[PATCH] powerpc/booke: Eliminate rfi from exception entry path.

[Scott Wood]

On 07/10/2012 07:36 PM, Benjamin Herrenschmidt wrote:
> On Tue, 2012-07-10 at 19:34 -0500, Scott Wood wrote:
>> Unlike classic, we don't really need the MSR change to be atomic with the
>> branch.  This eliminates a trap as a KVM guest (in the absence of
>> hardware hypervisor extensions), where mtmsr is paravirtualized but rfi
>> is not.  For a virtualized guest without any paravirtualization, this
>> eliminates an additional two traps (SRR0/1).
> 
> In fact, I wonder, what do we write into the MSR at this point that
> wasn't already in it in BookE ? RI ? I wonder if we could get away
> without the mtmsr alltogether...

Doesn't EE get set there for some exceptions?

-Scott