Subject: Re: [PATCH 1/3] powerpc/kvm: Remove redundant save of SIER AND MMCR2

From: Michael Ellerman <[email-masked]>
Date: Fri, 04 Jul 2014 12:16:49 +1000

On Thu, 2014-07-03 at 15:42 +0930, Joel Stanley wrote:
> These two registers are already saved in the block above. Aside from
> being unnecessary, by the time we get down to the second save location
> r8 no longer contains MMCR2, so we are clobbering the saved value with
> PMC5.

MMCR2 primarily consists of counter freeze bits. So restoring the value of PMC5
into MMCR2 will most likely have the effect of freezing counters.

Fixes: 72cde5a88d37 ("KVM: PPC: Book3S HV: Save/restore host PMU registers that are new in POWER8")
Cc: [email-masked]

With the above added:

Acked-by: Michael Ellerman <[email-masked]>

cheers