[PATCH v4 08/33] drm/xe/uapi: Add DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR flag

[Matthew Brost <matthew.brost@intel.com>]

Add the DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR flag, which is used to
create unpopulated virtual memory areas (VMAs) without memory backing or
GPU page tables. These VMAs are referred to as CPU address mirror VMAs.
The idea is that upon a page fault or prefetch, the memory backing and
GPU page tables will be populated.

CPU address mirror VMAs only update GPUVM state; they do not have an
internal page table (PT) state, nor do they have GPU mappings.

It is expected that CPU address mirror VMAs will be mixed with buffer
object (BO) VMAs within a single VM. In other words, system allocations
and runtime allocations can be mixed within a single user-mode driver
(UMD) program.

Expected usage:

- Bind the entire virtual address (VA) space upon program load using the
  DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR flag.
- If a buffer object (BO) requires GPU mapping (runtime allocation),
  allocate a CPU address using mmap(PROT_NONE), bind the BO to the
  mmapped address using existing bind IOCTLs. If a CPU map of the BO is
  needed, mmap it again to the same CPU address using mmap(MAP_FIXED)
- If a BO no longer requires GPU mapping, munmap it from the CPU address
  space and them bind the mapping address with the
  DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR flag.
- Any malloc'd or mmapped CPU address accessed by the GPU will be
  faulted in via the SVM implementation (system allocation).
- Upon freeing any mmapped or malloc'd data, the SVM implementation will
  remove GPU mappings.

Only supporting 1 to 1 mapping between user address space and GPU
address space at the moment as that is the expected use case. uAPI
defines interface for non 1 to 1 but enforces 1 to 1, this restriction
can be lifted if use cases arrise for non 1 to 1 mappings.

This patch essentially short-circuits the code in the existing VM bind
paths to avoid populating page tables when the
DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR flag is set.

v3:
 - Call vm_bind_ioctl_ops_fini on -ENODATA
 - Don't allow DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR on non-faulting VMs
 - s/DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR/DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR (Thomas)
 - Rework commit message for expected usage (Thomas)
 - Describe state of code after patch in commit message (Thomas)
v4:
 - Fix alignment (Checkpatch)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_pt.c       |  76 ++++++++++++----
 drivers/gpu/drm/xe/xe_vm.c       | 150 +++++++++++++++++++------------
 drivers/gpu/drm/xe/xe_vm.h       |   8 +-
 drivers/gpu/drm/xe/xe_vm_types.h |   3 +
 include/uapi/drm/xe_drm.h        |  19 +++-
 5 files changed, 182 insertions(+), 74 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
index 1ddcc7e79a93..99b97bf37c05 100644
--- a/drivers/gpu/drm/xe/xe_pt.c
+++ b/drivers/gpu/drm/xe/xe_pt.c
@@ -1069,6 +1069,11 @@ static int op_add_deps(struct xe_vm *vm, struct xe_vma_op *op,
 {
 	int err = 0;
 
+	/*
+	 * No need to check for is_cpu_addr_mirror here as vma_add_deps is a
+	 * NOP if VMA is_cpu_addr_mirror
+	 */
+
 	switch (op->base.op) {
 	case DRM_GPUVA_OP_MAP:
 		if (!op->map.immediate && xe_vm_in_fault_mode(vm))
@@ -1646,6 +1651,7 @@ static int bind_op_prepare(struct xe_vm *vm, struct xe_tile *tile,
 	struct xe_vm_pgtable_update_op *pt_op = &pt_update_ops->ops[current_op];
 	int err;
 
+	xe_tile_assert(tile, !xe_vma_is_cpu_addr_mirror(vma));
 	xe_bo_assert_held(xe_vma_bo(vma));
 
 	vm_dbg(&xe_vma_vm(vma)->xe->drm,
@@ -1713,6 +1719,7 @@ static int unbind_op_prepare(struct xe_tile *tile,
 	if (!((vma->tile_present | vma->tile_staged) & BIT(tile->id)))
 		return 0;
 
