[PATCH v4 i-g-t 0/2] test/intel/xe_vm: Add overcommit and no‑overcommit handling tests

[PATCH v4 i-g-t 0/2] test/intel/xe_vm: Add overcommit and no‑overcommit handling tests

[Sobin Thomas]

IGT tests to validate overcommit behaviour across different VM modes.

Patch 1 sync the drm-uapi/xe header with kernel.

Patch 2 increase coverage to xe_vm tests by adding tests for
 - Over-commit test in fault and non fault mode
 - No-Over-Commit tests in fault mode


Sobin Thomas (2):
  drm-uapi/xe: sync with kernel header
  tests/intel/xe_vm: Add support for overcommit tests

 include/drm-uapi/xe_drm.h |  22 +-
 tests/intel/xe_vm.c       | 483 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 493 insertions(+), 12 deletions(-)

-- 
2.52.0

[PATCH v4 i-g-t 1/2] drm-uapi/xe: sync with kernel header

[Sobin Thomas]

This commit is for sync with kernel header.
Align with kernel commit 369cc8804985 ("drm/xe/uapi: Introduce a flag to
disallow VM overcommit in fault mode").

Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>
---
 include/drm-uapi/xe_drm.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/drm-uapi/xe_drm.h b/include/drm-uapi/xe_drm.h
index 077e66a68..fc71a6cd1 100644
--- a/include/drm-uapi/xe_drm.h
+++ b/include/drm-uapi/xe_drm.h
@@ -3,8 +3,8 @@
  * Copyright © 2023 Intel Corporation
  */
 
-#ifndef _UAPI_XE_DRM_H_
-#define _UAPI_XE_DRM_H_
+#ifndef _XE_DRM_H_
+#define _XE_DRM_H_
 
 #include "drm.h"
 
@@ -142,7 +142,7 @@ extern "C" {
  * redefine the interface more easily than an ever growing struct of
  * increasing complexity, and for large parts of that interface to be
  * entirely optional. The downside is more pointer chasing; chasing across
- * the __user boundary with pointers encapsulated inside u64.
+ * the boundary with pointers encapsulated inside u64.
  *
  * Example chaining:
  *
@@ -335,10 +335,6 @@ struct drm_xe_mem_region {
 	__u64 total_size;
 	/**
 	 * @used: Estimate of the memory used in bytes for this region.
-	 *
-	 * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable
-	 * accounting.  Without this the value here will always equal
-	 * zero.
 	 */
 	__u64 used;
 	/**
@@ -363,9 +359,7 @@ struct drm_xe_mem_region {
 	 * @cpu_visible_used: Estimate of CPU visible memory used, in
 	 * bytes.
 	 *
-	 * Requires CAP_PERFMON or CAP_SYS_ADMIN to get reliable
-	 * accounting. Without this the value here will always equal
-	 * zero.  Note this is only currently tracked for
+	 * Note this is only currently tracked for
 	 * DRM_XE_MEM_REGION_CLASS_VRAM regions (for other types the value
 	 * here will always be zero).
 	 */
@@ -975,6 +969,11 @@ struct drm_xe_gem_mmap_offset {
  *    demand when accessed, and also allows per-VM overcommit of memory.
  *    The xe driver internally uses recoverable pagefaults to implement
  *    this.
+ *  - %DRM_XE_VM_CREATE_FLAG_NO_VM_OVERCOMMIT - Requires also
+ *    DRM_XE_VM_CREATE_FLAG_FAULT_MODE. This disallows per-VM overcommit
+ *    but only during a &DRM_IOCTL_XE_VM_BIND operation with the
+ *    %DRM_XE_VM_BIND_FLAG_IMMEDIATE flag set. This may be useful for
+ *    user-space naively probing the amount of available memory.
  */
 struct drm_xe_vm_create {
 	/** @extensions: Pointer to the first extension struct, if any */
@@ -983,6 +982,7 @@ struct drm_xe_vm_create {
 #define DRM_XE_VM_CREATE_FLAG_SCRATCH_PAGE	(1 << 0)
 #define DRM_XE_VM_CREATE_FLAG_LR_MODE	        (1 << 1)
 #define DRM_XE_VM_CREATE_FLAG_FAULT_MODE	(1 << 2)
+#define DRM_XE_VM_CREATE_FLAG_NO_VM_OVERCOMMIT  (1 << 3)
 	/** @flags: Flags */
 	__u32 flags;
 
@@ -2361,4 +2361,4 @@ struct drm_xe_exec_queue_set_property {
 }
 #endif
 
-#endif /* _UAPI_XE_DRM_H_ */
+#endif /* _XE_DRM_H_ */
-- 
2.52.0

[PATCH v4 i-g-t 2/2] tests/intel/xe_vm: Add support for overcommit tests

[Sobin Thomas]

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 external BO and
                             no 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.

v4 - Addressed review comments (reset sync objects and nits).
     Added check in cleanup

Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
Signed-off-by: root <root@DUT2933PVC.iind.intel.com>
Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
---
 tests/intel/xe_vm.c | 483 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 482 insertions(+), 1 deletion(-)

diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
index ccff8f804..c02bb6945 100644
--- a/tests/intel/xe_vm.c
+++ b/tests/intel/xe_vm.c
@@ -20,6 +20,7 @@
 #include "xe/xe_query.h"
 #include "xe/xe_spin.h"
 #include <string.h>
+#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
 
 static uint32_t
 addr_low(uint64_t addr)
@@ -2376,6 +2377,475 @@ 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)
+{
+	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
+
+	return __xe_wait_ufence(fd, (uint64_t *)sync_data, USER_FENCE_VALUE, exec_queue, &wait_ns);
+}
+
+static int wait_nonfault(int fd, uint32_t exec_queue, void *sync_data,
+			 int64_t *timeout)
+{
+	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
+
+	if (!syncobj_wait(fd, (uint32_t *)sync_data, 1, wait_ns, 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 external, uint32_t *bo)
+{
+	uint32_t placement;
+	int ret;
+
+	/* Try VRAM first */
+	placement = vram_memory(fd, gt_id) ?: system_memory(fd);
+	igt_debug("Using VRAM placement: 0x%x\n", placement);
+
+	ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
+			     bo_flags, NULL, bo);
+	if (ret) {
+		igt_info("VRAM allocation failed, falling back to system memory\n");
+		placement = system_memory(fd);
+		igt_assert_f(placement != 0, "Invalid placement: system_memory(fd) returned 0\n");
+		ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
+				     bo_flags, NULL, bo);
+	}
+	return ret;
+}
+
+/**
+ * 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;
+	int 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	{ }
+};
+
+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)
+{
+	size_t sync_size;
+	size_t nf_bo_size = 64 * 1024 * 1024;  // 64MB per BO
+	uint64_t overcommit_size, off, bind_exec_queue, data_addr;
+	uint32_t vm = 0, *bos, batch_bo = 0, exec_queue = 0, placement = 0;
+	uint64_t sync_addr = 0x101a0000, batch_addr = 0x200000000;
+	uint64_t stride = 1024 * 1024, lr_vm_sync = 0, base_size;
+	int64_t timeout = 20 * NSEC_PER_SEC, ret;
+	int i, b, create_ret, bind_err, res, num_bos;
+	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;
+	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),
+		},
+	};
+
+	/* 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,
+			.handle = 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 > base_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);
+	placement = c->use_vram ? vram_memory(fd, eci->gt_id) : system_memory(fd);
+	/* 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 = __xe_bo_create(fd, vm, nf_bo_size, placement,
+					    c->bo_flags, NULL, &bos[i]);
+
+		if (create_ret) {
+			overcommit_detected = true;
+			num_bos = i;
+			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));
+			break;
+		}
+
+		/* Map and bind BO */
+		data = xe_bo_map(fd, bos[i], nf_bo_size);
+		igt_assert(data);
+		memset(data, 0, nf_bo_size);
+		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) {
+			munmap(data, nf_bo_size);
+			gem_close(fd, bos[i]);
+			bos[i] = 0;
+			overcommit_detected = true;
+			num_bos = i;
+			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));
+			break;
+		}
+		if (data->vm_sync != USER_FENCE_VALUE)
+			xe_wait_ufence(fd, &data->vm_sync, USER_FENCE_VALUE,
+				       bind_exec_queue, 20 * NSEC_PER_SEC);
+		data->vm_sync = 0;
+		munmap(data, nf_bo_size);
+
+		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("Overcommit correctly rejected at BO creation/bind (created %d BOs)\n",
+			  num_bos);
+		goto cleanup;
+	}
+
+	 /* Create batch buffer */
+	ret = vm_overcommit_create_bo(fd, vm, 0x1000, 0, eci->gt_id, c->external, &batch_bo);
+	igt_assert_eq(ret, 0);
+
+	igt_debug("Mapping the created BO");
+	batch_data = xe_bo_map(fd, batch_bo, 0x1000);
+	igt_assert(batch_data);
+	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);
+		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
+			xe_wait_ufence(fd, &batch_data[0].vm_sync, USER_FENCE_VALUE,
+				       bind_exec_queue, NSEC_PER_SEC);
+
+		batch_data[0].vm_sync = 0;
+
+		xe_vm_bind_async(fd, vm, bind_exec_queue, batch_bo, 0, batch_addr, 0x1000,
+				 bind_sync, 1);
+		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
+			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);
+		lr_vm_sync = 0;
+	} else {
+		igt_debug("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 && !is_lr_mode) {
+				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 cleanup;
+				}
+				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);
+				user_fence_sync[0] = 0;
+			} 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);
+				batch_data->vm_sync = 0;
+
+			} 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 cleanup;
+			}
+		}
+
+		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);
+		igt_assert(verify_data);
+
+		for (off = 0; off < nf_bo_size; off += stride) {
+			uint32_t expected = 0xBB;
+			uint32_t actual = *(uint32_t *)((char *)verify_data + off);
+
+			if (actual != expected) {
+				if (errors < 5)
+					igt_debug("Mismatch at BO %d offset 0x%llx",
+						  i, (unsigned long long)off);
+				errors++;
+			}
+		}
+
+		munmap(verify_data, nf_bo_size);
+		igt_assert_f(errors == 0, "Data verification failed for BO %d with %d errors\n",
+			     i, errors);
+	}
+
+cleanup:
+	/* Cleanup */
+	if (!is_fault_mode && !is_lr_mode && exec_sync[0].handle)
+		syncobj_destroy(fd, exec_sync[0].handle);
+	if (exec_queue)
+		xe_exec_queue_destroy(fd, exec_queue);
+	if (bind_exec_queue)
+		xe_exec_queue_destroy(fd, bind_exec_queue);
+	if (batch_data)
+		munmap(batch_data, 0x1000);
+	if (batch_bo)
+		gem_close(fd, batch_bo);
+
+	if (is_fault_mode && user_fence_sync)
+		munmap(user_fence_sync, sync_size);
+
+	if (bos) {
+		for (i = 0; i < num_bos; i++) {
+			if (bos[i])
+				gem_close(fd, bos[i]);
+		}
+		free(bos);
+	}
+	if (vm > 0)
+		xe_vm_destroy(fd, vm);
+}
+
 /**
  * SUBTEST: out-of-memory
  * Description: Test if vm_bind ioctl results in oom
@@ -2385,7 +2855,6 @@ static void invalid_vm_id(int fd)
  */
 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;
@@ -2850,6 +3319,18 @@ 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

