[PATCH v4 3/3] drm/i915/gvt: init mmio by lri command in vgpu inhibit context

Li, Weinan Z weinan.z.li at intel.com
Fri Feb 23 00:54:52 UTC 2018


-----Original Message-----
From: Zhenyu Wang [mailto:zhenyuw at linux.intel.com] 
Sent: Thursday, February 22, 2018 5:00 PM
To: Li, Weinan Z <weinan.z.li at intel.com>
Cc: intel-gvt-dev at lists.freedesktop.org; Tian, Kevin <kevin.tian at intel.com>
Subject: Re: [PATCH v4 3/3] drm/i915/gvt: init mmio by lri command in vgpu inhibit context

On 2018.02.13 13:24:33 +0800, Weinan Li wrote:
> There is one issue relates to Coarse Power Gating(CPG) on KBL NUC in 
> GVT-g, vgpu can't get the correct default context by updating the 
> registers before inhibit context submission. It always get back the 
> hardware default value unless the inhibit context submission happened 
> before the 1st time forcewake put. With this wrong default context, 
> vgpu will run with incorrect state and meet unknown issues.
> 
> The solution is initialize these mmios by adding lri command in ring 
> buffer of the inhibit context, then gpu hardware has no chance to go 
> down RC6 when lri commands are right being executed, and then vgpu can 
> get correct default context for further use.
> 
> v3:
> - fix code fault, use 'for' to loop through mmio render list(Zhenyu)
> 
> v4:
> - save the count of engine mmio need to be restored for inhibit context and
>   refine some comments. (Kevin)
>

Now this one has conflict with recent i915_request renaming, could you rebase this onto recent staging branch?

