Re: [PATCH 21/29] drm/i915/gem: Use the proto-context to handle create parameters (v2)

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, May 27, 2021 at 11:26:42AM -0500, Jason Ekstrand wrote:
> This means that the proto-context needs to grow support for engine
> configuration information as well as setparam logic.  Fortunately, we'll
> be deleting a lot of setparam logic on the primary context shortly so it
> will hopefully balance out.
> 
> There's an extra bit of fun here when it comes to setting SSEU and the
> way it interacts with PARAM_ENGINES.  Unfortunately, thanks to
> SET_CONTEXT_PARAM and not being allowed to pick the order in which we
> handle certain parameters, we have think about those interactions.
> 
> v2 (Daniel Vetter):
>  - Add a proto_context_free_user_engines helper
>  - Comment on SSEU in the commit message
>  - Use proto_context_set_persistence in set_proto_ctx_param
> 
> Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
> ---
>  drivers/gpu/drm/i915/gem/i915_gem_context.c   | 552 +++++++++++++++++-
>  .../gpu/drm/i915/gem/i915_gem_context_types.h |  58 ++
>  2 files changed, 588 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> index cf7c281977a3e..d68c111bc824a 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
> @@ -191,10 +191,24 @@ static int validate_priority(struct drm_i915_private *i915,
>  	return 0;
>  }
>  
> +static void proto_context_free_user_engines(struct i915_gem_proto_context *pc)
> +{
> +	int i;
> +
> +	if (pc->user_engines) {
> +		for (i = 0; i < pc->num_user_engines; i++)
> +			kfree(pc->user_engines[i].siblings);
> +		kfree(pc->user_engines);
> +	}
> +	pc->user_engines = NULL;
> +	pc->num_user_engines = -1;
> +}
> +
>  static void proto_context_close(struct i915_gem_proto_context *pc)
>  {
>  	if (pc->vm)
>  		i915_vm_put(pc->vm);
> +	proto_context_free_user_engines(pc);
>  	kfree(pc);
>  }
>  
> @@ -211,7 +225,7 @@ static int proto_context_set_persistence(struct drm_i915_private *i915,
>  		if (!i915->params.enable_hangcheck)
>  			return -EINVAL;
>  
> -		__set_bit(UCONTEXT_PERSISTENCE, &pc->user_flags);
> +		pc->user_flags |= BIT(UCONTEXT_PERSISTENCE);
>  	} else {
>  		/* To cancel a context we use "preempt-to-idle" */
>  		if (!(i915->caps.scheduler & I915_SCHEDULER_CAP_PREEMPTION))
> @@ -233,7 +247,7 @@ static int proto_context_set_persistence(struct drm_i915_private *i915,
>  		if (!intel_has_reset_engine(&i915->gt))
>  			return -ENODEV;
>  
> -		__clear_bit(UCONTEXT_PERSISTENCE, &pc->user_flags);
> +		pc->user_flags &= ~BIT(UCONTEXT_PERSISTENCE);

Squashed into wrong patch I think. Also the one right above.

>  	}
>  
>  	return 0;
> @@ -248,6 +262,9 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
>  	if (!pc)
>  		return ERR_PTR(-ENOMEM);
>  
> +	pc->num_user_engines = -1;
> +	pc->user_engines = NULL;

If you go with my proto_context_reset_user_engines() suggestion below you
could use that here too. It's overkill, but it makes the code a bit
clearer in what it does I think.

> +
>  	if (HAS_FULL_PPGTT(i915)) {
>  		struct i915_ppgtt *ppgtt;
>  
> @@ -261,9 +278,8 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
>  		pc->vm = &ppgtt->vm;
>  	}
>  
> -	pc->user_flags = 0;
> -	__set_bit(UCONTEXT_BANNABLE, &pc->user_flags);
> -	__set_bit(UCONTEXT_RECOVERABLE, &pc->user_flags);
> +	pc->user_flags = BIT(UCONTEXT_BANNABLE) |
> +			 BIT(UCONTEXT_RECOVERABLE);

Same here.