[PATCH v4 i-g-t 0/2] test/intel/xe_vm: Add overcommit and no‑overcommit handling tests

[Sobin Thomas]

IGT tests to validate overcommit behaviour across different VM modes.

Patch 1 sync the drm-uapi/xe header with kernel.

Patch 2 increase coverage to xe_vm tests by adding tests for
 - Over-commit test in fault and non fault mode
 - No-Over-Commit tests in fault mode


Sobin Thomas (2):
  drm-uapi/xe: sync with kernel header
  tests/intel/xe_vm: Add support for overcommit tests

 include/drm-uapi/xe_drm.h |  22 +-
 tests/intel/xe_vm.c       | 483 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 493 insertions(+), 12 deletions(-)

-- 
2.52.0

[PATCH v4 i-g-t 2/2] tests/intel/xe_vm: Add support for overcommit tests

[Sobin Thomas]

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 external BO and
                             no 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.

v4 - Addressed review comments (reset sync objects and nits).
     Added check in cleanup

Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
---
 tests/intel/xe_vm.c | 483 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 482 insertions(+), 1 deletion(-)

diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
index ccff8f804..c02bb6945 100644
--- a/tests/intel/xe_vm.c
+++ b/tests/intel/xe_vm.c
@@ -20,6 +20,7 @@
 #include "xe/xe_query.h"
 #include "xe/xe_spin.h"
 #include <string.h>
+#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
 