+	xe_tile_assert(tile, !xe_vma_is_cpu_addr_mirror(vma));
 	xe_bo_assert_held(xe_vma_bo(vma));
 
 	vm_dbg(&xe_vma_vm(vma)->xe->drm,
@@ -1759,15 +1766,21 @@ static int op_prepare(struct xe_vm *vm,
 
 	switch (op->base.op) {
 	case DRM_GPUVA_OP_MAP:
-		if (!op->map.immediate && xe_vm_in_fault_mode(vm))
+		if ((!op->map.immediate && xe_vm_in_fault_mode(vm)) ||
+		    op->map.is_cpu_addr_mirror)
 			break;
 
 		err = bind_op_prepare(vm, tile, pt_update_ops, op->map.vma);
 		pt_update_ops->wait_vm_kernel = true;
 		break;
 	case DRM_GPUVA_OP_REMAP:
-		err = unbind_op_prepare(tile, pt_update_ops,
-					gpuva_to_vma(op->base.remap.unmap->va));
+	{
+		struct xe_vma *old = gpuva_to_vma(op->base.remap.unmap->va);
+
+		if (xe_vma_is_cpu_addr_mirror(old))
+			break;
+
+		err = unbind_op_prepare(tile, pt_update_ops, old);
 
 		if (!err && op->remap.prev) {
 			err = bind_op_prepare(vm, tile, pt_update_ops,
@@ -1780,15 +1793,28 @@ static int op_prepare(struct xe_vm *vm,
 			pt_update_ops->wait_vm_bookkeep = true;
 		}
 		break;
+	}
 	case DRM_GPUVA_OP_UNMAP:
-		err = unbind_op_prepare(tile, pt_update_ops,
-					gpuva_to_vma(op->base.unmap.va));
+	{
+		struct xe_vma *vma = gpuva_to_vma(op->base.unmap.va);
+
+		if (xe_vma_is_cpu_addr_mirror(vma))
+			break;
+
+		err = unbind_op_prepare(tile, pt_update_ops, vma);
 		break;
+	}
 	case DRM_GPUVA_OP_PREFETCH:
-		err = bind_op_prepare(vm, tile, pt_update_ops,
-				      gpuva_to_vma(op->base.prefetch.va));
+	{
+		struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
+
+		if (xe_vma_is_cpu_addr_mirror(vma))
+			break;
+
+		err = bind_op_prepare(vm, tile, pt_update_ops, vma);
 		pt_update_ops->wait_vm_kernel = true;
 		break;
+	}
 	default:
 		drm_warn(&vm->xe->drm, "NOT POSSIBLE");
 	}
@@ -1858,6 +1884,8 @@ static void bind_op_commit(struct xe_vm *vm, struct xe_tile *tile,
 			   struct xe_vma *vma, struct dma_fence *fence,
 			   struct dma_fence *fence2)
 {
+	xe_tile_assert(tile, !xe_vma_is_cpu_addr_mirror(vma));
+
 	if (!xe_vma_has_no_bo(vma) && !xe_vma_bo(vma)->vm) {
 		dma_resv_add_fence(xe_vma_bo(vma)->ttm.base.resv, fence,
 				   pt_update_ops->wait_vm_bookkeep ?
@@ -1891,6 +1919,8 @@ static void unbind_op_commit(struct xe_vm *vm, struct xe_tile *tile,
 			     struct xe_vma *vma, struct dma_fence *fence,
 			     struct dma_fence *fence2)
 {
+	xe_tile_assert(tile, !xe_vma_is_cpu_addr_mirror(vma));
+
 	if (!xe_vma_has_no_bo(vma) && !xe_vma_bo(vma)->vm) {
 		dma_resv_add_fence(xe_vma_bo(vma)->ttm.base.resv, fence,
 				   pt_update_ops->wait_vm_bookkeep ?
@@ -1925,16 +1955,21 @@ static void op_commit(struct xe_vm *vm,
 
 	switch (op->base.op) {
 	case DRM_GPUVA_OP_MAP:
-		if (!op->map.immediate && xe_vm_in_fault_mode(vm))
+		if ((!op->map.immediate && xe_vm_in_fault_mode(vm)) ||
+		    op->map.is_cpu_addr_mirror)
 			break;
 