>  	proto_context_set_persistence(i915, pc, true);
>  	pc->sched.priority = I915_PRIORITY_NORMAL;
>  
> @@ -282,6 +298,429 @@ proto_context_create(struct drm_i915_private *i915, unsigned int flags)
>  	return err;
>  }
>  
> +static int set_proto_ctx_vm(struct drm_i915_file_private *fpriv,
> +			    struct i915_gem_proto_context *pc,
> +			    const struct drm_i915_gem_context_param *args)
> +{
> +	struct i915_address_space *vm;
> +
> +	if (args->size)
> +		return -EINVAL;
> +
> +	if (!pc->vm)

I got confused by this and then realized it's checking for
HAS_FULL_PPGTT(). I wonder whether we should lock this down more with
runtime checks, or at least have a comment that ctx->vm is only set for
HAS_FULL_PPGTT.

If you concur I'd do the kerneldoc warning that this is tied to full
ppgtt, switch this check to HAS_FULL_PPGTT() and maybe do a 

	WARN_ON(!!ctx->vm == HAS_FULL_PPGTT());

in the context destroy (not proto context destroy). Or drop this
suggestion if you feel like this is all obvious.

> +		return -ENODEV;
> +
> +	if (upper_32_bits(args->value))
> +		return -ENOENT;
> +
> +	vm = i915_gem_vm_lookup(fpriv, args->value);
> +	if (!vm)
> +		return -ENOENT;
> +
> +	i915_vm_put(pc->vm);
> +	pc->vm = vm;
> +
> +	return 0;
> +}
> +
> +struct set_proto_ctx_engines {
> +	struct drm_i915_private *i915;
> +	unsigned num_engines;
> +	struct i915_gem_proto_engine *engines;
> +};
> +
> +static int
> +set_proto_ctx_engines_balance(struct i915_user_extension __user *base,
> +			      void *data)
> +{
> +	struct i915_context_engines_load_balance __user *ext =
> +		container_of_user(base, typeof(*ext), base);
> +	const struct set_proto_ctx_engines *set = data;
> +	struct drm_i915_private *i915 = set->i915;
> +	struct intel_engine_cs **siblings;
> +	u16 num_siblings, idx;
> +	unsigned int n;
> +	int err;
> +
> +	if (!HAS_EXECLISTS(i915))
> +		return -ENODEV;
> +
> +	if (intel_uc_uses_guc_submission(&i915->gt.uc))
> +		return -ENODEV; /* not implement yet */
> +
> +	if (get_user(idx, &ext->engine_index))
> +		return -EFAULT;
> +
> +	if (idx >= set->num_engines) {
> +		drm_dbg(&i915->drm, "Invalid placement value, %d >= %d\n",
> +			idx, set->num_engines);
> +		return -EINVAL;
> +	}
> +
> +	idx = array_index_nospec(idx, set->num_engines);
> +	if (set->engines[idx].type != I915_GEM_ENGINE_TYPE_INVALID) {
> +		drm_dbg(&i915->drm,
> +			"Invalid placement[%d], already occupied\n", idx);
> +		return -EEXIST;
> +	}
> +
> +	if (get_user(num_siblings, &ext->num_siblings))
> +		return -EFAULT;
> +
> +	err = check_user_mbz(&ext->flags);
> +	if (err)
> +		return err;
> +
> +	err = check_user_mbz(&ext->mbz64);
> +	if (err)
> +		return err;
> +
> +	if (num_siblings == 0)
> +		return 0;
> +
> +	siblings = kmalloc_array(num_siblings, sizeof(*siblings), GFP_KERNEL);
> +	if (!siblings)
> +		return -ENOMEM;
> +
> +	for (n = 0; n < num_siblings; n++) {
> +		struct i915_engine_class_instance ci;
> +
> +		if (copy_from_user(&ci, &ext->engines[n], sizeof(ci))) {
> +			err = -EFAULT;
> +			goto err_siblings;
> +		}
> +
> +		siblings[n] = intel_engine_lookup_user(i915,
> +						       ci.engine_class,
> +						       ci.engine_instance);
> +		if (!siblings[n]) {
> +			drm_dbg(&i915->drm,
> +				"Invalid sibling[%d]: { class:%d, inst:%d }\n",
> +				n, ci.engine_class, ci.engine_instance);
> +			err = -EINVAL;
> +			goto err_siblings;
> +		}
> +	}
> +
> +	if (num_siblings == 1) {
> +		set->engines[idx].type = I915_GEM_ENGINE_TYPE_PHYSICAL;
> +		set->engines[idx].engine = siblings[0];
