Re: [Intel-xe] [PATCH v2 2/2] drm/xe: switch to using drm_exec

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

On Thu, Jul 13, 2023 at 01:17:11PM +0000, Francois Dugast wrote:
> Replace the use of ttm_execbuf_util helpers with the drm_exec helpers.
> 
> v2:
> - Call dma-resv locking functions directly in xe_bo_lock and
>   xe_vm_lock functions (Matthew Brost)
> - Switch to execution context for GEM buffers v7 (Christian König)
> - Use DRM_EXEC_INTERRUPTIBLE_WAIT
> 
> Signed-off-by: Francois Dugast <francois.dugast@intel.com>
> ---
>  drivers/gpu/drm/xe/Kconfig           |   1 +
>  drivers/gpu/drm/xe/xe_bo.c           |  29 +++-
>  drivers/gpu/drm/xe/xe_bo_types.h     |   1 -
>  drivers/gpu/drm/xe/xe_exec.c         |  30 +---
>  drivers/gpu/drm/xe/xe_gt_pagefault.c |  55 +-----
>  drivers/gpu/drm/xe/xe_vm.c           | 246 +++++++++++++--------------
>  drivers/gpu/drm/xe/xe_vm.h           |  32 ++--
>  7 files changed, 168 insertions(+), 226 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> index d44794f99338..b739faa401d3 100644
> --- a/drivers/gpu/drm/xe/Kconfig
> +++ b/drivers/gpu/drm/xe/Kconfig
> @@ -8,6 +8,7 @@ config DRM_XE
>  	select SHMEM
>  	select TMPFS
>  	select DRM_BUDDY
> +	select DRM_EXEC
>  	select DRM_KMS_HELPER
>  	select DRM_PANEL
>  	select DRM_SUBALLOC_HELPER
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 6353afa8d846..aafe69ed4320 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -1806,17 +1806,32 @@ int xe_gem_mmap_offset_ioctl(struct drm_device *dev, void *data,
>  int xe_bo_lock(struct xe_bo *bo, struct ww_acquire_ctx *ww,
>  	       int num_resv, bool intr)
>  {
> -	struct ttm_validate_buffer tv_bo;
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> +	struct dma_resv *obj;
> +	int err;
>  
>  	XE_BUG_ON(!ww);
>  
> -	tv_bo.num_shared = num_resv;
> -	tv_bo.bo = &bo->ttm;;
> -	list_add_tail(&tv_bo.head, &objs);
> +	obj = bo->ttm.base.resv;
> +	ww_acquire_init(ww, &reservation_ww_class);
> +
> +	if (intr)
> +		err = dma_resv_lock_interruptible(obj, ww);
> +	else
> +		err = dma_resv_lock(obj, ww);
> +
> +	if (unlikely(err))
> +		return err;
> +
> +	num_resv = max(num_resv, 1);

Why? If the user ask to reserve 0 fences this will reserve 1.

> +	err = dma_resv_reserve_fences(obj, num_resv);
> +	if (err)
> +		goto out_err;
>  
> -	return ttm_eu_reserve_buffers(ww, &objs, intr, &dups);
> +	return 0;
> +
> +out_err:
> +	dma_resv_unlock(obj);
> +	return err;
>  }
>  
>  void xe_bo_unlock(struct xe_bo *bo, struct ww_acquire_ctx *ww)
> diff --git a/drivers/gpu/drm/xe/xe_bo_types.h b/drivers/gpu/drm/xe/xe_bo_types.h
> index f6ee920303af..bc67263c6713 100644
> --- a/drivers/gpu/drm/xe/xe_bo_types.h
> +++ b/drivers/gpu/drm/xe/xe_bo_types.h
> @@ -11,7 +11,6 @@
>  #include <drm/drm_mm.h>
>  #include <drm/ttm/ttm_bo.h>
>  #include <drm/ttm/ttm_device.h>
> -#include <drm/ttm/ttm_execbuf_util.h>
>  #include <drm/ttm/ttm_placement.h>
>  
>  struct xe_device;
> diff --git a/drivers/gpu/drm/xe/xe_exec.c b/drivers/gpu/drm/xe/xe_exec.c
> index ba13d20ed348..32a6e16ec177 100644
> --- a/drivers/gpu/drm/xe/xe_exec.c
> +++ b/drivers/gpu/drm/xe/xe_exec.c
> @@ -6,6 +6,7 @@
>  #include "xe_exec.h"