 		bind_op_commit(vm, tile, pt_update_ops, op->map.vma, fence,
 			       fence2);
 		break;
 	case DRM_GPUVA_OP_REMAP:
-		unbind_op_commit(vm, tile, pt_update_ops,
-				 gpuva_to_vma(op->base.remap.unmap->va), fence,
-				 fence2);
+	{
+		struct xe_vma *old = gpuva_to_vma(op->base.remap.unmap->va);
+
+		if (xe_vma_is_cpu_addr_mirror(old))
+			break;
+
+		unbind_op_commit(vm, tile, pt_update_ops, old, fence, fence2);
 
 		if (op->remap.prev)
 			bind_op_commit(vm, tile, pt_update_ops, op->remap.prev,
@@ -1943,14 +1978,25 @@ static void op_commit(struct xe_vm *vm,
 			bind_op_commit(vm, tile, pt_update_ops, op->remap.next,
 				       fence, fence2);
 		break;
+	}
 	case DRM_GPUVA_OP_UNMAP:
-		unbind_op_commit(vm, tile, pt_update_ops,
-				 gpuva_to_vma(op->base.unmap.va), fence, fence2);
+	{
+		struct xe_vma *vma = gpuva_to_vma(op->base.unmap.va);
+
+		if (!xe_vma_is_cpu_addr_mirror(vma))
+			unbind_op_commit(vm, tile, pt_update_ops, vma, fence,
+					 fence2);
 		break;
+	}
 	case DRM_GPUVA_OP_PREFETCH:
-		bind_op_commit(vm, tile, pt_update_ops,
-			       gpuva_to_vma(op->base.prefetch.va), fence, fence2);
+	{
+		struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
+
+		if (!xe_vma_is_cpu_addr_mirror(vma))
+			bind_op_commit(vm, tile, pt_update_ops, vma, fence,
+				       fence2);
 		break;
+	}
 	default:
 		drm_warn(&vm->xe->drm, "NOT POSSIBLE");
 	}
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 690330352d4c..dff10dfa9c69 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -901,9 +901,10 @@ static void xe_vma_free(struct xe_vma *vma)
 		kfree(vma);
 }
 
-#define VMA_CREATE_FLAG_READ_ONLY	BIT(0)
-#define VMA_CREATE_FLAG_IS_NULL		BIT(1)
-#define VMA_CREATE_FLAG_DUMPABLE	BIT(2)
+#define VMA_CREATE_FLAG_READ_ONLY		BIT(0)
+#define VMA_CREATE_FLAG_IS_NULL			BIT(1)
+#define VMA_CREATE_FLAG_DUMPABLE		BIT(2)
+#define VMA_CREATE_FLAG_IS_SYSTEM_ALLOCATOR	BIT(3)
 
 static struct xe_vma *xe_vma_create(struct xe_vm *vm,
 				    struct xe_bo *bo,
@@ -917,6 +918,8 @@ static struct xe_vma *xe_vma_create(struct xe_vm *vm,
 	bool read_only = (flags & VMA_CREATE_FLAG_READ_ONLY);
 	bool is_null = (flags & VMA_CREATE_FLAG_IS_NULL);
 	bool dumpable = (flags & VMA_CREATE_FLAG_DUMPABLE);
+	bool is_cpu_addr_mirror =
+		(flags & VMA_CREATE_FLAG_IS_SYSTEM_ALLOCATOR);
 
 	xe_assert(vm->xe, start < end);
 	xe_assert(vm->xe, end < vm->size);
@@ -925,7 +928,7 @@ static struct xe_vma *xe_vma_create(struct xe_vm *vm,
 	 * Allocate and ensure that the xe_vma_is_userptr() return
 	 * matches what was allocated.
 	 */
-	if (!bo && !is_null) {
+	if (!bo && !is_null && !is_cpu_addr_mirror) {
 		struct xe_userptr_vma *uvma = kzalloc(sizeof(*uvma), GFP_KERNEL);
 
 		if (!uvma)
@@ -937,6 +940,8 @@ static struct xe_vma *xe_vma_create(struct xe_vm *vm,
 		if (!vma)
 			return ERR_PTR(-ENOMEM);
 