> +		kfree(siblings);
> +	} else {
> +		set->engines[idx].type = I915_GEM_ENGINE_TYPE_BALANCED;
> +		set->engines[idx].num_siblings = num_siblings;
> +		set->engines[idx].siblings = siblings;
> +	}
> +
> +	return 0;
> +
> +err_siblings:
> +	kfree(siblings);
> +
> +	return err;
> +}
> +
> +static int
> +set_proto_ctx_engines_bond(struct i915_user_extension __user *base, void *data)
> +{
> +	struct i915_context_engines_bond __user *ext =
> +		container_of_user(base, typeof(*ext), base);
> +	const struct set_proto_ctx_engines *set = data;
> +	struct drm_i915_private *i915 = set->i915;
> +	struct i915_engine_class_instance ci;
> +	struct intel_engine_cs *master;
> +	u16 idx, num_bonds;
> +	int err, n;
> +
> +	if (get_user(idx, &ext->virtual_index))
> +		return -EFAULT;
> +
> +	if (idx >= set->num_engines) {
> +		drm_dbg(&i915->drm,
> +			"Invalid index for virtual engine: %d >= %d\n",
> +			idx, set->num_engines);
> +		return -EINVAL;
> +	}
> +
> +	idx = array_index_nospec(idx, set->num_engines);
> +	if (set->engines[idx].type == I915_GEM_ENGINE_TYPE_INVALID) {
> +		drm_dbg(&i915->drm, "Invalid engine at %d\n", idx);
> +		return -EINVAL;
> +	}
> +
> +	if (set->engines[idx].type != I915_GEM_ENGINE_TYPE_PHYSICAL) {
> +		drm_dbg(&i915->drm,
> +			"Bonding with virtual engines not allowed\n");
> +		return -EINVAL;
> +	}
> +
> +	err = check_user_mbz(&ext->flags);
> +	if (err)
> +		return err;
> +
> +	for (n = 0; n < ARRAY_SIZE(ext->mbz64); n++) {
> +		err = check_user_mbz(&ext->mbz64[n]);
> +		if (err)
> +			return err;
> +	}
> +
> +	if (copy_from_user(&ci, &ext->master, sizeof(ci)))
> +		return -EFAULT;
> +
> +	master = intel_engine_lookup_user(i915,
> +					  ci.engine_class,
> +					  ci.engine_instance);
> +	if (!master) {
> +		drm_dbg(&i915->drm,
> +			"Unrecognised master engine: { class:%u, instance:%u }\n",
> +			ci.engine_class, ci.engine_instance);
> +		return -EINVAL;
> +	}
> +
> +	if (get_user(num_bonds, &ext->num_bonds))
> +		return -EFAULT;
> +
> +	for (n = 0; n < num_bonds; n++) {
> +		struct intel_engine_cs *bond;
> +
> +		if (copy_from_user(&ci, &ext->engines[n], sizeof(ci)))
> +			return -EFAULT;
> +
> +		bond = intel_engine_lookup_user(i915,
> +						ci.engine_class,
> +						ci.engine_instance);
> +		if (!bond) {
> +			drm_dbg(&i915->drm,
> +				"Unrecognised engine[%d] for bonding: { class:%d, instance: %d }\n",
> +				n, ci.engine_class, ci.engine_instance);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static const i915_user_extension_fn set_proto_ctx_engines_extensions[] = {
> +	[I915_CONTEXT_ENGINES_EXT_LOAD_BALANCE] = set_proto_ctx_engines_balance,
> +	[I915_CONTEXT_ENGINES_EXT_BOND] = set_proto_ctx_engines_bond,
> +};
> +
> +static int set_proto_ctx_engines(struct drm_i915_file_private *fpriv,
> +			         struct i915_gem_proto_context *pc,
> +			         const struct drm_i915_gem_context_param *args)
> +{
> +	struct drm_i915_private *i915 = fpriv->dev_priv;
> +	struct set_proto_ctx_engines set = { .i915 = i915 };
> +	struct i915_context_param_engines __user *user =
> +		u64_to_user_ptr(args->value);
> +	unsigned int n;
> +	u64 extensions;
> +	int err;
> +
> +	if (!args->size) {
> +		proto_context_free_user_engines(pc);
> +		memset(&pc->legacy_rcs_sseu, 0, sizeof(pc->legacy_rcs_sseu));

Hm I wonder whether we shouldn't put this into the cleanup helper, and
then maybe call it proto_context_reset_user_engines()? I think that makes
the entire user engines vs sseu flow a notch clearer again.