>  
>  #include <drm/drm_device.h>
> +#include <drm/drm_exec.h>
>  #include <drm/drm_file.h>
>  #include <drm/xe_drm.h>
>  #include <linux/delay.h>
> @@ -95,23 +96,18 @@
>  
>  #define XE_EXEC_BIND_RETRY_TIMEOUT_MS 1000
>  
> -static int xe_exec_begin(struct xe_engine *e, struct ww_acquire_ctx *ww,
> -			 struct ttm_validate_buffer tv_onstack[],
> -			 struct ttm_validate_buffer **tv,
> -			 struct list_head *objs)
> +static int xe_exec_begin(struct xe_engine *e, struct drm_exec *exec)
>  {
>  	struct xe_vm *vm = e->vm;
>  	struct xe_vma *vma;
> -	LIST_HEAD(dups);
>  	ktime_t end = 0;
>  	int err = 0;
>  
> -	*tv = NULL;
>  	if (xe_vm_no_dma_fences(e->vm))
>  		return 0;
>  
>  retry:
> -	err = xe_vm_lock_dma_resv(vm, ww, tv_onstack, tv, objs, true, 1);
> +	err = xe_vm_lock_dma_resv(vm, exec, true, 1);
>  	if (err)
>  		return err;
>  
> @@ -128,8 +124,7 @@ static int xe_exec_begin(struct xe_engine *e, struct ww_acquire_ctx *ww,
>  
>  		err = xe_bo_validate(xe_vma_bo(vma), vm, false);
>  		if (err) {
> -			xe_vm_unlock_dma_resv(vm, tv_onstack, *tv, ww, objs);
> -			*tv = NULL;
> +			xe_vm_unlock_dma_resv(vm, exec);
>  			break;
>  		}
>  	}
> @@ -153,14 +148,10 @@ static int xe_exec_begin(struct xe_engine *e, struct ww_acquire_ctx *ww,
>  	return err;
>  }
>  
> -static void xe_exec_end(struct xe_engine *e,
> -			struct ttm_validate_buffer *tv_onstack,
> -			struct ttm_validate_buffer *tv,
> -			struct ww_acquire_ctx *ww,
> -			struct list_head *objs)
> +static void xe_exec_end(struct xe_engine *e, struct drm_exec *exec)
>  {
>  	if (!xe_vm_no_dma_fences(e->vm))
> -		xe_vm_unlock_dma_resv(e->vm, tv_onstack, tv, ww, objs);
> +		xe_vm_unlock_dma_resv(e->vm, exec);
>  }
>  
>  int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
> @@ -173,14 +164,11 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  	struct xe_engine *engine;
>  	struct xe_sync_entry *syncs = NULL;
>  	u64 addresses[XE_HW_ENGINE_MAX_INSTANCE];
> -	struct ttm_validate_buffer tv_onstack[XE_ONSTACK_TV];
> -	struct ttm_validate_buffer *tv = NULL;
>  	u32 i, num_syncs = 0;
>  	struct xe_sched_job *job;
>  	struct dma_fence *rebind_fence;
>  	struct xe_vm *vm;
> -	struct ww_acquire_ctx ww;
> -	struct list_head objs;
> +	struct drm_exec exec;
>  	bool write_locked;
>  	int err = 0;
>  
> @@ -293,7 +281,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  			goto err_unlock_list;
>  	}
>  
> -	err = xe_exec_begin(engine, &ww, tv_onstack, &tv, &objs);
> +	err = xe_exec_begin(engine, &exec);
>  	if (err)
>  		goto err_unlock_list;
>  
> @@ -412,7 +400,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  	if (err)
>  		xe_sched_job_put(job);
>  err_engine_end:
> -	xe_exec_end(engine, tv_onstack, tv, &ww, &objs);
> +	xe_exec_end(engine, &exec);
>  err_unlock_list:
>  	if (write_locked)
>  		up_write(&vm->lock);
> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> index 125e4744fa38..94f59c29ba9b 100644
> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
> @@ -8,8 +8,8 @@
>  #include <linux/bitfield.h>
>  #include <linux/circ_buf.h>
>  
> +#include <drm/drm_exec.h>
>  #include <drm/drm_managed.h>
> -#include <drm/ttm/ttm_execbuf_util.h>
>  
