KVM: s390: protvirt: UV calls in support of diag308 0, 1

diag 308 subcode 0 and 1 require several KVM and Ultravisor interactions.
Specific to these "soft" reboots are

* The "unshare all" UVC
* The "prepare for reset" UVC
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[borntraeger@de.ibm.com: patch merging, splitting, fixing]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

arch/s390/include/asm/uv.h

@@ -36,6 +36,8 @@
 #define UVC_CMD_SET_SEC_CONF_PARAMS	0x0300
 #define UVC_CMD_UNPACK_IMG		0x0301
 #define UVC_CMD_VERIFY_IMG		0x0302
+#define UVC_CMD_PREPARE_RESET		0x0320
+#define UVC_CMD_SET_UNSHARE_ALL		0x0340
 #define UVC_CMD_PIN_PAGE_SHARED		0x0341
 #define UVC_CMD_UNPIN_PAGE_SHARED	0x0342
 #define UVC_CMD_SET_SHARED_ACCESS	0x1000
@@ -56,6 +58,8 @@ enum uv_cmds_inst {
 	BIT_UVC_CMD_SET_SEC_PARMS = 11,
 	BIT_UVC_CMD_UNPACK_IMG = 13,
 	BIT_UVC_CMD_VERIFY_IMG = 14,
+	BIT_UVC_CMD_PREPARE_RESET = 18,
+	BIT_UVC_CMD_UNSHARE_ALL = 20,
 	BIT_UVC_CMD_PIN_PAGE_SHARED = 21,
 	BIT_UVC_CMD_UNPIN_PAGE_SHARED = 22,
 };

arch/s390/kvm/kvm-s390.c

@@ -2328,6 +2328,28 @@ static int kvm_s390_handle_pv(struct kvm *kvm, struct kvm_pv_cmd *cmd)
 			     cmd->rrc);
 		break;
 	}
+	case KVM_PV_PREP_RESET: {
+		r = -EINVAL;
+		if (!kvm_s390_pv_is_protected(kvm))
+			break;
+
+		r = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
+				  UVC_CMD_PREPARE_RESET, &cmd->rc, &cmd->rrc);
+		KVM_UV_EVENT(kvm, 3, "PROTVIRT PREP RESET: rc %x rrc %x",
+			     cmd->rc, cmd->rrc);
+		break;
+	}
+	case KVM_PV_UNSHARE_ALL: {
+		r = -EINVAL;
+		if (!kvm_s390_pv_is_protected(kvm))
+			break;
+
+		r = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm),
+				  UVC_CMD_SET_UNSHARE_ALL, &cmd->rc, &cmd->rrc);
+		KVM_UV_EVENT(kvm, 3, "PROTVIRT UNSHARE: rc %x rrc %x",
+			     cmd->rc, cmd->rrc);
+		break;
+	}
 	default:
 		r = -ENOTTY;
 	}

include/uapi/linux/kvm.h

@@ -1500,6 +1500,8 @@ enum pv_cmd_id {
 	KVM_PV_SET_SEC_PARMS,
 	KVM_PV_UNPACK,
 	KVM_PV_VERIFY,
+	KVM_PV_PREP_RESET,
+	KVM_PV_UNSHARE_ALL,
 };
 
 struct kvm_pv_cmd {