[PATCH v3] drm/i915/gvt: only copy the first page for restore inhibit context

[Yuan, Hang]

Thanks for the patch. I think it's a good optimization. Acked-by Hang Yuan.

> -----Original Message-----
> From: intel-gvt-dev [mailto:intel-gvt-dev-bounces at lists.freedesktop.org] On
> Behalf Of Zhao Yan
> Sent: Wednesday, August 1, 2018 12:16 PM
> To: intel-gvt-dev at lists.freedesktop.org
> Cc: Zhao, Yan Y <yan.y.zhao at intel.com>
> Subject: [PATCH v3] drm/i915/gvt: only copy the first page for restore inhibit
> context
> 
> if a context is a restore inhibit context, gfx hw only load the first page for
> ring context, so we only need to copy from guest the 1 page too.
> 
> v3: use "return" instead of "goto" for inhibit case. (zhenyu wang)
> v2: move judgement of restore inhibit to a macro in  mmio_context.h
> 
> Signed-off-by: Zhao Yan <yan.y.zhao at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/mmio_context.h |  3 ++
>  drivers/gpu/drm/i915/gvt/scheduler.c    | 60 +++++++++++++------------
>  2 files changed, 34 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.h
> b/drivers/gpu/drm/i915/gvt/mmio_context.h
> index 5c3b9ff9f96a..f7eaa442403f 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio_context.h
> +++ b/drivers/gpu/drm/i915/gvt/mmio_context.h
> @@ -53,5 +53,8 @@ bool is_inhibit_context(struct intel_context *ce);
> 
>  int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
>  				       struct i915_request *req);
> +#define IS_RESTORE_INHIBIT(a)	\
> +	(_MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT)
> == \
> +	((a) &
> _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT)))
> 
>  #endif
> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c
> b/drivers/gpu/drm/i915/gvt/scheduler.c
> index b0e566956b8d..8087354317c2 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -132,35 +132,6 @@ static int populate_shadow_context(struct
> intel_vgpu_workload *workload)
>  	unsigned long context_gpa, context_page_num;
>  	int i;
> 
> -	gvt_dbg_sched("ring id %d workload lrca %x", ring_id,
> -			workload->ctx_desc.lrca);
> -
> -	context_page_num = gvt->dev_priv->engine[ring_id]->context_size;
> -
> -	context_page_num = context_page_num >> PAGE_SHIFT;
> -
> -	if (IS_BROADWELL(gvt->dev_priv) && ring_id == RCS)
> -		context_page_num = 19;
> -
> -	i = 2;
> -
> -	while (i < context_page_num) {
> -		context_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm,
> -				(u32)((workload->ctx_desc.lrca + i) <<
> -				I915_GTT_PAGE_SHIFT));
> -		if (context_gpa == INTEL_GVT_INVALID_ADDR) {
> -			gvt_vgpu_err("Invalid guest context descriptor\n");
> -			return -EFAULT;
> -		}
> -
> -		page = i915_gem_object_get_page(ctx_obj,
> LRC_HEADER_PAGES + i);
> -		dst = kmap(page);
> -		intel_gvt_hypervisor_read_gpa(vgpu, context_gpa, dst,
> -				I915_GTT_PAGE_SIZE);
> -		kunmap(page);
> -		i++;
> -	}
> -
>  	page = i915_gem_object_get_page(ctx_obj, LRC_STATE_PN);
>  	shadow_ring_context = kmap(page);
> 
> @@ -195,6 +166,37 @@ static int populate_shadow_context(struct
> intel_vgpu_workload *workload)
> 
>  	sr_oa_regs(workload, (u32 *)shadow_ring_context, false);
>  	kunmap(page);
> +
> +	if (IS_RESTORE_INHIBIT(shadow_ring_context->ctx_ctrl.val))
> +		return 0;
> +
> +	gvt_dbg_sched("ring id %d workload lrca %x", ring_id,
> +			workload->ctx_desc.lrca);
> +
> +	context_page_num = gvt->dev_priv->engine[ring_id]->context_size;
> +
> +	context_page_num = context_page_num >> PAGE_SHIFT;
> +
> +	if (IS_BROADWELL(gvt->dev_priv) && ring_id == RCS)
> +		context_page_num = 19;
> +
> +	i = 2;
> +	while (i < context_page_num) {
> +		context_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm,
> +				(u32)((workload->ctx_desc.lrca + i) <<
> +				I915_GTT_PAGE_SHIFT));
> +		if (context_gpa == INTEL_GVT_INVALID_ADDR) {
> +			gvt_vgpu_err("Invalid guest context descriptor\n");
> +			return -EFAULT;
> +		}
> +
> +		page = i915_gem_object_get_page(ctx_obj,
> LRC_HEADER_PAGES + i);
> +		dst = kmap(page);
> +		intel_gvt_hypervisor_read_gpa(vgpu, context_gpa, dst,
> +				I915_GTT_PAGE_SIZE);
> +		kunmap(page);
> +		i++;
> +	}
>  	return 0;
>  }
> 
> --
> 2.17.1
> 
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