arch/s390/Kconfig

   1 config MMU
   2         def_bool y
   3
   4 config ZONE_DMA
   5         def_bool y
   6
   7 config LOCKDEP_SUPPORT
   8         def_bool y
   9
  10 config STACKTRACE_SUPPORT
  11         def_bool y
  12
  13 config HAVE_LATENCYTOP_SUPPORT
  14         def_bool y
  15
  16 config RWSEM_GENERIC_SPINLOCK
  17         bool
  18
  19 config RWSEM_XCHGADD_ALGORITHM
  20         def_bool y
  21
  22 config ARCH_HAS_ILOG2_U32
  23         def_bool n
  24
  25 config ARCH_HAS_ILOG2_U64
  26         def_bool n
  27
  28 config GENERIC_HWEIGHT
  29         def_bool y
  30
  31 config GENERIC_BUG
  32         def_bool y if BUG
  33
  34 config GENERIC_BUG_RELATIVE_POINTERS
  35         def_bool y
  36
  37 config NO_IOMEM
  38         def_bool y
  39
  40 config NO_DMA
  41         def_bool y
  42
  43 config ARCH_DMA_ADDR_T_64BIT
  44         def_bool 64BIT
  45
  46 config GENERIC_LOCKBREAK
  47         def_bool y if SMP && PREEMPT
  48
  49 config PGSTE
  50         def_bool y if KVM
  51
  52 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  53         def_bool y
  54
  55 config KEXEC
  56         def_bool y
  57
  58 config AUDIT_ARCH
  59         def_bool y
  60
  61 config S390
  62         def_bool y
  63         select USE_GENERIC_SMP_HELPERS if SMP
  64         select GENERIC_CPU_DEVICES if !SMP
  65         select HAVE_SYSCALL_WRAPPERS
  66         select HAVE_FUNCTION_TRACER
  67         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  68         select HAVE_FTRACE_MCOUNT_RECORD
  69         select HAVE_C_RECORDMCOUNT
  70         select HAVE_SYSCALL_TRACEPOINTS
  71         select SYSCTL_EXCEPTION_TRACE
  72         select HAVE_DYNAMIC_FTRACE
  73         select HAVE_FUNCTION_GRAPH_TRACER
  74         select HAVE_REGS_AND_STACK_ACCESS_API
  75         select HAVE_OPROFILE
  76         select HAVE_KPROBES
  77         select HAVE_KRETPROBES
  78         select HAVE_KVM if 64BIT
  79         select HAVE_ARCH_TRACEHOOK
  80         select INIT_ALL_POSSIBLE
  81         select HAVE_IRQ_WORK
  82         select HAVE_PERF_EVENTS
  83         select ARCH_HAVE_NMI_SAFE_CMPXCHG
  84         select HAVE_DEBUG_KMEMLEAK
  85         select HAVE_KERNEL_GZIP
  86         select HAVE_KERNEL_BZIP2
  87         select HAVE_KERNEL_LZMA
  88         select HAVE_KERNEL_LZO
  89         select HAVE_KERNEL_XZ
  90         select HAVE_ARCH_MUTEX_CPU_RELAX
  91         select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
  92         select HAVE_BPF_JIT if 64BIT && PACK_STACK
  93         select ARCH_SAVE_PAGE_KEYS if HIBERNATION
  94         select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
  95         select HAVE_MEMBLOCK
  96         select HAVE_MEMBLOCK_NODE_MAP
  97         select HAVE_CMPXCHG_LOCAL
  98         select HAVE_CMPXCHG_DOUBLE
  99         select HAVE_ALIGNED_STRUCT_PAGE if SLUB
 100         select HAVE_VIRT_CPU_ACCOUNTING
 101         select VIRT_CPU_ACCOUNTING
 102         select ARCH_DISCARD_MEMBLOCK
 103         select BUILDTIME_EXTABLE_SORT
 104         select ARCH_INLINE_SPIN_TRYLOCK
 105         select ARCH_INLINE_SPIN_TRYLOCK_BH
 106         select ARCH_INLINE_SPIN_LOCK
 107         select ARCH_INLINE_SPIN_LOCK_BH
 108         select ARCH_INLINE_SPIN_LOCK_IRQ
 109         select ARCH_INLINE_SPIN_LOCK_IRQSAVE
 110         select ARCH_INLINE_SPIN_UNLOCK
