Commit 521db22a authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/xe: Invalidate userptr VMA on page pin fault 



Rather than return an error to the user or ban the VM when userptr VMA
page pin fails with -EFAULT, invalidate VMA mappings. This supports the
UMD use case of freeing userptr while still having bindings.

Now that non-faulting VMs can invalidate VMAs, drop the usm prefix for
the tile_invalidated member.

v2:
 - Fix build error (CI)
v3:
 - Don't invalidate VMA if in fault mode, rather kill VM (Thomas)
 - Update commit message with tile_invalidated name chagne (Thomas)
 - Wait VM bookkeep slots with VM resv lock (Thomas)
v4:
 - Move list_del_init(&userptr.repin_link) after error check (Thomas)
 - Assert not in fault mode (Matthew)

Fixes: dd08ebf6 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240312183907.933835-1-matthew.brost@intel.com
parent 8e61e319

drivers/gpu/drm/xe/xe_gt_pagefault.c

+2 −2
Original line number Diff line number Diff line
@@ -69,7 +69,7 @@ static bool access_is_atomic(enum access_type access_type) 
static bool vma_is_valid(struct xe_tile *tile, struct xe_vma *vma)

{

	return BIT(tile->id) & vma->tile_present &&

		!(BIT(tile->id) & vma->usm.tile_invalidated);

		!(BIT(tile->id) & vma->tile_invalidated);

}



static bool vma_matches(struct xe_vma *vma, u64 page_addr)
@@ -226,7 +226,7 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf) 


	if (xe_vma_is_userptr(vma))

		ret = xe_vma_userptr_check_repin(to_userptr_vma(vma));

	vma->usm.tile_invalidated &= ~BIT(tile->id);

	vma->tile_invalidated &= ~BIT(tile->id);



unlock_dma_resv:

	drm_exec_fini(&exec);

drivers/gpu/drm/xe/xe_trace.h

+1 −1
Original line number Diff line number Diff line
@@ -468,7 +468,7 @@ DEFINE_EVENT(xe_vma, xe_vma_userptr_invalidate, 
	     TP_ARGS(vma)

);



DEFINE_EVENT(xe_vma, xe_vma_usm_invalidate,

DEFINE_EVENT(xe_vma, xe_vma_invalidate,

	     TP_PROTO(struct xe_vma *vma),

	     TP_ARGS(vma)

);

drivers/gpu/drm/xe/xe_vm.c

+24 −8
Original line number Diff line number Diff line
@@ -708,6 +708,7 @@ int xe_vm_userptr_pin(struct xe_vm *vm) 
	int err = 0;

	LIST_HEAD(tmp_evict);



	xe_assert(vm->xe, !xe_vm_in_fault_mode(vm));

	lockdep_assert_held_write(&vm->lock);



	/* Collect invalidated userptrs */
@@ -724,11 +725,27 @@ int xe_vm_userptr_pin(struct xe_vm *vm) 
	list_for_each_entry_safe(uvma, next, &vm->userptr.repin_list,

				 userptr.repin_link) {

		err = xe_vma_userptr_pin_pages(uvma);

		if (err == -EFAULT) {

			list_del_init(&uvma->userptr.repin_link);



			/* Wait for pending binds */

			xe_vm_lock(vm, false);

			dma_resv_wait_timeout(xe_vm_resv(vm),

					      DMA_RESV_USAGE_BOOKKEEP,

					      false, MAX_SCHEDULE_TIMEOUT);



			err = xe_vm_invalidate_vma(&uvma->vma);

			xe_vm_unlock(vm);

			if (err)

				return err;

		} else {

			if (err < 0)

				return err;



			list_del_init(&uvma->userptr.repin_link);

		list_move_tail(&uvma->vma.combined_links.rebind, &vm->rebind_list);

			list_move_tail(&uvma->vma.combined_links.rebind,

				       &vm->rebind_list);

		}

	}



	return 0;
@@ -2024,7 +2041,7 @@ static int xe_vm_prefetch(struct xe_vm *vm, struct xe_vma *vma, 
			return err;

	}



	if (vma->tile_mask != (vma->tile_present & ~vma->usm.tile_invalidated)) {

	if (vma->tile_mask != (vma->tile_present & ~vma->tile_invalidated)) {

		return xe_vm_bind(vm, vma, q, xe_vma_bo(vma), syncs, num_syncs,

				  true, first_op, last_op);

	} else {
@@ -3214,9 +3231,8 @@ int xe_vm_invalidate_vma(struct xe_vma *vma) 
	u8 id;

	int ret;



	xe_assert(xe, xe_vm_in_fault_mode(xe_vma_vm(vma)));

	xe_assert(xe, !xe_vma_is_null(vma));

	trace_xe_vma_usm_invalidate(vma);

	trace_xe_vma_invalidate(vma);



	/* Check that we don't race with page-table updates */

	if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
@@ -3254,7 +3270,7 @@ int xe_vm_invalidate_vma(struct xe_vma *vma) 
		}

	}



	vma->usm.tile_invalidated = vma->tile_mask;

	vma->tile_invalidated = vma->tile_mask;



	return 0;

}

drivers/gpu/drm/xe/xe_vm_types.h

+2 −5
Original line number Diff line number Diff line
@@ -84,11 +84,8 @@ struct xe_vma { 
		struct work_struct destroy_work;

	};



	/** @usm: unified shared memory state */

	struct {

	/** @tile_invalidated: VMA has been invalidated */

	u8 tile_invalidated;

	} usm;



	/** @tile_mask: Tile mask of where to create binding for this VMA */

	u8 tile_mask;