On Mon, 2014-06-30 at 15:55 +0300, Mihai Caraman wrote: > For FSL e6500 core the kernel uses power management SPR register (PWRMGTCR0) > to enable idle power down for cores and devices by setting up the idle count > period at boot time. With the host already controlling the power management > configuration the guest could simply benefit from it, so emulate guest request > as nop. > > Signed-off-by: Mihai Caraman <mihai.cara...@freescale.com> > --- > arch/powerpc/kvm/e500_emulate.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/powerpc/kvm/e500_emulate.c b/arch/powerpc/kvm/e500_emulate.c > index 002d517..98a22e5 100644 > --- a/arch/powerpc/kvm/e500_emulate.c > +++ b/arch/powerpc/kvm/e500_emulate.c > @@ -250,6 +250,10 @@ int kvmppc_core_emulate_mtspr_e500(struct kvm_vcpu > *vcpu, int sprn, ulong spr_va > spr_val); > break; > > + case SPRN_PWRMGTCR0: > + /* Guest relies on host power management configurations */ > + break; > + > /* extra exceptions */ > case SPRN_IVOR32: > vcpu->arch.ivor[BOOKE_IRQPRIO_SPE_UNAVAIL] = spr_val; > @@ -355,6 +359,10 @@ int kvmppc_core_emulate_mfspr_e500(struct kvm_vcpu > *vcpu, int sprn, ulong *spr_v > *spr_val = 0; > break; > > + case SPRN_PWRMGTCR0: > + *spr_val = 0; > + break; > + > case SPRN_MMUCFG: > *spr_val = vcpu->arch.mmucfg; > break;
When reading, is it better to return zero, or the current host value, or the value last written by the guest (even though it wasn't written to hardware)? -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