> +		return 0;
> +	}
> +
> +	if (args->size < sizeof(*user) ||
> +	    !IS_ALIGNED(args->size - sizeof(*user), sizeof(*user->engines))) {
> +		drm_dbg(&i915->drm, "Invalid size for engine array: %d\n",
> +			args->size);
> +		return -EINVAL;
> +	}
> +
> +	set.num_engines = (args->size - sizeof(*user)) / sizeof(*user->engines);
> +	/* RING_MASK has no shift so we can use it directly here */
> +	if (set.num_engines > I915_EXEC_RING_MASK + 1)
> +		return -EINVAL;
> +
> +	set.engines = kmalloc_array(set.num_engines, sizeof(*set.engines), GFP_KERNEL);
> +	if (!set.engines)
> +		return -ENOMEM;
> +
> +	for (n = 0; n < set.num_engines; n++) {
> +		struct i915_engine_class_instance ci;
> +		struct intel_engine_cs *engine;
> +
> +		if (copy_from_user(&ci, &user->engines[n], sizeof(ci))) {
> +			kfree(set.engines);
> +			return -EFAULT;
> +		}
> +
> +		memset(&set.engines[n], 0, sizeof(set.engines[n]));
> +
> +		if (ci.engine_class == (u16)I915_ENGINE_CLASS_INVALID &&
> +		    ci.engine_instance == (u16)I915_ENGINE_CLASS_INVALID_NONE)
> +			continue;
> +
> +		engine = intel_engine_lookup_user(i915,
> +						  ci.engine_class,
> +						  ci.engine_instance);
> +		if (!engine) {
> +			drm_dbg(&i915->drm,
> +				"Invalid engine[%d]: { class:%d, instance:%d }\n",
> +				n, ci.engine_class, ci.engine_instance);
> +			kfree(set.engines);
> +			return -ENOENT;
> +		}
> +
> +		set.engines[n].type = I915_GEM_ENGINE_TYPE_PHYSICAL;
> +		set.engines[n].engine = engine;
> +	}
> +
> +	err = -EFAULT;
> +	if (!get_user(extensions, &user->extensions))
> +		err = i915_user_extensions(u64_to_user_ptr(extensions),
> +					   set_proto_ctx_engines_extensions,
> +					   ARRAY_SIZE(set_proto_ctx_engines_extensions),
> +					   &set);
> +	if (err) {
> +		kfree(set.engines);
> +		return err;
> +	}
> +
> +	proto_context_free_user_engines(pc);
> +	pc->num_user_engines = set.num_engines;
> +	pc->user_engines = set.engines;
> +
> +	return 0;
> +}
> +
> +static int set_proto_ctx_sseu(struct drm_i915_file_private *fpriv,
> +			      struct i915_gem_proto_context *pc,
> +			      struct drm_i915_gem_context_param *args)
> +{
> +	struct drm_i915_private *i915 = fpriv->dev_priv;
> +	struct drm_i915_gem_context_param_sseu user_sseu;
> +	struct intel_sseu *sseu;
> +	int ret;
> +
> +	if (args->size < sizeof(user_sseu))
> +		return -EINVAL;
> +
> +	if (!IS_GEN(i915, 11))
> +		return -ENODEV;
> +
> +	if (copy_from_user(&user_sseu, u64_to_user_ptr(args->value),
> +			   sizeof(user_sseu)))
> +		return -EFAULT;
> +
> +	if (user_sseu.rsvd)
> +		return -EINVAL;
> +
> +	if (user_sseu.flags & ~(I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX))
> +		return -EINVAL;
> +
> +	if (!!(user_sseu.flags & I915_CONTEXT_SSEU_FLAG_ENGINE_INDEX) != (pc->num_user_engines >= 0))
> +		return -EINVAL;
> +
> +	if (pc->num_user_engines >= 0) {
> +		int idx = user_sseu.engine.engine_instance;
> +		struct i915_gem_proto_engine *pe;
> +
> +		if (idx >= pc->num_user_engines)
> +			return -EINVAL;
> +
> +		pe = &pc->user_engines[idx];
> +
> +		/* Only render engine supports RPCS configuration. */
> +		if (pe->engine->class != RENDER_CLASS)
> +			return -EINVAL;
> +
> +		sseu = &pe->sseu;
> +	} else {
> +		/* Only render engine supports RPCS configuration. */
> +		if (user_sseu.engine.engine_class != I915_ENGINE_CLASS_RENDER)
> +			return -EINVAL;
> +
> +		/* There is only one render engine */
> +		if (user_sseu.engine.engine_instance != 0)
> +			return -EINVAL;
> +
> +		sseu = &pc->legacy_rcs_sseu;
> +	}
> +
> +	ret = i915_gem_user_to_context_sseu(&i915->gt, &user_sseu, sseu);
> +	if (ret)
> +		return ret;
> +
> +	args->size = sizeof(user_sseu);
> +
> +	return 0;
> +}
> +
> +static int set_proto_ctx_param(struct drm_i915_file_private *fpriv,
> +			       struct i915_gem_proto_context *pc,
> +			       struct drm_i915_gem_context_param *args)
> +{
> +	int ret = 0;
> +
> +	switch (args->param) {
> +	case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
> +		if (args->size)
> +			ret = -EINVAL;
> +		else if (args->value)
> +			pc->user_flags |= BIT(UCONTEXT_NO_ERROR_CAPTURE);
> +		else
> +			pc->user_flags &= ~BIT(UCONTEXT_NO_ERROR_CAPTURE);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_BANNABLE:
> +		if (args->size)
> +			ret = -EINVAL;
> +		else if (!capable(CAP_SYS_ADMIN) && !args->value)
> +			ret = -EPERM;
> +		else if (args->value)
> +			pc->user_flags |= BIT(UCONTEXT_BANNABLE);
> +		else
> +			pc->user_flags &= ~BIT(UCONTEXT_BANNABLE);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_RECOVERABLE:
> +		if (args->size)
> +			ret = -EINVAL;
> +		else if (args->value)
> +			pc->user_flags |= BIT(UCONTEXT_RECOVERABLE);
> +		else
> +			pc->user_flags &= ~BIT(UCONTEXT_RECOVERABLE);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_PRIORITY:
> +		ret = validate_priority(fpriv->dev_priv, args);
> +		if (!ret)
> +			pc->sched.priority = args->value;
> +		break;
> +
> +	case I915_CONTEXT_PARAM_SSEU:
> +		ret = set_proto_ctx_sseu(fpriv, pc, args);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_VM:
> +		ret = set_proto_ctx_vm(fpriv, pc, args);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_ENGINES:
> +		ret = set_proto_ctx_engines(fpriv, pc, args);
> +		break;
> +
> +	case I915_CONTEXT_PARAM_PERSISTENCE:
> +		if (args->size)
> +			ret = -EINVAL;
> +		proto_context_set_persistence(fpriv->dev_priv, pc, args->value);