+		if (is_cpu_addr_mirror)
+			vma->gpuva.flags |= XE_VMA_SYSTEM_ALLOCATOR;
 		if (is_null)
 			vma->gpuva.flags |= DRM_GPUVA_SPARSE;
 		if (bo)
@@ -979,7 +984,7 @@ static struct xe_vma *xe_vma_create(struct xe_vm *vm,
 		drm_gpuva_link(&vma->gpuva, vm_bo);
 		drm_gpuvm_bo_put(vm_bo);
 	} else /* userptr or null */ {
-		if (!is_null) {
+		if (!is_null && !is_cpu_addr_mirror) {
 			struct xe_userptr *userptr = &to_userptr_vma(vma)->userptr;
 			u64 size = end - start + 1;
 			int err;
@@ -1029,7 +1034,7 @@ static void xe_vma_destroy_late(struct xe_vma *vma)
 		 */
 		mmu_interval_notifier_remove(&userptr->notifier);
 		xe_vm_put(vm);
-	} else if (xe_vma_is_null(vma)) {
+	} else if (xe_vma_is_null(vma) || xe_vma_is_cpu_addr_mirror(vma)) {
 		xe_vm_put(vm);
 	} else {
 		xe_bo_put(xe_vma_bo(vma));
@@ -1068,7 +1073,7 @@ static void xe_vma_destroy(struct xe_vma *vma, struct dma_fence *fence)
 		spin_lock(&vm->userptr.invalidated_lock);
 		list_del(&to_userptr_vma(vma)->userptr.invalidate_link);
 		spin_unlock(&vm->userptr.invalidated_lock);
-	} else if (!xe_vma_is_null(vma)) {
+	} else if (!xe_vma_is_null(vma) && !xe_vma_is_cpu_addr_mirror(vma)) {
 		xe_bo_assert_held(xe_vma_bo(vma));
 
 		drm_gpuva_unlink(&vma->gpuva);
@@ -1968,6 +1973,8 @@ vm_bind_ioctl_ops_create(struct xe_vm *vm, struct xe_bo *bo,
 			op->map.read_only =
 				flags & DRM_XE_VM_BIND_FLAG_READONLY;
 			op->map.is_null = flags & DRM_XE_VM_BIND_FLAG_NULL;
+			op->map.is_cpu_addr_mirror = flags &
+				DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR;
 			op->map.dumpable = flags & DRM_XE_VM_BIND_FLAG_DUMPABLE;
 			op->map.pat_index = pat_index;
 		} else if (__op->op == DRM_GPUVA_OP_PREFETCH) {
@@ -2160,6 +2167,8 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 				VMA_CREATE_FLAG_IS_NULL : 0;
 			flags |= op->map.dumpable ?
 				VMA_CREATE_FLAG_DUMPABLE : 0;
+			flags |= op->map.is_cpu_addr_mirror ?
+				VMA_CREATE_FLAG_IS_SYSTEM_ALLOCATOR : 0;
 
 			vma = new_vma(vm, &op->base.map, op->map.pat_index,
 				      flags);
@@ -2167,7 +2176,8 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 				return PTR_ERR(vma);
 
 			op->map.vma = vma;
-			if (op->map.immediate || !xe_vm_in_fault_mode(vm))
+			if ((op->map.immediate || !xe_vm_in_fault_mode(vm)) &&
+			    !op->map.is_cpu_addr_mirror)
 				xe_vma_ops_incr_pt_update_ops(vops,
 							      op->tile_mask);
 			break;
@@ -2176,21 +2186,24 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 		{
 			struct xe_vma *old =
 				gpuva_to_vma(op->base.remap.unmap->va);
+			bool skip = xe_vma_is_cpu_addr_mirror(old);
 
 			op->remap.start = xe_vma_start(old);
 			op->remap.range = xe_vma_size(old);
 
