hwe);
+
 	igt_fixture {
 		xe_vm_destroy(fd, vm);
 		drm_close_driver(fd);
-- 
2.25.1