[Intel-gfx] [PATCH 1/2] drm/i915: Allow DRM_ROOT_ONLY|DRM_MASTER to submit privileged batchbuffers

Jesse Barnes jbarnes at virtuousgeek.org
Wed Oct 17 18:31:21 CEST 2012


On Wed, 17 Oct 2012 12:09:54 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> With the introduction of per-process GTT space, the hardware designers
> thought it wise to also limit the ability to write to MMIO space to only
> a "secure" batch buffer. The ability to rewrite registers is the only
> way to program the hardware to perform certain operations like scanline
> waits (required for tear-free windowed updates). So we either have a
> choice of adding an interface to perform those synchronized updates
> inside the kernel, or we permit certain processes the ability to write
> to the "safe" registers from within its command stream. This patch
> exposes the ability to submit a SECURE batch buffer to
> DRM_ROOT_ONLY|DRM_MASTER processes.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_dma.c            |    3 +++
>  drivers/gpu/drm/i915/i915_gem_execbuffer.c |   21 ++++++++++++++++++---
>  drivers/gpu/drm/i915/i915_trace.h          |   10 ++++++----
>  drivers/gpu/drm/i915/intel_ringbuffer.c    |   23 +++++++++++++++--------
>  drivers/gpu/drm/i915/intel_ringbuffer.h    |    4 +++-
>  include/drm/i915_drm.h                     |    6 ++++++
>  6 files changed, 51 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index 5779e8f..f92c849 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1015,6 +1015,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
>  	case I915_PARAM_HAS_PRIME_VMAP_FLUSH:
>  		value = 1;
>  		break;
> +	case I915_PARAM_HAS_SECURE_BATCHES:
> +		value = capable(CAP_SYS_ADMIN);
> +		break;
>  	default:
>  		DRM_DEBUG_DRIVER("Unknown parameter %d\n",
>  				 param->param);
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index bcd5aa2..4bbd088 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -816,6 +816,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  	u32 exec_start, exec_len;
>  	u32 seqno;
>  	u32 mask;
> +	u32 flags;
>  	int ret, mode, i;
>  
>  	if (!i915_gem_check_execbuffer(args)) {
> @@ -827,6 +828,14 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  	if (ret)
>  		return ret;
>  
> +	flags = 0;
> +	if (args->flags & I915_EXEC_SECURE) {
> +		if (!file->is_master || !capable(CAP_SYS_ADMIN))
> +		    return -EPERM;
> +
> +		flags |= I915_DISPATCH_SECURE;
> +	}
> +
>  	switch (args->flags & I915_EXEC_RING_MASK) {
>  	case I915_EXEC_DEFAULT:
>  	case I915_EXEC_RENDER:
> @@ -999,6 +1008,9 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  	}
>  	batch_obj->base.pending_read_domains |= I915_GEM_DOMAIN_COMMAND;
>  
> +	if (flags & I915_DISPATCH_SECURE && !batch_obj->has_global_gtt_mapping)
> +		i915_gem_gtt_bind_object(batch_obj, batch_obj->cache_level);
> +
>  	ret = i915_gem_execbuffer_move_to_gpu(ring, &objects);
>  	if (ret)
>  		goto err;
> @@ -1044,7 +1056,7 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  			goto err;
>  	}
>  
> -	trace_i915_gem_ring_dispatch(ring, seqno);
> +	trace_i915_gem_ring_dispatch(ring, seqno, flags);
>  
>  	exec_start = batch_obj->gtt_offset + args->batch_start_offset;
>  	exec_len = args->batch_len;
> @@ -1056,12 +1068,15 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
>  				goto err;
>  
>  			ret = ring->dispatch_execbuffer(ring,
> -							exec_start, exec_len);
> +							exec_start, exec_len,
> +							flags);
>  			if (ret)
>  				goto err;
>  		}
>  	} else {
> -		ret = ring->dispatch_execbuffer(ring, exec_start, exec_len);
> +		ret = ring->dispatch_execbuffer(ring,
> +						exec_start, exec_len,
> +						flags);
>  		if (ret)
>  			goto err;
>  	}
> diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
> index 8134421..3db4a68 100644
> --- a/drivers/gpu/drm/i915/i915_trace.h
> +++ b/drivers/gpu/drm/i915/i915_trace.h
> @@ -229,24 +229,26 @@ TRACE_EVENT(i915_gem_evict_everything,
>  );
>  
>  TRACE_EVENT(i915_gem_ring_dispatch,
> -	    TP_PROTO(struct intel_ring_buffer *ring, u32 seqno),
> -	    TP_ARGS(ring, seqno),
> +	    TP_PROTO(struct intel_ring_buffer *ring, u32 seqno, u32 flags),
> +	    TP_ARGS(ring, seqno, flags),
>  
>  	    TP_STRUCT__entry(
>  			     __field(u32, dev)
>  			     __field(u32, ring)
>  			     __field(u32, seqno)
> +			     __field(u32, flags)
>  			     ),
>  
>  	    TP_fast_assign(
>  			   __entry->dev = ring->dev->primary->index;
>  			   __entry->ring = ring->id;
>  			   __entry->seqno = seqno;
> +			   __entry->flags = flags;
>  			   i915_trace_irq_get(ring, seqno);
>  			   ),
>  
> -	    TP_printk("dev=%u, ring=%u, seqno=%u",
