[Intel-gfx] [PATCH 1/5] drm/i915: make intel_gvt_init() later instead of too early

[Zhenyu Wang]

On 2017.01.11 11:13:06 +0800, Jike Song wrote:
> On 01/10/2017 02:52 PM, Zhenyu Wang wrote:
> > Previously intel_gvt_init() was called very early even before
> > MMIO initialization which had several drawbacks:
> > - Have to handle MMIO access for initial MMIO state dump if golden
> >   state firmware is not available
> > - Hypervisor detection should depend on pvinfo only instead of detecting
> >   hypervisor status.
> > - Don't know hw resource size e.g aperture, ggtt size to determine
> >   for vGPU type, etc.
> > 
> > This trys to move intel_gvt_init() call late after required info
> > has already been initialized for GVT host.
> > 
> > Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/gvt/gvt.c   | 20 ++++++++------------
> >  drivers/gpu/drm/i915/i915_drv.c  | 14 +++++++-------
> >  drivers/gpu/drm/i915/intel_gvt.c |  5 +++++
> >  3 files changed, 20 insertions(+), 19 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gvt/gvt.c b/drivers/gpu/drm/i915/gvt/gvt.c
> > index e6bf5c533fbe..35264a991776 100644
> > --- a/drivers/gpu/drm/i915/gvt/gvt.c
> > +++ b/drivers/gpu/drm/i915/gvt/gvt.c
> > @@ -73,23 +73,19 @@ int intel_gvt_init_host(void)
> >  	if (intel_gvt_host.initialized)
> >  		return 0;
> >  
> > -	/* Xen DOM U */
> > -	if (xen_domain() && !xen_initial_domain())
> > -		return -ENODEV;
> > -
> >  	/* Try to load MPT modules for hypervisors */
> > -	if (xen_initial_domain()) {
> > +#if IS_ENABLED(CONFIG_DRM_I915_GVT_KVMGT)
> > +	/* Try KVMGT */
> > +	intel_gvt_host.mpt = try_then_request_module(
> > +		symbol_get(kvmgt_mpt), "kvmgt");
> > +	intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_KVM;
> > +#endif
> > +
> > +	if (!intel_gvt_host.mpt && xen_initial_domain()) {
> >  		/* In Xen dom0 */
> >  		intel_gvt_host.mpt = try_then_request_module(
> >  				symbol_get(xengt_mpt), "xengt");
> >  		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_XEN;
> > -	} else {
> > -#if IS_ENABLED(CONFIG_DRM_I915_GVT_KVMGT)
> > -		/* not in Xen. Try KVMGT */
> > -		intel_gvt_host.mpt = try_then_request_module(
> > -				symbol_get(kvmgt_mpt), "kvmgt");
> > -		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_KVM;
> > -#endif
> >  	}
> >  
> 
> Hi Zhenyu,
> 
> It is always easy for xengt to detect dom0 case, but difficult for kvmgt
> to detect host, so I guess xen_initial_domain() should be removed from here,
> and placed in xengt.ko.
> 
> [xengt.ko]
> 
> 	static int __init xengt_init(void)
> 	{
> 	       if (!xen_initial_domain())
> 		       return -EINVAL;
> 		...
> 
> [gvt]
> 	request xengt_mpt
> 	if (failed)
> 		request kvmgt_mpt
> 
> With logic above, we can avoid calling xen_initial_domain(), and remove
> "#include <xen/xen.h>" from gvt.c.
> 
> What'd you say? :)
> 

yep, sounds good to me.

-- 
Open Source Technology Center, Intel ltd.

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