From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Zhang, Xiantao" <xiantao.zhang@intel.com>
Subject: Re: iommu=dom0-passthrough behavior
Date: Fri, 16 Nov 2012 06:21:59 +0000
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To: Jan Beulich <JBeulich@suse.com>, "Zhang, Yang Z" <yang.z.zhang@intel.com>
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> >> Which, if I'm not mistaken, could be implemented entirely independent
> >> of "iommu=dom0-passthrough". I'll see if that helps on the offending
> system.
> >
> > I mean this one:
> >>>c) we could provide a command line option to allow fake devices to be
> >>>create
> >
> > Yes,  I don't think "iommu=dom0-passthrough" can meet your requirement.
> >  We had better add a cmd line option to  pass the related information
> > to hypervisor and VT-d can create the pass-through context entry  for
> > the undetectable device.
> 
> You misunderstood: What I was saying (and seeking confirmation) is that I
> don't think the new command line option would need to have any
> connection to the existing, non-suitable one. In particular, for it to take effect,
> "iommu=dom0-passthrough"
> wouldn't need to be specified at all.
Okay.  Back to your customer's issue, I don't think we have a clean solution if the device can't be detected by hypervisor.   We only can figure out how to workaround this issue through a new command line option.  
BTW,   if the device can't be detected,  how to load its driver by OS ?  
Xiantao