Sure, will rebase soon.
> Cc: Kevin Tian <kevin.tian at intel.com>
> Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> Signed-off-by: Weinan Li <weinan.z.li at intel.com>
> ---
>  drivers/gpu/drm/i915/gvt/gvt.h          |   5 +-
>  drivers/gpu/drm/i915/gvt/mmio_context.c | 172 +++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/i915/gvt/mmio_context.h |   3 +
>  drivers/gpu/drm/i915/gvt/scheduler.c    |   5 +
>  4 files changed, 181 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/gvt.h 
> b/drivers/gpu/drm/i915/gvt/gvt.h index 2b28b52..9131638 100644
> --- a/drivers/gpu/drm/i915/gvt/gvt.h
> +++ b/drivers/gpu/drm/i915/gvt/gvt.h
> @@ -310,7 +310,10 @@ struct intel_gvt {
>  	wait_queue_head_t service_thread_wq;
>  	unsigned long service_request;
>  
> -	struct engine_mmio *engine_mmio_list;
> +	struct {
> +		struct engine_mmio *mmio;
> +		int ctx_mmio_count[I915_NUM_ENGINES];
> +	} engine_mmio_list;
>  
>  	struct dentry *debugfs_root;
>  };
> diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c 
> b/drivers/gpu/drm/i915/gvt/mmio_context.c
> index c391c96..2aa564e 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio_context.c
> +++ b/drivers/gpu/drm/i915/gvt/mmio_context.c
> @@ -188,6 +188,153 @@ static void load_render_mocs(struct drm_i915_private *dev_priv)
>  	gen9_render_mocs.initialized = true;  }
>  
> +static int
> +restore_context_mmio_for_inhibit(struct intel_vgpu *vgpu,
> +				 struct drm_i915_gem_request *req) {
> +	u32 *cs;
> +	int ret;
> +	struct engine_mmio *mmio;
> +	struct intel_gvt *gvt = vgpu->gvt;
> +	int ring_id = req->engine->id;
> +	int count = gvt->engine_mmio_list.ctx_mmio_count[ring_id];
> +
> +	if (count == 0)
> +		return 0;
> +
> +	ret = req->engine->emit_flush(req, EMIT_BARRIER);
> +	if (ret)
> +		return ret;
> +
> +	cs = intel_ring_begin(req, count * 2 + 2);
> +	if (IS_ERR(cs))
> +		return PTR_ERR(cs);
> +
> +	*cs++ = MI_LOAD_REGISTER_IMM(count);
> +	for (mmio = gvt->engine_mmio_list.mmio;
> +	     i915_mmio_reg_valid(mmio->reg); mmio++) {
> +		if (mmio->ring_id != ring_id ||
> +		    !mmio->in_context)
> +			continue;
> +
> +		*cs++ = i915_mmio_reg_offset(mmio->reg);
> +		*cs++ = vgpu_vreg_t(vgpu, mmio->reg) |
> +				(mmio->mask << 16);
> +		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
> +			      *(cs-2), *(cs-1), vgpu->id, ring_id);
> +	}
> +
> +	*cs++ = MI_NOOP;
> +	intel_ring_advance(req, cs);
> +
> +	ret = req->engine->emit_flush(req, EMIT_BARRIER);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int
> +restore_render_mocs_control_for_inhibit(struct intel_vgpu *vgpu,
> +					struct drm_i915_gem_request *req) {
> +	unsigned int index;
> +	u32 *cs;
> +
> +	cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE + 2);
> +	if (IS_ERR(cs))
> +		return PTR_ERR(cs);
> +
> +	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE);
> +
> +	for (index = 0; index < GEN9_MOCS_SIZE; index++) {
> +		*cs++ = i915_mmio_reg_offset(GEN9_GFX_MOCS(index));
> +		*cs++ = vgpu_vreg_t(vgpu, GEN9_GFX_MOCS(index));
> +		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
> +			      *(cs-2), *(cs-1), vgpu->id, req->engine->id);
> +
> +	}
> +
> +	*cs++ = MI_NOOP;
> +	intel_ring_advance(req, cs);
> +
> +	return 0;
> +}
> +
> +static int
> +restore_render_mocs_l3cc_for_inhibit(struct intel_vgpu *vgpu,
> +				     struct drm_i915_gem_request *req) {
> +	unsigned int index;
> +	u32 *cs;
> +
> +	cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE / 2 + 2);
> +	if (IS_ERR(cs))
> +		return PTR_ERR(cs);
> +
> +	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE / 2);
> +
> +	for (index = 0; index < GEN9_MOCS_SIZE / 2; index++) {
> +		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(index));
> +		*cs++ = vgpu_vreg_t(vgpu, GEN9_LNCFCMOCS(index));
> +		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
> +			      *(cs-2), *(cs-1), vgpu->id, req->engine->id);
> +
> +	}
> +
> +	*cs++ = MI_NOOP;
> +	intel_ring_advance(req, cs);
> +
> +	return 0;
> +}
> +
> +/*
> + * Use lri command to initialize the mmio which is in context state 
> +image for
> + * inhibit context, it contains tracked engine mmio, render_mocs and