>  #include "xe_bo.h"
>  #include "xe_gt.h"
> @@ -84,11 +84,6 @@ static bool vma_matches(struct xe_vma *vma, u64 page_addr)
>  	return true;
>  }
>  
> -static bool only_needs_bo_lock(struct xe_bo *bo)
> -{
> -	return bo && bo->vm;
> -}
> -
>  static struct xe_vma *lookup_vma(struct xe_vm *vm, u64 page_addr)
>  {
>  	struct xe_vma *vma = NULL;
> @@ -110,10 +105,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
>  	struct xe_vm *vm;
>  	struct xe_vma *vma = NULL;
>  	struct xe_bo *bo;
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> -	struct ttm_validate_buffer tv_bo, tv_vm;
> -	struct ww_acquire_ctx ww;
> +	struct drm_exec exec;
>  	struct dma_fence *fence;
>  	bool write_locked;
>  	int ret = 0;
> @@ -171,20 +163,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
>  
>  	/* Lock VM and BOs dma-resv */
>  	bo = xe_vma_bo(vma);
> -	if (only_needs_bo_lock(bo)) {
> -		/* This path ensures the BO's LRU is updated */
> -		ret = xe_bo_lock(bo, &ww, xe->info.tile_count, false);
> -	} else {
> -		tv_vm.num_shared = xe->info.tile_count;
> -		tv_vm.bo = xe_vm_ttm_bo(vm);
> -		list_add(&tv_vm.head, &objs);
> -		if (bo) {
> -			tv_bo.bo = &bo->ttm;
> -			tv_bo.num_shared = xe->info.tile_count;
> -			list_add(&tv_bo.head, &objs);
> -		}
> -		ret = ttm_eu_reserve_buffers(&ww, &objs, false, &dups);
> -	}
> +	ret = xe_vm_bo_lock(vm, bo, &exec, xe->info.tile_count, false);
>  	if (ret)
>  		goto unlock_vm;
>  
> @@ -227,10 +206,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
>  	vma->usm.tile_invalidated &= ~BIT(gt_to_tile(gt)->id);
>  
>  unlock_dma_resv:
> -	if (only_needs_bo_lock(bo))
> -		xe_bo_unlock(bo, &ww);
> -	else
> -		ttm_eu_backoff_reservation(&ww, &objs);
> +	xe_vm_bo_unlock(vm, bo, &exec, true);
>  unlock_vm:
>  	if (!ret)
>  		vm->usm.last_fault_vma = vma;
> @@ -498,10 +474,7 @@ static int handle_acc(struct xe_gt *gt, struct acc *acc)
>  	struct xe_vm *vm;
>  	struct xe_vma *vma;
>  	struct xe_bo *bo;
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> -	struct ttm_validate_buffer tv_bo, tv_vm;
> -	struct ww_acquire_ctx ww;
> +	struct drm_exec exec;
>  	int ret = 0;
>  
>  	/* We only support ACC_TRIGGER at the moment */
> @@ -534,28 +507,14 @@ static int handle_acc(struct xe_gt *gt, struct acc *acc)
>  
>  	/* Lock VM and BOs dma-resv */
>  	bo = xe_vma_bo(vma);
> -	if (only_needs_bo_lock(bo)) {
> -		/* This path ensures the BO's LRU is updated */
> -		ret = xe_bo_lock(bo, &ww, xe->info.tile_count, false);
> -	} else {
> -		tv_vm.num_shared = xe->info.tile_count;
> -		tv_vm.bo = xe_vm_ttm_bo(vm);
> -		list_add(&tv_vm.head, &objs);
> -		tv_bo.bo = &bo->ttm;
> -		tv_bo.num_shared = xe->info.tile_count;
> -		list_add(&tv_bo.head, &objs);
> -		ret = ttm_eu_reserve_buffers(&ww, &objs, false, &dups);
> -	}
> +	ret = xe_vm_bo_lock(vm, bo, &exec, xe->info.tile_count, false);
>  	if (ret)
>  		goto unlock_vm;
>  
>  	/* Migrate to VRAM, move should invalidate the VMA first */
>  	ret = xe_bo_migrate(bo, XE_PL_VRAM0 + tile->id);
>  
> -	if (only_needs_bo_lock(bo))
> -		xe_bo_unlock(bo, &ww);
> -	else
> -		ttm_eu_backoff_reservation(&ww, &objs);
> +	xe_vm_bo_unlock(vm, bo, &exec, true);
>  unlock_vm:
