[PATCH v7 10/17] drm/i915/pxp: interfaces for using protected objects

Rodrigo Vivi rodrigo.vivi at intel.com
Tue Aug 31 21:30:28 UTC 2021


On Fri, Aug 27, 2021 at 06:27:31PM -0700, Daniele Ceraolo Spurio wrote:
> This api allow user mode to create protected buffers and to mark
> contexts as making use of such objects. Only when using contexts
> marked in such a way is the execution guaranteed to work as expected.
> 
> Contexts can only be marked as using protected content at creation time
> (i.e. the parameter is immutable) and they must be both bannable and not
> recoverable. Given that the protected session gets invalidated on
> suspend, contexts created this way hold a runtime pm wakeref until
> they're either destroyed or invalidated.
> 
> All protected objects and contexts will be considered invalid when the
> PXP session is destroyed and all new submissions using them will be
> rejected. All intel contexts within the invalidated gem contexts will be
> marked banned. Userspace can detect that an invalidation has occurred via
> the RESET_STATS ioctl, where we report it the same way as a ban due to a
> hang.
> 
> v5: squash patches, rebase on proto_ctx, update kerneldoc
> 
> v6: rebase on obj create_ext changes
> 
> v7: Use session counter to check if an object it valid, hold wakeref in
>     context, don't add a new flag to RESET_STATS (Daniel)
> 
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Signed-off-by: Bommu Krishnaiah <krishnaiah.bommu at intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Cc: Jason Ekstrand <jason at jlekstrand.net>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com> #v5
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_context.c   | 98 ++++++++++++++++---
>  drivers/gpu/drm/i915/gem/i915_gem_context.h   |  6 ++
>  .../gpu/drm/i915/gem/i915_gem_context_types.h | 28 ++++++
>  drivers/gpu/drm/i915/gem/i915_gem_create.c    | 72 ++++++++++----
>  .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 18 ++++
>  drivers/gpu/drm/i915/gem/i915_gem_object.c    |  1 +
>  drivers/gpu/drm/i915/gem/i915_gem_object.h    |  6 ++
>  .../gpu/drm/i915/gem/i915_gem_object_types.h  |  8 ++
>  .../gpu/drm/i915/gem/selftests/mock_context.c |  4 +-
>  drivers/gpu/drm/i915/pxp/intel_pxp.c          | 83 ++++++++++++++++
>  drivers/gpu/drm/i915/pxp/intel_pxp.h          | 12 +++
>  drivers/gpu/drm/i915/pxp/intel_pxp_session.c  |  6 ++
>  drivers/gpu/drm/i915/pxp/intel_pxp_types.h    |  9 ++
>  include/uapi/drm/i915_drm.h                   | 55 ++++++++++-
>  14 files changed, 371 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index fd169cf2f75a..f411e26768fd 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -77,6 +77,8 @@
>  #include "gt/intel_gpu_commands.h"
>  #include "gt/intel_ring.h"
>  
> +#include "pxp/intel_pxp.h"
> +
>  #include "i915_gem_context.h"
>  #include "i915_trace.h"
>  #include "i915_user_extensions.h"
> @@ -186,10 +188,13 @@ static int validate_priority(struct drm_i915_private *i915,
>  	return 0;
>  }
>  
> -static void proto_context_close(struct i915_gem_proto_context *pc)
> +static void proto_context_close(struct drm_i915_private *i915,
> +				struct i915_gem_proto_context *pc)
>  {
>  	int i;
>  
> +	if (pc->pxp_wakeref)
> +		intel_runtime_pm_put(&i915->runtime_pm, pc->pxp_wakeref);
>  	if (pc->vm)
>  		i915_vm_put(pc->vm);
>  	if (pc->user_engines) {
> @@ -241,6 +246,33 @@ static int proto_context_set_persistence(struct drm_i915_private *i915,
>  	return 0;
>  }
>  
> +static int proto_context_set_protected(struct drm_i915_private *i915,
> +				       struct i915_gem_proto_context *pc,
> +				       bool protected)
> +{
> +	int ret = 0;
> +
> +	if (!intel_pxp_is_enabled(&i915->gt.pxp)) {
> +		ret = -ENODEV;
> +	} else if (!protected) {
> +		pc->uses_protected_content = false;
> +	} else if ((pc->user_flags & BIT(UCONTEXT_RECOVERABLE)) ||
> +		   !(pc->user_flags & BIT(UCONTEXT_BANNABLE))) {
> +		ret = -EPERM;
> +	} else {
> +		pc->uses_protected_content = true;
> +
> +		/*
> +		 * protected context usage requires the PXP session to be up,
> +		 * which in turn requires the device to be active.