Error handling got lost here.

> +		break;
> +
> +	case I915_CONTEXT_PARAM_NO_ZEROMAP:
> +	case I915_CONTEXT_PARAM_BAN_PERIOD:
> +	case I915_CONTEXT_PARAM_RINGSIZE:
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
>  static struct i915_address_space *
>  context_get_vm_rcu(struct i915_gem_context *ctx)
>  {
> @@ -475,6 +914,56 @@ static struct i915_gem_engines *default_engines(struct i915_gem_context *ctx,
>  	return err;
>  }
>  
> +static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
> +					     unsigned int num_engines,
> +					     struct i915_gem_proto_engine *pe)
> +{
> +	struct i915_gem_engines *e, *err;
> +	unsigned int n;
> +
> +	e = alloc_engines(num_engines);
> +	for (n = 0; n < num_engines; n++) {
> +		struct intel_context *ce;
> +		int ret;
> +
> +		switch (pe[n].type) {
> +		case I915_GEM_ENGINE_TYPE_PHYSICAL:
> +			ce = intel_context_create(pe[n].engine);
> +			break;
> +
> +		case I915_GEM_ENGINE_TYPE_BALANCED:
> +			ce = intel_execlists_create_virtual(pe[n].siblings,
> +							    pe[n].num_siblings);
> +			break;
> +
> +		case I915_GEM_ENGINE_TYPE_INVALID:
> +		default:
> +			GEM_WARN_ON(pe[n].type != I915_GEM_ENGINE_TYPE_INVALID);
> +			continue;
> +		}
> +
> +		if (IS_ERR(ce)) {
> +			err = ERR_CAST(ce);
> +			goto free_engines;
> +		}
> +
> +		e->engines[n] = ce;
> +
> +		ret = intel_context_set_gem(ce, ctx, pe->sseu);
> +		if (ret) {
> +			err = ERR_PTR(ret);
> +			goto free_engines;
> +		}
> +	}
> +	e->num_engines = num_engines;
> +
> +	return e;
> +
> +free_engines:
> +	free_engines(e);
> +	return err;
> +}
> +
>  void i915_gem_context_release(struct kref *ref)
>  {
>  	struct i915_gem_context *ctx = container_of(ref, typeof(*ctx), ref);
> @@ -779,7 +1268,6 @@ __create_context(struct drm_i915_private *i915,
>  {
>  	struct i915_gem_context *ctx;
>  	struct i915_gem_engines *e;
> -	struct intel_sseu null_sseu = {};
>  	int err;
>  	int i;
>  
> @@ -797,7 +1285,7 @@ __create_context(struct drm_i915_private *i915,
>  	INIT_LIST_HEAD(&ctx->stale.engines);
>  
>  	mutex_init(&ctx->engines_mutex);
> -	e = default_engines(ctx, null_sseu);
> +	e = default_engines(ctx, pc->legacy_rcs_sseu);
>  	if (IS_ERR(e)) {
>  		err = PTR_ERR(e);
>  		goto err_free;
> @@ -916,6 +1404,24 @@ i915_gem_create_context(struct drm_i915_private *i915,
>  		mutex_unlock(&ctx->mutex);
>  	}
>  
> +	if (pc->num_user_engines >= 0) {
> +		struct i915_gem_engines *engines;
> +
> +		engines = user_engines(ctx, pc->num_user_engines,
> +				       pc->user_engines);
> +		if (IS_ERR(engines)) {
> +			context_close(ctx);
> +			return ERR_CAST(engines);
> +		}
> +
> +		mutex_lock(&ctx->engines_mutex);
> +		i915_gem_context_set_user_engines(ctx);
> +		engines = rcu_replace_pointer(ctx->engines, engines, 1);
> +		mutex_unlock(&ctx->engines_mutex);
> +
> +		free_engines(engines);
> +	}
> +
>  	if (pc->single_timeline) {
>  		ret = drm_syncobj_create(&ctx->syncobj,
>  					 DRM_SYNCOBJ_CREATE_SIGNALED,
> @@ -1950,7 +2456,7 @@ static int ctx_setparam(struct drm_i915_file_private *fpriv,
>  }
>  
>  struct create_ext {
> -	struct i915_gem_context *ctx;
> +	struct i915_gem_proto_context *pc;
>  	struct drm_i915_file_private *fpriv;
>  };
>  
