Re: [Qemu-devel] [PATCH v5 15/18] intel_iommu: introduce IEC notifiers

[Peter Xu]

On Thu, Apr 28, 2016 at 09:26:01AM +0200, Jan Kiszka wrote:
> On 2016-04-28 09:05, Peter Xu wrote:
> > This patch introduces Intel VT-d IEC (Interrupt Entry Cache)
> > invalidation notifier list. When vIOMMU receives IEC invalidate request,
> > all the registered units will be notified with specific invalidation
> > requests.
> 
> This should be designed to be IOMMU-agnostic, i.e. become reusable for
> the AMD implementation. I suspect we will have the same need for route
> invalidations there as well...

Yes possibly...

I feel like there are lots of things that can be shared between
Intel and AMD IOMMUs. I just do not know what is the most suitable
"extent" that we should abstract these shared functionalities
between the two, and how.

For example, AFAIU, a better solution for current IOMMU
codes (including Intel and AMD) is to provide a common framework
(like...  X86IOMMU?), abstract these shared things out into a
framework, like per device name spaces, iotlb, IEC notifications,
etc... However, that will need a lot of further work. Also, I still
do not know whether this is a good idea even in the future.

So, will this be a good point that we start to think about common
code blocks for both Intel and AMD IOMMU?

Thanks,

-- peterx