> +		 */
> +		pc->pxp_wakeref = intel_runtime_pm_get(&i915->runtime_pm);
> +		ret = intel_pxp_wait_for_arb_start(&i915->gt.pxp);
> +	}
> +
> +	return ret;
> +}
> +
>  static struct i915_gem_proto_context *
>  proto_context_create(struct drm_i915_private *i915, unsigned int flags)
>  {
> @@ -269,7 +301,7 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
>  	return pc;
>  
>  proto_close:
> -	proto_context_close(pc);
> +	proto_context_close(i915, pc);
>  	return err;
>  }
>  
> @@ -693,6 +725,8 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
>  			ret = -EPERM;
>  		else if (args->value)
>  			pc->user_flags |= BIT(UCONTEXT_BANNABLE);
> +		else if (pc->uses_protected_content)
> +			ret = -EPERM;
>  		else
>  			pc->user_flags &= ~BIT(UCONTEXT_BANNABLE);
>  		break;
> @@ -700,10 +734,12 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
>  	case I915_CONTEXT_PARAM_RECOVERABLE:
>  		if (args->size)
>  			ret = -EINVAL;
> -		else if (args->value)
> -			pc->user_flags |= BIT(UCONTEXT_RECOVERABLE);
> -		else
> +		else if (!args->value)
>  			pc->user_flags &= ~BIT(UCONTEXT_RECOVERABLE);
> +		else if (pc->uses_protected_content)
> +			ret = -EPERM;
> +		else
> +			pc->user_flags |= BIT(UCONTEXT_RECOVERABLE);
>  		break;
>  
>  	case I915_CONTEXT_PARAM_PRIORITY:
> @@ -731,6 +767,11 @@ static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
>  						    args->value);
>  		break;
>  
> +	case I915_CONTEXT_PARAM_PROTECTED_CONTENT:
> +		ret = proto_context_set_protected(fpriv->dev_priv, pc,
> +						  args->value);
> +		break;
> +
>  	case I915_CONTEXT_PARAM_NO_ZEROMAP:
>  	case I915_CONTEXT_PARAM_BAN_PERIOD:
>  	case I915_CONTEXT_PARAM_RINGSIZE:
> @@ -1215,6 +1256,9 @@ static void context_close(struct i915_gem_context *ctx)
>  	if (ctx->syncobj)
>  		drm_syncobj_put(ctx->syncobj);
>  
> +	if (ctx->pxp_wakeref)
> +		intel_runtime_pm_put(&ctx->i915->runtime_pm, ctx->pxp_wakeref);
> +
>  	ctx->file_priv = ERR_PTR(-EBADF);
>  
>  	/*
> @@ -1363,6 +1407,11 @@ i915_gem_create_context(struct drm_i915_private *i915,
>  			goto err_engines;
>  	}
>  
> +	if (pc->uses_protected_content) {
> +		ctx->pxp_wakeref = intel_runtime_pm_get(&i915->runtime_pm);
> +		ctx->uses_protected_content = true;
> +	}
> +
>  	trace_i915_context_create(ctx);
>  
>  	return ctx;
> @@ -1434,7 +1483,7 @@ int i915_gem_context_open(struct drm_i915_private *i915,
>  	}
>  
>  	ctx = i915_gem_create_context(i915, pc);
> -	proto_context_close(pc);
> +	proto_context_close(i915, pc);
>  	if (IS_ERR(ctx)) {
>  		err = PTR_ERR(ctx);
>  		goto err;
> @@ -1461,7 +1510,7 @@ void i915_gem_context_close(struct drm_file *file)
>  	unsigned long idx;
>  
>  	xa_for_each(&file_priv->proto_context_xa, idx, pc)
> -		proto_context_close(pc);
> +		proto_context_close(file_priv->dev_priv, pc);
>  	xa_destroy(&file_priv->proto_context_xa);
>  	mutex_destroy(&file_priv->proto_context_lock);
>  
> @@ -1761,6 +1810,18 @@ static int set_priority(struct i915_gem_context *ctx,
>  	return 0;
>  }
>  
> +static int get_protected(struct i915_gem_context *ctx,
> +			 struct drm_i915_gem_context_param *args)
> +{
