[RFC] EAL: legacy memory fixed address translations

[Dmitry Kozlyuk]

2022-07-27 17:43 (UTC-0400), Don Wallwork:
> On 7/27/2022 4:36 PM, Dmitry Kozlyuk wrote:
> > I now understand more about_why_  you want this feature
> > but became less confident_what_  do you're proposing specifically.  
> 
> Let me try to give a trivial example of how it would work
> to make sure we're on the same page and then we can get
> back to details..

Thanks you, Don.
Now it's perfectly clear what EAL should do and we can discuss API.

[...]
> So in this example, we have a fixed offset of 9G to translate
> between VA to PA or vice versa.This works whether the huge
> pages happen to be allocated statically (legacy mode) or
> dynamically.

True!

One special case is external memory (rte_extmem_*)
which has user-controlled VA and IOVA.
If all non-external memory is mapped within one VA region,
it is possible to detect that an address is in external memory,
although it's an extra check.