-			if (op->base.remap.prev) {
-				flags |= op->base.remap.unmap->va->flags &
-					XE_VMA_READ_ONLY ?
-					VMA_CREATE_FLAG_READ_ONLY : 0;
-				flags |= op->base.remap.unmap->va->flags &
-					DRM_GPUVA_SPARSE ?
-					VMA_CREATE_FLAG_IS_NULL : 0;
-				flags |= op->base.remap.unmap->va->flags &
-					XE_VMA_DUMPABLE ?
-					VMA_CREATE_FLAG_DUMPABLE : 0;
+			flags |= op->base.remap.unmap->va->flags &
+				XE_VMA_READ_ONLY ?
+				VMA_CREATE_FLAG_READ_ONLY : 0;
+			flags |= op->base.remap.unmap->va->flags &
+				DRM_GPUVA_SPARSE ?
+				VMA_CREATE_FLAG_IS_NULL : 0;
+			flags |= op->base.remap.unmap->va->flags &
+				XE_VMA_DUMPABLE ?
+				VMA_CREATE_FLAG_DUMPABLE : 0;
+			flags |= xe_vma_is_cpu_addr_mirror(old) ?
+				VMA_CREATE_FLAG_IS_SYSTEM_ALLOCATOR : 0;
 
+			if (op->base.remap.prev) {
 				vma = new_vma(vm, op->base.remap.prev,
 					      old->pat_index, flags);
 				if (IS_ERR(vma))
@@ -2202,9 +2215,10 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 				 * Userptr creates a new SG mapping so
 				 * we must also rebind.
 				 */
-				op->remap.skip_prev = !xe_vma_is_userptr(old) &&
+				op->remap.skip_prev = skip ||
+					(!xe_vma_is_userptr(old) &&
 					IS_ALIGNED(xe_vma_end(vma),
-						   xe_vma_max_pte_size(old));
+						   xe_vma_max_pte_size(old)));
 				if (op->remap.skip_prev) {
 					xe_vma_set_pte_size(vma, xe_vma_max_pte_size(old));
 					op->remap.range -=
@@ -2220,16 +2234,6 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 			}
 
 			if (op->base.remap.next) {
-				flags |= op->base.remap.unmap->va->flags &
-					XE_VMA_READ_ONLY ?
-					VMA_CREATE_FLAG_READ_ONLY : 0;
-				flags |= op->base.remap.unmap->va->flags &
-					DRM_GPUVA_SPARSE ?
-					VMA_CREATE_FLAG_IS_NULL : 0;
-				flags |= op->base.remap.unmap->va->flags &
-					XE_VMA_DUMPABLE ?
-					VMA_CREATE_FLAG_DUMPABLE : 0;
-
 				vma = new_vma(vm, op->base.remap.next,
 					      old->pat_index, flags);
 				if (IS_ERR(vma))
@@ -2241,9 +2245,10 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 				 * Userptr creates a new SG mapping so
 				 * we must also rebind.
 				 */
-				op->remap.skip_next = !xe_vma_is_userptr(old) &&
+				op->remap.skip_next = skip ||
+					(!xe_vma_is_userptr(old) &&
 					IS_ALIGNED(xe_vma_start(vma),
-						   xe_vma_max_pte_size(old));
+						   xe_vma_max_pte_size(old)));
 				if (op->remap.skip_next) {
 					xe_vma_set_pte_size(vma, xe_vma_max_pte_size(old));
 					op->remap.range -=
@@ -2256,14 +2261,27 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops,
 					xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
 				}
 			}
-			xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
+			if (!skip)
+				xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
 			break;
 		}
 		case DRM_GPUVA_OP_UNMAP:
+		{
+			struct xe_vma *vma = gpuva_to_vma(op->base.unmap.va);
+
+			if (!xe_vma_is_cpu_addr_mirror(vma))
+				xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
+			break;
+		}
 		case DRM_GPUVA_OP_PREFETCH:
+		{
+			struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
+
 			/* FIXME: Need to skip some prefetch ops */
-			xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
+			if (!xe_vma_is_cpu_addr_mirror(vma))
+				xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);
 			break;
+		}
 		default:
 			drm_warn(&vm->xe->drm, "NOT POSSIBLE");
 		}
@@ -2665,10 +2683,12 @@ static void vm_bind_ioctl_ops_fini(struct xe_vm *vm, struct xe_vma_ops *vops,
 	}
 	if (ufence)
 		xe_sync_ufence_put(ufence);
-	for (i = 0; i < vops->num_syncs; i++)
-		xe_sync_entry_signal(vops->syncs + i, fence);
-	xe_exec_queue_last_fence_set(wait_exec_queue, vm, fence);
-	dma_fence_put(fence);
+	if (fence) {
+		for (i = 0; i < vops->num_syncs; i++)
+			xe_sync_entry_signal(vops->syncs + i, fence);
+		xe_exec_queue_last_fence_set(wait_exec_queue, vm, fence);
+		dma_fence_put(fence);
+	}
 }
 