 111         select ARCH_INLINE_SPIN_UNLOCK_BH
 112         select ARCH_INLINE_SPIN_UNLOCK_IRQ
 113         select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
 114         select ARCH_INLINE_READ_TRYLOCK
 115         select ARCH_INLINE_READ_LOCK
 116         select ARCH_INLINE_READ_LOCK_BH
 117         select ARCH_INLINE_READ_LOCK_IRQ
 118         select ARCH_INLINE_READ_LOCK_IRQSAVE
 119         select ARCH_INLINE_READ_UNLOCK
 120         select ARCH_INLINE_READ_UNLOCK_BH
 121         select ARCH_INLINE_READ_UNLOCK_IRQ
 122         select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
 123         select ARCH_INLINE_WRITE_TRYLOCK
 124         select ARCH_INLINE_WRITE_LOCK
 125         select ARCH_INLINE_WRITE_LOCK_BH
 126         select ARCH_INLINE_WRITE_LOCK_IRQ
 127         select ARCH_INLINE_WRITE_LOCK_IRQSAVE
 128         select ARCH_INLINE_WRITE_UNLOCK
 129         select ARCH_INLINE_WRITE_UNLOCK_BH
 130         select ARCH_INLINE_WRITE_UNLOCK_IRQ
 131         select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
 132         select HAVE_UID16 if 32BIT
 133         select ARCH_WANT_IPC_PARSE_VERSION
 134         select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT
 135         select GENERIC_SMP_IDLE_THREAD
 136         select GENERIC_TIME_VSYSCALL_OLD
 137         select GENERIC_CLOCKEVENTS
 138         select KTIME_SCALAR if 32BIT
 139         select HAVE_ARCH_SECCOMP_FILTER
 140         select GENERIC_KERNEL_THREAD
 141         select GENERIC_KERNEL_EXECVE
 142         select HAVE_MOD_ARCH_SPECIFIC
 143         select MODULES_USE_ELF_RELA
 144
 145 config SCHED_OMIT_FRAME_POINTER
 146         def_bool y
 147
 148 source "init/Kconfig"
 149
 150 source "kernel/Kconfig.freezer"
 151
 152 menu "Processor type and features"
 153
 154 config HAVE_MARCH_Z900_FEATURES
 155         def_bool n
 156
 157 config HAVE_MARCH_Z990_FEATURES
 158         def_bool n
 159         select HAVE_MARCH_Z900_FEATURES
 160
 161 config HAVE_MARCH_Z9_109_FEATURES
 162         def_bool n
 163         select HAVE_MARCH_Z990_FEATURES
 164
 165 config HAVE_MARCH_Z10_FEATURES
 166         def_bool n
 167         select HAVE_MARCH_Z9_109_FEATURES
 168
 169 config HAVE_MARCH_Z196_FEATURES
 170         def_bool n
 171         select HAVE_MARCH_Z10_FEATURES
 172
 173 choice
 174         prompt "Processor type"
 175         default MARCH_G5
 176
 177 config MARCH_G5
 178         bool "System/390 model G5 and G6"
 179         depends on !64BIT
 180         help
 181           Select this to build a 31 bit kernel that works
 182           on all ESA/390 and z/Architecture machines.
 183
 184 config MARCH_Z900
 185         bool "IBM zSeries model z800 and z900"
 186         select HAVE_MARCH_Z900_FEATURES if 64BIT
 187         help
 188           Select this to enable optimizations for model z800/z900 (2064 and
 189           2066 series). This will enable some optimizations that are not
 190           available on older ESA/390 (31 Bit) only CPUs.
 191
 192 config MARCH_Z990
 193         bool "IBM zSeries model z890 and z990"
 194         select HAVE_MARCH_Z990_FEATURES if 64BIT
 195         help
 196           Select this to enable optimizations for model z890/z990 (2084 and
 197           2086 series). The kernel will be slightly faster but will not work
 198           on older machines.
