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Re: Keystone Issue





On 10/06/2020 13:39, CodeWiz2280 wrote:
So the only way to solve this is actually to do the interrupt
deactivate inside Xen (using a maintenance interrupt).

That's a terrible hack, and one that would encourage badly integrated HW.
I appreciate the need to "make things work", but I'd be wary of putting
this in released SW. Broken HW must die. I have written more than my share
of these terrible hacks (see TX1 support), and I deeply regret it, as
it has only given Si vendors an excuse not to fix things.

Fully agree and I also had to do some hacks for the TX1 ;-)


I remember that I also had to do something specific for the
configuration of edge/level and priorities to have an almost proper
behaviour.

Well, the moment the GIC observes secure accesses when they should be
non-secure, all bets are off and you have to resort to the above hacks.
The fun part is that if you have secure SW running on this platform,
you can probably DoS it from non-secure. It's good, isn't it?

Definitely is but if I remember correctly they have 2 kind of SoC: one that can 
be only used in non-secure and an other which is meant to be use with secure 
and non secure.

Bertrand


Sadly I have no access to the code anymore, so I would need to guess
back what that was..

I'd say this *is* a good thing.
The problem is that a hack may be my only solution to getting this
working on this platform.  If TI says that they don't support it then
i'm stuck.

OOI, what's your end goal for Xen on Keystone?

Cheers,

--
Julien Grall



 


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