> -		      __entry->dev, __entry->ring, __entry->seqno)
> +	    TP_printk("dev=%u, ring=%u, seqno=%u, flags=%x",
> +		      __entry->dev, __entry->ring, __entry->seqno, __entry->flags)
>  );
>  
>  TRACE_EVENT(i915_gem_ring_flush,
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 133beb6..6a4b8fa 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -964,7 +964,9 @@ gen6_ring_put_irq(struct intel_ring_buffer *ring)
>  }
>  
>  static int
> -i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
> +i965_dispatch_execbuffer(struct intel_ring_buffer *ring,
> +			 u32 offset, u32 length,
> +			 unsigned flags)
>  {
>  	int ret;
>  
> @@ -975,7 +977,7 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
>  	intel_ring_emit(ring,
>  			MI_BATCH_BUFFER_START |
>  			MI_BATCH_GTT |
> -			MI_BATCH_NON_SECURE_I965);
> +			(flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE_I965));
>  	intel_ring_emit(ring, offset);
>  	intel_ring_advance(ring);
>  
> @@ -984,7 +986,8 @@ i965_dispatch_execbuffer(struct intel_ring_buffer *ring, u32 offset, u32 length)
>  
>  static int
>  i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
> -				u32 offset, u32 len)
> +				u32 offset, u32 len,
> +				unsigned flags)
>  {
>  	int ret;
>  
> @@ -993,7 +996,7 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
>  		return ret;
>  
>  	intel_ring_emit(ring, MI_BATCH_BUFFER);
> -	intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
> +	intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE));
>  	intel_ring_emit(ring, offset + len - 8);
>  	intel_ring_emit(ring, 0);
>  	intel_ring_advance(ring);
> @@ -1003,7 +1006,8 @@ i830_dispatch_execbuffer(struct intel_ring_buffer *ring,
>  
>  static int
>  i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
> -				u32 offset, u32 len)
> +			 u32 offset, u32 len,
> +			 unsigned flags)
>  {
>  	int ret;
>  
> @@ -1012,7 +1016,7 @@ i915_dispatch_execbuffer(struct intel_ring_buffer *ring,
>  		return ret;
>  
>  	intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_GTT);
> -	intel_ring_emit(ring, offset | MI_BATCH_NON_SECURE);
> +	intel_ring_emit(ring, offset | (flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE));
>  	intel_ring_advance(ring);
>  
>  	return 0;
> @@ -1410,7 +1414,8 @@ static int gen6_ring_flush(struct intel_ring_buffer *ring,
>  
>  static int
>  gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
> -			      u32 offset, u32 len)
> +			      u32 offset, u32 len,
> +			      unsigned flags)
>  {
>  	int ret;
>  
> @@ -1418,7 +1423,9 @@ gen6_ring_dispatch_execbuffer(struct intel_ring_buffer *ring,
>  	if (ret)
>  		return ret;
>  
> -	intel_ring_emit(ring, MI_BATCH_BUFFER_START | MI_BATCH_NON_SECURE_I965);
> +	intel_ring_emit(ring,
> +			MI_BATCH_BUFFER_START |
> +			(flags & I915_DISPATCH_SECURE ? 0 : MI_BATCH_NON_SECURE_I965));
>  	/* bit0-7 is the length on GEN6+ */
>  	intel_ring_emit(ring, offset);
>  	intel_ring_advance(ring);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 40b252e..2667f33 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -81,7 +81,9 @@ struct  intel_ring_buffer {
>  	u32		(*get_seqno)(struct intel_ring_buffer *ring,
>  				     bool lazy_coherency);
>  	int		(*dispatch_execbuffer)(struct intel_ring_buffer *ring,
> -					       u32 offset, u32 length);
> +					       u32 offset, u32 length,
> +					       unsigned flags);
> +#define I915_DISPATCH_SECURE 0x1
>  	void		(*cleanup)(struct intel_ring_buffer *ring);
>  	int		(*sync_to)(struct intel_ring_buffer *ring,
>  				   struct intel_ring_buffer *to,
> diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
> index acfb377..4f41f8d 100644
> --- a/include/drm/i915_drm.h
> +++ b/include/drm/i915_drm.h
> @@ -316,6 +316,7 @@ typedef struct drm_i915_irq_wait {
>  #define I915_PARAM_HAS_SEMAPHORES	 20
>  #define I915_PARAM_HAS_PRIME_VMAP_FLUSH	 21
>  #define I915_PARAM_RSVD_FOR_FUTURE_USE	 22
> +#define I915_PARAM_HAS_SECURE_BATCHES	 23
>  
>  typedef struct drm_i915_getparam {
>  	int param;
> @@ -694,6 +695,11 @@ struct drm_i915_gem_execbuffer2 {
>  /** Resets the SO write offset registers for transform feedback on gen7. */
>  #define I915_EXEC_GEN7_SOL_RESET	(1<<8)
>  
> +/** Request a privileged ("secure") batch buffer. Note only available for
> + * DRM_ROOT_ONLY | DRM_MASTER processes.
> + */
> +#define I915_EXEC_SECURE		(1<<9)
> +
>  #define I915_EXEC_CONTEXT_ID_MASK	(0xffffffff)
>  #define i915_execbuffer2_set_context_id(eb2, context) \
>  	(eb2).rsvd1 = context & I915_EXEC_CONTEXT_ID_MASK

Yeah looks good.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center



More information about the Intel-gfx mailing list