>  	up_read(&vm->lock);
>  	xe_vm_put(vm);
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index 6c216350084b..c89b10d5feb5 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -7,8 +7,8 @@
>  
>  #include <linux/dma-fence-array.h>
>  
> +#include <drm/drm_exec.h>
>  #include <drm/drm_print.h>
> -#include <drm/ttm/ttm_execbuf_util.h>
>  #include <drm/ttm/ttm_tt.h>
>  #include <drm/xe_drm.h>
>  #include <linux/delay.h>
> @@ -321,11 +321,8 @@ static void resume_and_reinstall_preempt_fences(struct xe_vm *vm)
>  
>  int xe_vm_add_compute_engine(struct xe_vm *vm, struct xe_engine *e)
>  {
> -	struct ttm_validate_buffer tv_onstack[XE_ONSTACK_TV];
> -	struct ttm_validate_buffer *tv;
> -	struct ww_acquire_ctx ww;
> -	struct list_head objs;
>  	struct dma_fence *pfence;
> +	struct drm_exec exec;
>  	int err;
>  	bool wait;
>  
> @@ -333,7 +330,7 @@ int xe_vm_add_compute_engine(struct xe_vm *vm, struct xe_engine *e)
>  
>  	down_write(&vm->lock);
>  
> -	err = xe_vm_lock_dma_resv(vm, &ww, tv_onstack, &tv, &objs, true, 1);
> +	err = xe_vm_lock_dma_resv(vm, &exec, true, 1);
>  	if (err)
>  		goto out_unlock_outer;
>  
> @@ -367,7 +364,7 @@ int xe_vm_add_compute_engine(struct xe_vm *vm, struct xe_engine *e)
>  	up_read(&vm->userptr.notifier_lock);
>  
>  out_unlock:
> -	xe_vm_unlock_dma_resv(vm, tv_onstack, tv, &ww, &objs);
> +	xe_vm_unlock_dma_resv(vm, &exec);
>  out_unlock_outer:
>  	up_write(&vm->lock);
>  
> @@ -397,68 +394,43 @@ int __xe_vm_userptr_needs_repin(struct xe_vm *vm)
>   * xe_vm_lock_dma_resv() - Lock the vm dma_resv object and the dma_resv
>   * objects of the vm's external buffer objects.
>   * @vm: The vm.
> - * @ww: Pointer to a struct ww_acquire_ctx locking context.
> - * @tv_onstack: Array size XE_ONSTACK_TV of storage for the struct
> - * ttm_validate_buffers used for locking.
> - * @tv: Pointer to a pointer that on output contains the actual storage used.
> - * @objs: List head for the buffer objects locked.
> + * @exec: Pointer to a struct drm_exec execution context.
>   * @intr: Whether to lock interruptible.
>   * @num_shared: Number of dma-fence slots to reserve in the locked objects.
>   *
>   * Locks the vm dma-resv objects and all the dma-resv objects of the
> - * buffer objects on the vm external object list. The TTM utilities require
> - * a list of struct ttm_validate_buffers pointing to the actual buffer
> - * objects to lock. Storage for those struct ttm_validate_buffers should
> - * be provided in @tv_onstack, and is typically reserved on the stack
> - * of the caller. If the size of @tv_onstack isn't sufficient, then
> - * storage will be allocated internally using kvmalloc().
> + * buffer objects on the vm external object list using helpers provided
> + * by drm_exec.
>   *
>   * The function performs deadlock handling internally, and after a
>   * successful return the ww locking transaction should be considered
>   * sealed.
>   *
> - * Return: 0 on success, Negative error code on error. In particular if
> - * @intr is set to true, -EINTR or -ERESTARTSYS may be returned. In case
> - * of error, any locking performed has been reverted.
> + * Return: 0 on success, Negative error code on error.
