[PATCH v1 3/5] drm/i915/gvt: GVTg support context submission pvmmio optimization

[Zhenyu Wang]

On 2018.11.05 17:20:47 +0800, Xiaolin Zhang wrote:
> implemented context submission pvmmio optimizaiton with GVTg.
> 
> GVTg to read context submission data (elsp_data) from the shared_page
> directly without trap cost to improve guest GPU peformrnace.
> 
> v1: rebase
> v0: RFC
> 
> Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> Cc: Zhi Wang <zhi.a.wang at intel.com>
> Cc: Min He<min.he at intel.com>
> Cc: Fei Jiang <fei.jiang at intel.com>
> Cc: Zhipeng Gong <zhipeng.gong at intel.com>
> Cc: Hang Yuan <hang.yuan at intel.com>
> Cc: Zhiyuan Lv <zhiyuan.lv at intel.com>
> Signed-off-by: Xiaolin Zhang <xiaolin.zhang at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/handlers.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/handlers.c b/drivers/gpu/drm/i915/gvt/handlers.c
> index bf14c66..cd3b602 100644
> --- a/drivers/gpu/drm/i915/gvt/handlers.c
> +++ b/drivers/gpu/drm/i915/gvt/handlers.c
> @@ -1667,6 +1667,8 @@ static int elsp_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
>  	int ring_id = intel_gvt_render_mmio_to_ring_id(vgpu->gvt, offset);
>  	struct intel_vgpu_execlist *execlist;
>  	u32 data = *(u32 *)p_data;
> +	u32 elsp_data[4];
> +	u32 elsp_data_off;
>  	int ret = 0;
>  
>  	if (WARN_ON(ring_id < 0 || ring_id >= I915_NUM_ENGINES))
> @@ -1674,6 +1676,16 @@ static int elsp_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
>  
>  	execlist = &vgpu->submission.execlist[ring_id];
>  
> +	if (VGPU_PVMMIO(vgpu) & PVMMIO_ELSP_SUBMIT) {
> +		elsp_data_off = offsetof(struct gvt_shared_page, elsp_data);
> +		intel_gvt_read_shared_page(vgpu, elsp_data_off, &elsp_data, 16);
> +		execlist->elsp_dwords.data[3] = elsp_data[0];
> +		execlist->elsp_dwords.data[2] = elsp_data[1];
> +		execlist->elsp_dwords.data[1] = elsp_data[2];
> +		execlist->elsp_dwords.data[0] = data;
> +		return intel_vgpu_submit_execlist(vgpu, ring_id);
> +	}

I think we still need to do more check, e.g if ctx address is in valid vgpu range, etc?

> +
>  	execlist->elsp_dwords.data[3 - execlist->elsp_dwords.index] = data;
>  	if (execlist->elsp_dwords.index == 3) {
>  		ret = intel_vgpu_submit_execlist(vgpu, ring_id);
> -- 
> 2.7.4
> 

-- 
Open Source Technology Center, Intel ltd.

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