Re: [Qemu-devel] [PATCH v6 1/3] IOMMU: add option to enable VTD_CAP_CM to vIOMMU capility exposoed to guest

[Michael S. Tsirkin]

On Tue, Nov 22, 2016 at 12:11:21PM +0800, Jason Wang wrote:
> Yes, that's the interesting point. The fault is not guaranteed but
> conditional. And we have similar issue for IEC.
> 
> So in conclusion (since I can't find a hardware IOMMU that have CM set):
> 
> 1) If we don't cache fault conditions, we are still in question that whether
> it was spec compatible.
> 2) If we do cache fault conditions, we are 100% sure it was spec compatible.
> 
> Consider 2) is not complicated, we'd better do it I believe?
> 
> Thanks

IMO it's just a confusing jargon used by intel architects.
CM is there exactly so you can shadow the tables, but
they were trying hard to use wording that also makes
sense to hardware/driver developers.

Nothing to worry about.

-- 
MST