[PATCH i-g-t] tests/xe_vm: Report OOM for vm_bind ioctl under memory pressure

[priyanka.dandamudi at intel.com]

From: Priyanka Dandamudi <priyanka.dandamudi at intel.com>

Add a test which create buffer objects on an LR vm and vm_binding
buffer objects in a loop until it reaches OOM.
This is to check that buffer objects on a single vm doesnot get evicted
and instead report with ENOMEM or ENOSPC in non fault mode.

v2: When vm_bind fails with oom even before the memory allocation goes
beyond visible vram size. Test should still pass when VRAM is smaller than
expected may be due to leaked VRAM memory with a warning.
VM bind error could be ENOMEM or ENOSPC for oom. VM bind should happen
atleast once for sanity check purpose. Modified code to handle
these changes.

Cc: Thomas Hellstrom <thomas.hellstrom at intel.com>
Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi at intel.com>
---
 tests/intel/xe_vm.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
index c1abb08bb..0c08b583d 100644
--- a/tests/intel/xe_vm.c
+++ b/tests/intel/xe_vm.c
@@ -2368,6 +2368,89 @@ static void invalid_vm_id(int fd)
 	do_ioctl_err(fd, DRM_IOCTL_XE_VM_DESTROY, &destroy, ENOENT);
 }
 
+/**
+ * SUBTEST: out-of-memory
+ * Description: Test if vm_bind ioctl results in oom
+ * when creating and vm_binding buffer objects on an LR vm beyond available visible vram size.
+ * Functionality: oom
+ * Test category: functionality test
+ */
+static void test_oom(int fd)
+{
+#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
+#define BO_SIZE xe_bb_size(fd, SZ_512M)
+#define MAX_BUFS (int)(xe_visible_vram_size(fd, 0) / BO_SIZE)
+	uint64_t addr = 0x1a0000;
+	uint64_t vm_sync;
+	uint32_t bo[MAX_BUFS + 1];
+	uint32_t *data[MAX_BUFS + 1];
+	uint32_t vm;
+	struct drm_xe_sync sync[1] = {
+		{ .type = DRM_XE_SYNC_TYPE_USER_FENCE, .flags = DRM_XE_SYNC_FLAG_SIGNAL,
+		  .timeline_value = USER_FENCE_VALUE },
+	};
+	size_t bo_size = BO_SIZE;
+	int total_bufs = MAX_BUFS;
+	int bind_vm = 0;
+	bool oom = false;
+
+	vm = xe_vm_create(fd, DRM_XE_VM_CREATE_FLAG_LR_MODE, 0);
+	for (int iter = 0; iter <= total_bufs; iter++) {
+		int err = 0;
+		bo[iter] = xe_bo_create(fd, 0, bo_size,
+					vram_if_possible(fd, 0),
+					DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING |
+					DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
+
+		sync[0].addr = to_user_pointer(&vm_sync);
+		err = __xe_vm_bind(fd, vm, 0, bo[iter], 0,
+				   addr + bo_size * iter, bo_size,
+				   DRM_XE_VM_BIND_OP_MAP, 0, sync,
+				   1, 0, DEFAULT_PAT_INDEX, 0);
+
+		if (err) {
+			if (err == -ENOMEM || err == -ENOSPC) {
+				oom = true;
+				break;
+			}
+			else
+				igt_assert_f(err, "Unexpected error %d for vm bind\n",
+					     err);
+		}
+		else
+			bind_vm = bind_vm + 1;
+
+		xe_wait_ufence(fd, &vm_sync, USER_FENCE_VALUE, 0, NSEC_PER_SEC);
+		vm_sync = 0;
+		data[iter] = xe_bo_map(fd, bo[iter], bo_size);
+		memset(data[iter], 0, bo_size);
+	}
+
+	igt_assert_f(oom, "OOM scenario is not working as expected\n");
+
+	if (bind_vm < total_bufs - 1) {
+		for (int iter = 0; iter < bind_vm; iter++) {
+			sync[0].addr = to_user_pointer(&vm_sync);
+			xe_vm_unbind_async(fd, vm, 0, 0, addr + bo_size * iter, bo_size,
+					   sync, 1);
+			xe_wait_ufence(fd, &vm_sync, USER_FENCE_VALUE, 0, NSEC_PER_SEC);
+			munmap(data[iter], bo_size);
+			gem_close(fd, bo[iter]);
+		}
+		igt_warn("VRAM was smaller than estimated, may due to leaked VRAM memory\n");
+	}
+	else {
+		for (int iter = 0; iter < total_bufs; iter++) {
+			sync[0].addr = to_user_pointer(&vm_sync);
+			xe_vm_unbind_async(fd, vm, 0, 0, addr + bo_size * iter, bo_size,
+					   sync, 1);
+			xe_wait_ufence(fd, &vm_sync, USER_FENCE_VALUE, 0, NSEC_PER_SEC);
+			munmap(data[iter], bo_size);
+			gem_close(fd, bo[iter]);
+		}
+	}
+}
+
 igt_main
 {
 	struct drm_xe_engine_class_instance *hwe, *hwe_non_copy = NULL;
@@ -2759,6 +2842,12 @@ igt_main
 	igt_subtest("invalid-vm-id")
 		invalid_vm_id(fd);
 
+	igt_subtest("out-of-memory") {
+		igt_require(xe_has_vram(fd));
+		igt_assert(xe_visible_vram_size(fd, 0));
+		test_oom(fd);
+	}
+
 	igt_fixture
 		drm_close_driver(fd);
 }
-- 
2.34.1