>   */
> -int xe_vm_lock_dma_resv(struct xe_vm *vm, struct ww_acquire_ctx *ww,
> -			struct ttm_validate_buffer *tv_onstack,
> -			struct ttm_validate_buffer **tv,
> -			struct list_head *objs,
> -			bool intr,
> -			unsigned int num_shared)
> -{
> -	struct ttm_validate_buffer *tv_vm, *tv_bo;
> +int xe_vm_lock_dma_resv(struct xe_vm *vm, struct drm_exec *exec,
> +			bool intr, unsigned int num_shared)
> +{
>  	struct xe_vma *vma, *next;
> -	LIST_HEAD(dups);
> +	struct drm_gem_object *obj;
>  	int err;
>  
>  	lockdep_assert_held(&vm->lock);
>  
> -	if (vm->extobj.entries < XE_ONSTACK_TV) {
> -		tv_vm = tv_onstack;
> -	} else {
> -		tv_vm = kvmalloc_array(vm->extobj.entries + 1, sizeof(*tv_vm),
> -				       GFP_KERNEL);
> -		if (!tv_vm)
> -			return -ENOMEM;
> +	drm_exec_init(exec, intr ? DRM_EXEC_INTERRUPTIBLE_WAIT : 0);
> +	drm_exec_until_all_locked(exec) {
> +		err = drm_exec_prepare_obj(exec, xe_vm_gem(vm), num_shared);
> +		drm_exec_retry_on_contention(exec);
> +		if (unlikely(err) && err != -EALREADY)
> +			goto out_err;
> +		list_for_each_entry(vma, &vm->extobj.list, extobj.link) {
> +			obj = &xe_vma_bo(vma)->ttm.base;
> +			err = drm_exec_prepare_obj(exec, obj, num_shared);
> +			drm_exec_retry_on_contention(exec);
> +			if (unlikely(err) && err != -EALREADY)
> +				goto out_err;
> +		}
>  	}
> -	tv_bo = tv_vm + 1;
> -
> -	INIT_LIST_HEAD(objs);
> -	list_for_each_entry(vma, &vm->extobj.list, extobj.link) {
> -		tv_bo->num_shared = num_shared;
> -		tv_bo->bo = &xe_vma_bo(vma)->ttm;
> -
> -		list_add_tail(&tv_bo->head, objs);
> -		tv_bo++;
> -	}
> -	tv_vm->num_shared = num_shared;
> -	tv_vm->bo = xe_vm_ttm_bo(vm);
> -	list_add_tail(&tv_vm->head, objs);
> -	err = ttm_eu_reserve_buffers(ww, objs, intr, &dups);
> -	if (err)
> -		goto out_err;
>  
>  	spin_lock(&vm->notifier.list_lock);
>  	list_for_each_entry_safe(vma, next, &vm->notifier.rebind_list,
> @@ -470,14 +442,10 @@ int xe_vm_lock_dma_resv(struct xe_vm *vm, struct ww_acquire_ctx *ww,
>  			list_move_tail(&vma->rebind_link, &vm->rebind_list);
>  	}
>  	spin_unlock(&vm->notifier.list_lock);
> -
> -	*tv = tv_vm;
>  	return 0;
>  
>  out_err:
> -	if (tv_vm != tv_onstack)
> -		kvfree(tv_vm);
> -
> +	drm_exec_fini(exec);
>  	return err;
>  }
>  
> @@ -485,20 +453,16 @@ int xe_vm_lock_dma_resv(struct xe_vm *vm, struct ww_acquire_ctx *ww,
>   * xe_vm_unlock_dma_resv() - Unlock reservation objects locked by
>   * xe_vm_lock_dma_resv()
>   * @vm: The vm.
> - * @tv_onstack: The @tv_onstack array given to xe_vm_lock_dma_resv().
> - * @tv: The value of *@tv given by xe_vm_lock_dma_resv().
> - * @ww: The ww_acquire_context used for locking.
> - * @objs: The list returned from xe_vm_lock_dma_resv().
> + * @exec: The @drm_exec given to xe_vm_lock_dma_resv().
>   *
>   * Unlocks the reservation objects and frees any memory allocated by
>   * xe_vm_lock_dma_resv().
>   */
> -void xe_vm_unlock_dma_resv(struct xe_vm *vm,
> -			   struct ttm_validate_buffer *tv_onstack,
> -			   struct ttm_validate_buffer *tv,
> -			   struct ww_acquire_ctx *ww,
> -			   struct list_head *objs)
> +void xe_vm_unlock_dma_resv(struct xe_vm *vm, struct drm_exec *exec)
>  {
> +	struct drm_gem_object *obj, *skip = xe_vm_gem(vm);
> +	unsigned long index;
> +
>  	/*
>  	 * Nothing should've been able to enter the list while we were locked,
>  	 * since we've held the dma-resvs of all the vm's external objects,
> @@ -507,9 +471,13 @@ void xe_vm_unlock_dma_resv(struct xe_vm *vm,
>  	 */
>  	XE_WARN_ON(!list_empty(&vm->notifier.rebind_list));
>  
> -	ttm_eu_backoff_reservation(ww, objs);
> -	if (tv && tv != tv_onstack)
> -		kvfree(tv);
> +	drm_exec_for_each_locked_object(exec, index, obj) {
