KVM: s390: onereg for timer related registers

Enhance the KVM ONE_REG capability within S390 to allow
getting/setting the following special cpu registers: clock comparator
and the cpu timer. These are needed for migration.
Signed-off-by: Jason J. herne <jjherne@us.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/s390/include/asm/kvm.h

@@ -55,4 +55,6 @@ struct kvm_sync_regs {
 
 #define KVM_REG_S390_TODPR	(KVM_REG_S390 | KVM_REG_SIZE_U32 | 0x1)
 #define KVM_REG_S390_EPOCHDIFF	(KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x2)
+#define KVM_REG_S390_CPU_TIMER  (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x3)
+#define KVM_REG_S390_CLOCK_COMP (KVM_REG_S390 | KVM_REG_SIZE_U64 | 0x4)
 #endif

arch/s390/kvm/kvm-s390.c

@@ -454,6 +454,14 @@ static int kvm_arch_vcpu_ioctl_get_one_reg(struct kvm_vcpu *vcpu,
 		r = put_user(vcpu->arch.sie_block->epoch,
 			     (u64 __user *)reg->addr);
 		break;
+	case KVM_REG_S390_CPU_TIMER:
+		r = put_user(vcpu->arch.sie_block->cputm,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_CLOCK_COMP:
+		r = put_user(vcpu->arch.sie_block->ckc,
+			     (u64 __user *)reg->addr);
+		break;
 	default:
 		break;
 	}
@@ -475,6 +483,14 @@ static int kvm_arch_vcpu_ioctl_set_one_reg(struct kvm_vcpu *vcpu,
 		r = get_user(vcpu->arch.sie_block->epoch,
 			     (u64 __user *)reg->addr);
 		break;
+	case KVM_REG_S390_CPU_TIMER:
+		r = get_user(vcpu->arch.sie_block->cputm,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_CLOCK_COMP:
+		r = get_user(vcpu->arch.sie_block->ckc,
+			     (u64 __user *)reg->addr);
+		break;
 	default:
 		break;
 	}