[Intel-gfx] [PATCH v3 8/8] drm/i915: Support alias ppgtt in VM if ppgtt is enabled

[Tvrtko Ursulin]

On 11/13/2014 12:02 PM, Yu Zhang wrote:
> The current Intel GVT-g only supports alias ppgtt. And the
> emulation is done in the host by first trapping PP_DIR_BASE
> mmio accesses. Updating PP_DIR_BASE by using instructions such
> as MI_LOAD_REGISTER_IMM are hard to detect and are not supported
> in current code. Therefore this patch also added a new callback
> routine - vgpu_mm_switch() to set the PP_DIR_BASE by mmio writes.
>
> v2:
> take Chris' comments:
>          - move the code into sanitize_enable_ppgtt()
>
> Signed-off-by: Yu Zhang <yu.c.zhang at linux.intel.com>
> Signed-off-by: Jike Song <jike.song at intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem_gtt.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 2dfac13..55307eb 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -44,6 +44,9 @@ static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
>   	if (IS_GEN8(dev))
>   		has_full_ppgtt = false; /* XXX why? */
>
> +	if (intel_vgpu_active(dev))
> +		has_full_ppgtt = false; /* emulation is too hard */
> +
>   	if (enable_ppgtt == 0 || !has_aliasing_ppgtt)
>   		return 0;
>
> @@ -733,6 +736,16 @@ static int hsw_mm_switch(struct i915_hw_ppgtt *ppgtt,
>   	return 0;
>   }
>
> +static int vgpu_mm_switch(struct i915_hw_ppgtt *ppgtt,
> +			 struct intel_engine_cs *ring)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(ppgtt->base.dev);
> +
> +	I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
> +	I915_WRITE(RING_PP_DIR_BASE(ring), get_pd_offset(ppgtt));
> +	return 0;
> +}
> +
>   static int gen7_mm_switch(struct i915_hw_ppgtt *ppgtt,
>   			  struct intel_engine_cs *ring)
>   {
> @@ -1059,6 +1072,9 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
>   	} else
>   		BUG();
>
> +	if (intel_vgpu_active(dev))
> +		ppgtt->switch_mm = vgpu_mm_switch;
> +
>   	ret = gen6_ppgtt_alloc(ppgtt);
>   	if (ret)
>   		return ret;
>

Pending potential "checkpatch.pl --strict" fixes,

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>