Re: [PATCH v4 07/29] drm/i915/gvt: Error out on an attempt to shadowing an unknown GTT entry type

[Yan Zhao]

Reviewed-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>

On Fri, Jul 28, 2023 at 06:35:13PM -0700, Sean Christopherson wrote:
> Bail from ppgtt_populate_shadow_entry() if an unexpected GTT entry type
> is encountered instead of subtly falling through to the common "direct
> shadow" path.  Eliminating the default/error path's reliance on the common
> handling will allow hoisting intel_gvt_dma_map_guest_page() into the case
> statements so that the 2MiB case can try intel_gvt_dma_map_guest_page()
> and fallback to splitting the entry on failure.
> 
> Reviewed-by: Zhi Wang <zhi.a.wang@xxxxxxxxx>
> Tested-by: Yongwei Ma <yongwei.ma@xxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/i915/gvt/gtt.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index 2aed31b497c9..61e38acee2d5 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -1306,6 +1306,7 @@ static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
>  		return -EINVAL;
>  	default:
>  		GEM_BUG_ON(1);
> +		return -EINVAL;
>  	}
>  
>  	/* direct shadow */
> -- 
> 2.41.0.487.g6d72f3e995-goog
>