> +	if (!intel_pxp_is_enabled(&ctx->i915->gt.pxp))
> +		return -ENODEV;
> +
> +	args->size = 0;
> +	args->value = i915_gem_context_uses_protected_content(ctx);
> +
> +	return 0;
> +}
> +
>  static int ctx_setparam(struct drm_i915_file_private *fpriv,
>  			struct i915_gem_context *ctx,
>  			struct drm_i915_gem_context_param *args)
> @@ -1784,6 +1845,8 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
>  			ret = -EPERM;
>  		else if (args->value)
>  			i915_gem_context_set_bannable(ctx);
> +		else if (i915_gem_context_uses_protected_content(ctx))
> +			ret = -EPERM; /* can't clear this for protected contexts */
>  		else
>  			i915_gem_context_clear_bannable(ctx);
>  		break;
> @@ -1791,10 +1854,12 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
>  	case I915_CONTEXT_PARAM_RECOVERABLE:
>  		if (args->size)
>  			ret = -EINVAL;
> -		else if (args->value)
> -			i915_gem_context_set_recoverable(ctx);
> -		else
> +		else if (!args->value)
>  			i915_gem_context_clear_recoverable(ctx);
> +		else if (i915_gem_context_uses_protected_content(ctx))
> +			ret = -EPERM; /* can't set this for protected contexts */
> +		else
> +			i915_gem_context_set_recoverable(ctx);
>  		break;
>  
>  	case I915_CONTEXT_PARAM_PRIORITY:
> @@ -1809,6 +1874,7 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
>  		ret = set_persistence(ctx, args);
>  		break;
>  
> +	case I915_CONTEXT_PARAM_PROTECTED_CONTENT:
>  	case I915_CONTEXT_PARAM_NO_ZEROMAP:
>  	case I915_CONTEXT_PARAM_BAN_PERIOD:
>  	case I915_CONTEXT_PARAM_RINGSIZE:
> @@ -1887,7 +1953,7 @@ finalize_create_context_locked(struct drm_i915_file_private *file_priv,
>  
>  	old = xa_erase(&file_priv->proto_context_xa, id);
>  	GEM_BUG_ON(old != pc);
> -	proto_context_close(pc);
> +	proto_context_close(file_priv->dev_priv, pc);
>  
>  	/* One for the xarray and one for the caller */
>  	return i915_gem_context_get(ctx);
> @@ -1973,7 +2039,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
>  			goto err_pc;
>  		}
>  
> -		proto_context_close(ext_data.pc);
> +		proto_context_close(i915, ext_data.pc);
>  		gem_context_register(ctx, ext_data.fpriv, id);
>  	} else {
>  		ret = proto_context_register(ext_data.fpriv, ext_data.pc, &id);
> @@ -1987,7 +2053,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
>  	return 0;
>  
>  err_pc:
> -	proto_context_close(ext_data.pc);
> +	proto_context_close(i915, ext_data.pc);
>  	return ret;
>  }
>  
> @@ -2018,7 +2084,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
>  	GEM_WARN_ON(ctx && pc);
>  
>  	if (pc)
> -		proto_context_close(pc);
> +		proto_context_close(file_priv->dev_priv, pc);
>  
>  	if (ctx)
>  		context_close(ctx);
> @@ -2137,6 +2203,10 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
>  		args->value = i915_gem_context_is_persistent(ctx);
>  		break;
>  
> +	case I915_CONTEXT_PARAM_PROTECTED_CONTENT:
> +		ret = get_protected(ctx, args);
> +		break;
> +
>  	case I915_CONTEXT_PARAM_NO_ZEROMAP:
>  	case I915_CONTEXT_PARAM_BAN_PERIOD:
>  	case I915_CONTEXT_PARAM_ENGINES:
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
