[PATCH v5 21/32] drm/xe: Add SVM device memory mirroring
Ghimiray, Himal Prasad
himal.prasad.ghimiray at intel.com
Thu Feb 13 11:28:56 UTC 2025
On 13-02-2025 07:41, Matthew Brost wrote:
> Add SVM device memory mirroring which enables device pages for
> migration. Enabled via CONFIG_XE_DEVMEM_MIRROR Kconfig. Kconfig option
> defaults to enabled. If not enabled, SVM will work sans migration and
> KMD memory footprint will be less.
>
> v3:
> - Add CONFIG_XE_DEVMEM_MIRROR
> v4:
> - Fix Kconfig (Himal)
> - Use %pe to print errors (Thomas)
> - Fix alignment issue (Checkpatch)
> v5:
> - s/xe_mem_region/xe_vram_region (Rebase)
>
> Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
> Signed-off-by: Oak Zeng <oak.zeng at intel.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> ---
> drivers/gpu/drm/xe/Kconfig | 9 ++++
> drivers/gpu/drm/xe/xe_device_types.h | 8 ++++
> drivers/gpu/drm/xe/xe_svm.c | 62 +++++++++++++++++++++++++++-
> drivers/gpu/drm/xe/xe_svm.h | 3 ++
> drivers/gpu/drm/xe/xe_tile.c | 5 +++
> 5 files changed, 85 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
> index 60b922f75001..4bc03d6f6720 100644
> --- a/drivers/gpu/drm/xe/Kconfig
> +++ b/drivers/gpu/drm/xe/Kconfig
> @@ -74,6 +74,15 @@ config DRM_XE_DP_TUNNEL
>
> If in doubt say "Y".
>
> +config DRM_XE_DEVMEM_MIRROR
> + bool "Enable device memory mirror"
> + depends on DRM_XE
> + select GET_FREE_REGION
> + default y
> + help
> + Disable this option only if you want to compile out without device
> + memory mirror. Will reduce KMD memory footprint when disabled.
> +
> config DRM_XE_FORCE_PROBE
> string "Force probe xe for selected Intel hardware IDs"
> depends on DRM_XE
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index 6a41f608a7a1..00873d80b10d 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -106,6 +106,14 @@ struct xe_vram_region {
> resource_size_t actual_physical_size;
> /** @mapping: pointer to VRAM mappable space */
> void __iomem *mapping;
> + /** @pagemap: Used to remap device memory as ZONE_DEVICE */
> + struct dev_pagemap pagemap;
> + /**
> + * @hpa_base: base host physical address
> + *
> + * This is generated when remap device memory as ZONE_DEVICE
> + */
> + resource_size_t hpa_base;
> /** @ttm: VRAM TTM manager */
> struct xe_ttm_vram_mgr ttm;
> };
> diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
> index 7b1076c184e3..b1947c75c249 100644
> --- a/drivers/gpu/drm/xe/xe_svm.c
> +++ b/drivers/gpu/drm/xe/xe_svm.c
> @@ -29,6 +29,11 @@ static unsigned long xe_svm_range_end(struct xe_svm_range *range)
> return drm_gpusvm_range_end(&range->base);
> }
>
> +static void *xe_svm_devm_owner(struct xe_device *xe)
> +{
> + return xe;
> +}
> +
> static struct drm_gpusvm_range *
> xe_svm_range_alloc(struct drm_gpusvm *gpusvm)
> {
> @@ -317,8 +322,8 @@ int xe_svm_init(struct xe_vm *vm)
> xe_svm_garbage_collector_work_func);
>
> err = drm_gpusvm_init(&vm->svm.gpusvm, "Xe SVM", &vm->xe->drm,
> - current->mm, NULL, 0, vm->size,
> - SZ_512M, &gpusvm_ops, fault_chunk_sizes,
> + current->mm, xe_svm_devm_owner(vm->xe), 0,
> + vm->size, SZ_512M, &gpusvm_ops, fault_chunk_sizes,
> ARRAY_SIZE(fault_chunk_sizes));
> if (err)
> return err;
> @@ -453,3 +458,56 @@ bool xe_svm_has_mapping(struct xe_vm *vm, u64 start, u64 end)
> {
> return drm_gpusvm_has_mapping(&vm->svm.gpusvm, start, end);
> }
> +
> +#if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
> +/**
> + * xe_devm_add: Remap and provide memmap backing for device memory
> + * @tile: tile that the memory region belongs to
> + * @vr: vram memory region to remap
> + *
> + * This remap device memory to host physical address space and create
> + * struct page to back device memory
> + *
> + * Return: 0 on success standard error code otherwise
> + */
> +int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr)
> +{
> + struct xe_device *xe = tile_to_xe(tile);
> + struct device *dev = &to_pci_dev(xe->drm.dev)->dev;
> + struct resource *res;
> + void *addr;
> + int ret;
> +
> + res = devm_request_free_mem_region(dev, &iomem_resource,
> + vr->usable_size);
> + if (IS_ERR(res)) {
> + ret = PTR_ERR(res);
> + return ret;
> + }
> +
> + vr->pagemap.type = MEMORY_DEVICE_PRIVATE;
> + vr->pagemap.range.start = res->start;
> + vr->pagemap.range.end = res->end;
> + vr->pagemap.nr_range = 1;
> + vr->pagemap.ops = drm_gpusvm_pagemap_ops_get();
> + vr->pagemap.owner = xe_svm_devm_owner(xe);
> + addr = devm_memremap_pages(dev, &vr->pagemap);
> + if (IS_ERR(addr)) {
> + devm_release_mem_region(dev, res->start, resource_size(res));
> + ret = PTR_ERR(addr);
> + drm_err(&xe->drm, "Failed to remap tile %d memory, errno %pe\n",
> + tile->id, ERR_PTR(ret));
> + return ret;
> + }
> + vr->hpa_base = res->start;
> +
> + drm_info(&xe->drm, "Added tile %d memory [%llx-%llx] to devm, remapped to %pr\n",
> + tile->id, vr->io_start, vr->io_start + vr->usable_size, res);
> + return 0;
> +}
> +#else
> +int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr)
> +{
> + return 0;
> +}
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
> index 50d47024d2db..0fa525d34987 100644
> --- a/drivers/gpu/drm/xe/xe_svm.h
> +++ b/drivers/gpu/drm/xe/xe_svm.h
> @@ -11,6 +11,7 @@
>
> #define XE_INTERCONNECT_VRAM DRM_INTERCONNECT_DRIVER
>
> +struct xe_vram_region;
> struct xe_tile;
> struct xe_vm;
> struct xe_vma;
> @@ -36,6 +37,8 @@ struct xe_svm_range {
> u8 tile_invalidated;
> };
>
> +int xe_devm_add(struct xe_tile *tile, struct xe_vram_region *vr);
> +
> int xe_svm_init(struct xe_vm *vm);
>
> void xe_svm_fini(struct xe_vm *vm);
> diff --git a/drivers/gpu/drm/xe/xe_tile.c b/drivers/gpu/drm/xe/xe_tile.c
> index d9a7a04ff652..51cda137cfbc 100644
> --- a/drivers/gpu/drm/xe/xe_tile.c
> +++ b/drivers/gpu/drm/xe/xe_tile.c
> @@ -13,6 +13,7 @@
> #include "xe_migrate.h"
> #include "xe_pcode.h"
> #include "xe_sa.h"
> +#include "xe_svm.h"
> #include "xe_tile.h"
> #include "xe_tile_sysfs.h"
> #include "xe_ttm_vram_mgr.h"
> @@ -160,6 +161,7 @@ static int tile_ttm_mgr_init(struct xe_tile *tile)
> */
> int xe_tile_init_noalloc(struct xe_tile *tile)
> {
> + struct xe_device *xe = tile_to_xe(tile);
> int err;
>
> err = tile_ttm_mgr_init(tile);
> @@ -168,6 +170,9 @@ int xe_tile_init_noalloc(struct xe_tile *tile)
>
> xe_wa_apply_tile_workarounds(tile);
>
> + if (xe->info.has_usm && IS_DGFX(xe))
> + xe_devm_add(tile, &tile->mem.vram);
> +
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
> err = xe_tile_sysfs_init(tile);
>
> return 0;
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