KVM: PPC: Book3S HV: Handle new LPCR bits on POWER8

POWER8 has a bit in the LPCR to enable or disable the PURR and SPURR
registers to count when in the guest.  Set this bit.

POWER8 has a field in the LPCR called AIL (Alternate Interrupt Location)
which is used to enable relocation-on interrupts.  Allow userspace to
set this field.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/powerpc/include/asm/reg.h

@@ -305,8 +305,10 @@
 #define   LPCR_RMLS    0x1C000000      /* impl dependent rmo limit sel */
 #define	  LPCR_RMLS_SH	(63-37)
 #define   LPCR_ILE     0x02000000      /* !HV irqs set MSR:LE */
+#define   LPCR_AIL	0x01800000	/* Alternate interrupt location */
 #define   LPCR_AIL_0	0x00000000	/* MMU off exception offset 0x0 */
 #define   LPCR_AIL_3	0x01800000	/* MMU on exception offset 0xc00...4xxx */
+#define   LPCR_ONL	0x00040000	/* online - PURR/SPURR count */
 #define   LPCR_PECE	0x0001f000	/* powersave exit cause enable */
 #define     LPCR_PECEDP	0x00010000	/* directed priv dbells cause exit */
 #define     LPCR_PECEDH	0x00008000	/* directed hyp dbells cause exit */

arch/powerpc/kvm/book3s_hv.c

@@ -789,8 +789,11 @@ static void kvmppc_set_lpcr(struct kvm_vcpu *vcpu, u64 new_lpcr)
 	/*
 	 * Userspace can only modify DPFD (default prefetch depth),
 	 * ILE (interrupt little-endian) and TC (translation control).
+	 * On POWER8 userspace can also modify AIL (alt. interrupt loc.)
 	 */
 	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC;
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
+		mask |= LPCR_AIL;
 	vc->lpcr = (vc->lpcr & ~mask) | (new_lpcr & mask);
 	spin_unlock(&vc->lock);
 }
@@ -2166,6 +2169,9 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 			LPCR_VPM0 | LPCR_VPM1;
 		kvm->arch.vrma_slb_v = SLB_VSID_B_1T |
 			(VRMA_VSID << SLB_VSID_SHIFT_1T);
+		/* On POWER8 turn on online bit to enable PURR/SPURR */
+		if (cpu_has_feature(CPU_FTR_ARCH_207S))
+			lpcr |= LPCR_ONL;
 	}
 	kvm->arch.lpcr = lpcr;