[Intel-gfx] [PATCH v3 13/16] drm/i915/pxp: User interface for Protected buffer

[Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>]

From: Bommu Krishnaiah <krishnaiah.bommu@intel.com>

This api allow user mode to create Protected buffers. Only contexts
marked as protected are allowed to operate on protected buffers.

We only allow setting the flags at creation time.

All protected objects that have backing storage will be considered
invalid when the session is destroyed and they won't be usable anymore.

This is a rework of the original code by Bommu Krishnaiah. I've
authorship unchanged since significant chunks have not been modified.

v2: split context changes, fix defines and improve documentation (Chris),
    add object invalidation logic
v3: fix spinlock definition and usage, only validate objects when
    they're first added to a context lut, only remove them once (Chris),
    make protected context flag not mandatory in protected object execbuf
    to avoid abuse (Lionel)

Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Telukuntla Sreedhar <sreedhar.telukuntla@intel.com>
Cc: Kondapally Kalyan <kalyan.kondapally@intel.com>
Cc: Gupta Anshuman <Anshuman.Gupta@intel.com>
Cc: Huang Sean Z <sean.z.huang@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_create.c    | 27 ++++++++++--
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 16 ++++++++
 drivers/gpu/drm/i915/gem/i915_gem_object.c    |  6 +++
 drivers/gpu/drm/i915/gem/i915_gem_object.h    | 12 ++++++
 .../gpu/drm/i915/gem/i915_gem_object_types.h  | 13 ++++++
 drivers/gpu/drm/i915/pxp/intel_pxp.c          | 41 +++++++++++++++++++
 drivers/gpu/drm/i915/pxp/intel_pxp.h          | 13 ++++++
 drivers/gpu/drm/i915/pxp/intel_pxp_types.h    |  5 +++
 include/uapi/drm/i915_drm.h                   | 20 +++++++++
 9 files changed, 150 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
index 3ad3413c459f..d02e5938afbe 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_create.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c
@@ -5,6 +5,7 @@
 
 #include "gem/i915_gem_ioctls.h"
 #include "gem/i915_gem_region.h"
+#include "pxp/intel_pxp.h"
 
 #include "i915_drv.h"
 #include "i915_user_extensions.h"
@@ -13,7 +14,8 @@ static int
 i915_gem_create(struct drm_file *file,
 		struct intel_memory_region *mr,
 		u64 *size_p,
-		u32 *handle_p)
+		u32 *handle_p,
+		u64 user_flags)
 {
 	struct drm_i915_gem_object *obj;
 	u32 handle;
@@ -35,12 +37,17 @@ i915_gem_create(struct drm_file *file,
 
 	GEM_BUG_ON(size != obj->base.size);
 
+	obj->user_flags = user_flags;
+
 	ret = drm_gem_handle_create(file, &obj->base, &handle);
 	/* drop reference from allocate - handle holds it now */
 	i915_gem_object_put(obj);
 	if (ret)
 		return ret;
 
+	if (user_flags & I915_GEM_OBJECT_PROTECTED)
+		intel_pxp_object_add(obj);
+
 	*handle_p = handle;
 	*size_p = size;
 	return 0;
@@ -89,11 +96,12 @@ i915_gem_dumb_create(struct drm_file *file,
 	return i915_gem_create(file,
 			       intel_memory_region_by_type(to_i915(dev),
 							   mem_type),
-			       &args->size, &args->handle);
+			       &args->size, &args->handle, 0);
 }
 
 struct create_ext {
 	struct drm_i915_private *i915;
+	unsigned long user_flags;
 };
 
 static int __create_setparam(struct drm_i915_gem_object_param *args,
@@ -104,6 +112,19 @@ static int __create_setparam(struct drm_i915_gem_object_param *args,
 		return -EINVAL;
 	}
 
+	switch (lower_32_bits(args->param)) {
+	case I915_OBJECT_PARAM_PROTECTED_CONTENT:
+		if (!intel_pxp_is_enabled(&ext_data->i915->gt.pxp))
+			return -ENODEV;
+		if (args->size) {
+			return -EINVAL;
+		} else if (args->data) {
+			ext_data->user_flags |= I915_GEM_OBJECT_PROTECTED;
+			return 0;
+		}
+	break;
+	}
+
 	return -EINVAL;
 }
 
@@ -148,5 +169,5 @@ i915_gem_create_ioctl(struct drm_device *dev, void *data,
 	return i915_gem_create(file,
 			       intel_memory_region_by_type(i915,
 							   INTEL_MEMORY_SYSTEM),
-			       &args->size, &args->handle);
+			       &args->size, &args->handle, ext_data.user_flags);
 }
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 72c2470fcfe6..2fb6579ad301 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -20,6 +20,7 @@
 #include "gt/intel_gt_buffer_pool.h"
 #include "gt/intel_gt_pm.h"
 #include "gt/intel_ring.h"
+#include "pxp/intel_pxp.h"
 