> +		struct xe_bo *bo = gem_to_xe_bo(obj);
> +
> +		if (obj != skip)
> +			ttm_bo_move_to_lru_tail_unlocked(&bo->ttm);
> +	}
> +	drm_exec_fini(exec);
>  }
>  
>  #define XE_VM_REBIND_RETRY_TIMEOUT_MS 1000
> @@ -536,10 +504,7 @@ static void preempt_rebind_work_func(struct work_struct *w)
>  {
>  	struct xe_vm *vm = container_of(w, struct xe_vm, preempt.rebind_work);
>  	struct xe_vma *vma;
> -	struct ttm_validate_buffer tv_onstack[XE_ONSTACK_TV];
> -	struct ttm_validate_buffer *tv;
> -	struct ww_acquire_ctx ww;
> -	struct list_head objs;
> +	struct drm_exec exec;
>  	struct dma_fence *rebind_fence;
>  	unsigned int fence_count = 0;
>  	LIST_HEAD(preempt_fences);
> @@ -582,8 +547,7 @@ static void preempt_rebind_work_func(struct work_struct *w)
>  			goto out_unlock_outer;
>  	}
>  
> -	err = xe_vm_lock_dma_resv(vm, &ww, tv_onstack, &tv, &objs,
> -				  false, vm->preempt.num_engines);
> +	err = xe_vm_lock_dma_resv(vm, &exec, false, vm->preempt.num_engines);
>  	if (err)
>  		goto out_unlock_outer;
>  
> @@ -662,7 +626,7 @@ static void preempt_rebind_work_func(struct work_struct *w)
>  	up_read(&vm->userptr.notifier_lock);
>  
>  out_unlock:
> -	xe_vm_unlock_dma_resv(vm, tv_onstack, tv, &ww, &objs);
> +	xe_vm_unlock_dma_resv(vm, &exec);
>  out_unlock_outer:
>  	if (err == -EAGAIN) {
>  		trace_xe_vm_rebind_worker_retry(vm);
> @@ -1105,27 +1069,17 @@ static void xe_vma_destroy(struct xe_vma *vma, struct dma_fence *fence)
>  
>  static void xe_vma_destroy_unlocked(struct xe_vma *vma)
>  {
> -	struct ttm_validate_buffer tv[2];
> -	struct ww_acquire_ctx ww;
> +	struct xe_vm *vm = xe_vma_vm(vma);
>  	struct xe_bo *bo = xe_vma_bo(vma);
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> +	struct drm_exec exec;
>  	int err;
>  
> -	memset(tv, 0, sizeof(tv));
> -	tv[0].bo = xe_vm_ttm_bo(xe_vma_vm(vma));
> -	list_add(&tv[0].head, &objs);
> -
> -	if (bo) {
> -		tv[1].bo = &xe_bo_get(bo)->ttm;
> -		list_add(&tv[1].head, &objs);
> -	}
> -	err = ttm_eu_reserve_buffers(&ww, &objs, false, &dups);
> +	err = xe_vm_bo_lock(vm, xe_bo_get(bo), &exec, 0, false);
>  	XE_WARN_ON(err);
>  
>  	xe_vma_destroy(vma, NULL);
>  
> -	ttm_eu_backoff_reservation(&ww, &objs);
> +	xe_vm_bo_unlock(vm, bo, &exec, false);
>  	if (bo)
>  		xe_bo_put(bo);
>  }
> @@ -2125,21 +2079,6 @@ static int xe_vm_prefetch(struct xe_vm *vm, struct xe_vma *vma,
>  
>  #define VM_BIND_OP(op)	(op & 0xffff)
>  
> -struct ttm_buffer_object *xe_vm_ttm_bo(struct xe_vm *vm)
> -{
> -	int idx = vm->flags & XE_VM_FLAG_MIGRATION ?
> -		XE_VM_FLAG_GT_ID(vm->flags) : 0;
> -
> -	/* Safe to use index 0 as all BO in the VM share a single dma-resv lock */
> -	return &vm->pt_root[idx]->bo->ttm;
> -}
> -
> -static void xe_vm_tv_populate(struct xe_vm *vm, struct ttm_validate_buffer *tv)
> -{
> -	tv->num_shared = 1;
> -	tv->bo = xe_vm_ttm_bo(vm);
> -}
> -
>  static void vm_set_async_error(struct xe_vm *vm, int err)
>  {
>  	lockdep_assert_held(&vm->lock);
> @@ -2577,17 +2516,12 @@ static int xe_vma_op_commit(struct xe_vm *vm, struct xe_vma_op *op)
>  static int __xe_vma_op_execute(struct xe_vm *vm, struct xe_vma *vma,
>  			       struct xe_vma_op *op)
>  {
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> -	struct ttm_validate_buffer tv_bo, tv_vm;
> -	struct ww_acquire_ctx ww;
>  	struct xe_bo *vbo;
> +	struct drm_exec exec;
>  	int err;
>  
>  	lockdep_assert_held_write(&vm->lock);
>  
> -	xe_vm_tv_populate(vm, &tv_vm);
> -	list_add_tail(&tv_vm.head, &objs);
>  	vbo = xe_vma_bo(vma);
>  	if (vbo) {
>  		/*
> @@ -2596,16 +2530,10 @@ static int __xe_vma_op_execute(struct xe_vm *vm, struct xe_vma *vma,
>  		 * take a reference here.