> index 18060536b0c2..a62e4454e829 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
> @@ -108,6 +108,12 @@ i915_gem_context_clear_user_engines(struct i915_gem_context *ctx)
>  	clear_bit(CONTEXT_USER_ENGINES, &ctx->flags);
>  }
>  
> +static inline bool
> +i915_gem_context_uses_protected_content(const struct i915_gem_context *ctx)
> +{
> +	return ctx->uses_protected_content;
> +}
> +
>  /* i915_gem_context.c */
>  void i915_gem_init__contexts(struct drm_i915_private *i915);
>  
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> index 94c03a97cb77..8e59a86ef5a1 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> @@ -198,6 +198,12 @@ struct i915_gem_proto_context {
>  
>  	/** @single_timeline: See See &i915_gem_context.syncobj */
>  	bool single_timeline;
> +
> +	/** @uses_protected_content: See &i915_gem_context.uses_protected_content */
> +	bool uses_protected_content;
> +
> +	/** @pxp_wakeref: See &i915_gem_context.pxp_wakeref */
> +	intel_wakeref_t pxp_wakeref;
>  };
>  
>  /**
> @@ -309,6 +315,28 @@ struct i915_gem_context {
>  #define CONTEXT_CLOSED			0
>  #define CONTEXT_USER_ENGINES		1
>  
> +	/**
> +	 * @uses_protected_content: context uses PXP-encrypted objects.
> +	 *
> +	 * This flag can only be set at ctx creation time and it's immutable for
> +	 * the lifetime of the context. See I915_CONTEXT_PARAM_PROTECTED_CONTENT
> +	 * in uapi/drm/i915_drm.h for more info on setting restrictions and
> +	 * expected behaviour of marked contexts.
> +	 */
> +	bool uses_protected_content;
> +
> +	/**
> +	 * @pxp_wakeref: wakeref to keep the device awake when PXP is in use
> +	 *
> +	 * PXP sessions are invalidated when the device is suspended, which in
> +	 * turns invalidates all contexts and objects using it. To keep the
> +	 * flow simple, we keep the device awake when contexts using PXP objects
> +	 * are in use. It is expected that the userspace application only uses
> +	 * PXP when the display is on, so taking a wakeref here shouldn't worsen
> +	 * our power metrics.
> +	 */
> +	intel_wakeref_t pxp_wakeref;
> +
>  	/** @mutex: guards everything that isn't engines or handles_vma */
>  	struct mutex mutex;
>  
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
> index 1d341b8c47c0..8955d6abcef1 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_create.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c
> @@ -6,6 +6,7 @@
>  #include "gem/i915_gem_ioctls.h"
>  #include "gem/i915_gem_lmem.h"
>  #include "gem/i915_gem_region.h"
> +#include "pxp/intel_pxp.h"
>  
>  #include "i915_drv.h"
>  #include "i915_trace.h"
> @@ -82,21 +83,11 @@ static int i915_gem_publish(struct drm_i915_gem_object *obj,
>  	return 0;
>  }
>  
> -/**
> - * Creates a new object using the same path as DRM_I915_GEM_CREATE_EXT
> - * @i915: i915 private
> - * @size: size of the buffer, in bytes
> - * @placements: possible placement regions, in priority order
> - * @n_placements: number of possible placement regions
> - *
> - * This function is exposed primarily for selftests and does very little
> - * error checking.  It is assumed that the set of placement regions has
> - * already been verified to be valid.
