[Intel-gfx] [PATCH v2 5/6] drm/i915: guest i915 notification for Intel GVT-g

[Joonas Lahtinen]

On pe, 2015-08-28 at 15:41 +0800, Zhiyuan Lv wrote:
> When i915 drivers run inside a VM with Intel GVT-g, some explicit
> notifications are needed from guest to host device model through PV
> INFO page write. The notifications include:
> 
> 	PPGTT create
> 	PPGTT destroy
> 
> They are used for the shadow implementation of PPGTT. Intel GVT-g
> needs to write-protect the guest pages of PPGTT, and clear the write
> protection when they end their life cycle.
> 
> v2:
> - Use lower_32_bits()/upper_32_bits() for qword operations;
> - Remove the notification of guest context creation/destroy;
> 
> Signed-off-by: Zhiyuan Lv <zhiyuan.lv at intel.com>
> Signed-off-by: Zhi Wang <zhi.a.wang at intel.com>
> 

Again, as there's really no formal spec of what the hypervisor expects
to see, that part is hard to comment on, so apart from that:

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

PS. Adding people who previously commented on the patch as CC, makes
the reviewing go much smoother (new revisions get picked up faster).

> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 41
> +++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 56cc8e8..df60227 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -899,6 +899,41 @@ static int gen8_init_scratch(struct
> i915_address_space *vm)
>  	return 0;
>  }
>  
> +static int gen8_ppgtt_notify_vgt(struct i915_hw_ppgtt *ppgtt, bool
> create)
> +{
> +	enum vgt_g2v_type msg;
> +	struct drm_device *dev = ppgtt->base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	unsigned int offset = vgtif_reg(pdp0_lo);
> +	int i;
> +
> +	if (USES_FULL_48BIT_PPGTT(dev)) {
> +		u64 daddr = px_dma(&ppgtt->pml4);
> +
> +		I915_WRITE(offset, lower_32_bits(daddr));
> +		I915_WRITE(offset + 4, upper_32_bits(daddr));
> +
> +		msg = (create ? VGT_G2V_PPGTT_L4_PAGE_TABLE_CREATE :
> +				VGT_G2V_PPGTT_L4_PAGE_TABLE_DESTROY)
> ;
> +	} else {
> +		for (i = 0; i < GEN8_LEGACY_PDPES; i++) {
> +			u64 daddr = i915_page_dir_dma_addr(ppgtt,
> i);
> +
> +			I915_WRITE(offset, lower_32_bits(daddr));
> +			I915_WRITE(offset + 4,
> upper_32_bits(daddr));
> +
> +			offset += 8;
> +		}
> +
> +		msg = (create ? VGT_G2V_PPGTT_L3_PAGE_TABLE_CREATE :
> +				VGT_G2V_PPGTT_L3_PAGE_TABLE_DESTROY)
> ;
> +	}
> +
> +	I915_WRITE(vgtif_reg(g2v_notify), msg);
> +
> +	return 0;
> +}
> +
>  static void gen8_free_scratch(struct i915_address_space *vm)
>  {
>  	struct drm_device *dev = vm->dev;
> @@ -945,6 +980,9 @@ static void gen8_ppgtt_cleanup(struct
> i915_address_space *vm)
>  	struct i915_hw_ppgtt *ppgtt =
>  		container_of(vm, struct i915_hw_ppgtt, base);
>  
> +	if (intel_vgpu_active(vm->dev))
> +		gen8_ppgtt_notify_vgt(ppgtt, false);
> +
>  	if (!USES_FULL_48BIT_PPGTT(ppgtt->base.dev))
>  		gen8_ppgtt_cleanup_3lvl(ppgtt->base.dev, &ppgtt
> ->pdp);
>  	else
> @@ -1519,6 +1557,9 @@ static int gen8_ppgtt_init(struct i915_hw_ppgtt
> *ppgtt)
>  		}
>  	}
>  
> +	if (intel_vgpu_active(ppgtt->base.dev))
> +		gen8_ppgtt_notify_vgt(ppgtt, true);
> +
>  	return 0;
>  
>  free_scratch: