summaryrefslogtreecommitdiffstats
path: root/arch/s390/Kconfig
blob: 5029ebf7110eb53be7c563e562daedca855be835 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
config MMU
	def_bool y

config ZONE_DMA
	def_bool y

config LOCKDEP_SUPPORT
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y

config HAVE_LATENCYTOP_SUPPORT
	def_bool y

config RWSEM_GENERIC_SPINLOCK
	bool

config RWSEM_XCHGADD_ALGORITHM
	def_bool y

config ARCH_HAS_ILOG2_U32
	def_bool n

config ARCH_HAS_ILOG2_U64
	def_bool n

config GENERIC_HWEIGHT
	def_bool y

config GENERIC_BUG
	def_bool y if BUG

config GENERIC_BUG_RELATIVE_POINTERS
	def_bool y

config NO_IOMEM
	def_bool y

config NO_DMA
	def_bool y

config ARCH_DMA_ADDR_T_64BIT
	def_bool 64BIT

config GENERIC_LOCKBREAK
	def_bool y if SMP && PREEMPT

config PGSTE
	def_bool y if KVM

config ARCH_SUPPORTS_DEBUG_PAGEALLOC
	def_bool y

config KEXEC
	def_bool y

config AUDIT_ARCH
	def_bool y

config S390
	def_bool y
	select USE_GENERIC_SMP_HELPERS if SMP
	select GENERIC_CPU_DEVICES if !SMP
	select HAVE_SYSCALL_WRAPPERS
	select HAVE_FUNCTION_TRACER
	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
	select HAVE_FTRACE_MCOUNT_RECORD
	select HAVE_C_RECORDMCOUNT
	select HAVE_SYSCALL_TRACEPOINTS
	select SYSCTL_EXCEPTION_TRACE
	select HAVE_DYNAMIC_FTRACE
	select HAVE_FUNCTION_GRAPH_TRACER
	select HAVE_REGS_AND_STACK_ACCESS_API
	select HAVE_OPROFILE
	select HAVE_KPROBES
	select HAVE_KRETPROBES
	select HAVE_KVM if 64BIT
	select HAVE_ARCH_TRACEHOOK
	select INIT_ALL_POSSIBLE
	select HAVE_IRQ_WORK
	select HAVE_PERF_EVENTS
	select ARCH_HAVE_NMI_SAFE_CMPXCHG
	select HAVE_DEBUG_KMEMLEAK
	select HAVE_KERNEL_GZIP
	select HAVE_KERNEL_BZIP2
	select HAVE_KERNEL_LZMA
	select HAVE_KERNEL_LZO
	select HAVE_KERNEL_XZ
	select HAVE_ARCH_MUTEX_CPU_RELAX
	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
	select HAVE_BPF_JIT if 64BIT && PACK_STACK
	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
	select HAVE_MEMBLOCK
	select HAVE_MEMBLOCK_NODE_MAP
	select HAVE_CMPXCHG_LOCAL
	select HAVE_CMPXCHG_DOUBLE
	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
	select HAVE_VIRT_CPU_ACCOUNTING
	select VIRT_CPU_ACCOUNTING
	select ARCH_DISCARD_MEMBLOCK
	select BUILDTIME_EXTABLE_SORT
	select ARCH_INLINE_SPIN_TRYLOCK
	select ARCH_INLINE_SPIN_TRYLOCK_BH
	select ARCH_INLINE_SPIN_LOCK
	select ARCH_INLINE_SPIN_LOCK_BH
	select ARCH_INLINE_SPIN_LOCK_IRQ
	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
	select ARCH_INLINE_SPIN_UNLOCK
	select ARCH_INLINE_SPIN_UNLOCK_BH
	select ARCH_INLINE_SPIN_UNLOCK_IRQ
	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
	select ARCH_INLINE_READ_TRYLOCK
	select ARCH_INLINE_READ_LOCK
	select ARCH_INLINE_READ_LOCK_BH
	select ARCH_INLINE_READ_LOCK_IRQ
	select ARCH_INLINE_READ_LOCK_IRQSAVE
	select ARCH_INLINE_READ_UNLOCK
	select ARCH_INLINE_READ_UNLOCK_BH
	select ARCH_INLINE_READ_UNLOCK_IRQ
	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
	select ARCH_INLINE_WRITE_TRYLOCK
	select ARCH_INLINE_WRITE_LOCK
	select ARCH_INLINE_WRITE_LOCK_BH
	select ARCH_INLINE_WRITE_LOCK_IRQ
	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
	select ARCH_INLINE_WRITE_UNLOCK
	select ARCH_INLINE_WRITE_UNLOCK_BH
	select ARCH_INLINE_WRITE_UNLOCK_IRQ
	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
	select HAVE_UID16 if 32BIT
	select ARCH_WANT_IPC_PARSE_VERSION
	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT
	select GENERIC_SMP_IDLE_THREAD
	select GENERIC_TIME_VSYSCALL_OLD
	select GENERIC_CLOCKEVENTS
	select KTIME_SCALAR if 32BIT
	select HAVE_ARCH_SECCOMP_FILTER
	select HAVE_MOD_ARCH_SPECIFIC
	select MODULES_USE_ELF_RELA
	select CLONE_BACKWARDS2

