On Wed, 2025-01-29 at 11:51 -0800, Matthew Brost wrote:
> 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_M
> IRROR (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.br...@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellst...@linux.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_op
> s(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;
>
