[PATCH v3 1/4] drm/i915/gvt: use cmd to restore in-context mmios to hw for gen9 platform

[Li, Weinan Z]

> -----Original Message-----
> From: Zhao, Yan Y
> Sent: Monday, April 29, 2019 4:13 PM
> To: intel-gvt-dev at lists.freedesktop.org
> Cc: Zhao, Yan Y <yan.y.zhao at intel.com>; Li, Weinan Z <weinan.z.li at intel.com>
> Subject: [PATCH v3 1/4] drm/i915/gvt: use cmd to restore in-context mmios
> to hw for gen9 platform
> 
> for restore-inhibit context, hardware will not load in-context mmios (engine
> context part) to hardware, but hardware will save the mmio values in
> hardware back to context image. So, in order to save correct values of vGPU
> back to context image, values of vGPU mmios have to be loaded into
> hardware first for restore-inhibit context.
> 
> In this patch, the mechanism is applied to all gen9 platform.
> 
> The reason excluding gen8 platforms is only because of lacking of testing on
> those platforms.
> 
> v2: update vreg when scanning indirect context for inhibit context for
> gen9
> 
> Cc: Weinan Li <weinan.z.li at intel.com>
> Signed-off-by: Yan Zhao <yan.y.zhao at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/cmd_parser.c   | 14 +++++++++-----
>  drivers/gpu/drm/i915/gvt/mmio_context.c |  5 ++---
>  drivers/gpu/drm/i915/gvt/scheduler.c    |  4 +---
>  3 files changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c
> b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> index ab002cfd3cab..5cb59c0b4bbe 100644
> --- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
> +++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
> @@ -896,12 +896,16 @@ static int cmd_reg_handler(struct
> parser_exec_state *s,
>  	}
> 
>  	/* TODO
> -	 * Right now only scan LRI command on KBL and in inhibit context.
> -	 * It's good enough to support initializing mmio by lri command in
> -	 * vgpu inhibit context on KBL.
> +	 * In order to let workload with inhibit context to generate
> +	 * correct image data into memory, vregs values will be loaded to
> +	 * hw via LRIs in the workload with inhibit context. But as
> +	 * indirect context is loaded prior to LRIs in workload, we don't
> +	 * want reg values specified in indirect context overwritten by
> +	 * LRIs in workloads. So, when scanning an indirect context, we
> +	 * update reg values in it into vregs, so LRIs in workload with
> +	 * inhibit context will restore with correct values
>  	 */
> -	if ((IS_KABYLAKE(s->vgpu->gvt->dev_priv)
> -		|| IS_COFFEELAKE(s->vgpu->gvt->dev_priv)) &&
> +	if (IS_GEN(gvt->dev_priv, 9) &&
>  			intel_gvt_mmio_is_in_ctx(gvt, offset) &&
>  			!strncmp(cmd, "lri", 3)) {
>  		intel_gvt_hypervisor_read_gpa(s->vgpu,
> diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c
> b/drivers/gpu/drm/i915/gvt/mmio_context.c
> index e7e14c842be4..a51c51b2c82e 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio_context.c
> +++ b/drivers/gpu/drm/i915/gvt/mmio_context.c
> @@ -469,11 +469,10 @@ static void switch_mmio(struct intel_vgpu *pre,
>  			continue;
>  		/*
>  		 * No need to do save or restore of the mmio which is in context
> -		 * state image on kabylake, it's initialized by lri command and
> +		 * state image on gen9, it's initialized by lri command and
>  		 * save or restore with context together.
>  		 */
> -		if ((IS_KABYLAKE(dev_priv) || IS_BROXTON(dev_priv)
> -			|| IS_COFFEELAKE(dev_priv)) && mmio->in_context)
> +		if (IS_GEN(dev_priv, 9) && mmio->in_context)
>  			continue;
> 
>  		// save

@@ -392,9 +392,7 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next,
                return;

        if (ring_id == RCS0 &&
-           (IS_KABYLAKE(dev_priv) ||
-            IS_BROXTON(dev_priv) ||
-            IS_COFFEELAKE(dev_priv)))
+           IS_GEN(dev_priv, 9))
                return;
we can ignore the MOCS save/restore if it's RCS, since it's in context MMIO.

> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c
> b/drivers/gpu/drm/i915/gvt/scheduler.c
> index 8998fa5ab198..1f3ba8efb994 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -299,9 +299,7 @@ static int copy_workload_to_ring_buffer(struct
> intel_vgpu_workload *workload)
>  	void *shadow_ring_buffer_va;
>  	u32 *cs;
> 
> -	if ((IS_KABYLAKE(req->i915) || IS_BROXTON(req->i915)
> -		|| IS_COFFEELAKE(req->i915))
> -		&& is_inhibit_context(req->hw_context))
> +	if (IS_GEN(req->i915, 9) && is_inhibit_context(req->hw_context))
>  		intel_vgpu_restore_inhibit_context(vgpu, req);
> 
>  	/* allocate shadow ring buffer */
> --
> 2.17.1