>  		 */
>  		xe_bo_get(vbo);
> -
> -		if (!vbo->vm) {
> -			tv_bo.bo = &vbo->ttm;
> -			tv_bo.num_shared = 1;
> -			list_add(&tv_bo.head, &objs);
> -		}
>  	}
>  
>  again:
> -	err = ttm_eu_reserve_buffers(&ww, &objs, true, &dups);
> +	err = xe_vm_bo_lock(vm, vbo, &exec, 1, true);
>  	if (err) {
>  		xe_bo_put(vbo);
>  		return err;
> @@ -2687,7 +2615,7 @@ static int __xe_vma_op_execute(struct xe_vm *vm, struct xe_vma *vma,
>  		XE_BUG_ON("NOT POSSIBLE");
>  	}
>  
> -	ttm_eu_backoff_reservation(&ww, &objs);
> +	xe_vm_bo_unlock(vm, vbo, &exec, false);
>  	if (err == -EAGAIN && xe_vma_is_userptr(vma)) {
>  		lockdep_assert_held_write(&vm->lock);
>  		err = xe_vma_userptr_pin_pages(vma);
> @@ -3338,24 +3266,47 @@ int xe_vm_bind_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
>  	return err == -ENODATA ? 0 : err;
>  }
>  
> +struct drm_gem_object *xe_vm_gem(struct xe_vm *vm)
> +{
> +	int idx = vm->flags & XE_VM_FLAG_MIGRATION ?
> +		XE_VM_FLAG_GT_ID(vm->flags) : 0;
> +
> +	/* Safe to use index 0 as all BO in the VM share a single dma-resv lock */
> +	return &vm->pt_root[idx]->bo->ttm.base;
> +}
> +
>  /*
> - * XXX: Using the TTM wrappers for now, likely can call into dma-resv code
> - * directly to optimize. Also this likely should be an inline function.
> + * XXX: This likely should be an inline function.
>   */
>  int xe_vm_lock(struct xe_vm *vm, struct ww_acquire_ctx *ww,
>  	       int num_resv, bool intr)
>  {
> -	struct ttm_validate_buffer tv_vm;
> -	LIST_HEAD(objs);
> -	LIST_HEAD(dups);
> +	struct dma_resv *obj;
> +	int err;
>  
>  	XE_BUG_ON(!ww);
>  
> -	tv_vm.num_shared = num_resv;
> -	tv_vm.bo = xe_vm_ttm_bo(vm);;
> -	list_add_tail(&tv_vm.head, &objs);
> +	obj = xe_vm_gem(vm)->resv;
> +	ww_acquire_init(ww, &reservation_ww_class);
> +
> +	if (intr)
> +		err = dma_resv_lock_interruptible(obj, ww);
> +	else
> +		err = dma_resv_lock(obj, ww);
> +
> +	if (unlikely(err))
> +		return err;
> +
> +	num_resv = max(num_resv, 1);

Same question as above here.

