[PATCH v2 29/32] drm/xe/svm: Consult madvise preferred location in prefetch

[Matthew Brost]

On Mon, Apr 07, 2025 at 03:47:16PM +0530, Himal Prasad Ghimiray wrote:
> When prefetch region is DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC, prefetch svm
> ranges to preferred location provided by madvise.
> 
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_vm.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index 0f9c45ce82b4..e5246c633e62 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -2924,9 +2924,12 @@ static int prefetch_ranges_lock_and_prep(struct xe_vm *vm,
>  		if (!xe_vma_is_cpu_addr_mirror(vma))
>  			return 0;
>  
> -		region = op->prefetch_range.region;
> +		region = (op->prefetch_range.region == DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC) ?
> +			  vma->attr.preferred_loc.devmem_fd : op->prefetch_range.region;

Again incongruence between devmem_fd and region.

>  
> -		/* TODO: Threading the migration */
> +		/* TODO: Threading the migration
> +		 * TODO: Multigpu support migration
> +		 */
>  		for (i = 0; i < op->prefetch_range.ranges_count; i++) {
>  			svm_range = xa_load(&op->prefetch_range.range, i);
>  			if (xe_svm_range_needs_migrate_to_vram(svm_range, vma, region)) {
> @@ -3001,7 +3004,8 @@ static int op_lock_and_prep(struct drm_exec *exec, struct xe_vm *vm,
>  		else
>  			region = op->prefetch.region;
>  
> -		xe_assert(vm->xe, region <= ARRAY_SIZE(region_to_mem_type));
> +		xe_assert(vm->xe, region == DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC ||
> +			  region <= ARRAY_SIZE(region_to_mem_type));
>  
>  		err = vma_lock_and_validate(exec,
>  					    gpuva_to_vma(op->base.prefetch.va),
> @@ -3426,8 +3430,9 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
>  				 op == DRM_XE_VM_BIND_OP_PREFETCH) ||
>  		    XE_IOCTL_DBG(xe, prefetch_region &&
>  				 op != DRM_XE_VM_BIND_OP_PREFETCH) ||
> -		    XE_IOCTL_DBG(xe, !(BIT(prefetch_region) &
> -				       xe->info.mem_region_mask)) ||
> +		    XE_IOCTL_DBG(xe, (is_cpu_addr_mirror &&
> +				      prefetch_region != DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC) &&

Why do you check is_cpu_addr_mirror here? Isn't
DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC valid for all VMAs?

Matt

> +				      !(BIT(prefetch_region) & xe->info.mem_region_mask)) ||
>  		    XE_IOCTL_DBG(xe, obj &&
>  				 op == DRM_XE_VM_BIND_OP_UNMAP)) {
>  			err = -EINVAL;
> -- 
> 2.34.1
>