Re: [PATCH 08/13] drm/i915: Enable register whitelist checks

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 29 Jan 2014, bradley.d.volkin@intel.com wrote:
> From: Brad Volkin <bradley.d.volkin@intel.com>
>
> MI_STORE_REGISTER_MEM, MI_LOAD_REGISTER_MEM, and MI_LOAD_REGISTER_IMM
> commands allow userspace access to registers. Only certain registers
> should be allowed for such access, so enable checking for those commands.
> Each ring gets its own register whitelist.
>
> MI_LOAD_REGISTER_REG on HSW also allows register access but is currently
> unused by userspace components. Leave it rejected.
>
> PIPE_CONTROL and MEDIA_VFE_STATE allow register access based on certain
> bits being set. Reject those as well.
>
> OTC-Tracker: AXIA-4631
> Change-Id: Ie614a2f0eb2e5917de809e5a17957175d24cc44f
> Signed-off-by: Brad Volkin <bradley.d.volkin@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_cmd_parser.c | 23 ++++++++++++++++++++---
>  drivers/gpu/drm/i915/i915_reg.h        |  3 +++
>  2 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
> index 296e322..5d3e303 100644
> --- a/drivers/gpu/drm/i915/i915_cmd_parser.c
> +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
> @@ -63,9 +63,12 @@ static const struct drm_i915_cmd_descriptor common_cmds[] = {
>  	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
>  	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
>  	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
> -	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   R  ),
> -	CMD(  MI_STORE_REGISTER_MEM(1),         SMI,   !F,  0xFF,   R  ),
> -	CMD(  MI_LOAD_REGISTER_MEM,             SMI,   !F,  0xFF,   R  ),
> +	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
> +	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
> +	CMD(  MI_STORE_REGISTER_MEM(1),         SMI,   !F,  0xFF,   W,
> +	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
> +	CMD(  MI_LOAD_REGISTER_MEM,             SMI,   !F,  0xFF,   W,
> +	      .reg = { .offset = 1, .mask = 0x007FFFFC }               ),
>  	CMD(  MI_BATCH_BUFFER_START,            SMI,   !F,  0xFF,   S  ),
>  };
>  
> @@ -82,9 +85,23 @@ static const struct drm_i915_cmd_descriptor render_cmds[] = {
>  	CMD(  MI_CONDITIONAL_BATCH_BUFFER_END,  SMI,   !F,  0xFF,   S  ),
>  	CMD(  GFX_OP_3DSTATE_VF_STATISTICS,     S3D,    F,  1,      S  ),
>  	CMD(  PIPELINE_SELECT,                  S3D,    F,  1,      S  ),
> +	CMD(  MEDIA_VFE_STATE,			S3D,   !F,  0xFFFF, B,
> +	      .bits = {{
> +			.offset = 2,
> +			.mask = MEDIA_VFE_STATE_MMIO_ACCESS_MASK,
> +			.expected = 0
> +	      }},
> +	      .bits_count = 1					       ),

>From my bikeshedding dept.: here too I think it would be beneficial to
have the count decided by an empty element, or a .valid = 1 field or
something.


>  	CMD(  GPGPU_OBJECT,                     S3D,   !F,  0xFF,   S  ),
>  	CMD(  GPGPU_WALKER,                     S3D,   !F,  0xFF,   S  ),
>  	CMD(  GFX_OP_3DSTATE_SO_DECL_LIST,      S3D,   !F,  0x1FF,  S  ),
> +	CMD(  GFX_OP_PIPE_CONTROL(5),           S3D,   !F,  0xFF,   B,
> +	      .bits = {{
> +			.offset = 1,
> +			.mask = PIPE_CONTROL_MMIO_WRITE,
> +			.expected = 0
> +	      }},
> +	      .bits_count = 1					       ),
>  };
>  
>  static const struct drm_i915_cmd_descriptor hsw_render_cmds[] = {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index b99bacf..6592d0d 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -319,6 +319,7 @@
>  #define   DISPLAY_PLANE_B           (1<<20)
>  #define GFX_OP_PIPE_CONTROL(len)	((0x3<<29)|(0x3<<27)|(0x2<<24)|(len-2))
>  #define   PIPE_CONTROL_GLOBAL_GTT_IVB			(1<<24) /* gen7+ */
> +#define   PIPE_CONTROL_MMIO_WRITE			(1<<23)
>  #define   PIPE_CONTROL_CS_STALL				(1<<20)
>  #define   PIPE_CONTROL_TLB_INVALIDATE			(1<<18)
>  #define   PIPE_CONTROL_QW_WRITE				(1<<14)
> @@ -359,6 +360,8 @@
>  
>  #define PIPELINE_SELECT                ((0x3<<29)|(0x1<<27)|(0x1<<24)|(0x4<<16))
>  #define GFX_OP_3DSTATE_VF_STATISTICS   ((0x3<<29)|(0x1<<27)|(0x0<<24)|(0xB<<16))
> +#define MEDIA_VFE_STATE                ((0x3<<29)|(0x2<<27)|(0x0<<24)|(0x0<<16))
> +#define  MEDIA_VFE_STATE_MMIO_ACCESS_MASK (0x18)
>  #define GPGPU_OBJECT                   ((0x3<<29)|(0x2<<27)|(0x1<<24)|(0x4<<16))
>  #define GPGPU_WALKER                   ((0x3<<29)|(0x2<<27)|(0x1<<24)|(0x5<<16))
>  #define GFX_OP_3DSTATE_DX9_CONSTANTF_VS \
> -- 
> 1.8.5.2
>
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-- 
Jani Nikula, Intel Open Source Technology Center