Matt

> +	err = dma_resv_reserve_fences(obj, num_resv);
> +	if (err)
> +		goto out_err;
>  
> -	return ttm_eu_reserve_buffers(ww, &objs, intr, &dups);
> +	return 0;
> +
> +out_err:
> +	dma_resv_unlock(&vm->resv);
> +	return err;
>  }
>  
>  void xe_vm_unlock(struct xe_vm *vm, struct ww_acquire_ctx *ww)
> @@ -3364,6 +3315,43 @@ void xe_vm_unlock(struct xe_vm *vm, struct ww_acquire_ctx *ww)
>  	ww_acquire_fini(ww);
>  }
>  
> +int xe_vm_bo_lock(struct xe_vm *vm, struct xe_bo *bo, struct drm_exec *exec,
> +		  int num_resv, bool intr)
> +{
> +	int err;
> +
> +	drm_exec_init(exec, intr ? DRM_EXEC_INTERRUPTIBLE_WAIT : 0);
> +	drm_exec_until_all_locked(exec) {
> +		err = drm_exec_prepare_obj(exec, xe_vm_gem(vm),
> +					   num_resv);
> +		drm_exec_retry_on_contention(exec);
> +		if (err && err != -EALREADY)
> +			goto out_err;
> +
> +		if (bo && !bo->vm) {
> +			err = drm_exec_prepare_obj(exec, &bo->ttm.base,
> +						   num_resv);
> +			drm_exec_retry_on_contention(exec);
> +			if (err && err != -EALREADY)
> +				goto out_err;
> +		}
> +	}
> +
> +	return 0;
> +
> +out_err:
> +	drm_exec_fini(exec);
> +	return err;
> +}
> +
> +void xe_vm_bo_unlock(struct xe_vm *vm, struct xe_bo *bo, struct drm_exec *exec,
> +		     bool lru_update)
> +{
> +	if (lru_update && bo && (!bo->vm || xe_vm_no_dma_fences(vm)))
> +		ttm_bo_move_to_lru_tail_unlocked(&bo->ttm);
> +	drm_exec_fini(exec);
> +}
> +
>  /**
>   * xe_vm_invalidate_vma - invalidate GPU mappings for VMA without a lock
>   * @vma: VMA to invalidate
> diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
> index eaf11ac8ff51..62a062bd5078 100644
> --- a/drivers/gpu/drm/xe/xe_vm.h
> +++ b/drivers/gpu/drm/xe/xe_vm.h
> @@ -12,6 +12,7 @@
>  #include "xe_vm_types.h"
>  
>  struct drm_device;
> +struct drm_exec;
>  struct drm_printer;
>  struct drm_file;
>  
> @@ -39,11 +40,17 @@ static inline void xe_vm_put(struct xe_vm *vm)
>  	kref_put(&vm->refcount, xe_vm_free);
>  }
>  
> +struct drm_gem_object *xe_vm_gem(struct xe_vm *vm);
> +
>  int xe_vm_lock(struct xe_vm *vm, struct ww_acquire_ctx *ww,
>  	       int num_resv, bool intr);
> -
>  void xe_vm_unlock(struct xe_vm *vm, struct ww_acquire_ctx *ww);
>  
> +int xe_vm_bo_lock(struct xe_vm *vm, struct xe_bo *bo, struct drm_exec *exec,
> +		  int num_resv, bool intr);
> +void xe_vm_bo_unlock(struct xe_vm *vm, struct xe_bo *bo, struct drm_exec *exec,
> +		     bool lru_update);
> +
>  static inline bool xe_vm_is_closed(struct xe_vm *vm)
>  {
>  	/* Only guaranteed not to change when vm->lock is held */
> @@ -183,8 +190,6 @@ int xe_vm_async_fence_wait_start(struct dma_fence *fence);
>  
>  extern struct ttm_device_funcs xe_ttm_funcs;
>  
> -struct ttm_buffer_object *xe_vm_ttm_bo(struct xe_vm *vm);
> -
>  /**
>   * xe_vm_reactivate_rebind() - Reactivate the rebind functionality on compute
>   * vms.
> @@ -212,23 +217,10 @@ static inline void xe_vm_queue_rebind_worker(struct xe_vm *vm)
>  	queue_work(vm->xe->ordered_wq, &vm->preempt.rebind_work);
>  }
>  
> -/*
> - * XE_ONSTACK_TV is used to size the tv_onstack array that is input
> - * to xe_vm_lock_dma_resv() and xe_vm_unlock_dma_resv().
> - */
> -#define XE_ONSTACK_TV 20
> -int xe_vm_lock_dma_resv(struct xe_vm *vm, struct ww_acquire_ctx *ww,
> -			struct ttm_validate_buffer *tv_onstack,
> -			struct ttm_validate_buffer **tv,
> -			struct list_head *objs,
> -			bool intr,
> -			unsigned int num_shared);
> -
> -void xe_vm_unlock_dma_resv(struct xe_vm *vm,
> -			   struct ttm_validate_buffer *tv_onstack,
> -			   struct ttm_validate_buffer *tv,
> -			   struct ww_acquire_ctx *ww,
> -			   struct list_head *objs);
> +int xe_vm_lock_dma_resv(struct xe_vm *vm, struct drm_exec *exec,
> +			bool intr, unsigned int num_shared);
> +
> +void xe_vm_unlock_dma_resv(struct xe_vm *vm, struct drm_exec *exec);
>  
>  void xe_vm_fence_all_extobjs(struct xe_vm *vm, struct dma_fence *fence,
>  			     enum dma_resv_usage usage);
> -- 
> 2.34.1
>