 static uint32_t
 addr_low(uint64_t addr)
@@ -2376,6 +2377,475 @@ 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)
+{
+	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
+
+	return __xe_wait_ufence(fd, (uint64_t *)sync_data, USER_FENCE_VALUE, exec_queue, &wait_ns);
+}
+
+static int wait_nonfault(int fd, uint32_t exec_queue, void *sync_data,
+			 int64_t *timeout)
+{
+	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
+
+	if (!syncobj_wait(fd, (uint32_t *)sync_data, 1, wait_ns, 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 external, uint32_t *bo)
+{
+	uint32_t placement;
+	int ret;
+
+	/* Try VRAM first */
+	placement = vram_memory(fd, gt_id) ?: system_memory(fd);
+	igt_debug("Using VRAM placement: 0x%x\n", placement);
+
+	ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
+			     bo_flags, NULL, bo);
+	if (ret) {
+		igt_info("VRAM allocation failed, falling back to system memory\n");
+		placement = system_memory(fd);
+		igt_assert_f(placement != 0, "Invalid placement: system_memory(fd) returned 0\n");
+		ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
+				     bo_flags, NULL, bo);
+	}
+	return ret;
+}
+
+/**
+ * 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;
+	int 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	/* 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,
+	},
+	{ }
+};
+
+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)
+{
+	size_t sync_size;
+	size_t nf_bo_size = 64 * 1024 * 1024;  // 64MB per BO
+	uint64_t overcommit_size, off, bind_exec_queue, data_addr;
+	uint32_t vm = 0, *bos, batch_bo = 0, exec_queue = 0, placement = 0;
+	uint64_t sync_addr = 0x101a0000, batch_addr = 0x200000000;
+	uint64_t stride = 1024 * 1024, lr_vm_sync = 0, base_size;
+	int64_t timeout = 20 * NSEC_PER_SEC, ret;
+	int i, b, create_ret, bind_err, res, num_bos;
+	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;
+	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),
+		},
+	};
+
+	/* 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,
+			.handle = 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 > base_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);
+	placement = c->use_vram ? vram_memory(fd, eci->gt_id) : system_memory(fd);
+	/* 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 = __xe_bo_create(fd, vm, nf_bo_size, placement,
+					    c->bo_flags, NULL, &bos[i]);
+
+		if (create_ret) {
+			overcommit_detected = true;
+			num_bos = i;
+			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));
+			break;
+		}
+
+		/* Map and bind BO */
+		data = xe_bo_map(fd, bos[i], nf_bo_size);
+		igt_assert(data);
+		memset(data, 0, nf_bo_size);
+		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) {
+			munmap(data, nf_bo_size);
+			gem_close(fd, bos[i]);
+			bos[i] = 0;
+			overcommit_detected = true;
+			num_bos = i;
+			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));
+			break;
+		}
+		if (data->vm_sync != USER_FENCE_VALUE)
+			xe_wait_ufence(fd, &data->vm_sync, USER_FENCE_VALUE,
+				       bind_exec_queue, 20 * NSEC_PER_SEC);
+		data->vm_sync = 0;
+		munmap(data, nf_bo_size);
+
+		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("Overcommit correctly rejected at BO creation/bind (created %d BOs)\n",
+			  num_bos);
+		goto cleanup;
+	}
+
+	 /* Create batch buffer */
+	ret = vm_overcommit_create_bo(fd, vm, 0x1000, 0, eci->gt_id, c->external, &batch_bo);
+	igt_assert_eq(ret, 0);
+
+	igt_debug("Mapping the created BO");
+	batch_data = xe_bo_map(fd, batch_bo, 0x1000);
+	igt_assert(batch_data);
+	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);
+		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
+			xe_wait_ufence(fd, &batch_data[0].vm_sync, USER_FENCE_VALUE,
+				       bind_exec_queue, NSEC_PER_SEC);
+
+		batch_data[0].vm_sync = 0;
+
+		xe_vm_bind_async(fd, vm, bind_exec_queue, batch_bo, 0, batch_addr, 0x1000,
+				 bind_sync, 1);
+		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
+			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);
+		lr_vm_sync = 0;
+	} else {
+		igt_debug("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 && !is_lr_mode) {
+				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 cleanup;
+				}
+				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);
+				user_fence_sync[0] = 0;
+			} 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);
+				batch_data->vm_sync = 0;
+
+			} 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 cleanup;
+			}
+		}
+
+		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);
+		igt_assert(verify_data);
+
+		for (off = 0; off < nf_bo_size; off += stride) {
+			uint32_t expected = 0xBB;
+			uint32_t actual = *(uint32_t *)((char *)verify_data + off);
+
+			if (actual != expected) {
+				if (errors < 5)
+					igt_debug("Mismatch at BO %d offset 0x%llx",
+						  i, (unsigned long long)off);
+				errors++;
+			}
+		}
+
+		munmap(verify_data, nf_bo_size);
+		igt_assert_f(errors == 0, "Data verification failed for BO %d with %d errors\n",
+			     i, errors);
+	}
+
+cleanup:
+	/* Cleanup */
+	if (!is_fault_mode && !is_lr_mode && exec_sync[0].handle)
+		syncobj_destroy(fd, exec_sync[0].handle);
+	if (exec_queue)
+		xe_exec_queue_destroy(fd, exec_queue);
+	if (bind_exec_queue)
+		xe_exec_queue_destroy(fd, bind_exec_queue);
+	if (batch_data)
+		munmap(batch_data, 0x1000);
+	if (batch_bo)
+		gem_close(fd, batch_bo);
+
+	if (is_fault_mode && user_fence_sync)
+		munmap(user_fence_sync, sync_size);
+
+	if (bos) {
+		for (i = 0; i < num_bos; i++) {
+			if (bos[i])
+				gem_close(fd, bos[i]);
+		}
+		free(bos);
+	}
+	if (vm > 0)
+		xe_vm_destroy(fd, vm);
+}
+
 /**
  * SUBTEST: out-of-memory
  * Description: Test if vm_bind ioctl results in oom
@@ -2385,7 +2855,6 @@ static void invalid_vm_id(int fd)
  */
 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;
@@ -2850,6 +3319,18 @@ 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

Re: [PATCH v4 i-g-t 2/2] tests/intel/xe_vm: Add support for overcommit tests

[Sharma, Nishit]

On 3/11/2026 11:38 AM, Sobin Thomas wrote:
> 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 external BO and
>                               no 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.
>
> v4 - Addressed review comments (reset sync objects and nits).
>       Added check in cleanup
>
> Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
> ---
>   tests/intel/xe_vm.c | 483 +++++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 482 insertions(+), 1 deletion(-)
>
> diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
> index ccff8f804..c02bb6945 100644
> --- a/tests/intel/xe_vm.c
> +++ b/tests/intel/xe_vm.c
> @@ -20,6 +20,7 @@
>   #include "xe/xe_query.h"
>   #include "xe/xe_spin.h"
>   #include <string.h>
> +#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
>   
>   static uint32_t
>   addr_low(uint64_t addr)
> @@ -2376,6 +2377,475 @@ 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)
> +{
> +	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
> +
> +	return __xe_wait_ufence(fd, (uint64_t *)sync_data, USER_FENCE_VALUE, exec_queue, &wait_ns);
> +}
> +
> +static int wait_nonfault(int fd, uint32_t exec_queue, void *sync_data,
> +			 int64_t *timeout)
> +{
> +	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
> +
> +	if (!syncobj_wait(fd, (uint32_t *)sync_data, 1, wait_ns, 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 external, uint32_t *bo)
> +{
> +	uint32_t placement;
> +	int ret;
> +
> +	/* Try VRAM first */
> +	placement = vram_memory(fd, gt_id) ?: system_memory(fd);
> +	igt_debug("Using VRAM placement: 0x%x\n", placement);
if VRAM not available still this igt_debug shows VRAM
> +
> +	ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
> +			     bo_flags, NULL, bo);
> +	if (ret) {
> +		igt_info("VRAM allocation failed, falling back to system memory\n");
> +		placement = system_memory(fd);
> +		igt_assert_f(placement != 0, "Invalid placement: system_memory(fd) returned 0\n");
> +		ret = __xe_bo_create(fd, external ? 0 : vm, bo_size, placement,
> +				     bo_flags, NULL, bo);
Why in failure case __xe_bo_create() is called again? This is called 
after igt_assert() which will dead code as control will not reach after 
test is asserted.
> On what condition or error placement = system_memory() chosen? ret should be checked for error number __xo_bo_create() can fail with number of reasons but if decision has to be made

like placement should be system_memory() then explicitly call out. 
Placement was defined before vm_overcommit_create_bo() call, that can be 
directly passed as one of the arguments. For debug/info purpose

you can print placement location (VRAM/SRAM)

You can change the name of this function as nothing related to 
overcommit being done in this. It's simple bo creation


> +	}
> +	return ret;
> +}
> +
> +/**
> + * 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;
> +	int 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	{ }
> +};
> +
> +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)
> +{
> +	size_t sync_size;
> +	size_t nf_bo_size = 64 * 1024 * 1024;  // 64MB per BO
> +	uint64_t overcommit_size, off, bind_exec_queue, data_addr;
> +	uint32_t vm = 0, *bos, batch_bo = 0, exec_queue = 0, placement = 0;
> +	uint64_t sync_addr = 0x101a0000, batch_addr = 0x200000000;
> +	uint64_t stride = 1024 * 1024, lr_vm_sync = 0, base_size;
> +	int64_t timeout = 20 * NSEC_PER_SEC, ret;
> +	int i, b, create_ret, bind_err, res, num_bos;
> +	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;
> +	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),
> +		},
> +	};
> +
> +	/* 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,
> +			.handle = 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 > base_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);
> +	}
As per this logic only SRAM is considered and SRAM will be used throughout
> +
> +	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);
> +	placement = c->use_vram ? vram_memory(fd, eci->gt_id) : system_memory(fd);
> +	/* 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 = __xe_bo_create(fd, vm, nf_bo_size, placement,
> +					    c->bo_flags, NULL, &bos[i]);
> +
> +		if (create_ret) {
> +			overcommit_detected = true;
> +			num_bos = i;
> +			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));
> +			break;

This break is dead code here, once assert happens test execution will be 
halted and control doesn't come at break.

Shouldn't free resources before igt_assert_f()?  you are setting 
overcommit_detected flag as true if some error happens in 
__xo_bo_create() irrespective error should be

ENOMEM,/EPERM/ENOSPC/E2BIG. overcommit_detected should be true if driver 
returns error related to overcommit and then continue

Overcommit error return should be handled in case of non-fault mode but 
above implementation will be called for DRM_XE_VM_CREATE_FLAG_FAULT_MODE

> +		}
> +
> +		/* Map and bind BO */
> +		data = xe_bo_map(fd, bos[i], nf_bo_size);
> +		igt_assert(data);
> +		memset(data, 0, nf_bo_size);
> +		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) {
> +			munmap(data, nf_bo_size);
> +			gem_close(fd, bos[i]);
> +			bos[i] = 0;
> +			overcommit_detected = true;
> +			num_bos = i;
> +			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));

same as above. set overcommit_detected = true if overcommit related 
error/s returned from driver.

