[PATCH 14/14] drm/amdgpu: set TMZ bits in PTEs for secure bo (v2)

[Huang, Ray]

From: Alex Deucher <alexander.deucher at amd.com>

If one bo is secure (created with AMDGPU_GEM_CREATE_ENCRYPTED), the TMZ bits of
PTEs that belongs that bo should be set. Then psp is able to protect the pages
of this bo to avoid the access from an "untrust" domain such as CPU.

v1: design and draft the skeletion of tmz bits setting on PTEs (Alex)
v2: return failure once create secure bo on no-tmz platform  (Ray)

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Reviewed-by: Huang Rui <ray.huang at amd.com>
Signed-off-by: Huang Rui <ray.huang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c    | 12 +++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 10 ++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    |  5 +++++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 22eab74..5332104 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -222,7 +222,8 @@ int amdgpu_gem_create_ioctl(struct drm_device *dev, void *data,
 		      AMDGPU_GEM_CREATE_CPU_GTT_USWC |
 		      AMDGPU_GEM_CREATE_VRAM_CLEARED |
 		      AMDGPU_GEM_CREATE_VM_ALWAYS_VALID |
-		      AMDGPU_GEM_CREATE_EXPLICIT_SYNC))
+		      AMDGPU_GEM_CREATE_EXPLICIT_SYNC |
+		      AMDGPU_GEM_CREATE_ENCRYPTED))
 
 		return -EINVAL;
 
@@ -230,6 +231,11 @@ int amdgpu_gem_create_ioctl(struct drm_device *dev, void *data,
 	if (args->in.domains & ~AMDGPU_GEM_DOMAIN_MASK)
 		return -EINVAL;
 
+	if (!adev->tmz.enabled && (flags & AMDGPU_GEM_CREATE_ENCRYPTED)) {
+		DRM_ERROR("Cannot allocate secure buffer while tmz is disabled\n");
+		return -EINVAL;
+	}
+
 	/* create a gem object to contain this object in */
 	if (args->in.domains & (AMDGPU_GEM_DOMAIN_GDS |
 	    AMDGPU_GEM_DOMAIN_GWS | AMDGPU_GEM_DOMAIN_OA)) {
@@ -251,6 +257,10 @@ int amdgpu_gem_create_ioctl(struct drm_device *dev, void *data,
 		resv = vm->root.base.bo->tbo.resv;
 	}
 
+	if (flags & AMDGPU_GEM_CREATE_ENCRYPTED) {
+		/* XXX: pad out alignment to meet TMZ requirements */
+	}
+
 	r = amdgpu_gem_object_create(adev, size, args->in.alignment,
 				     (u32)(0xffffffff & args->in.domains),
 				     flags, ttm_bo_type_device, resv, &gobj);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
index 5a3c177..286e2e2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
@@ -224,6 +224,16 @@ static inline bool amdgpu_bo_explicit_sync(struct amdgpu_bo *bo)
 	return bo->flags & AMDGPU_GEM_CREATE_EXPLICIT_SYNC;
 }
 
+/**
+ * amdgpu_bo_encrypted - return whether the bo is encrypted
+ */
+static inline bool amdgpu_bo_encrypted(struct amdgpu_bo *bo)
+{
+	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+
+	return adev->tmz.enabled && (bo->flags & AMDGPU_GEM_CREATE_ENCRYPTED);
+}
+
 bool amdgpu_bo_is_amdgpu_bo(struct ttm_buffer_object *bo);
 void amdgpu_bo_placement_from_domain(struct amdgpu_bo *abo, u32 domain);
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 3663655..8f00bb2 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1434,6 +1434,8 @@ bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
 uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_mem_reg *mem)
 {
 	uint64_t flags = 0;
+	struct ttm_buffer_object *tbo = ttm_mem_reg_to_bo(mem);
+	struct amdgpu_bo *abo = ttm_to_amdgpu_bo(tbo);
 
 	if (mem && mem->mem_type != TTM_PL_SYSTEM)
 		flags |= AMDGPU_PTE_VALID;
@@ -1444,6 +1446,9 @@ uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_mem_reg *mem)
 		if (ttm->caching_state == tt_cached)
 			flags |= AMDGPU_PTE_SNOOPED;
 	}
+	if (amdgpu_bo_encrypted(abo)) {
+		flags |= AMDGPU_PTE_TMZ;
+	}
 
 	return flags;
 }
-- 
2.7.4