[PATCH v3 i-g-t 2/2] tests/intel/xe_vm: Add support for overcommit tests

Sobin Thomas
2026-03-04T11:05:18Z

Current tests focus on VM creation with basic mode selection and do not
support overcommit scenarios.

This change adds tests to verify overcommit behavior across different VM
modes.

Non-fault mode tests:
- vram-lr-defer: DEFER_BACKING rejects overcommit at bind time
- vram-lr-external-nodefer: Long-running mode with defer backing
- vram-no-lr: Non-LR mode

Fault mode tests:
- vram-lr-fault: Fault handling allows graceful overcommit via page
faults
- vram-lr-fault-no-overcommit: Verifies NO_VM_OVERCOMMIT blocks same-VM
BO eviction during VM_BIND while still allowing eviction during
pagefault OOM

These tests validate that VMs handle memory pressure appropriately based
on their configuration—rejecting at bind, failing at exec, or handling
it gracefully via page faults.

v2 - Added Additional test cases for LR mode and No Overcommit.

v3 - Refactored into single api call based on the VM / BO Flags.

Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
---
tests/intel/xe_vm.c | 494 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 494 insertions(+)

diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
index ccff8f804..61853a425 100644
--- a/tests/intel/xe_vm.c
+++ b/tests/intel/xe_vm.c
@@ -2376,6 +2376,488 @@ static void invalid_vm_id(int fd)
do_ioctl_err(fd, DRM_IOCTL_XE_VM_DESTROY, &destroy, ENOENT);
}