error handling should be done for non-fault mode

> +			break;
> +		}
> +		if (data->vm_sync != USER_FENCE_VALUE)
> +			xe_wait_ufence(fd, &data->vm_sync, USER_FENCE_VALUE,
> +				       bind_exec_queue, 20 * NSEC_PER_SEC);
> +		data->vm_sync = 0;
> +		munmap(data, nf_bo_size);
> +
> +		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("Overcommit correctly rejected at BO creation/bind (created %d BOs)\n",
> +			  num_bos);
> +		goto cleanup;
> +	}
> +
> +	 /* Create batch buffer */
> +	ret = vm_overcommit_create_bo(fd, vm, 0x1000, 0, eci->gt_id, c->external, &batch_bo);
> +	igt_assert_eq(ret, 0);
> +
> +	igt_debug("Mapping the created BO");
> +	batch_data = xe_bo_map(fd, batch_bo, 0x1000);
> +	igt_assert(batch_data);
> +	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);
> +		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
> +			xe_wait_ufence(fd, &batch_data[0].vm_sync, USER_FENCE_VALUE,
> +				       bind_exec_queue, NSEC_PER_SEC);
> +
> +		batch_data[0].vm_sync = 0;
> +
> +		xe_vm_bind_async(fd, vm, bind_exec_queue, batch_bo, 0, batch_addr, 0x1000,
> +				 bind_sync, 1);
> +		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
> +			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);
> +		lr_vm_sync = 0;
> +	} else {
> +		igt_debug("Going for vm bind sync");
> +		xe_vm_bind_sync(fd, vm, batch_bo, 0, batch_addr, 0x1000);
> +	}
All vm_bind() calls used calls __xe_vm_bind. Instead calling directly 
__xe_vm_bind, wrappers are provided. Use that Wrapper depending upon the 
condition is_fault_mode/is_lr_mode
> +
> +	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 && !is_lr_mode) {
> +				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 cleanup;
> +				}
> +				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);
> +				user_fence_sync[0] = 0;
> +			} 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);
> +				batch_data->vm_sync = 0;
> +
> +			} else {
> +				ret = wait_nonfault(fd, exec_queue, &exec_sync[0].handle, &timeout);
> +			}

For above wait_fault(), __xe_wait_fence(), wait_nonfault() you can make 
more readable code calling single function for all 3 case as

enum wait_mode { --> Define globally
     WAIT_FAULT,
     WAIT_LR,
     WAIT_NONFAULT
};

if (is_fault_mode) {
     ret = wait_sync(WAIT_FAULT, fd, exec_queue, &user_fence_sync[0], 
&timeout);
     user_fence_sync[0] = 0;
} else if (is_lr_mode) {
     timeout = 5 * NSEC_PER_SEC;
     ret = wait_sync(WAIT_LR, fd, exec_queue, &batch_data->vm_sync, 
&timeout);
     batch_data->vm_sync = 0;
} else {
     ret = wait_sync(WAIT_NONFAULT, fd, exec_queue, 
&exec_sync[0].handle, &timeout);
}

static int wait_sync(enum wait_mode mode, int fd, uint32_t exec_queue, 
void *sync_data, int64_t *timeout)
{
     int64_t wait_ns = timeout ? *timeout : INT64_MAX;

     if (mode == WAIT_FAULT || mode == WAIT_LR) {
         // For both fault and LR mode, use user fence wait
         return __xe_wait_ufence(fd, (uint64_t *)sync_data, 
USER_FENCE_VALUE, exec_queue, &wait_ns);
     } else if (mode == WAIT_NONFAULT) {
         // For non-fault mode, use syncobj wait
         if (!syncobj_wait(fd, (uint32_t *)sync_data, 1, wait_ns, 0, NULL))
             return -1;
         return 0;
     }
     return -1; // Invalid mode
}

Try

> +
> +			if (ret != 0) {
> +				igt_debug("Batch wait failed at BO %d offset 0x%lx\n",
> +					  i, off);
> +				goto cleanup;
> +			}
> +		}
> +
> +		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);
> +		igt_assert(verify_data);
> +
> +		for (off = 0; off < nf_bo_size; off += stride) {
> +			uint32_t expected = 0xBB;
> +			uint32_t actual = *(uint32_t *)((char *)verify_data + off);
> +
> +			if (actual != expected) {
> +				if (errors < 5)
> +					igt_debug("Mismatch at BO %d offset 0x%llx",
> +						  i, (unsigned long long)off);
> +				errors++;
> +			}
> +		}
> +
> +		munmap(verify_data, nf_bo_size);
> +		igt_assert_f(errors == 0, "Data verification failed for BO %d with %d errors\n",
> +			     i, errors);
> +	}
> +
> +cleanup:
> +	/* Cleanup */
> +	if (!is_fault_mode && !is_lr_mode && exec_sync[0].handle)
> +		syncobj_destroy(fd, exec_sync[0].handle);
> +	if (exec_queue)
> +		xe_exec_queue_destroy(fd, exec_queue);
> +	if (bind_exec_queue)
> +		xe_exec_queue_destroy(fd, bind_exec_queue);
> +	if (batch_data)
> +		munmap(batch_data, 0x1000);
> +	if (batch_bo)
> +		gem_close(fd, batch_bo);
> +
> +	if (is_fault_mode && user_fence_sync)
user_fence_sync handled above during mmap when is_fault_mode = 1, so you 
can avoid using it here in &&
> +		munmap(user_fence_sync, sync_size);
> +
> +	if (bos) {
> +		for (i = 0; i < num_bos; i++) {
> +			if (bos[i])
> +				gem_close(fd, bos[i]);
> +		}
> +		free(bos);
> +	}
> +	if (vm > 0)
> +		xe_vm_destroy(fd, vm);
> +}
> +
>   /**
>    * SUBTEST: out-of-memory
>    * Description: Test if vm_bind ioctl results in oom
> @@ -2385,7 +2855,6 @@ static void invalid_vm_id(int fd)
>    */
>   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;
> @@ -2850,6 +3319,18 @@ 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));
what's the point of using assert on xe_visible_vram_size()? This API 
gives CPU visible VRAM size on GPU.
> +			test_vm_overcommit(fd, hwe, c, (igt_get_avail_ram_mb() << 20),
> +					   xe_visible_vram_size(fd, 0));
> +		}
> +	}
> +
>   	igt_fixture()
>   		drm_close_driver(fd);
>   }