 static int vm_bind_ioctl_ops_execute(struct xe_vm *vm,
@@ -2691,6 +2711,8 @@ static int vm_bind_ioctl_ops_execute(struct xe_vm *vm,
 		fence = ops_execute(vm, vops);
 		if (IS_ERR(fence)) {
 			err = PTR_ERR(fence);
+			if (err == -ENODATA)
+				vm_bind_ioctl_ops_fini(vm, vops, NULL);
 			goto unlock;
 		}
 
@@ -2707,7 +2729,8 @@ ALLOW_ERROR_INJECTION(vm_bind_ioctl_ops_execute, ERRNO);
 	(DRM_XE_VM_BIND_FLAG_READONLY | \
 	 DRM_XE_VM_BIND_FLAG_IMMEDIATE | \
 	 DRM_XE_VM_BIND_FLAG_NULL | \
-	 DRM_XE_VM_BIND_FLAG_DUMPABLE)
+	 DRM_XE_VM_BIND_FLAG_DUMPABLE | \
+	 DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR)
 
 #ifdef TEST_VM_OPS_ERROR
 #define SUPPORTED_FLAGS	(SUPPORTED_FLAGS_STUB | FORCE_OP_ERROR)
@@ -2718,7 +2741,7 @@ ALLOW_ERROR_INJECTION(vm_bind_ioctl_ops_execute, ERRNO);
 #define XE_64K_PAGE_MASK 0xffffull
 #define ALL_DRM_XE_SYNCS_FLAGS (DRM_XE_SYNCS_FLAG_WAIT_FOR_OP)
 
-static int vm_bind_ioctl_check_args(struct xe_device *xe,
+static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
 				    struct drm_xe_vm_bind *args,
 				    struct drm_xe_vm_bind_op **bind_ops)
 {
@@ -2763,9 +2786,23 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe,
 		u64 obj_offset = (*bind_ops)[i].obj_offset;
 		u32 prefetch_region = (*bind_ops)[i].prefetch_mem_region_instance;
 		bool is_null = flags & DRM_XE_VM_BIND_FLAG_NULL;
+		bool is_cpu_addr_mirror = flags &
+			DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR;
 		u16 pat_index = (*bind_ops)[i].pat_index;
 		u16 coh_mode;
 
+		/* FIXME: Disabling CPU address mirror for now */
+		if (XE_IOCTL_DBG(xe, is_cpu_addr_mirror)) {
+			err = -EOPNOTSUPP;
+			goto free_bind_ops;
+		}
+
+		if (XE_IOCTL_DBG(xe, is_cpu_addr_mirror &&
+				 !xe_vm_in_fault_mode(vm))) {
+			err = -EINVAL;
+			goto free_bind_ops;
+		}
+
 		if (XE_IOCTL_DBG(xe, pat_index >= xe->pat.n_entries)) {
 			err = -EINVAL;
 			goto free_bind_ops;
@@ -2786,13 +2823,14 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe,
 
