[PATCH v4 11/33] drm/xe: Nuke VM's mapping upon close

[Matthew Brost]

On Fri, Feb 07, 2025 at 11:15:38AM +0100, Thomas Hellström wrote:
> On Wed, 2025-01-29 at 11:51 -0800, Matthew Brost wrote:
> > Clear root PT entry and invalidate entire VM's address space when
> > closing the VM. Will prevent the GPU from accessing any of the VM's
> > memory after closing.
> > 
> > v2:
> >  - s/vma/vm in kernel doc (CI)
> >  - Don't nuke migration VM as this occur at driver unload (CI)
> > v3:
> >  - Rebase and pull into SVM series (Thomas)
> >  - Wait for pending binds (Thomas)
> > 
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c | 24
> > +++++++++++++++++++++
> >  drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h |  2 ++
> >  drivers/gpu/drm/xe/xe_pt.c                  | 14 ++++++++++++
> >  drivers/gpu/drm/xe/xe_pt.h                  |  3 +++
> >  drivers/gpu/drm/xe/xe_vm.c                  | 22 +++++++++++++++++++
> >  5 files changed, 65 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > index 0a93831c0a02..1ef21ed01d1b 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > @@ -410,6 +410,30 @@ int xe_gt_tlb_invalidation_range(struct xe_gt
> > *gt,
> >  	return send_tlb_invalidation(&gt->uc.guc, fence, action,
> > len);
> >  }
> >  
> > +/**
> > + * xe_gt_tlb_invalidation_vm - Issue a TLB invalidation on this GT
> > for a VM
> > + * @gt: graphics tile
> > + * @vm: VM to invalidate
> > + *
> > + * Invalidate entire VM's address space
> > + */
> > +void xe_gt_tlb_invalidation_vm(struct xe_gt *gt, struct xe_vm *vm)
> > +{
> > +	struct xe_gt_tlb_invalidation_fence fence;
> > +	u64 range = 1ull << vm->xe->info.va_bits;
> > +	int ret;
> > +
> > +	xe_gt_tlb_invalidation_fence_init(gt, &fence, true);
> > +
> > +	ret = xe_gt_tlb_invalidation_range(gt, &fence, 0, range, vm-
> > >usm.asid);
> > +	if (ret < 0) {
> > +		xe_gt_tlb_invalidation_fence_fini(&fence);
> > +		return;
> > +	}
> > +
> > +	xe_gt_tlb_invalidation_fence_wait(&fence);
> > +}
> > +
> >  /**
> >   * xe_gt_tlb_invalidation_vma - Issue a TLB invalidation on this GT
> > for a VMA
> >   * @gt: GT structure
> > diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h
> > b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h
> > index 672acfcdf0d7..abe9b03d543e 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h
> > +++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.h
> > @@ -12,6 +12,7 @@
> >  
> >  struct xe_gt;
> >  struct xe_guc;
> > +struct xe_vm;
> >  struct xe_vma;
> >  
> >  int xe_gt_tlb_invalidation_init_early(struct xe_gt *gt);
> > @@ -21,6 +22,7 @@ int xe_gt_tlb_invalidation_ggtt(struct xe_gt *gt);
> >  int xe_gt_tlb_invalidation_vma(struct xe_gt *gt,
> >  			       struct xe_gt_tlb_invalidation_fence
> > *fence,
> >  			       struct xe_vma *vma);
> > +void xe_gt_tlb_invalidation_vm(struct xe_gt *gt, struct xe_vm *vm);
> >  int xe_gt_tlb_invalidation_range(struct xe_gt *gt,
> >  				 struct xe_gt_tlb_invalidation_fence
> > *fence,
> >  				 u64 start, u64 end, u32 asid);
> > diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> > index 99b97bf37c05..c5060011ad43 100644
> > --- a/drivers/gpu/drm/xe/xe_pt.c
> > +++ b/drivers/gpu/drm/xe/xe_pt.c
> > @@ -214,6 +214,20 @@ void xe_pt_destroy(struct xe_pt *pt, u32 flags,
> > struct llist_head *deferred)
> >  	xe_pt_free(pt);
> >  }
> >  
> > +/**
> > + * xe_pt_clear() - Clear a page-table.
> > + * @xe: xe device.
> > + * @pt: The page-table.
> > + *
> > + * Clears page-table by setting to zero.
> > + */
> > +void xe_pt_clear(struct xe_device *xe, struct xe_pt *pt)
> > +{
> > +	struct iosys_map *map = &pt->bo->vmap;
> > +
> > +	xe_map_memset(xe, map, 0, 0, SZ_4K);
> > +}
> > +
> >  /**
> >   * DOC: Pagetable building
> >   *
> > diff --git a/drivers/gpu/drm/xe/xe_pt.h b/drivers/gpu/drm/xe/xe_pt.h
> > index 9ab386431cad..8e43912ae8e9 100644
> > --- a/drivers/gpu/drm/xe/xe_pt.h
> > +++ b/drivers/gpu/drm/xe/xe_pt.h
> > @@ -13,6 +13,7 @@ struct dma_fence;
> >  struct xe_bo;
> >  struct xe_device;
> >  struct xe_exec_queue;
> > +struct xe_svm_range;
> >  struct xe_sync_entry;
> >  struct xe_tile;
> >  struct xe_vm;
> > @@ -35,6 +36,8 @@ void xe_pt_populate_empty(struct xe_tile *tile,
> > struct xe_vm *vm,
> >  
> >  void xe_pt_destroy(struct xe_pt *pt, u32 flags, struct llist_head
> > *deferred);
> >  
> > +void xe_pt_clear(struct xe_device *xe, struct xe_pt *pt);
> > +
> >  int xe_pt_update_ops_prepare(struct xe_tile *tile, struct xe_vma_ops
> > *vops);
> >  struct dma_fence *xe_pt_update_ops_run(struct xe_tile *tile,
> >  				       struct xe_vma_ops *vops);
> > diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> > index bc34e6738c8c..82026c5a154d 100644
> > --- a/drivers/gpu/drm/xe/xe_vm.c
> > +++ b/drivers/gpu/drm/xe/xe_vm.c
> > @@ -1537,8 +1537,30 @@ struct xe_vm *xe_vm_create(struct xe_device
> > *xe, u32 flags)
> >  
> >  static void xe_vm_close(struct xe_vm *vm)
> >  {
> > +	bool migration = (vm->flags & XE_VM_FLAG_MIGRATION);
> 
> Do we need a separate bool here? Only used in one place AFAICT.
> 

Nope. Let me drop the bool.

Matt

> Otherwise,
> Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> 
> 
> > +
> >  	down_write(&vm->lock);
> > +
> >  	vm->size = 0;
> > +
> > +	if (!migration) {
> > +		struct xe_tile *tile;
> > +		struct xe_gt *gt;
> > +		u8 id;
> > +
> > +		/* Wait for pending binds */
> > +		dma_resv_wait_timeout(xe_vm_resv(vm),
> > +				      DMA_RESV_USAGE_BOOKKEEP,
> > +				      false, MAX_SCHEDULE_TIMEOUT);
> > +
> > +		for_each_tile(tile, vm->xe, id)
> > +			if (vm->pt_root[id])
> > +				xe_pt_clear(vm->xe, vm-
> > >pt_root[id]);
> > +
> > +		for_each_gt(gt, vm->xe, id)
> > +			xe_gt_tlb_invalidation_vm(gt, vm);
> > +	}
> > +
> >  	up_write(&vm->lock);
> >  }
> >  
>