Re: Proposal for virtual IOMMU binding b/w vIOMMU and passthrough devices

[Elliott Mitchell <ehem+xen@xxxxxxx>]

On Mon, Oct 31, 2022 at 01:26:44PM +0000, Bertrand Marquis wrote:
> 
> > On 30 Oct 2022, at 21:14, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> > 
> > Ideally this would be something quick that can be easily invoked as the
> > first step of an external third-party build process.
> 
> I think that we are making this problem a lot to complex and I am not sure
> that all this complexity is required.

Speaking of complexity.  Is it just me or does a vIOMMU had an odd sort
of similarity with a Grant Table?

Both are about allowing foreign entities access to portions of the
current domain's memory.  Just in the case of a Grant Table the entity
happens to be another domain, whereas for a vIOMMU it is a hardware
device.

Perhaps some functionality could be shared between the two?  Perhaps
this is something for the designer of the next version of IOMMU to think
about?  (or perhaps I'm off the deep end and bringing in a silly idea)


-- 
(\___(\___(\______          --=> 8-) EHM <=--          ______/)___/)___/)
 \BS (    |         ehem+sigmsg@xxxxxxx  PGP 87145445         |    )   /
  \_CS\   |  _____  -O #include <stddisclaimer.h> O-   _____  |   /  _/
8A19\___\_|_/58D2 7E3D DDF4 7BA6 <-PGP-> 41D1 B375 37D0 8714\_|_/___/5445