cannot install FreeBSD 12.0 Xen 4.12.1 on Intel Core i7 CPU 930

[Roger Pau Monné]

On Wed, Oct 16, 2019 at 01:09:11PM +0300, Stefan Parvu wrote:
> thank you guys for tips.
> 
> > Are you sure it's VT-d and not VT-x what you have enabled in the BIOS?
> 
> Yes, I think the ASUS BIOS had listed VT-d. But will double check tonight. But it might be 
> that the CPU does not support VT-d. Thats very true. Hmmm. Is there any point even to
> update the CPU on this system, would it even support some new CPU models ? 

I'm afraid I have no idea. I don't deal with hardware setup myself.

> > Linux dom0 would likely be in PV mode (note the missing H), which
> > doesn't require an iommu. OTOH FreeBSD only supports PVH dom0, which
> > does require an iommu.
> 
> Right. It could be tat I was using PV mode (paravirtualisation) mode, without HVM
> extensions which PVH uses. Right ? Thats I cant say. It was some time back. 

So in order to provide an overview:

 - PV doesn't require VT-x nor VT-d.
 - PV guests with pci-passthrough devices require VT-d for safety
   reasons.
 - PVH/HVM require VT-x.
 - PVH dom0 or HVM/PVH guests with pci-passthrough devices require
   both VT-d and VT-x.

Roger.