> - */
> -struct drm_i915_gem_object *
> -__i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
> -			      struct intel_memory_region **placements,
> -			      unsigned int n_placements)
> +static struct drm_i915_gem_object *
> +__i915_gem_object_create_user_ext(struct drm_i915_private *i915, u64 size,
> +				  struct intel_memory_region **placements,
> +				  unsigned int n_placements,
> +				  unsigned int ext_flags)
>  {
>  	struct intel_memory_region *mr = placements[0];
>  	struct drm_i915_gem_object *obj;
> @@ -135,6 +126,9 @@ __i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
>  
>  	GEM_BUG_ON(size != obj->base.size);
>  
> +	/* Add any flag set by create_ext options */
> +	obj->flags |= ext_flags;
> +
>  	trace_i915_gem_object_create(obj);
>  	return obj;
>  
> @@ -145,6 +139,26 @@ __i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
>  	return ERR_PTR(ret);
>  }
>  
> +/**
> + * Creates a new object using the same path as DRM_I915_GEM_CREATE_EXT
> + * @i915: i915 private
> + * @size: size of the buffer, in bytes
> + * @placements: possible placement regions, in priority order
> + * @n_placements: number of possible placement regions
> + *
> + * This function is exposed primarily for selftests and does very little
> + * error checking.  It is assumed that the set of placement regions has
> + * already been verified to be valid.
> + */
> +struct drm_i915_gem_object *
> +__i915_gem_object_create_user(struct drm_i915_private *i915, u64 size,
> +			      struct intel_memory_region **placements,
> +			      unsigned int n_placements)
> +{
> +	return __i915_gem_object_create_user_ext(i915, size, placements,
> +						 n_placements, 0);
> +}
> +
>  int
>  i915_gem_dumb_create(struct drm_file *file,
>  		     struct drm_device *dev,
> @@ -224,6 +238,7 @@ struct create_ext {
>  	struct drm_i915_private *i915;
>  	struct intel_memory_region *placements[INTEL_REGION_UNKNOWN];
>  	unsigned int n_placements;
> +	unsigned long flags;
>  };
>  
>  static void repr_placements(char *buf, size_t size,
> @@ -353,8 +368,28 @@ static int ext_set_placements(struct i915_user_extension __user *base,
>  	return set_placements(&ext, data);
>  }
>  
> +static int ext_set_protected(struct i915_user_extension __user *base, void *data)
> +{
> +	struct drm_i915_gem_create_ext_protected_content ext;
> +	struct create_ext *ext_data = data;
> +
> +	if (copy_from_user(&ext, base, sizeof(ext)))
> +		return -EFAULT;
> +
> +	if (ext.flags)
> +		return -EINVAL;
> +
> +	if (!intel_pxp_is_enabled(&ext_data->i915->gt.pxp))
> +		return -ENODEV;
> +
> +	ext_data->flags |= I915_BO_PROTECTED;
> +
> +	return 0;
> +}
> +
>  static const i915_user_extension_fn create_extensions[] = {
>  	[I915_GEM_CREATE_EXT_MEMORY_REGIONS] = ext_set_placements,
> +	[I915_GEM_CREATE_EXT_PROTECTED_CONTENT] = ext_set_protected,
>  };
>  
>  /**
> @@ -389,9 +424,10 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data,
>  		ext_data.n_placements = 1;
>  	}
>  
> -	obj = __i915_gem_object_create_user(i915, args->size,
> -					    ext_data.placements,
> -					    ext_data.n_placements);
> +	obj = __i915_gem_object_create_user_ext(i915, args->size,
> +						ext_data.placements,
> +						ext_data.n_placements,
> +						ext_data.flags);
>  	if (IS_ERR(obj))
>  		return PTR_ERR(obj);
>  
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 8290bdadd167..bd17741f462f 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -21,6 +21,8 @@
>  #include "gt/intel_gt_pm.h"
>  #include "gt/intel_ring.h"
>  
> +#include "pxp/intel_pxp.h"
> +
>  #include "i915_drv.h"
>  #include "i915_gem_clflush.h"
>  #include "i915_gem_context.h"
> @@ -825,6 +827,22 @@ 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)) {
> +			err = intel_pxp_key_check(&vm->gt->pxp, obj);
> +			if (err) {
> +				i915_gem_object_put(obj);
> +				return ERR_PTR(err);
> +			}
> +		}
> +
>  		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 6fb9afb65034..e85f2d9fddee 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"
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> index 48112b9d76df..ed171daf49a7 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
> @@ -269,6 +269,12 @@ i915_gem_object_clear_tiling_quirk(struct drm_i915_gem_object *obj)
>  	clear_bit(I915_TILING_QUIRK_BIT, &obj->flags);
>  }
>  
> +static inline bool
> +i915_gem_object_is_protected(const struct drm_i915_gem_object *obj)
> +{
> +	return obj->flags & I915_BO_PROTECTED;
> +}
> +
>  static inline bool
>  i915_gem_object_type_has(const struct drm_i915_gem_object *obj,
>  			 unsigned long flags)
> 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 2471f36aaff3..7d7e9c77f199 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
> @@ -298,6 +298,7 @@ struct drm_i915_gem_object {
>  			     I915_BO_ALLOC_USER)
>  #define I915_BO_READONLY         BIT(4)
>  #define I915_TILING_QUIRK_BIT    5 /* unknown swizzling; do not release! */
> +#define I915_BO_PROTECTED        BIT(6)
>  
>  	/**
>  	 * @mem_flags - Mutable placement-related flags
> @@ -537,6 +538,13 @@ struct drm_i915_gem_object {
>  		bool created:1;
>  	} ttm;
>  
> +	/*
> +	 * Record which PXP key instance this object was created against (if
> +	 * any), so we can use it to determine if the encryption is valid by
> +	 * comparing against the current key instance.