> + * render_mocs_l3cc.
> + */
> +int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
> +				       struct drm_i915_gem_request *req) {
> +	int ret;
> +	u32 *cs;
> +
> +	cs = intel_ring_begin(req, 2);
> +	if (IS_ERR(cs))
> +		return PTR_ERR(cs);
> +
> +	*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
> +	*cs++ = MI_NOOP;
> +	intel_ring_advance(req, cs);
> +
> +	ret = restore_context_mmio_for_inhibit(vgpu, req);
> +	if (ret)
> +		goto out;
> +
> +	/* no MOCS register in context except render engine */
> +	if (req->engine->id != RCS)
> +		goto out;
> +
> +	ret = restore_render_mocs_control_for_inhibit(vgpu, req);
> +	if (ret)
> +		goto out;
> +
> +	ret = restore_render_mocs_l3cc_for_inhibit(vgpu, req);
> +	if (ret)
> +		goto out;
> +
> +out:
> +	cs = intel_ring_begin(req, 2);
> +	if (IS_ERR(cs))
> +		return PTR_ERR(cs);
> +
> +	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
> +	*cs++ = MI_NOOP;
> +	intel_ring_advance(req, cs);
> +
> +	return ret;
> +}
> +
>  static void handle_tlb_pending_event(struct intel_vgpu *vgpu, int 
> ring_id)  {
>  	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv; @@ -254,6 
> +401,9 @@ static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next,
>  	if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
>  		return;
>  
> +	if (IS_KABYLAKE(dev_priv) && ring_id == RCS)
> +		return;
> +
>  	if (!pre && !gen9_render_mocs.initialized)
>  		load_render_mocs(dev_priv);
>  
> @@ -320,10 +470,18 @@ static void switch_mmio(struct intel_vgpu *pre,
>  	if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
>  		switch_mocs(pre, next, ring_id);
>  
> -	for (mmio = dev_priv->gvt->engine_mmio_list;
> +	for (mmio = dev_priv->gvt->engine_mmio_list.mmio;
>  	     i915_mmio_reg_valid(mmio->reg); mmio++) {
>  		if (mmio->ring_id != ring_id)
>  			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
> +		 * save or restore with context together.
> +		 */
> +		if (IS_KABYLAKE(dev_priv) && mmio->in_context)
> +			continue;
> +
>  		// save
>  		if (pre) {
>  			vgpu_vreg_t(pre, mmio->reg) = I915_READ_FW(mmio->reg); @@ -412,8 
> +570,16 @@ void intel_gvt_switch_mmio(struct intel_vgpu *pre,
>   */
>  void intel_gvt_init_engine_mmio_context(struct intel_gvt *gvt)  {
> +	struct engine_mmio *mmio;
> +
>  	if (IS_SKYLAKE(gvt->dev_priv) || IS_KABYLAKE(gvt->dev_priv))
> -		gvt->engine_mmio_list = gen9_engine_mmio_list;
> +		gvt->engine_mmio_list.mmio = gen9_engine_mmio_list;
>  	else
> -		gvt->engine_mmio_list = gen8_engine_mmio_list;
> +		gvt->engine_mmio_list.mmio = gen8_engine_mmio_list;
> +
> +	for (mmio = gvt->engine_mmio_list.mmio;
> +	     i915_mmio_reg_valid(mmio->reg); mmio++) {
> +		if (mmio->in_context)
> +			gvt->engine_mmio_list.ctx_mmio_count[mmio->ring_id]++;
> +	}
>  }
> diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.h 
> b/drivers/gpu/drm/i915/gvt/mmio_context.h
> index 4df87c7..0b1d985 100644
> --- a/drivers/gpu/drm/i915/gvt/mmio_context.h
> +++ b/drivers/gpu/drm/i915/gvt/mmio_context.h
> @@ -51,4 +51,7 @@ void intel_gvt_switch_mmio(struct intel_vgpu *pre,
>  
>  bool is_inhibit_context(struct i915_gem_context *ctx, int ring_id);
>  
> +int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
> +				       struct drm_i915_gem_request *req);
> +
>  #endif
> diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c 
> b/drivers/gpu/drm/i915/gvt/scheduler.c
> index 9a64bd0..439f3a1 100644
> --- a/drivers/gpu/drm/i915/gvt/scheduler.c
> +++ b/drivers/gpu/drm/i915/gvt/scheduler.c
> @@ -225,6 +225,11 @@ static int copy_workload_to_ring_buffer(struct intel_vgpu_workload *workload)
>  	struct intel_vgpu *vgpu = workload->vgpu;
>  	void *shadow_ring_buffer_va;
>  	u32 *cs;
> +	struct drm_i915_gem_request *req = workload->req;
> +
> +	if (IS_KABYLAKE(req->i915) &&
> +	    is_inhibit_context(req->ctx, req->engine->id))
> +		intel_vgpu_restore_inhibit_context(vgpu, req);
>  
>  	/* allocate shadow ring buffer */
>  	cs = intel_ring_begin(workload->req, workload->rb_len / 
> sizeof(u32));
> --
> 1.9.1
> 
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