[PATCH 0/2] arm64: PMU: Sanitize usage of PMSELR_EL0.SEL

[Itaru Kitayama]

Successfully verified them on a Rev B0 CPU. Thank you for quickly 
providing the fix.

On 2016/12/03 0:50, Marc Zyngier wrote:
> An ugly interaction between the use of PMSELR_EL0 in a host kernel and
> the use of PMXEVCNTR_EL0 in a guest has recently come to light [1],
> leading to the guest taking an UNDEF exception in EL1 when using the
> PMU.
>
> The fix is pretty simple ("don't do that!"), making the PMU useable on
> X-Gene, which seems to have a stricter (but nonetheless valid)
> interpretation of the architecture.
>
> Patches against 4.9-rc6.
>
> [1] https://lists.cs.columbia.edu/pipermail/kvmarm/2016-November/022545.html
>
> Marc Zyngier (2):
>   arm64: PMU: Do not use PMSELR_EL0 to access PMCCFILTR_EL0
>   arm64: PMU: Reset PMSELR_EL0 to a sane value at boot time
>
>  arch/arm64/kernel/perf_event.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>