 199
 200 config MARCH_Z9_109
 201         bool "IBM System z9"
 202         select HAVE_MARCH_Z9_109_FEATURES if 64BIT
 203         help
 204           Select this to enable optimizations for IBM System z9 (2094 and
 205           2096 series). The kernel will be slightly faster but will not work
 206           on older machines.
 207
 208 config MARCH_Z10
 209         bool "IBM System z10"
 210         select HAVE_MARCH_Z10_FEATURES if 64BIT
 211         help
 212           Select this to enable optimizations for IBM System z10 (2097 and
 213           2098 series). The kernel will be slightly faster but will not work
 214           on older machines.
 215
 216 config MARCH_Z196
 217         bool "IBM zEnterprise 114 and 196"
 218         select HAVE_MARCH_Z196_FEATURES if 64BIT
 219         help
 220           Select this to enable optimizations for IBM zEnterprise 114 and 196
 221           (2818 and 2817 series). The kernel will be slightly faster but will
 222           not work on older machines.
 223
 224 endchoice
 225
 226 config 64BIT
 227         def_bool y
 228         prompt "64 bit kernel"
 229         help
 230           Select this option if you have an IBM z/Architecture machine
 231           and want to use the 64 bit addressing mode.
 232
 233 config 32BIT
 234         def_bool y if !64BIT
 235
 236 config COMPAT
 237         def_bool y
 238         prompt "Kernel support for 31 bit emulation"
 239         depends on 64BIT
 240         select COMPAT_BINFMT_ELF if BINFMT_ELF
 241         select ARCH_WANT_OLD_COMPAT_IPC
 242         help
 243           Select this option if you want to enable your system kernel to
 244           handle system-calls from ELF binaries for 31 bit ESA.  This option
 245           (and some other stuff like libraries and such) is needed for
 246           executing 31 bit applications.  It is safe to say "Y".
 247
 248 config SYSVIPC_COMPAT
 249         def_bool y if COMPAT && SYSVIPC
 250
 251 config KEYS_COMPAT
 252         def_bool y if COMPAT && KEYS
 253
 254 config SMP
 255         def_bool y
 256         prompt "Symmetric multi-processing support"
 257         ---help---
 258           This enables support for systems with more than one CPU. If you have
 259           a system with only one CPU, like most personal computers, say N. If
 260           you have a system with more than one CPU, say Y.
 261
 262           If you say N here, the kernel will run on single and multiprocessor
 263           machines, but will use only one CPU of a multiprocessor machine. If
 264           you say Y here, the kernel will run on many, but not all,
 265           singleprocessor machines. On a singleprocessor machine, the kernel
 266           will run faster if you say N here.
 267
 268           See also the SMP-HOWTO available at
 269           <http://www.tldp.org/docs.html#howto>.
 270
 271           Even if you don't know what to do here, say Y.
 272
 273 config NR_CPUS
 274         int "Maximum number of CPUs (2-64)"
 275         range 2 64
 276         depends on SMP
 277         default "32" if !64BIT
 278         default "64" if 64BIT
 279         help
 280           This allows you to specify the maximum number of CPUs which this
 281           kernel will support.  The maximum supported value is 64 and the
 282           minimum value which makes sense is 2.
 283
 284           This is purely to save memory - each supported CPU adds
 285           approximately sixteen kilobytes to the kernel image.
 286
 287 config HOTPLUG_CPU
 288         def_bool y
 289         prompt "Support for hot-pluggable CPUs"
 290         depends on SMP
 291         select HOTPLUG
 292         help
 293           Say Y here to be able to turn CPUs off and on. CPUs
 294           can be controlled through /sys/devices/system/cpu/cpu#.
 295           Say N if you want to disable CPU hotplug.
 296
 297 config SCHED_MC
 298         def_bool n
 299
 300 config SCHED_BOOK
 301         def_bool y
 302         prompt "Book scheduler support"
 303         depends on SMP
 304         select SCHED_MC
 305         help
 306           Book scheduler support improves the CPU scheduler's decision making
 307           when dealing with machines that have several books.