Re: [PATCH v4 i-g-t 2/2] tests/intel/xe_vm: Add support for overcommit tests

[Hellstrom, Thomas]

Hi Thomas

On Wed, 2026-03-11 at 06:08 +0000, Sobin Thomas wrote:
> 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 external BO and
>                              no 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.
> 
> v4 - Addressed review comments (reset sync objects and nits).
>      Added check in cleanup
> 
> Signed-off-by: Sobin Thomas <sobin.thomas@intel.com>
> ---
>  tests/intel/xe_vm.c | 483
> +++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 482 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
> index ccff8f804..c02bb6945 100644
> --- a/tests/intel/xe_vm.c
> +++ b/tests/intel/xe_vm.c
> @@ -20,6 +20,7 @@
>  #include "xe/xe_query.h"
>  #include "xe/xe_spin.h"
>  #include <string.h>
> +#define USER_FENCE_VALUE 0xdeadbeefdeadbeefull
>  
>  static uint32_t
>  addr_low(uint64_t addr)
> @@ -2376,6 +2377,475 @@ 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)
> +{
> +	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
> +
> +	return __xe_wait_ufence(fd, (uint64_t *)sync_data,
> USER_FENCE_VALUE, exec_queue, &wait_ns);
> +}
> +
> +static int wait_nonfault(int fd, uint32_t exec_queue, void
> *sync_data,
> +			 int64_t *timeout)
> +{
> +	int64_t wait_ns = timeout ? *timeout : INT64_MAX;
> +
> +	if (!syncobj_wait(fd, (uint32_t *)sync_data, 1, wait_ns, 0,
> +			  NULL))
> +		return -1;
> +
> +	return 0;
> +}
> +

Why do we need to distinguish between fault mode and non-fault mode
here? Can't we use user-fences for both?

> +static int vm_overcommit_create_bo(int fd, uint32_t vm, size_t
> bo_size,
> +				   uint32_t bo_flags, uint16_t
> gt_id,
> +				   bool external, uint32_t *bo)
> +{
> +	uint32_t placement;
> +	int ret;
> +
> +	/* Try VRAM first */
> +	placement = vram_memory(fd, gt_id) ?: system_memory(fd);
> +	igt_debug("Using VRAM placement: 0x%x\n", placement);
> +
> +	ret = __xe_bo_create(fd, external ? 0 : vm, bo_size,
> placement,
> +			     bo_flags, NULL, bo);

> +	if (ret) {
> +		igt_info("VRAM allocation failed, falling back to
> system memory\n"

Can't you let the kernel create a system bo as a backup by OR-ing the
placement flags?

> +		placement = system_memory(fd);
> +		igt_assert_f(placement != 0, "Invalid placement:
> system_memory(fd) returned 0\n");
> +		ret = __xe_bo_create(fd, external ? 0 : vm, bo_size,
> placement,
> +				     bo_flags, NULL, bo);
> +	}
> +	return ret;
> +}
> +
> +/**
> + * 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;
> +	int 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	/* 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,
> +	},
> +	{ }
> +};
> +
> +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)

In general there are a lot of if (xxx_mode) in this function that makes
it hard to follow. If you use user-fences as sync-objects across the
board then it should likely work for all modes. Also for the vm bind, I
'd encourage the use of
 
xe_vm_bind_lr_sync()

which sounds like it would work only in lr mode but should work in all
modes.

I figure you might need to add a variant that doesn't assert but return
an error code.

