Commit f0e4238f authored by Matthew Brost's avatar Matthew Brost
Browse files

drm/xe: Do not allow CPU address mirror VMA unbind if 



uAPI is designed with the use case that only mapping a BO to a malloc'd
address will unbind a CPU-address mirror VMA. Therefore, allowing a
CPU-address mirror VMA to unbind when the GPU has bindings in the range
being unbound does not make much sense. This behavior is not supported,
as it simplifies the code. This decision can always be revisited if a
use case arises.

v3:
 - s/arrises/arises (Thomas)
 - s/system allocator/GPU address mirror (Thomas)
 - Kernel doc (Thomas)
 - Newline between function defs (Thomas)
v5:
 - Kernel doc (Thomas)
v6:
 - Only compile if CONFIG_DRM_GPUSVM selected (CI, Lucas)

Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarHimal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250306012657.3505757-18-matthew.brost@intel.com
parent d1e6efdf

drivers/gpu/drm/xe/xe_svm.c

+15 −0
Original line number Diff line number Diff line
@@ -434,3 +434,18 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 


	return err;

}



/**

 * xe_svm_has_mapping() - SVM has mappings

 * @vm: The VM.

 * @start: Start address.

 * @end: End address.

 *

 * Check if an address range has SVM mappings.

 *

 * Return: True if address range has a SVM mapping, False otherwise

 */

bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end)

{

	return drm_gpusvm_has_mapping(&vm->svm.gpusvm, start, end);

}

drivers/gpu/drm/xe/xe_svm.h

+8 −0
Original line number Diff line number Diff line
@@ -57,6 +57,8 @@ void xe_svm_close(struct xe_vm *vm); 
int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,

			    struct xe_tile *tile, u64 fault_addr,

			    bool atomic);



bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end);

#else

static inline bool xe_svm_range_pages_valid(struct xe_svm_range *range)

{
@@ -86,6 +88,12 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma, 
{

	return 0;

}



static inline

bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end)

{

	return false;

}

#endif



/**

drivers/gpu/drm/xe/xe_vm.c

+16 −0
Original line number Diff line number Diff line
@@ -2486,6 +2486,17 @@ 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);

			u64 start = xe_vma_start(old), end = xe_vma_end(old);



			if (op->base.remap.prev)

				start = op->base.remap.prev->va.addr +

					op->base.remap.prev->va.range;

			if (op->base.remap.next)

				end = op->base.remap.next->va.addr;



			if (xe_vma_is_cpu_addr_mirror(old) &&

			    xe_svm_has_mapping(vm, start, end))

				return -EBUSY;



			op->remap.start = xe_vma_start(old);

			op->remap.range = xe_vma_size(old);
@@ -2567,6 +2578,11 @@ static int vm_bind_ioctl_ops_parse(struct xe_vm *vm, struct drm_gpuva_ops *ops, 
		case DRM_GPUVA_OP_UNMAP:

			vma = gpuva_to_vma(op->base.unmap.va);



			if (xe_vma_is_cpu_addr_mirror(vma) &&

			    xe_svm_has_mapping(vm, xe_vma_start(vma),

					       xe_vma_end(vma)))

				return -EBUSY;



			if (!xe_vma_is_cpu_addr_mirror(vma))

				xe_vma_ops_incr_pt_update_ops(vops, op->tile_mask);

			break;