 308
 309 source kernel/Kconfig.preempt
 310
 311 config MATHEMU
 312         def_bool y
 313         prompt "IEEE FPU emulation"
 314         depends on MARCH_G5
 315         help
 316           This option is required for IEEE compliant floating point arithmetic
 317           on older ESA/390 machines. Say Y unless you know your machine doesn't
 318           need this.
 319
 320 source kernel/Kconfig.hz
 321
 322 endmenu
 323
 324 menu "Memory setup"
 325
 326 config ARCH_SPARSEMEM_ENABLE
 327         def_bool y
 328         select SPARSEMEM_VMEMMAP_ENABLE
 329         select SPARSEMEM_VMEMMAP
 330         select SPARSEMEM_STATIC if !64BIT
 331
 332 config ARCH_SPARSEMEM_DEFAULT
 333         def_bool y
 334
 335 config ARCH_SELECT_MEMORY_MODEL
 336         def_bool y
 337
 338 config ARCH_ENABLE_MEMORY_HOTPLUG
 339         def_bool y if SPARSEMEM
 340
 341 config ARCH_ENABLE_MEMORY_HOTREMOVE
 342         def_bool y
 343
 344 config FORCE_MAX_ZONEORDER
 345         int
 346         default "9"
 347
 348 source "mm/Kconfig"
 349
 350 config PACK_STACK
 351         def_bool y
 352         prompt "Pack kernel stack"
 353         help
 354           This option enables the compiler option -mkernel-backchain if it
 355           is available. If the option is available the compiler supports
 356           the new stack layout which dramatically reduces the minimum stack
 357           frame size. With an old compiler a non-leaf function needs a
 358           minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
 359           -mkernel-backchain the minimum size drops to 16 byte on 31 bit
 360           and 24 byte on 64 bit.
 361
 362           Say Y if you are unsure.
 363
 364 config SMALL_STACK
 365         def_bool n
 366         prompt "Use 8kb for kernel stack instead of 16kb"
 367         depends on PACK_STACK && 64BIT && !LOCKDEP
 368         help
 369           If you say Y here and the compiler supports the -mkernel-backchain
 370           option the kernel will use a smaller kernel stack size. The reduced
 371           size is 8kb instead of 16kb. This allows to run more threads on a
 372           system and reduces the pressure on the memory management for higher
 373           order page allocations.
 374
 375           Say N if you are unsure.
 376
 377 config CHECK_STACK
 378         def_bool y
 379         prompt "Detect kernel stack overflow"
 380         help
 381           This option enables the compiler option -mstack-guard and
 382           -mstack-size if they are available. If the compiler supports them
 383           it will emit additional code to each function prolog to trigger
 384           an illegal operation if the kernel stack is about to overflow.
 385
 386           Say N if you are unsure.
 387
 388 config STACK_GUARD
 389         int "Size of the guard area (128-1024)"
 390         range 128 1024
 391         depends on CHECK_STACK
 392         default "256"
 393         help
 394           This allows you to specify the size of the guard area at the lower
 395           end of the kernel stack. If the kernel stack points into the guard
 396           area on function entry an illegal operation is triggered. The size
 397           needs to be a power of 2. Please keep in mind that the size of an
 398           interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
 399           The minimum size for the stack guard should be 256 for 31 bit and
 400           512 for 64 bit.
 401
 402 config WARN_DYNAMIC_STACK
 403         def_bool n
 404         prompt "Emit compiler warnings for function with dynamic stack usage"
 405         help
 406           This option enables the compiler option -mwarn-dynamicstack. If the
 407           compiler supports this options generates warnings for functions
 408           that dynamically allocate stack space using alloca.
 409
 410           Say N if you are unsure.
 411
 412 endmenu
 413
 414 menu "I/O subsystem"
 415
 416 config QDIO
 417         def_tristate y
 418         prompt "QDIO support"
 419         ---help---
 420           This driver provides the Queued Direct I/O base support for
 421           IBM System z.
 422
 423           To compile this driver as a module, choose M here: the
 424           module will be called qdio.
 425
 426           If unsure, say Y.
 427
 428 config CHSC_SCH
 429         def_tristate m
 430         prompt "Support for CHSC subchannels"
 431         help
 432           This driver allows usage of CHSC subchannels. A CHSC subchannel
 433           is usually present on LPAR only.