> +	 */
> +	u32 pxp_key_instance;
> +
>  	/** Record of address bit 17 of each page at last unbind. */
>  	unsigned long *bit_17;
>  
> diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_context.c b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
> index fee070df1c97..753a2c9248f5 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/mock_context.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/mock_context.c
> @@ -87,7 +87,7 @@ live_context(struct drm_i915_private *i915, struct file *file)
>  		return ERR_CAST(pc);
>  
>  	ctx = i915_gem_create_context(i915, pc);
> -	proto_context_close(pc);
> +	proto_context_close(i915, pc);
>  	if (IS_ERR(ctx))
>  		return ctx;
>  
> @@ -162,7 +162,7 @@ kernel_context(struct drm_i915_private *i915,
>  	}
>  
>  	ctx = i915_gem_create_context(i915, pc);
> -	proto_context_close(pc);
> +	proto_context_close(i915, pc);
>  	if (IS_ERR(ctx))
>  		return ctx;
>  
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> index b0c7edc10cc3..9beac9746c00 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> @@ -7,6 +7,7 @@
>  #include "intel_pxp_irq.h"
>  #include "intel_pxp_session.h"
>  #include "intel_pxp_tee.h"
> +#include "gem/i915_gem_context.h"
>  #include "gt/intel_context.h"
>  #include "i915_drv.h"
>  
> @@ -166,3 +167,85 @@ void intel_pxp_fini_hw(struct intel_pxp *pxp)
>  
>  	intel_pxp_irq_disable(pxp);
>  }
> +
> +int intel_pxp_key_check(struct intel_pxp *pxp, struct drm_i915_gem_object *obj)
> +{
> +	if (!intel_pxp_is_active(pxp))
> +		return -ENODEV;
> +
> +	if (!i915_gem_object_is_protected(obj))
> +		return -EINVAL;
> +
> +	GEM_BUG_ON(!pxp->key_instance);
> +
> +	/*
> +	 * If this is the first time we're using this object, it's not
> +	 * encrypted yet; it will be encrypted with the current key, so mark it
> +	 * as such. If the object is already encrypted, check instead if the
> +	 * used key is still valid.
> +	 */
> +	if (!obj->pxp_key_instance)
> +		obj->pxp_key_instance = pxp->key_instance;
> +	else if (obj->pxp_key_instance != pxp->key_instance)
> +		return -ENOEXEC;
> +
> +	return 0;
> +}
> +
> +void intel_pxp_invalidate(struct intel_pxp *pxp)
> +{
> +	struct drm_i915_private *i915 = pxp_to_gt(pxp)->i915;
> +	struct i915_gem_context *ctx, *cn;
> +
> +	/* 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) {
> +		struct i915_gem_engines_iter it;
> +		struct intel_context *ce;
> +
> +		if (!kref_get_unless_zero(&ctx->ref))
> +			continue;
> +
> +		if (likely(!i915_gem_context_uses_protected_content(ctx))) {
> +			i915_gem_context_put(ctx);
> +			continue;
> +		}
> +
> +		spin_unlock_irq(&i915->gem.contexts.lock);
> +
> +		/*
> +		 * By the time we get here, the HW keys are already long gone,
> +		 * so any batch using them that's already on the engines is very
> +		 * likely a lost cause (and it has probably already hung the
> +		 * engine). Therefore, we skip attempting to pull the running
> +		 * context out of the HW and we prioritize bringing the session
> +		 * back as soon as possible.
