On Mon, Nov 18, 2024 at 02:44:58PM +0100, Thomas Hellström wrote:
> On Tue, 2024-10-15 at 20:24 -0700, Matthew Brost wrote:
> > Add the DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR flag, which is used to
> > create unpopulated virtual memory areas (VMAs) without memory backing
> > or
> > GPU page tables. These VMAs are referred to as system allocator VMAs.
> > The idea is that upon a page fault or prefetch, the memory backing
> > and
> > GPU page tables will be populated.
>
> It would be good if the commit message could describe the state of the
> code after this patch. It seems we do a lot more than just adding a
> flag, but no real implementation. Perhaps just adjust the current code
> to avoid code-paths that are not taken when the flag is set?
>
Sure can add a description of what the patch does which aligns with your
assessment - it updates the bind code to create VMA without creating
page tables when this flag is set.
> >
> > System allocator 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 system allocator 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.
>
> This sounds like compute API-level terminology describing where the app
> gets its buffer objects: System allocator - malloc, Runtime allocator -
> the compute runtime (allocating buffer objects under the hood).
>
> Not sure what would be the best terminology, though, but something
> along DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR? (And when setteled change
> inside code as well).
>
DRM_XE_VM_BIND_FLAG_CPU_ADDR_MIRROR seems reasonible. Then also
s/xe_vma_is_system_allocator/s/xe_vma_is_cpu_addr_mirror too?
> Otherwise it gets weird if someone asks why is it called "System
> Allocator", and the reply is "a compute runtime would typically use
> this functionality when an app has allocated the memory using malloc()
> which can be called a system allocator".
>
> IOW we name the functionality based on what KMD does and not how the
> app uses it through UMD.
>
> >
> > Expected usage:
> >
> > - Bind the entire virtual address (VA) space upon program load using
> > the
> > DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR flag.
> > - If a buffer object (BO) requires GPU mapping, allocate an address
> > using malloc, and bind the BO to the malloc'd address using
> > existing
> > bind IOCTLs (runtime allocation).
>
> allocate a cpu address using mmap(PROT_NONE), bind the BO to the
> malloced 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)
>
Will adjust.
> > - If a BO no longer requires GPU mapping, bind the mapping address
> > with
> > the DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR flag.
>
> unmap it from cpu space and then...
Yes. Will add.
>
> > - Any malloc'd address accessed by the GPU will be faulted in via the
> > SVM implementation (system allocation).
> > - Upon freeing any 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.
> >
> > Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> > ---
> > drivers/gpu/drm/xe/xe_pt.c | 76 +++++++++++++++++-----
> > drivers/gpu/drm/xe/xe_vm.c | 107 ++++++++++++++++++++---------
> > --
> > 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, 157 insertions(+), 56 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> > index f27f579f4d85..39357e829b6d 100644
> > --- a/drivers/gpu/drm/xe/xe_pt.c
> > +++ b/drivers/gpu/drm/xe/xe_pt.c
> > @@ -1068,6 +1068,11 @@ static int op_add_deps(struct xe_vm *vm,
> > struct xe_vma_op *op,
> > {
> > int err = 0;
> >
> > + /*
> > + * No need to check for is_system_allocator here as
> > vma_add_deps is a
> > + * NOP if VMA is_system_allocator
> > + */
> > +
> > 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_system_allocator(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_system_allocator(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_system_allocator)
> > 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_system_allocator(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_system_allocator(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_system_allocator(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");
> > }
> > @@ -1857,6 +1883,8 @@ 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_system_allocator(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 ?
> > @@ -1890,6 +1918,8 @@ 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_system_allocator(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 ?
> > @@ -1924,16 +1954,21 @@ 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_system_allocator)
> > 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_system_allocator(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,
> > @@ -1942,14 +1977,25 @@ 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_system_allocator(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_system_allocator(vma))
> > + bind_op_commit(vm, tile, pt_update_ops, vma,
> > fence,
> > + fence2);
>
> Wouldn't we want to support prefetch? Or perhaps the implementation is
> deferred?
>
Yes, this will be deferred. Himal is looking at this piece.
Matt
>
> > 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 c99380271de6..0d887fb9de59 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_system_allocator =
> > + (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_system_allocator) {
> > 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_system_allocator)
> > + 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_system_allocator) {
> > 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_system_allocator(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_system_allocator(vma)) {
> > xe_bo_assert_held(xe_vma_bo(vma));
> >
> > drm_gpuva_unlink(&vma->gpuva);
> > @@ -1967,6 +1972,8 @@ 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_system_allocator = flags &
> > + DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR
> > ;
> > op->map.dumpable = flags &
> > DRM_XE_VM_BIND_FLAG_DUMPABLE;
> > op->map.pat_index = pat_index;
> > } else if (__op->op == DRM_GPUVA_OP_PREFETCH) {
> > @@ -2158,6 +2165,8 @@ 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_system_allocator ?