 434           The driver creates a device /dev/chsc, which may be used to
 435           obtain I/O configuration information about the machine and
 436           to issue asynchronous chsc commands (DANGEROUS).
 437           You will usually only want to use this interface on a special
 438           LPAR designated for system management.
 439
 440           To compile this driver as a module, choose M here: the
 441           module will be called chsc_sch.
 442
 443           If unsure, say N.
 444
 445 config SCM_BUS
 446         def_bool y
 447         depends on 64BIT
 448         prompt "SCM bus driver"
 449         help
 450           Bus driver for Storage Class Memory.
 451
 452 config EADM_SCH
 453         def_tristate m
 454         prompt "Support for EADM subchannels"
 455         depends on SCM_BUS
 456         help
 457           This driver allows usage of EADM subchannels. EADM subchannels act
 458           as a communication vehicle for SCM increments.
 459
 460           To compile this driver as a module, choose M here: the
 461           module will be called eadm_sch.
 462
 463 endmenu
 464
 465 menu "Dump support"
 466
 467 config CRASH_DUMP
 468         bool "kernel crash dumps"
 469         depends on 64BIT && SMP
 470         select KEXEC
 471         help
 472           Generate crash dump after being started by kexec.
 473           Crash dump kernels are loaded in the main kernel with kexec-tools
 474           into a specially reserved region and then later executed after
 475           a crash by kdump/kexec.
 476           For more details see Documentation/kdump/kdump.txt
 477
 478 config ZFCPDUMP
 479         def_bool n
 480         prompt "zfcpdump support"
 481         select SMP
 482         help
 483           Select this option if you want to build an zfcpdump enabled kernel.
 484           Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
 485
 486 endmenu
 487
 488 menu "Executable file formats / Emulations"
 489
 490 source "fs/Kconfig.binfmt"
 491
 492 config SECCOMP
 493         def_bool y
 494         prompt "Enable seccomp to safely compute untrusted bytecode"
 495         depends on PROC_FS
 496         help
 497           This kernel feature is useful for number crunching applications
 498           that may need to compute untrusted bytecode during their
 499           execution. By using pipes or other transports made available to
 500           the process as file descriptors supporting the read/write
 501           syscalls, it's possible to isolate those applications in
 502           their own address space using seccomp. Once seccomp is
 503           enabled via /proc/<pid>/seccomp, it cannot be disabled
 504           and the task is only allowed to execute a few safe syscalls
 505           defined by each seccomp mode.
 506
 507           If unsure, say Y.
 508
 509 endmenu
 510
 511 menu "Power Management"
 512
 513 config ARCH_HIBERNATION_POSSIBLE
 514         def_bool y if 64BIT
 515
 516 source "kernel/power/Kconfig"
 517
 518 endmenu
 519
 520 source "net/Kconfig"
 521
 522 config PCMCIA
 523         def_bool n
 524
 525 config CCW
 526         def_bool y
 527
 528 source "drivers/Kconfig"
 529
 530 source "fs/Kconfig"
 531
 532 source "arch/s390/Kconfig.debug"
 533
 534 source "security/Kconfig"
 535
 536 source "crypto/Kconfig"
 537
 538 source "lib/Kconfig"
 539
 540 menu "Virtualization"
 541
 542 config PFAULT
 543         def_bool y
 544         prompt "Pseudo page fault support"
 545         help
 546           Select this option, if you want to use PFAULT pseudo page fault
 547           handling under VM. If running native or in LPAR, this option
 548           has no effect. If your VM does not support PFAULT, PAGEEX
 549           pseudo page fault handling will be used.
 550           Note that VM 4.2 supports PFAULT but has a bug in its
 551           implementation that causes some problems.
 552           Everybody who wants to run Linux under VM != VM4.2 should select
 553           this option.
 554
 555 config SHARED_KERNEL
 556         bool "VM shared kernel support"
 557         depends on !JUMP_LABEL
 558         help
 559           Select this option, if you want to share the text segment of the
 560           Linux kernel between different VM guests. This reduces memory
 561           usage with lots of guests but greatly increases kernel size.