> +		 * For each context we ban we increase the ctx->guilty_count, so
> +		 * that userspace can see that all the intel contexts have been
> +		 * banned (on a non-recoverable gem context, guilty intel
> +		 * contexts are banned immediately on reset, so we report the
> +		 * same way here).

hmm... but guilty specifically means that they indeed caused the GPU hang.
does the umd really need this indication? any other way of doing this?

> +		 */
> +		for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it)
> +			if (!intel_context_ban(ce, NULL))
> +				atomic_inc(&ctx->guilty_count);
> +		i915_gem_context_unlock_engines(ctx);
> +
> +		/*
> +		 * The context has been killed, no need to keep the wakeref.
> +		 * This is safe from races because the only other place this
> +		 * is touched is context_close and we're holding a ctx ref
> +		 */

The comments make sense, but maybe we should avoid the optimization here,
but maybe we should avoid the optimization and just keep it locked?

> +		if (ctx->pxp_wakeref) {
> +			intel_runtime_pm_put(&i915->runtime_pm,
> +					     ctx->pxp_wakeref);
> +			ctx->pxp_wakeref = 0;
> +		}
> +
> +		spin_lock_irq(&i915->gem.contexts.lock);
> +		list_safe_reset_next(ctx, cn, link);
> +		i915_gem_context_put(ctx);
> +	}
> +	spin_unlock_irq(&i915->gem.contexts.lock);
> +}
> +
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.h b/drivers/gpu/drm/i915/pxp/intel_pxp.h
> index 8f1e86caa53f..f942bdd2af0c 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 +35,10 @@ 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_key_check(struct intel_pxp *pxp, 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)
>  {
> @@ -46,6 +52,12 @@ static inline int intel_pxp_wait_for_arb_start(struct intel_pxp *pxp)
>  {
>  	return -ENODEV;
>  }
> +
> +static inline int intel_pxp_key_check(struct intel_pxp *pxp,
> +				      struct drm_i915_gem_object *obj)
> +{
> +	return -ENODEV;
> +}
>  #endif
>  
>  #endif /* __INTEL_PXP_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> index 67c30e534d50..c6a5e4197e40 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_session.c
> @@ -72,6 +72,9 @@ static int pxp_create_arb_session(struct intel_pxp *pxp)
>  		return ret;
>  	}
>  
> +	if (!++pxp->key_instance)
> +		++pxp->key_instance;
> +
>  	pxp->arb_is_valid = true;
>  
>  	return 0;
> @@ -85,6 +88,9 @@ static int pxp_terminate_arb_session_and_global(struct intel_pxp *pxp)
>  	/* must mark termination in progress calling this function */
>  	GEM_WARN_ON(pxp->arb_is_valid);
>  
> +	/* invalidate protected objects */
> +	intel_pxp_invalidate(pxp);
> +
>  	/* terminate the hw sessions */
>  	ret = intel_pxp_terminate_session(pxp, ARB_SESSION);
>  	if (ret) {
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> index 5a170e43c959..c394ab2e452b 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> @@ -7,7 +7,9 @@
>  #define __INTEL_PXP_TYPES_H__
>  
>  #include <linux/completion.h>
> +#include <linux/list.h>
>  #include <linux/mutex.h>
> +#include <linux/spinlock.h>
>  #include <linux/types.h>
>  #include <linux/workqueue.h>
>  
> @@ -27,6 +29,13 @@ struct intel_pxp {
>  	 */
>  	bool arb_is_valid;
>  
> +	/*
> +	 * Keep track of which key instance we're on, so we can use it to
> +	 * determine if an object was created using the current key or a
> +	 * previous one.