 #include "pxp/intel_pxp.h"
 
@@ -839,6 +840,21 @@ static struct i915_vma *eb_lookup_vma(struct i915_execbuffer *eb, u32 handle)
 		if (unlikely(!obj))
 			return ERR_PTR(-ENOENT);
 
+		/*
+		 * If the user has opted-in for protected-object tracking, make
+		 * sure the object encryption can be used.
+		 * We only need to do this when the object is first used with
+		 * this context, because the context itself will be banned when
+		 * the protected objects become invalid.
+		 */
+		if (i915_gem_context_uses_protected_content(eb->gem_context) &&
+		    i915_gem_object_is_protected(obj)) {
+			if (!intel_pxp_is_active(&vm->gt->pxp))
+				return ERR_PTR(-ENODEV);
+			if (!i915_gem_object_has_valid_protection(obj))
+				return ERR_PTR(-EIO);
+		}
+
 		vma = i915_vma_instance(obj, vm, NULL);
 		if (IS_ERR(vma)) {
 			i915_gem_object_put(obj);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index ea74cbca95be..80ccefd641e8 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -25,6 +25,7 @@
 #include <linux/sched/mm.h>
 
 #include "display/intel_frontbuffer.h"
+#include "pxp/intel_pxp.h"
 #include "i915_drv.h"
 #include "i915_gem_clflush.h"
 #include "i915_gem_context.h"
@@ -70,6 +71,8 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
 	INIT_LIST_HEAD(&obj->lut_list);
 	spin_lock_init(&obj->lut_lock);
 
+	INIT_LIST_HEAD(&obj->pxp_link);
+
 	spin_lock_init(&obj->mmo.lock);
 	obj->mmo.offsets = RB_ROOT;
 
@@ -232,6 +235,9 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
 			spin_unlock(&obj->vma.lock);
 		}
 
+		if (i915_gem_object_has_valid_protection(obj))
+			intel_pxp_object_remove(obj);
+
 		__i915_gem_object_free_mmaps(obj);
 
 		GEM_BUG_ON(!list_empty(&obj->lut_list));
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 2ebd79537aea..61b101560352 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -288,6 +288,18 @@ i915_gem_object_never_mmap(const struct drm_i915_gem_object *obj)
 	return i915_gem_object_type_has(obj, I915_GEM_OBJECT_NO_MMAP);
 }
 
+static inline bool
+i915_gem_object_is_protected(const struct drm_i915_gem_object *obj)
+{
+	return obj->user_flags & I915_GEM_OBJECT_PROTECTED;
+}
+
+static inline bool
+i915_gem_object_has_valid_protection(const struct drm_i915_gem_object *obj)
+{
+	return i915_gem_object_is_protected(obj) && !list_empty(&obj->pxp_link);
+}
+
 static inline bool
 i915_gem_object_is_framebuffer(const struct drm_i915_gem_object *obj)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 8e485cb3343c..0d4bd2747375 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -167,6 +167,11 @@ struct drm_i915_gem_object {
 	} mmo;
 
 	I915_SELFTEST_DECLARE(struct list_head st_link);
+	/**
+	 * @user_flags: small set of booleans set by the user
+	 */
+	unsigned long user_flags;
+#define I915_GEM_OBJECT_PROTECTED BIT(0)
 
 	unsigned long flags;
 #define I915_BO_ALLOC_CONTIGUOUS BIT(0)
@@ -286,6 +291,14 @@ struct drm_i915_gem_object {
 		bool dirty:1;
 	} mm;
 
+	/*
+	 * When the PXP session is invalidated, we need to mark all protected
+	 * objects as invalid. To easily do so we add them all to a list. The
+	 * presence on the list is used to check if the encryption is valid or
+	 * not.
+	 */
+	struct list_head pxp_link;
+
 	/** Record of address bit 17 of each page at last unbind. */
 	unsigned long *bit_17;
 
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
index cbc5249a1bf9..7f9902eac7ec 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
@@ -69,6 +69,9 @@ void intel_pxp_init(struct intel_pxp *pxp)
 	if (!HAS_PXP(gt->i915))
 		return;
 
+	spin_lock_init(&pxp->lock);
+	INIT_LIST_HEAD(&pxp->protected_objects);
+
 	/*
 	 * we'll use the completion to check if there is a termination pending,
 	 * so we start it as completed and we reinit it when a termination
@@ -173,11 +176,49 @@ void intel_pxp_fini_hw(struct intel_pxp *pxp)
 	intel_pxp_irq_disable(pxp);
 }
 