> @@ -1965,7 +2471,7 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data)
>  	if (local.param.ctx_id)
>  		return -EINVAL;
>  
> -	return ctx_setparam(arg->fpriv, arg->ctx, &local.param);
> +	return set_proto_ctx_param(arg->fpriv, arg->pc, &local.param);
>  }
>  
>  static int invalid_ext(struct i915_user_extension __user *ext, void *data)
> @@ -1988,7 +2494,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
>  {
>  	struct drm_i915_private *i915 = to_i915(dev);
>  	struct drm_i915_gem_context_create_ext *args = data;
> -	struct i915_gem_proto_context *pc;
> +	struct i915_gem_context *ctx;
>  	struct create_ext ext_data;
>  	int ret;
>  	u32 id;
> @@ -2011,25 +2517,27 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
>  		return -EIO;
>  	}
>  
> -	pc = proto_context_create(i915, args->flags);
> -	if (IS_ERR(pc))
> -		return PTR_ERR(pc);
> -
> -	ext_data.ctx = i915_gem_create_context(i915, pc);
> -	proto_context_close(pc);
> -	if (IS_ERR(ext_data.ctx))
> -		return PTR_ERR(ext_data.ctx);
> +	ext_data.pc = proto_context_create(i915, args->flags);
> +	if (IS_ERR(ext_data.pc))
> +		return PTR_ERR(ext_data.pc);
>  
>  	if (args->flags & I915_CONTEXT_CREATE_FLAGS_USE_EXTENSIONS) {
>  		ret = i915_user_extensions(u64_to_user_ptr(args->extensions),
>  					   create_extensions,
>  					   ARRAY_SIZE(create_extensions),
>  					   &ext_data);
> -		if (ret)
> -			goto err_ctx;
> +		if (ret) {
> +			proto_context_close(ext_data.pc);
> +			return ret;
> +		}
>  	}
>  
> -	ret = gem_context_register(ext_data.ctx, ext_data.fpriv, &id);
> +	ctx = i915_gem_create_context(i915, ext_data.pc);
> +	proto_context_close(ext_data.pc);
> +	if (IS_ERR(ctx))
> +		return PTR_ERR(ctx);
> +
> +	ret = gem_context_register(ctx, ext_data.fpriv, &id);
>  	if (ret < 0)
>  		goto err_ctx;
>  
> @@ -2039,7 +2547,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
>  	return 0;
>  
>  err_ctx:
> -	context_close(ext_data.ctx);
> +	context_close(ctx);
>  	return ret;
>  }
>  
> 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 0bf337b6d89ac..2ac341f805c8f 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h
> @@ -66,6 +66,55 @@ struct i915_gem_engines_iter {
>  	const struct i915_gem_engines *engines;
>  };
>  
> +/**
> + * enum i915_gem_engine_type - Describes the type of an i915_gem_proto_engine
> + */
> +enum i915_gem_engine_type {
> +	/** @I915_GEM_ENGINE_TYPE_INVALID: An invalid engine */
> +	I915_GEM_ENGINE_TYPE_INVALID = 0,
> +
> +	/** @I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine */
> +	I915_GEM_ENGINE_TYPE_PHYSICAL,
> +
> +	/** @I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set */
> +	I915_GEM_ENGINE_TYPE_BALANCED,
> +};
> +
> +/**
> + * struct i915_gem_proto_engine - prototype engine
> + *
> + * This struct describes an engine that a context may contain.  Engines
> + * have three types:
> + *
> + *  - I915_GEM_ENGINE_TYPE_INVALID: Invalid engines can be created but they
> + *    show up as a NULL in i915_gem_engines::engines[i] and any attempt to
> + *    use them by the user results in -EINVAL.  They are also useful during
> + *    proto-context construction because the client may create invalid
> + *    engines and then set them up later as bonded engines.

s/bonded/virtual/ because we have a few classes of different virtual
engines. Especially once we add the parallel engine as a proper virtual
engine class.


> + *
> + *  - I915_GEM_ENGINE_TYPE_PHYSICAL: A single physical engine, described by
> + *    i915_gem_proto_engine::engine.
> + *
> + *  - I915_GEM_ENGINE_TYPE_BALANCED: A load-balanced engine set, described
> + *    i915_gem_proto_engine::num_siblings and i915_gem_proto_engine::siblings.
> + */
> +struct i915_gem_proto_engine {
> +	/** @type: Type of this engine */
> +	enum i915_gem_engine_type type;
> +
> +	/** @engine: Engine, for physical */
> +	struct intel_engine_cs *engine;
> +
> +	/** @num_siblings: Number of balanced siblings */
> +	unsigned int num_siblings;
> +
> +	/** @siblings: Balanced siblings */
> +	struct intel_engine_cs **siblings;
> +
> +	/** @sseu: Client-set SSEU parameters */
> +	struct intel_sseu sseu;
> +};
> +
>  /**
>   * struct i915_gem_proto_context - prototype context
>   *
> @@ -84,6 +133,15 @@ struct i915_gem_proto_context {
>  	/** @sched: See i915_gem_context::sched */
>  	struct i915_sched_attr sched;
>  
> +	/** @num_user_engines: Number of user-specified engines or -1 */
> +	int num_user_engines;
> +
> +	/** @user_engines: User-specified engines */
> +	struct i915_gem_proto_engine *user_engines;
> +
> +	/** @sseu: Client-set SSEU parameters for the legacy RCS */
> +	struct intel_sseu legacy_rcs_sseu;
> +
>  	/** @single_timeline: See See i915_gem_context::syncobj */
>  	bool single_timeline;
>  };
> -- 
> 2.31.1

I didn't do a full review of the creation code, I checked that last time.
Just what changed. With the remaining nits and bits addressed:

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch