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

Tue Apr 30 08:51:38 UTC 2019

> -----Original Message-----
> From: intel-gvt-dev [mailto:intel-gvt-dev-bounces at lists.freedesktop.org] On
> Behalf Of Zhenyu Wang
> Sent: Tuesday, April 30, 2019 4:24 PM
> To: Li, Weinan Z <weinan.z.li at intel.com>
> Cc: intel-gvt-dev at lists.freedesktop.org; Zhao, Yan Y <yan.y.zhao at intel.com>
> Subject: Re: [PATCH v3 1/4] drm/i915/gvt: use cmd to restore in-context
> mmios to hw for gen9 platform
> 
> On 2019.04.29 08:38:59 +0000, Li, Weinan Z wrote:
> > > -----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.
> >
> 
> Why it is not skipped on SKL now?
Well. It's a long story. Basically I just skip it on KBL, but do not on the other platforms. Then BXT, CFL platforms enabled, it was added during the enable process.

> 
> > > 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
> >
> > _______________________________________________
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> > intel-gvt-dev at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
> 
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