> > + VMA_CREATE_FLAG_IS_SYSTEM_ALLOCATOR
> > : 0;
> >
> > vma = new_vma(vm, &op->base.map, op-
> > >map.pat_index,
> > flags);
> > @@ -2165,7 +2174,8 @@ 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_system_allocator)
> > xe_vma_ops_incr_pt_update_ops(vops,
> > op-
> > >tile_mask);
> > break;
> > @@ -2174,21 +2184,24 @@ 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_system_allocator(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_system_allocator(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))
> > @@ -2200,9 +2213,10 @@ 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 -=
> > @@ -2218,16 +2232,6 @@ 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))
> > @@ -2239,9 +2243,10 @@ 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 -=
> > @@ -2254,14 +2259,27 @@ 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_system_allocator(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_system_allocator(vma))
> > + xe_vma_ops_incr_pt_update_ops(vops,
> > op->tile_mask);
> > break;
> > + }
> > default:
> > drm_warn(&vm->xe->drm, "NOT POSSIBLE");
> > }
> > @@ -2702,7 +2720,8 @@ static int vm_bind_ioctl_ops_execute(struct
> > xe_vm *vm,
> > (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_SYSTEM_ALLOCATOR)
> >
> > #ifdef TEST_VM_OPS_ERROR
> > #define SUPPORTED_FLAGS (SUPPORTED_FLAGS_STUB |
> > FORCE_OP_ERROR)
> > @@ -2757,9 +2776,17 @@ 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_system_allocator = flags &
> > + DRM_XE_VM_BIND_FLAG_SYSTEM_ALLOCATOR;
> > u16 pat_index = (*bind_ops)[i].pat_index;
> > u16 coh_mode;
> >
> > + /* FIXME: Disabling system allocator for now */
> > + if (XE_IOCTL_DBG(xe, is_system_allocator)) {
> > + err = -EOPNOTSUPP;
> > + goto free_bind_ops;
> > + }
> > +
> > if (XE_IOCTL_DBG(xe, pat_index >= xe-
> > >pat.n_entries)) {
> > err = -EINVAL;
> > goto free_bind_ops;
> > @@ -2780,13 +2807,14 @@ 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_system_allocator)) ||
> > + XE_IOCTL_DBG(xe, obj_offset && (is_null ||
> > + is_system_allocator)) ||
> > XE_IOCTL_DBG(xe, op != DRM_XE_VM_BIND_OP_MAP &&
> > - is_null) ||
> > + (is_null || is_system_allocator))
> > ||
> > XE_IOCTL_DBG(xe, !obj &&
> > op == DRM_XE_VM_BIND_OP_MAP &&
> > - !is_null) ||
> > + !is_null && !is_system_allocator)
> > ||
> > XE_IOCTL_DBG(xe, !obj &&
> > op == DRM_XE_VM_BIND_OP_UNMAP_ALL)
> > ||
> > XE_IOCTL_DBG(xe, addr &&
> > @@ -3170,6 +3198,7 @@ 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_system_allocator(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 c864dba35e1d..1a5aed678214 100644
> > --- a/drivers/gpu/drm/xe/xe_vm.h
> > +++ b/drivers/gpu/drm/xe/xe_vm.h
> > @@ -151,6 +151,11 @@ static inline bool xe_vma_is_null(struct xe_vma
> > *vma)
> > return vma->gpuva.flags & DRM_GPUVA_SPARSE;
> > }
> >
> > +static inline bool xe_vma_is_system_allocator(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);
> > @@ -158,7 +163,8 @@ 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_system_allocator(vma);
> > }
> >
> > /**
> > diff --git a/drivers/gpu/drm/xe/xe_vm_types.h
> > b/drivers/gpu/drm/xe/xe_vm_types.h
> > index 7f9a303e51d8..1764781c376b 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_system_allocator: is system allocator binding */
> > + bool is_system_allocator;
> > /** @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 c4182e95a619..1e92fd498967 100644
> > --- a/include/uapi/drm/xe_drm.h
> > +++ b/include/uapi/drm/xe_drm.h
> > @@ -906,6 +906,12 @@ 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_SYSTEM_ALLOCATOR - When the system
> > allocator flag is
> > + * set, no mappings are created rather the range is reserved for
> > system
> > + * allocations which will be populated on GPU page faults. Only
> > valid on VMs
> > + * with DRM_XE_VM_CREATE_FLAG_FAULT_MODE set. The system
> > allocator 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 */
> > @@ -958,7 +964,9 @@ 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_SYSTEM_ALLOCATOR bindings as for such
> > mapping
> > + * there is no actual memory being mapped.
> > */
> > __u16 pat_index;
> >
> > @@ -974,6 +982,14 @@ struct drm_xe_vm_bind_op {
> >
> > /** @userptr: user pointer to bind on */
> > __u64 userptr;
> > +
> > + /**
> > + * @system_allocator_offset: Offset from GPU @addr
> > to create
> > + * system allocator mappings. MBZ with current level
> > of support
> > + * (e.g. 1 to 1 mapping between GPU and CPU mappings
> > only
> > + * supported).
> > + */
> > + __s64 system_allocator_offset;
> > };
> >
> > /**
> > @@ -996,6 +1012,7 @@ 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_SYSTEM_ALLOCATOR (1 << 4)
> > /** @flags: Bind flags */
> > __u32 flags;
> >
>