 		if (XE_IOCTL_DBG(xe, op > DRM_XE_VM_BIND_OP_PREFETCH) ||
 		    XE_IOCTL_DBG(xe, flags & ~SUPPORTED_FLAGS) ||
-		    XE_IOCTL_DBG(xe, obj && is_null) ||
-		    XE_IOCTL_DBG(xe, obj_offset && is_null) ||
+		    XE_IOCTL_DBG(xe, obj && (is_null || is_cpu_addr_mirror)) ||
+		    XE_IOCTL_DBG(xe, obj_offset && (is_null ||
+						    is_cpu_addr_mirror)) ||
 		    XE_IOCTL_DBG(xe, op != DRM_XE_VM_BIND_OP_MAP &&
-				 is_null) ||
+				 (is_null || is_cpu_addr_mirror)) ||
 		    XE_IOCTL_DBG(xe, !obj &&
 				 op == DRM_XE_VM_BIND_OP_MAP &&
-				 !is_null) ||
+				 !is_null && !is_cpu_addr_mirror) ||
 		    XE_IOCTL_DBG(xe, !obj &&
 				 op == DRM_XE_VM_BIND_OP_UNMAP_ALL) ||
 		    XE_IOCTL_DBG(xe, addr &&
@@ -2934,15 +2972,19 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	int err;
 	int i;
 
-	err = vm_bind_ioctl_check_args(xe, args, &bind_ops);
+	vm = xe_vm_lookup(xef, args->vm_id);
+	if (XE_IOCTL_DBG(xe, !vm))
+		return -EINVAL;
+
+	err = vm_bind_ioctl_check_args(xe, vm, args, &bind_ops);
 	if (err)
-		return err;
+		goto put_vm;
 
 	if (args->exec_queue_id) {
 		q = xe_exec_queue_lookup(xef, args->exec_queue_id);
 		if (XE_IOCTL_DBG(xe, !q)) {
 			err = -ENOENT;
-			goto free_objs;
+			goto put_vm;
 		}
 
 		if (XE_IOCTL_DBG(xe, !(q->flags & EXEC_QUEUE_FLAG_VM))) {
@@ -2951,15 +2993,9 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		}
 	}
 
-	vm = xe_vm_lookup(xef, args->vm_id);
-	if (XE_IOCTL_DBG(xe, !vm)) {
-		err = -EINVAL;
-		goto put_exec_queue;
-	}
-
 	err = down_write_killable(&vm->lock);
 	if (err)
-		goto put_vm;
+		goto put_exec_queue;
 
 	if (XE_IOCTL_DBG(xe, xe_vm_is_closed_or_banned(vm))) {
 		err = -ENOENT;
@@ -3116,12 +3152,11 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		xe_bo_put(bos[i]);
 release_vm_lock:
 	up_write(&vm->lock);
-put_vm:
-	xe_vm_put(vm);
 put_exec_queue:
 	if (q)
 		xe_exec_queue_put(q);
-free_objs:
+put_vm:
+	xe_vm_put(vm);
 	kvfree(bos);
 	kvfree(ops);
 	if (args->num_binds > 1)
@@ -3178,6 +3213,7 @@ int xe_vm_invalidate_vma(struct xe_vma *vma)
 	int ret = 0;
 
 	xe_assert(xe, !xe_vma_is_null(vma));
+	xe_assert(xe, !xe_vma_is_cpu_addr_mirror(vma));
 	trace_xe_vma_invalidate(vma);
 
 	vm_dbg(&xe_vma_vm(vma)->xe->drm,
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index 23adb7442881..0e54a0e8768d 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/drivers/gpu/drm/xe/xe_vm.h
@@ -150,6 +150,11 @@ static inline bool xe_vma_is_null(struct xe_vma *vma)
 	return vma->gpuva.flags & DRM_GPUVA_SPARSE;
 }
 