+int intel_pxp_object_add(struct drm_i915_gem_object *obj)
+{
+	struct intel_pxp *pxp = &to_i915(obj->base.dev)->gt.pxp;
+
+	if (!intel_pxp_is_enabled(pxp))
+		return -ENODEV;
+
+	if (!list_empty(&obj->pxp_link))
+		return -EEXIST;
+
+	spin_lock_irq(&pxp->lock);
+	list_add(&obj->pxp_link, &pxp->protected_objects);
+	spin_unlock_irq(&pxp->lock);
+
+	return 0;
+}
+
+void intel_pxp_object_remove(struct drm_i915_gem_object *obj)
+{
+	struct intel_pxp *pxp = &to_i915(obj->base.dev)->gt.pxp;
+
+	if (!intel_pxp_is_enabled(pxp))
+		return;
+
+	spin_lock_irq(&pxp->lock);
+	list_del_init(&obj->pxp_link);
+	spin_unlock_irq(&pxp->lock);
+}
+
 void intel_pxp_invalidate(struct intel_pxp *pxp)
 {
 	struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
+	struct drm_i915_gem_object *obj, *tmp;
 	struct i915_gem_context *ctx, *cn;
 
+	/* delete objects that have been used with the invalidated session */
+	spin_lock_irq(&pxp->lock);
+	list_for_each_entry_safe(obj, tmp, &pxp->protected_objects, pxp_link) {
+		if (i915_gem_object_has_pages(obj))
+			list_del_init(&obj->pxp_link);
+	}
+	spin_unlock_irq(&pxp->lock);
+
 	/* ban all contexts marked as protected */
 	spin_lock_irq(&i915->gem.contexts.lock);
 	list_for_each_entry_safe(ctx, cn, &i915->gem.contexts.list, link) {
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
index 91c1a2056309..194b00149247 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp.h
@@ -9,6 +9,8 @@
 #include "gt/intel_gt_types.h"
 #include "intel_pxp_types.h"
 
+struct drm_i915_gem_object;
+
 static inline struct intel_gt *pxp_to_gt(const struct intel_pxp *pxp)
 {
 	return container_of(pxp, struct intel_gt, pxp);
@@ -33,6 +35,9 @@ void intel_pxp_fini_hw(struct intel_pxp *pxp);
 
 void intel_pxp_mark_termination_in_progress(struct intel_pxp *pxp);
 int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp);
+
+int intel_pxp_object_add(struct drm_i915_gem_object *obj);
+void intel_pxp_object_remove(struct drm_i915_gem_object *obj);
 void intel_pxp_invalidate(struct intel_pxp *pxp);
 #else
 static inline void intel_pxp_init(struct intel_pxp *pxp)
@@ -47,6 +52,14 @@ static inline int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
 {
 	return 0;
 }
+
+static inline int intel_pxp_object_add(struct drm_i915_gem_object *obj)
+{
+	return 0;
+}
+static inline void intel_pxp_object_remove(struct drm_i915_gem_object *obj)
+{
+}
 #endif
 
 #endif /* __INTEL_PXP_H__ */
diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
index 6c9265fb8e4b..665704d7793e 100644
--- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
+++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
@@ -7,8 +7,10 @@
 #define __INTEL_PXP_TYPES_H__
 
 #include <linux/completion.h>
+#include <linux/list.h>
 #include <linux/types.h>
 #include <linux/mutex.h>
+#include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
 struct intel_context;
@@ -33,6 +35,9 @@ struct intel_pxp {
 	u32 session_events; /* protected with gt->irq_lock */
 #define PXP_TERMINATION_REQUEST  BIT(0)
 #define PXP_TERMINATION_COMPLETE BIT(1)
+
+	spinlock_t lock; /* protects the objects list */
+	struct list_head protected_objects;
 };
 
 #endif /* __INTEL_PXP_TYPES_H__ */
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index d5e502269a55..420412c08745 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -1756,6 +1756,26 @@ struct drm_i915_gem_object_param {
  */
 #define I915_OBJECT_PARAM  (1ull << 32)
 
+/*
+ * I915_OBJECT_PARAM_PROTECTED_CONTENT:
+ *
+ * If set to true, buffer contents is expected to be protected by PXP
+ * encryption and requires decryption for scan out and processing. This is
+ * only possible on platforms that have PXP enabled, on all other scenarios
+ * setting this flag will cause the ioctl to fail and return -ENODEV.
+ *
+ * The buffer contents are considered invalid after a PXP session teardown.
+ * It is recommended to use protected buffers only with contexts created
+ * using the I915_CONTEXT_PARAM_PROTECTED_CONTENT flag, as that will enable
+ * extra checks at submission time on the validity of the objects involved,
+ * which can lead to the following errors:
+ *
+ * -ENODEV: PXP session not currently active
+ * -EIO: buffer has become invalid after a teardown event
+ */
+#define I915_OBJECT_PARAM_PROTECTED_CONTENT  0x0
+/* Must be kept compact -- no holes and well documented */
+
 	__u64 param;
 
 	/* Data value or pointer */
-- 
2.29.2

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx