From 5f11f933c5ae87a097d91f5392d8ec51e9b66d3e Mon Sep 17 00:00:00 2001 From: jsg Date: Thu, 4 Apr 2024 07:33:22 +0000 Subject: [PATCH] drm/ttm: Make sure the mapped tt pages are decrypted when needed From Zack Rusin de125efb3bae7720d10364a9ab6785466e4e2461 in linux-6.6.y/6.6.24 71ce046327cfd3aef3f93d1c44e091395eb03f8f in mainline linux --- sys/dev/pci/drm/include/drm/ttm/ttm_tt.h | 9 ++++++++- sys/dev/pci/drm/ttm/ttm_bo_util.c | 13 +++++++++++-- sys/dev/pci/drm/ttm/ttm_tt.c | 13 +++++++++++++ 3 files changed, 32 insertions(+), 3 deletions(-) diff --git a/sys/dev/pci/drm/include/drm/ttm/ttm_tt.h b/sys/dev/pci/drm/include/drm/ttm/ttm_tt.h index ce22c3f28b3..c44421a3fce 100644 --- a/sys/dev/pci/drm/include/drm/ttm/ttm_tt.h +++ b/sys/dev/pci/drm/include/drm/ttm/ttm_tt.h @@ -81,6 +81,12 @@ struct ttm_tt { * page_flags = TTM_TT_FLAG_EXTERNAL | * TTM_TT_FLAG_EXTERNAL_MAPPABLE; * + * TTM_TT_FLAG_DECRYPTED: The mapped ttm pages should be marked as + * not encrypted. The framework will try to match what the dma layer + * is doing, but note that it is a little fragile because ttm page + * fault handling abuses the DMA api a bit and dma_map_attrs can't be + * used to assure pgprot always matches. + * * TTM_TT_FLAG_PRIV_POPULATED: TTM internal only. DO NOT USE. This is * set by TTM after ttm_tt_populate() has successfully returned, and is * then unset when TTM calls ttm_tt_unpopulate(). @@ -89,8 +95,9 @@ struct ttm_tt { #define TTM_TT_FLAG_ZERO_ALLOC BIT(1) #define TTM_TT_FLAG_EXTERNAL BIT(2) #define TTM_TT_FLAG_EXTERNAL_MAPPABLE BIT(3) +#define TTM_TT_FLAG_DECRYPTED BIT(4) -#define TTM_TT_FLAG_PRIV_POPULATED BIT(4) +#define TTM_TT_FLAG_PRIV_POPULATED BIT(5) uint32_t page_flags; /** @num_pages: Number of pages in the page array. */ uint32_t num_pages; diff --git a/sys/dev/pci/drm/ttm/ttm_bo_util.c b/sys/dev/pci/drm/ttm/ttm_bo_util.c index d202b1ddf3b..a6cb1a86266 100644 --- a/sys/dev/pci/drm/ttm/ttm_bo_util.c +++ b/sys/dev/pci/drm/ttm/ttm_bo_util.c @@ -296,7 +296,13 @@ pgprot_t ttm_io_prot(struct ttm_buffer_object *bo, struct ttm_resource *res, enum ttm_caching caching; man = ttm_manager_type(bo->bdev, res->mem_type); - caching = man->use_tt ? bo->ttm->caching : res->bus.caching; + if (man->use_tt) { + caching = bo->ttm->caching; + if (bo->ttm->page_flags & TTM_TT_FLAG_DECRYPTED) + tmp = pgprot_decrypted(tmp); + } else { + caching = res->bus.caching; + } return ttm_prot_from_caching(caching, tmp); } @@ -348,6 +354,8 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo, .no_wait_gpu = false }; struct ttm_tt *ttm = bo->ttm; + struct ttm_resource_manager *man = + ttm_manager_type(bo->bdev, bo->resource->mem_type); pgprot_t prot; int ret; @@ -357,7 +365,8 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo, if (ret) return ret; - if (num_pages == 1 && ttm->caching == ttm_cached) { + if (num_pages == 1 && ttm->caching == ttm_cached && + !(man->use_tt && (ttm->page_flags & TTM_TT_FLAG_DECRYPTED))) { /* * We're mapping a single page, and the desired * page protection is consistent with the bo. diff --git a/sys/dev/pci/drm/ttm/ttm_tt.c b/sys/dev/pci/drm/ttm/ttm_tt.c index 21d1d9cfe70..0eee929b31d 100644 --- a/sys/dev/pci/drm/ttm/ttm_tt.c +++ b/sys/dev/pci/drm/ttm/ttm_tt.c @@ -31,11 +31,14 @@ #define pr_fmt(fmt) "[TTM] " fmt +#include #include #include #include #include #include +#include +#include #include #include @@ -60,6 +63,7 @@ static atomic_long_t ttm_dma32_pages_allocated; int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc) { struct ttm_device *bdev = bo->bdev; + struct drm_device *ddev = bo->base.dev; uint32_t page_flags = 0; dma_resv_assert_held(bo->base.resv); @@ -81,6 +85,15 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc) pr_err("Illegal buffer object type\n"); return -EINVAL; } + /* + * When using dma_alloc_coherent with memory encryption the + * mapped TT pages need to be decrypted or otherwise the drivers + * will end up sending encrypted mem to the gpu. + */ + if (bdev->pool.use_dma_alloc && cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) { + page_flags |= TTM_TT_FLAG_DECRYPTED; + drm_info(ddev, "TT memory decryption enabled."); + } bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags); if (unlikely(bo->ttm == NULL)) -- 2.20.1