 562           Also if a kernel was IPL'ed from a shared segment the kexec system
 563           call will not work.
 564           You should only select this option if you know what you are
 565           doing and want to exploit this feature.
 566
 567 config CMM
 568         def_tristate n
 569         prompt "Cooperative memory management"
 570         help
 571           Select this option, if you want to enable the kernel interface
 572           to reduce the memory size of the system. This is accomplished
 573           by allocating pages of memory and put them "on hold". This only
 574           makes sense for a system running under VM where the unused pages
 575           will be reused by VM for other guest systems. The interface
 576           allows an external monitor to balance memory of many systems.
 577           Everybody who wants to run Linux under VM should select this
 578           option.
 579
 580 config CMM_IUCV
 581         def_bool y
 582         prompt "IUCV special message interface to cooperative memory management"
 583         depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
 584         help
 585           Select this option to enable the special message interface to
 586           the cooperative memory management.
 587
 588 config APPLDATA_BASE
 589         def_bool n
 590         prompt "Linux - VM Monitor Stream, base infrastructure"
 591         depends on PROC_FS
 592         help
 593           This provides a kernel interface for creating and updating z/VM APPLDATA
 594           monitor records. The monitor records are updated at certain time
 595           intervals, once the timer is started.
 596           Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
 597           i.e. enables or disables monitoring on the Linux side.
 598           A custom interval value (in seconds) can be written to
 599           /proc/appldata/interval.
 600
 601           Defaults are 60 seconds interval and timer off.
 602           The /proc entries can also be read from, showing the current settings.
 603
 604 config APPLDATA_MEM
 605         def_tristate m
 606         prompt "Monitor memory management statistics"
 607         depends on APPLDATA_BASE && VM_EVENT_COUNTERS
 608         help
 609           This provides memory management related data to the Linux - VM Monitor
 610           Stream, like paging/swapping rate, memory utilisation, etc.
 611           Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
 612           APPLDATA monitor record, i.e. enables or disables monitoring this record
 613           on the z/VM side.
 614
 615           Default is disabled.
 616           The /proc entry can also be read from, showing the current settings.
 617
 618           This can also be compiled as a module, which will be called
 619           appldata_mem.o.
 620
 621 config APPLDATA_OS
 622         def_tristate m
 623         prompt "Monitor OS statistics"
 624         depends on APPLDATA_BASE
 625         help
 626           This provides OS related data to the Linux - VM Monitor Stream, like
 627           CPU utilisation, etc.
 628           Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
 629           APPLDATA monitor record, i.e. enables or disables monitoring this record
 630           on the z/VM side.
 631
 632           Default is disabled.
 633           This can also be compiled as a module, which will be called
 634           appldata_os.o.
 635
 636 config APPLDATA_NET_SUM
 637         def_tristate m
 638         prompt "Monitor overall network statistics"
 639         depends on APPLDATA_BASE && NET
 640         help
 641           This provides network related data to the Linux - VM Monitor Stream,
 642           currently there is only a total sum of network I/O statistics, no
 643           per-interface data.
 644           Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
 645           APPLDATA monitor record, i.e. enables or disables monitoring this record
 646           on the z/VM side.
 647
 648           Default is disabled.
 649           This can also be compiled as a module, which will be called
 650           appldata_net_sum.o.
 651
 652 config S390_HYPFS_FS
 653         def_bool y
 654         prompt "s390 hypervisor file system support"
 655         select SYS_HYPERVISOR
 656         help
 657           This is a virtual file system intended to provide accounting
 658           information in an s390 hypervisor environment.
 659
 660 source "arch/s390/kvm/Kconfig"
 661
 662 config S390_GUEST
 663         def_bool y
 664         prompt "s390 support for virtio devices (EXPERIMENTAL)"
 665         depends on 64BIT && EXPERIMENTAL
 666         select VIRTUALIZATION
 667         select VIRTIO
 668         select VIRTIO_CONSOLE
 669         help
 670           Enabling this option adds support for virtio based paravirtual device
 671           drivers on s390.
 672
 673           Select this option if you want to run the kernel as a guest under
 674           the KVM hypervisor.
 675
 676 endmenu