> +{
> +	size_t sync_size;
> +	size_t nf_bo_size = 64 * 1024 * 1024;  // 64MB per BO
> +	uint64_t overcommit_size, off, bind_exec_queue, data_addr;
> +	uint32_t vm = 0, *bos, batch_bo = 0, exec_queue = 0,
> placement = 0;
> +	uint64_t sync_addr = 0x101a0000, batch_addr = 0x200000000;
> +	uint64_t stride = 1024 * 1024, lr_vm_sync = 0, base_size;
> +	int64_t timeout = 20 * NSEC_PER_SEC, ret;
> +	int i, b, create_ret, bind_err, res, num_bos;
> +	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;
> +	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),
> +		},
> +	};
> +
> +	/* 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,
> +			.handle = 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 > base_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);
> +	placement = c->use_vram ? vram_memory(fd, eci->gt_id) :
> system_memory(fd);
> +	/* 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 = __xe_bo_create(fd, vm, nf_bo_size,
> placement,
> +					    c->bo_flags, NULL,
> &bos[i]);
> +
> +		if (create_ret) {
> +			overcommit_detected = true;
> +			num_bos = i;
> +			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));
> +			break;
> +		}
> +
> +		/* Map and bind BO */
> +		data = xe_bo_map(fd, bos[i], nf_bo_size);
> +		igt_assert(data);
> +		memset(data, 0, nf_bo_size);
> +		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) {
> +			munmap(data, nf_bo_size);
> +			gem_close(fd, bos[i]);
> +			bos[i] = 0;
> +			overcommit_detected = true;
> +			num_bos = i;
> +			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));
> +			break;
> +		}
> +		if (data->vm_sync != USER_FENCE_VALUE)
> +			xe_wait_ufence(fd, &data->vm_sync,
> USER_FENCE_VALUE,
> +				       bind_exec_queue, 20 *
> NSEC_PER_SEC);
> +		data->vm_sync = 0;
> +		munmap(data, nf_bo_size);
> +
> +		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("Overcommit correctly rejected at BO
> creation/bind (created %d BOs)\n",
> +			  num_bos);
> +		goto cleanup;
> +	}
> +
> +	 /* Create batch buffer */
> +	ret = vm_overcommit_create_bo(fd, vm, 0x1000, 0, eci->gt_id,
> c->external, &batch_bo);
> +	igt_assert_eq(ret, 0);
> +
> +	igt_debug("Mapping the created BO");
> +	batch_data = xe_bo_map(fd, batch_bo, 0x1000);
> +	igt_assert(batch_data);
> +	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);
> +		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
> +			xe_wait_ufence(fd, &batch_data[0].vm_sync,
> USER_FENCE_VALUE,
> +				       bind_exec_queue,
> NSEC_PER_SEC);
> +
> +		batch_data[0].vm_sync = 0;
> +
> +		xe_vm_bind_async(fd, vm, bind_exec_queue, batch_bo,
> 0, batch_addr, 0x1000,
> +				 bind_sync, 1);
> +		if (batch_data[0].vm_sync != USER_FENCE_VALUE)
> +			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);
> +		lr_vm_sync = 0;
> +	} else {
> +		igt_debug("Going for vm bind sync");
> +		xe_vm_bind_sync(fd, vm, batch_bo, 0, batch_addr,
> 0x1000);
> +	}

Just use xe_vm_bind_lr_sync() for all modes?

> +
> +	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 && !is_lr_mode) {
> +				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 cleanup;
> +				}
> +				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);
> +				user_fence_sync[0] = 0;
> +			} 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);
> +				batch_data->vm_sync = 0;
> +
> +			} 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 cleanup;
> +			}
> +		}
> +
> +		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);
> +		igt_assert(verify_data);
> +
> +		for (off = 0; off < nf_bo_size; off += stride) {
> +			uint32_t expected = 0xBB;
> +			uint32_t actual = *(uint32_t *)((char
> *)verify_data + off);
> +
> +			if (actual != expected) {
> +				if (errors < 5)
> +					igt_debug("Mismatch at BO %d
> offset 0x%llx",
> +						  i, (unsigned long
> long)off);
> +				errors++;
> +			}
> +		}
> +
> +		munmap(verify_data, nf_bo_size);
> +		igt_assert_f(errors == 0, "Data verification failed
> for BO %d with %d errors\n",
> +			     i, errors);
> +	}
> +

Perhaps split this huge function so that each loop has its own static
function. Again for readability.

Thanks,
Thomas



> +cleanup:
> +	/* Cleanup */
> +	if (!is_fault_mode && !is_lr_mode && exec_sync[0].handle)
> +		syncobj_destroy(fd, exec_sync[0].handle);
> +	if (exec_queue)
> +		xe_exec_queue_destroy(fd, exec_queue);
> +	if (bind_exec_queue)
> +		xe_exec_queue_destroy(fd, bind_exec_queue);
> +	if (batch_data)
> +		munmap(batch_data, 0x1000);
> +	if (batch_bo)
> +		gem_close(fd, batch_bo);
> +
> +	if (is_fault_mode && user_fence_sync)
> +		munmap(user_fence_sync, sync_size);
> +
> +	if (bos) {
> +		for (i = 0; i < num_bos; i++) {
> +			if (bos[i])
> +				gem_close(fd, bos[i]);
> +		}
> +		free(bos);
> +	}
> +	if (vm > 0)
> +		xe_vm_destroy(fd, vm);
> +}
> +
>  /**
>   * SUBTEST: out-of-memory
>   * Description: Test if vm_bind ioctl results in oom
> @@ -2385,7 +2855,6 @@ static void invalid_vm_id(int fd)
>   */
>  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;
> @@ -2850,6 +3319,18 @@ 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);
>  }