+static int wait_fault(int fd, uint32_t exec_queue, void *sync_data,
+ int64_t *timeout)
+{
+ uint64_t *user_fence = sync_data;
+ int64_t wait_ns = timeout ? *timeout : INT64_MAX;
+ int res;
+ #define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
+ (void)exec_queue;
+
+ res = __xe_wait_ufence(fd, user_fence, USER_FENCE_VALUE, exec_queue, &wait_ns);
+
+ return res;
+}
+
+static int wait_nonfault(int fd, uint32_t exec_queue, void *sync_data,
+ int64_t *timeout)
+{
+ struct drm_xe_sync *exec_sync = sync_data;
+
+ (void)exec_queue;
+ (void)timeout;
+
+ if (!syncobj_wait(fd, &exec_sync[0].handle, 1, INT64_MAX, 0,
+ NULL))
+ return -1;
+
+ return 0;
+}
+
+static int
+vm_overcommit_create_bo(int fd, uint32_t vm, size_t bo_size, uint32_t bo_flags,
+ uint16_t gt_id, bool use_vram, bool external,
+ uint32_t *bo)
+{
+ uint32_t placement;
+
+ if (use_vram) {
+ placement = vram_memory(fd, gt_id) ?: system_memory(fd);
+ igt_debug("Using VRAM placement: 0x%x\n", placement);
+ } else {
+ igt_debug("Placement is in system memory\n");
+ placement = system_memory(fd);
+ igt_debug("Using system memory placement: 0x%x\n", placement);
+ }
+ igt_assert_f(placement != 0, "Invalid placement: system_memory(fd) returned 0\n");
+
+ return __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
+ bo_flags, NULL, bo);
+}
+
+/**
+ * SUBTEST: overcommit-fault-%s
+ * Description: Test VM overcommit behavior in fault mode with %arg[1] configuration
+ * Functionality: overcommit
+ * Test category: functionality test
+ *
+ * arg[1]:
+ *
+ * @vram-lr-fault:VRAM with LR and fault mode, expects exec to pass
+ * @vram-lr-fault-no-overcommit:VRAM with LR, fault and NO_VM_OVERCOMMIT, expects bind rejection
+ */
+
+/**
+ * SUBTEST: overcommit-nonfault-%s
+ * Description: Test VM overcommit behavior in nonfault mode with %arg[1] configuration
+ * Functionality: overcommit
+ * Test category: functionality test
+ *
+ * arg[1]:
+ *
+ * @vram-lr-defer:VRAM with LR and defer backing, expects bind rejection
+ * @vram-lr-external-nodefer:VRAM with LR and external BO without defer, expects exec fail
+ * @vram-no-lr:VRAM without LR mode, expects exec to fail
+ */
+struct vm_overcommit_case {
+ const char *name;
+ uint32_t vm_flags;
+ uint32_t bo_flags;
+ bool use_vram;
+ bool external;
+ uint64_t data_addr;
+ uint32_t pat_index;
+ double overcommit_mult;
+};
+
+static const struct vm_overcommit_case overcommit_cases[] = {
+ /* Case 1: DEFER_BACKING */
+ {
+ .name = "vram-lr-defer",
+ .vm_flags = DRM_XE_VM_CREATE_FLAG_LR_MODE,
+ .bo_flags = DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING |
+ DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ .external = false,
+ .use_vram = true,
+ .data_addr = 0x1a0000,
+ .pat_index = DEFAULT_PAT_INDEX,
+ .overcommit_mult = 2.0,
+ },
+ /* Case 1b: External BO without defer backing */
+ {
+ .name = "vram-lr-external-nodefer",
+ .vm_flags = DRM_XE_VM_CREATE_FLAG_LR_MODE,
+ .bo_flags = DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ .external = true,
+ .use_vram = true,
+ .data_addr = 0x1a0000,
+ .pat_index = DEFAULT_PAT_INDEX,
+ .overcommit_mult = 2.0,
+ },
+ /* Case 2: LR + FAULT - should not fail on exec */
+ {
+ .name = "vram-lr-fault",
+ .vm_flags = DRM_XE_VM_CREATE_FLAG_LR_MODE |
+ DRM_XE_VM_CREATE_FLAG_FAULT_MODE,
+ .bo_flags = DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ .external = false,
+ .use_vram = true,
+ .data_addr = 0x300000000,
+ .pat_index = 0,
+ .overcommit_mult = 2.0,
+ },
+ /* Case 3: !LR - overcommit should fail on exec */
+ {
+ .name = "vram-no-lr",
+ .vm_flags = 0,
+ .bo_flags = DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ .external = false,
+ .use_vram = true,
+ .data_addr = 0x300000000,