+static inline bool xe_vma_is_cpu_addr_mirror(struct xe_vma *vma)
+{
+	return vma->gpuva.flags & XE_VMA_SYSTEM_ALLOCATOR;
+}
+
 static inline bool xe_vma_has_no_bo(struct xe_vma *vma)
 {
 	return !xe_vma_bo(vma);
@@ -157,7 +162,8 @@ static inline bool xe_vma_has_no_bo(struct xe_vma *vma)
 
 static inline bool xe_vma_is_userptr(struct xe_vma *vma)
 {
-	return xe_vma_has_no_bo(vma) && !xe_vma_is_null(vma);
+	return xe_vma_has_no_bo(vma) && !xe_vma_is_null(vma) &&
+		!xe_vma_is_cpu_addr_mirror(vma);
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index 7f9a303e51d8..f6855e4fb9e6 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -42,6 +42,7 @@ struct xe_vm_pgtable_update_op;
 #define XE_VMA_PTE_64K		(DRM_GPUVA_USERBITS << 6)
 #define XE_VMA_PTE_COMPACT	(DRM_GPUVA_USERBITS << 7)
 #define XE_VMA_DUMPABLE		(DRM_GPUVA_USERBITS << 8)
+#define XE_VMA_SYSTEM_ALLOCATOR	(DRM_GPUVA_USERBITS << 9)
 
 /** struct xe_userptr - User pointer */
 struct xe_userptr {
@@ -294,6 +295,8 @@ struct xe_vma_op_map {
 	bool read_only;
 	/** @is_null: is NULL binding */
 	bool is_null;
+	/** @is_cpu_addr_mirror: is CPU address mirror binding */
+	bool is_cpu_addr_mirror;
 	/** @dumpable: whether BO is dumped on GPU hang */
 	bool dumpable;
 	/** @pat_index: The pat index to use for this operation. */
diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
index e2160330ad01..b86dc1b4c2fe 100644
--- a/include/uapi/drm/xe_drm.h
+++ b/include/uapi/drm/xe_drm.h
@@ -933,6 +933,12 @@ struct drm_xe_vm_destroy {
  *    will only be valid for DRM_XE_VM_BIND_OP_MAP operations, the BO
  *    handle MBZ, and the BO offset MBZ. This flag is intended to
  *    implement VK sparse bindings.
+ *  - %DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR - When the CPU address mirror flag is
+ *    set, no mappings are created rather the range is reserved for CPU address
+ *    mirroring which will be populated on GPU page faults or prefetches. Only
+ *    valid on VMs with DRM_XE_VM_CREATE_FLAG_FAULT_MODE set. The CPU address
+ *    mirror flag are only valid for DRM_XE_VM_BIND_OP_MAP operations, the BO
+ *    handle MBZ, and the BO offset MBZ.
  */
 struct drm_xe_vm_bind_op {
 	/** @extensions: Pointer to the first extension struct, if any */
@@ -985,7 +991,9 @@ struct drm_xe_vm_bind_op {
 	 * on the @pat_index. For such mappings there is no actual memory being
 	 * mapped (the address in the PTE is invalid), so the various PAT memory
 	 * attributes likely do not apply.  Simply leaving as zero is one
-	 * option (still a valid pat_index).
+	 * option (still a valid pat_index). Same applies to
+	 * DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR bindings as for such mapping
+	 * there is no actual memory being mapped.
 	 */
 	__u16 pat_index;
 
@@ -1001,6 +1009,14 @@ struct drm_xe_vm_bind_op {
 
 		/** @userptr: user pointer to bind on */
 		__u64 userptr;
+
+		/**
+		 * @cpu_addr_mirror_offset: Offset from GPU @addr to create
+		 * CPU address mirror mappings. MBZ with current level of
+		 * support (e.g. 1 to 1 mapping between GPU and CPU mappings
+		 * only supported).
+		 */
+		__s64 cpu_addr_mirror_offset;
 	};
 
 	/**
@@ -1023,6 +1039,7 @@ struct drm_xe_vm_bind_op {
 #define DRM_XE_VM_BIND_FLAG_IMMEDIATE	(1 << 1)
 #define DRM_XE_VM_BIND_FLAG_NULL	(1 << 2)
 #define DRM_XE_VM_BIND_FLAG_DUMPABLE	(1 << 3)
+#define DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR	(1 << 4)
 	/** @flags: Bind flags */
 	__u32 flags;
 
-- 
2.34.1