[PATCH v1 2/2] drm/i915: enable vGPU 48bit full PPGTT support

[Zhang, Tina]

> -----Original Message-----
> From: Zhenyu Wang [mailto:zhenyuw at linux.intel.com]
> Sent: Friday, May 5, 2017 12:55 PM
> To: Zhang, Tina <tina.zhang at intel.com>
> Cc: intel-gvt-dev at lists.freedesktop.org
> Subject: Re: [PATCH v1 2/2] drm/i915: enable vGPU 48bit full PPGTT support
> 
> On 2017.05.04 17:35:10 +0800, Tina Zhang wrote:
> > This patch is to enable the vGPU 48bit full ppgtt support.
> >
> > Signed-off-by: Tina Zhang <tina.zhang at intel.com>
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > index 8bab4ae..92df4c4 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> > @@ -141,12 +141,6 @@ int intel_sanitize_enable_ppgtt(struct
> drm_i915_private *dev_priv,
> >  	has_full_ppgtt = dev_priv->info.has_full_ppgtt;
> >  	has_full_48bit_ppgtt = dev_priv->info.has_full_48bit_ppgtt;
> >
> > -	if (intel_vgpu_active(dev_priv)) {
> > -		/* emulation is too hard */
> > -		has_full_ppgtt = false;
> > -		has_full_48bit_ppgtt = false;
> > -	}
> > -
> >  	if (!has_aliasing_ppgtt)
> >  		return 0;
> >
> 
> What if you run new kernel with this change on older gvt kernel?
The issue may come out again which may lead to GPU hang.

> We need compat check.
Do you mean we need a flag in pvinfo to tell the guest whether enabling the full ppgtt feature is allowed?


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