+ .pat_index = 0,
+ .overcommit_mult = 2.0,
+ },
+ /* Case 4: LR + FAULT + NO_VM_OVERCOMMIT */
+ {
+ .name = "vram-lr-fault-no-overcommit",
+ .vm_flags = DRM_XE_VM_CREATE_FLAG_NO_VM_OVERCOMMIT | DRM_XE_VM_CREATE_FLAG_LR_MODE |
+ DRM_XE_VM_CREATE_FLAG_FAULT_MODE,
+ .bo_flags = DRM_XE_GEM_CREATE_FLAG_DEFER_BACKING |
+ DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM,
+ .external = false,
+ .use_vram = true,
+ .data_addr = 0x300000000,
+ .pat_index = 0,
+ .overcommit_mult = 2.0,
+ },
+ { }
+};
+
+static void
+test_vm_overcommit(int fd, struct drm_xe_engine_class_instance *eci,
+ const struct vm_overcommit_case *c,
+ uint64_t system_size, uint64_t vram_size)
+{
+ uint64_t overcommit_size;
+ uint32_t vm;
+ uint32_t *bos;
+ int num_bos;
+ uint64_t off;
+ size_t nf_bo_size = 64 * 1024 * 1024; // 64MB per BO
+ uint32_t batch_bo;
+ size_t sync_size;
+ uint32_t bind_exec_queue;
+ uint64_t sync_addr = 0x101a0000;
+ uint64_t batch_addr = 0x200000000;
+ uint64_t data_addr;
+ uint32_t exec_queue;
+ uint64_t stride = 1024 * 1024;
+ int64_t timeout = 20 * NSEC_PER_SEC;
+ int i, b;
+ int create_ret;
+ int64_t ret;
+ int bind_err;
+ int res;
+ uint64_t base_size;
+ bool overcommit_detected = false;
+ bool is_fault_mode = (c->vm_flags & DRM_XE_VM_CREATE_FLAG_FAULT_MODE) != 0;
+ bool is_lr_mode = (c->vm_flags & DRM_XE_VM_CREATE_FLAG_LR_MODE) != 0;
+ uint64_t lr_vm_sync = 0;
+ struct drm_xe_sync bind_sync[1] = {
+ {
+ .type = DRM_XE_SYNC_TYPE_USER_FENCE,
+ .flags = DRM_XE_SYNC_FLAG_SIGNAL,
+ .timeline_value = USER_FENCE_VALUE
+ },
+ };
+ struct drm_xe_sync lr_sync[1] = {
+ {
+ .type = DRM_XE_SYNC_TYPE_USER_FENCE,
+ .flags = DRM_XE_SYNC_FLAG_SIGNAL,
+ .timeline_value = USER_FENCE_VALUE,
+ .addr = to_user_pointer(&lr_vm_sync),
+ },
+ };
+
+ #define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
+
+ /* For fault mode: user fence, for non-fault mode: syncobj */
+ struct drm_xe_sync exec_sync[1] = {
+ {
+ .type = (is_fault_mode || is_lr_mode) ?
+ DRM_XE_SYNC_TYPE_USER_FENCE : DRM_XE_SYNC_TYPE_SYNCOBJ,
+ .flags = DRM_XE_SYNC_FLAG_SIGNAL,
+ .timeline_value = (is_fault_mode || is_lr_mode) ? USER_FENCE_VALUE : 0,
+ },
+ };
+ struct drm_xe_exec exec = {
+ .num_batch_buffer = 1,
+ .num_syncs = 1,
+ .syncs = to_user_pointer(exec_sync),
+ };
+ struct {
+ uint32_t batch[16];
+ uint64_t pad;
+ uint32_t data;
+ uint64_t vm_sync;
+ } *batch_data;
+ uint64_t *user_fence_sync = NULL;
+
+ data_addr = c->data_addr;
+
+ base_size = c->use_vram ? vram_size : system_size;
+ overcommit_size = (uint64_t)(base_size * c->overcommit_mult);
+ overcommit_size = ALIGN(overcommit_size, 4096);
+ if (overcommit_size > system_size) {
+ igt_debug("Limiting overcommit size from %llu MB to %llu MB\n",
+ (unsigned long long)(overcommit_size >> 20),
+ (unsigned long long)(system_size >> 20));
+ overcommit_size = ALIGN(system_size, 4096);
+ }
+
+ num_bos = (overcommit_size / nf_bo_size) + 1;
+ bos = calloc(num_bos, sizeof(*bos));
+ igt_assert(bos);
+
+ igt_debug("Overcommit test: allocating %d BOs of %llu MB each",
+ num_bos, (unsigned long long)(nf_bo_size >> 20));
+ igt_debug(" total=%llu MB, vram=%llu MB\n",
+ (unsigned long long)(num_bos * nf_bo_size >> 20),
+ (unsigned long long)(vram_size >> 20));
+ /* Create VM with appropriate flags */
+ vm = xe_vm_create(fd, c->vm_flags, 0);
+ igt_assert(vm);
+ bind_exec_queue = xe_bind_exec_queue_create(fd, vm, 0);
+ /* For fault mode: create user fence sync area */
+ if (is_fault_mode) {
+ sync_size = sizeof(uint64_t) * num_bos;
+ sync_size = xe_bb_size(fd, sync_size);
+ user_fence_sync = mmap(NULL, sync_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ igt_assert(user_fence_sync != MAP_FAILED);
+ memset(user_fence_sync, 0, sync_size);
+ }
+ /* Create and bind BOs */
+ for (i = 0; i < num_bos; i++) {
+ struct {
+ uint64_t vm_sync;
+ } *data;
+
+ /* Create BO using the case's create function */
+ create_ret = vm_overcommit_create_bo(fd, vm, nf_bo_size, c->bo_flags,
+ eci->gt_id, c->use_vram, c->external, &bos[i]);
+
+ if (create_ret) {
+ igt_debug("BO create failed at %d/%d with error %d (%s)\n",
+ i, num_bos, -create_ret, strerror(-create_ret));
+ igt_assert_f(create_ret == -ENOMEM || create_ret == -ENOSPC ||
+ create_ret == -E2BIG || create_ret == -EPERM,
+ "Unexpected error %d (%s)\n",
+ -create_ret, strerror(-create_ret));
+ overcommit_detected = true;
+ num_bos = i;
+ break;
+ }
+
+ /* Map and bind BO */
+ data = xe_bo_map(fd, bos[i], 4096);
+ memset(data, 0, 4096);
+ bind_sync[0].addr = to_user_pointer(&data->vm_sync);
+
+ bind_err = __xe_vm_bind(fd, vm, bind_exec_queue, bos[i], 0,
+ data_addr + (i * nf_bo_size), nf_bo_size,
+ DRM_XE_VM_BIND_OP_MAP, 0, bind_sync, 1, 0,
+ c->pat_index, 0);
+
+ if (bind_err) {
+ igt_debug("Bind failed at %d/%d with error %d (%s)\n",
+ i, num_bos, -bind_err, strerror(-bind_err));
+ igt_assert_f(bind_err == -ENOMEM || bind_err == -ENOSPC ||
+ bind_err == -EPERM,
+ "Unexpected bind error %d (%s)\n",
+ -bind_err, strerror(-bind_err));
+ munmap(data, 4096);
+ gem_close(fd, bos[i]);
+ bos[i] = 0;
+ overcommit_detected = true;
+ num_bos = i;
+ break;
+ }
+
+ xe_wait_ufence(fd, &data->vm_sync, USER_FENCE_VALUE,
+ bind_exec_queue, 20 * NSEC_PER_SEC);
+ munmap(data, 4096);
+
+ igt_debug("Created and bound BO %d/%d at 0x%llx\n",
+ i + 1, num_bos,
+ (unsigned long long)(data_addr + (i * nf_bo_size)));
+ }
+ if (overcommit_detected) {
+ igt_debug("\nOvercommit correctly rejected at BO creation/bind (created %d BOs)\n",
+ num_bos);
+ goto cleanup;
+ }
+
+ /* Create batch buffer */
+ batch_bo = xe_bo_create(fd, vm, 0x1000, vram_memory(fd, eci->gt_id),
+ DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
+ igt_debug("\n Mapping the created BO");
+ batch_data = xe_bo_map(fd, batch_bo, 0x1000);
+ memset(batch_data, 0, 0x1000);
+
+ /* Bind batch buffer and sync areas */
+ if (is_fault_mode) {
+ batch_data[0].vm_sync = 0;
+ bind_sync[0].addr = to_user_pointer(&batch_data[0].vm_sync);
+
+ xe_vm_bind_userptr_async(fd, vm, bind_exec_queue, to_user_pointer(user_fence_sync),
+ sync_addr, sync_size, bind_sync, 1);
+ xe_wait_ufence(fd, &batch_data[0].vm_sync, USER_FENCE_VALUE, bind_exec_queue,
+ NSEC_PER_SEC);
+
+ xe_vm_bind_async(fd, vm, bind_exec_queue, batch_bo, 0, batch_addr, 0x1000,
+ bind_sync, 1);
+ xe_wait_ufence(fd, &batch_data[0].vm_sync, USER_FENCE_VALUE,
+ bind_exec_queue, NSEC_PER_SEC);
+ } else if (is_lr_mode) {
+ /* LR mode without fault - bind batch using user fence */
+ lr_vm_sync = 0; /* Reset before use */
+ lr_sync[0].addr = to_user_pointer(&lr_vm_sync);
+ bind_err = __xe_vm_bind(fd, vm, 0, batch_bo, 0, batch_addr, 0x1000,
+ DRM_XE_VM_BIND_OP_MAP, 0, lr_sync, 1, 0, c->pat_index, 0);
+ if (bind_err) {
+ igt_debug("Batch buffer bind failed with error %d (%s) - skipping GPU test\n",
+ -bind_err, strerror(-bind_err));
+ goto cleanup;
+ }
+ xe_wait_ufence(fd, &lr_vm_sync, USER_FENCE_VALUE, 0, NSEC_PER_SEC);
+ } else {
+ igt_debug("\n Going for vm bind sync");
+ xe_vm_bind_sync(fd, vm, batch_bo, 0, batch_addr, 0x1000);
+ }
+
+ igt_debug("VM binds done - batch_bo at 0x%llx\n", (unsigned long long)batch_addr);
+ /* Create exec queue */
+ exec_queue = xe_exec_queue_create(fd, vm, eci, 0);
+
+ /* Setup sync for exec */
+ if (is_fault_mode) {
+ exec_sync[0].addr = sync_addr;
+ } else if (is_lr_mode) {
+ /* LR mode - use batch_data->vm_sync (GPU accessible memory) */
+ batch_data->vm_sync = 0;
+ exec_sync[0].addr = to_user_pointer(&batch_data->vm_sync);
+ } else {
+ exec_sync[0].handle = syncobj_create(fd, 0);
+ }
+
+ /* Use GPU to write to each BO */
+ for (i = 0; i < num_bos; i++) {
+ igt_debug("Writing to BO %d/%d via GPU\n", i + 1, num_bos);
+
+ for (off = 0; off < nf_bo_size; off += stride) {
+ uint64_t target_addr = data_addr + (i * nf_bo_size) + off;
+
+ b = 0;
+ batch_data->batch[b++] = MI_STORE_DWORD_IMM_GEN4;
+ batch_data->batch[b++] = target_addr & 0xFFFFFFFF;
+ batch_data->batch[b++] = (target_addr >> 32) & 0xFFFFFFFF;
+ batch_data->batch[b++] = 0xBB;
+ batch_data->batch[b++] = MI_BATCH_BUFFER_END;
+
+ /* Reset sync for next exec */
+ if (is_fault_mode) {
+ user_fence_sync[0] = 0;
+ } else if (is_lr_mode) {
+ batch_data->vm_sync = 0;
+ } else {
+ if (off != 0 || i != 0) {
+ igt_assert(syncobj_wait(fd, &exec_sync[0].handle,
+ 1, INT64_MAX, 0, NULL));
+ }
+ syncobj_reset(fd, &exec_sync[0].handle, 1);
+ }
+
+ /* Submit batch */
+ exec.exec_queue_id = exec_queue;
+ exec.address = batch_addr;
+
+ res = igt_ioctl(fd, DRM_IOCTL_XE_EXEC, &exec);
+ if (res != 0) {
+ if (errno == ENOMEM || errno == ENOSPC) {
+ igt_debug("Expected fault/error: %d (%s)\n",
+ errno, strerror(errno));
+ goto gpu_done;
+ }
+ igt_assert_f(0, "Unexpected exec error: %d\n", errno);
+ }
+
+ /* Wait for completion using appropriate method */
+ if (is_fault_mode) {
+ ret = wait_fault(fd, exec_queue, &user_fence_sync[0], &timeout);
+ } else if (is_lr_mode) {
+ timeout = 5 * NSEC_PER_SEC;
+ ret = __xe_wait_ufence(fd, &batch_data->vm_sync, USER_FENCE_VALUE,
+ exec_queue, &timeout);
+ } else {
+ ret = wait_nonfault(fd, exec_queue, &exec_sync[0].handle, &timeout);
+ }
+
+ if (ret != 0) {
+ igt_debug("Batch wait failed at BO %d offset 0x%lx\n",
+ i, off);
+ goto gpu_done;
+ }
+ }
+
+ igt_debug("Accessed BO %d/%d via GPU\n", i + 1, num_bos);
+ }
+
+ igt_debug("All batches completed successfully\n");
+ /* Verify GPU writes */
+ igt_debug("Verifying GPU writes to BOs...\n");
+ for (i = 0; i < num_bos; i++) {
+ uint32_t *verify_data;
+ int errors = 0;
+
+ verify_data = xe_bo_map(fd, bos[i], nf_bo_size);
+
+ for (off = 0; off < nf_bo_size; off += stride) {
+ uint32_t expected = 0xBB;
+ uint32_t actual = verify_data[off / 4];
+
+ if (actual != expected) {
+ if (errors < 5)
+ igt_debug("Mismatch at BO %d offset 0x%llx\n",
+ i, (unsigned long long)off);
+ errors++;
+ }
+ }
+
+ munmap(verify_data, nf_bo_size);
+
+ if (errors == 0)
+ igt_debug("BO %d/%d verified successfully\n", i + 1, num_bos);
+ else
+ igt_debug("BO %d/%d had %d errors\n", i + 1, num_bos, errors);
+ }
+
+gpu_done:
+ igt_debug("Overcommit test completed\n");
+
+ /* Cleanup */
+ if (!is_fault_mode && !is_lr_mode)
+ syncobj_destroy(fd, exec_sync[0].handle);
+
+ xe_exec_queue_destroy(fd, exec_queue);
+ xe_exec_queue_destroy(fd, bind_exec_queue);
+ munmap(batch_data, 0x1000);
+ gem_close(fd, batch_bo);
+
+cleanup:
+ if (is_fault_mode && user_fence_sync)
+ munmap(user_fence_sync, sync_size);
+
+ for (i = 0; i < num_bos; i++) {
+ if (bos[i])
+ gem_close(fd, bos[i]);
+ }
+
+ free(bos);
+ xe_vm_destroy(fd, vm);
+}
+
/**
* SUBTEST: out-of-memory
* Description: Test if vm_bind ioctl results in oom
@@ -2850,6 +3332,18 @@ int igt_main()
test_oom(fd);
}

+ for (int i = 0; overcommit_cases[i].name; i++) {
+ const struct vm_overcommit_case *c = &overcommit_cases[i];
+ const char *mode = (c->vm_flags & DRM_XE_VM_CREATE_FLAG_FAULT_MODE) ?
+ "fault" : "nonfault";
+ igt_subtest_f("overcommit-%s-%s", mode, c->name) {
+ igt_require(xe_has_vram(fd));
+ igt_assert(xe_visible_vram_size(fd, 0));
+ test_vm_overcommit(fd, hwe, c, (igt_get_avail_ram_mb() << 20),
+ xe_visible_vram_size(fd, 0));
+ }
+ }
+
igt_fixture()
drm_close_driver(fd);
}
--
2.52.0