> +	 */
> +	u32 key_instance;
> +
>  	struct mutex tee_mutex; /* protects the tee channel binding */
>  
>  	/*
> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> index 920e9e852e5a..9ff77732428b 100644
> --- a/include/uapi/drm/i915_drm.h
> +++ b/include/uapi/drm/i915_drm.h
> @@ -1846,12 +1846,36 @@ struct drm_i915_gem_context_param {
>   * attempted to use it, never re-use this context param number.
>   */
>  #define I915_CONTEXT_PARAM_RINGSIZE	0xc
> +
> +/*
> + * I915_CONTEXT_PARAM_PROTECTED_CONTENT:
> + *
> + * Mark that the context makes use of protected content, which will result
> + * in the context being invalidated when the protected content session is. The
> + * invalidation is reported back to userspace by banning all the engine contexts
> + * within the gem context and increasing the guilty_count to match; this will
> + * be reported in the RESET_STATS ioctl the same way as if the bans were due to
> + * hangs. Given that the protected content session is killed on suspend, the
> + * device is kept awake for the lifetime of a protected context, so the user
> + * should make sure to dispose of them once done.
> + * This flag can only be set at context creation time and, when set to true,
> + * must be preceded by an explicit setting of I915_CONTEXT_PARAM_RECOVERABLE
> + * to false. This flag can't be set to true in conjunction with setting the
> + * I915_CONTEXT_PARAM_BANNABLE flag to false.
> + *
> + * In addition to the normal failure cases, setting this flag during context
> + * creation can result in the following errors:
> + *
> + * -ENODEV: feature not available
> + * -EPERM: trying to mark a recoverable or not bannable context as protected
> + */
> +#define I915_CONTEXT_PARAM_PROTECTED_CONTENT    0xd
>  /* Must be kept compact -- no holes and well documented */
>  
>  	__u64 value;
>  };
>  
> -/*
> +/**
>   * Context SSEU programming
>   *
>   * It may be necessary for either functional or performance reason to configure
> @@ -2979,8 +3003,12 @@ struct drm_i915_gem_create_ext {
>  	 *
>  	 * For I915_GEM_CREATE_EXT_MEMORY_REGIONS usage see
>  	 * struct drm_i915_gem_create_ext_memory_regions.
> +	 *
> +	 * For I915_GEM_CREATE_EXT_PROTECTED_CONTENT usage see
> +	 * struct drm_i915_gem_create_ext_protected_content.
>  	 */
>  #define I915_GEM_CREATE_EXT_MEMORY_REGIONS 0
> +#define I915_GEM_CREATE_EXT_PROTECTED_CONTENT 1
>  	__u64 extensions;
>  };
>  
> @@ -3038,6 +3066,31 @@ struct drm_i915_gem_create_ext_memory_regions {
>  	__u64 regions;
>  };
>  
> +/**
> + * struct drm_i915_gem_create_ext_protected_content - The
> + * I915_OBJECT_PARAM_PROTECTED_CONTENT extension.
> + *
> + * If this extension is provided, buffer contents are expected to be protected
> + * by PXP encryption and require decryption for scan out and processing. This
> + * is only possible on platforms that have PXP enabled, on all other scenarios
> + * using this extension will cause the ioctl to fail and return -ENODEV. The
> + * flags parameter is reserved for future expansion and must currently be set
> + * to zero.
> + *
> + * The buffer contents are considered invalid after a PXP session teardown.
> + *
> + * The encryption is guaranteed to be processed correctly only if the object
> + * is submitted with a context created using the
> + * I915_CONTEXT_PARAM_PROTECTED_CONTENT flag. This will also enable extra checks
> + * at submission time on the validity of the objects involved.
> + */
> +struct drm_i915_gem_create_ext_protected_content {
> +	/** @base: Extension link. See struct i915_user_extension. */
> +	struct i915_user_extension base;
> +	/** @flags: reserved for future usage, currently MBZ */
> +	__u32 flags;
> +};
> +
>  /* ID of the protected content session managed by i915 when PXP is active */
>  #define I915_PROTECTED_CONTENT_DEFAULT_SESSION 0xf
>  
> -- 
> 2.25.1
> 


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