[Intel-gfx] [PATCH] drm/i915: make context status notifier head be per engine

[Chris Wilson]

On Thu, Mar 09, 2017 at 07:27:24PM +0800, changbin.du at intel.com wrote:
> From: Changbin Du <changbin.du at intel.com>
> 
> GVTg has introduced the context status notifier to schedule the GVTg
> workload. At that time, the notifier is bound to GVTg context only,
> so GVTg is not aware of host workloads.
> 
> Now we are going to improve GVTg's guest workload scheduler policy,
> and add Guc emulation support for new Gen graphics. Both these two
> features require acknowledgment for all contexts running on hardware.
> (But will not alter host workload.) So here try to make some change.
> 
> The change is simple:
>   1. Move the context status notifier head from i915_gem_context to
>      intel_engine_cs. Which means there is a notifier head per engine
>      instead of per context. Execlist driver still call notifier for
>      each context sched-in/out events of current engine.
>   2. At GVTg side, it binds a notifier_block for each physical engine
>      at GVTg initialization period. Then GVTg can hear all context
>      status events.
> 
> In this patch, GVTg do nothing for host context event, but later
> will add a function there. But in any case, the notifier callback is
> a noop if this is no active vGPU.
> 
> Since intel_gvt_init() is called at early initialization stage and
> require the status notifier head has been initiated, I initiate it in
> intel_engine_setup().
> 
> Signed-off-by: Changbin Du <changbin.du at intel.com>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

I presume you will apply this via gvt?

> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
> index d3a56c9..64875ec 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -127,15 +127,14 @@ static int populate_shadow_context(struct intel_vgpu_workload *workload)
>  	return 0;
>  }
>  
> +

Bonus newline

>  static int shadow_context_status_change(struct notifier_block *nb,
>  		unsigned long action, void *data)
>  {
> -	struct intel_vgpu *vgpu = container_of(nb,
> -			struct intel_vgpu, shadow_ctx_notifier_block);
> -	struct drm_i915_gem_request *req =
> -		(struct drm_i915_gem_request *)data;
> -	struct intel_gvt_workload_scheduler *scheduler =
> -		&vgpu->gvt->scheduler;
> +	struct drm_i915_gem_request *req = (struct drm_i915_gem_request *)data;
> +	struct intel_gvt *gvt = container_of(nb, struct intel_gvt,
> +				shadow_ctx_notifier_block[req->engine->id]);
> +	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
>  	struct intel_vgpu_workload *workload =
>  		scheduler->current_workload[req->engine->id];
>  

-- 
Chris Wilson, Intel Open Source Technology Centre