config SCHED_OMIT_FRAME_POINTER
	def_bool y

source "init/Kconfig"

source "kernel/Kconfig.freezer"

menu "Processor type and features"

config HAVE_MARCH_Z900_FEATURES
	def_bool n

config HAVE_MARCH_Z990_FEATURES
	def_bool n
	select HAVE_MARCH_Z900_FEATURES

config HAVE_MARCH_Z9_109_FEATURES
	def_bool n
	select HAVE_MARCH_Z990_FEATURES

config HAVE_MARCH_Z10_FEATURES
	def_bool n
	select HAVE_MARCH_Z9_109_FEATURES

config HAVE_MARCH_Z196_FEATURES
	def_bool n
	select HAVE_MARCH_Z10_FEATURES

choice
	prompt "Processor type"
	default MARCH_G5

config MARCH_G5
	bool "System/390 model G5 and G6"
	depends on !64BIT
	help
	  Select this to build a 31 bit kernel that works
	  on all ESA/390 and z/Architecture machines.

config MARCH_Z900
	bool "IBM zSeries model z800 and z900"
	select HAVE_MARCH_Z900_FEATURES if 64BIT
	help
	  Select this to enable optimizations for model z800/z900 (2064 and
	  2066 series). This will enable some optimizations that are not
	  available on older ESA/390 (31 Bit) only CPUs.

config MARCH_Z990
	bool "IBM zSeries model z890 and z990"
	select HAVE_MARCH_Z990_FEATURES if 64BIT
	help
	  Select this to enable optimizations for model z890/z990 (2084 and
	  2086 series). The kernel will be slightly faster but will not work
	  on older machines.

config MARCH_Z9_109
	bool "IBM System z9"
	select HAVE_MARCH_Z9_109_FEATURES if 64BIT
	help
	  Select this to enable optimizations for IBM System z9 (2094 and
	  2096 series). The kernel will be slightly faster but will not work
	  on older machines.

config MARCH_Z10
	bool "IBM System z10"
	select HAVE_MARCH_Z10_FEATURES if 64BIT
	help
	  Select this to enable optimizations for IBM System z10 (2097 and
	  2098 series). The kernel will be slightly faster but will not work
	  on older machines.

config MARCH_Z196
	bool "IBM zEnterprise 114 and 196"
	select HAVE_MARCH_Z196_FEATURES if 64BIT
	help
	  Select this to enable optimizations for IBM zEnterprise 114 and 196
	  (2818 and 2817 series). The kernel will be slightly faster but will
	  not work on older machines.

endchoice

config 64BIT
	def_bool y
	prompt "64 bit kernel"
	help
	  Select this option if you have an IBM z/Architecture machine
	  and want to use the 64 bit addressing mode.

config 32BIT
	def_bool y if !64BIT

config COMPAT
	def_bool y
	prompt "Kernel support for 31 bit emulation"
	depends on 64BIT
	select COMPAT_BINFMT_ELF if BINFMT_ELF
	select ARCH_WANT_OLD_COMPAT_IPC
	help
	  Select this option if you want to enable your system kernel to
	  handle system-calls from ELF binaries for 31 bit ESA.  This option
	  (and some other stuff like libraries and such) is needed for
	  executing 31 bit applications.  It is safe to say "Y".

config SYSVIPC_COMPAT
	def_bool y if COMPAT && SYSVIPC

config KEYS_COMPAT
	def_bool y if COMPAT && KEYS

config SMP
	def_bool y
	prompt "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
	  a system with only one CPU, like most personal computers, say N. If
	  you have a system with more than one CPU, say Y.

	  If you say N here, the kernel will run on single and multiprocessor
	  machines, but will use only one CPU of a multiprocessor machine. If
	  you say Y here, the kernel will run on many, but not all,
	  singleprocessor machines. On a singleprocessor machine, the kernel
	  will run faster if you say N here.

	  See also the SMP-HOWTO available at
	  <http://www.tldp.org/docs.html#howto>.

	  Even if you don't know what to do here, say Y.

config NR_CPUS
	int "Maximum number of CPUs (2-64)"
	range 2 64
	depends on SMP
	default "32" if !64BIT
	default "64" if 64BIT
	help
	  This allows you to specify the maximum number of CPUs which this
	  kernel will support.  The maximum supported value is 64 and the
	  minimum value which makes sense is 2.

	  This is purely to save memory - each supported CPU adds
	  approximately sixteen kilobytes to the kernel image.

config HOTPLUG_CPU
	def_bool y
	prompt "Support for hot-pluggable CPUs"
	depends on SMP
	select HOTPLUG
	help
	  Say Y here to be able to turn CPUs off and on. CPUs
	  can be controlled through /sys/devices/system/cpu/cpu#.
	  Say N if you want to disable CPU hotplug.

config SCHED_MC
	def_bool n

config SCHED_BOOK
	def_bool y
	prompt "Book scheduler support"
	depends on SMP
	select SCHED_MC
	help
	  Book scheduler support improves the CPU scheduler's decision making
	  when dealing with machines that have several books.

source kernel/Kconfig.preempt

config MATHEMU
	def_bool y
	prompt "IEEE FPU emulation"
	depends on MARCH_G5
	help
	  This option is required for IEEE compliant floating point arithmetic
	  on older ESA/390 machines. Say Y unless you know your machine doesn't
	  need this.

source kernel/Kconfig.hz

endmenu

menu "Memory setup"

config ARCH_SPARSEMEM_ENABLE
	def_bool y
	select SPARSEMEM_VMEMMAP_ENABLE
	select SPARSEMEM_VMEMMAP
	select SPARSEMEM_STATIC if !64BIT

config ARCH_SPARSEMEM_DEFAULT
	def_bool y

config ARCH_SELECT_MEMORY_MODEL
	def_bool y

config ARCH_ENABLE_MEMORY_HOTPLUG
	def_bool y if SPARSEMEM

config ARCH_ENABLE_MEMORY_HOTREMOVE
	def_bool y

config FORCE_MAX_ZONEORDER
	int
	default "9"

source "mm/Kconfig"

config PACK_STACK
	def_bool y
	prompt "Pack kernel stack"
	help
	  This option enables the compiler option -mkernel-backchain if it
	  is available. If the option is available the compiler supports
	  the new stack layout which dramatically reduces the minimum stack
	  frame size. With an old compiler a non-leaf function needs a
	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
	  and 24 byte on 64 bit.

	  Say Y if you are unsure.

config SMALL_STACK
	def_bool n
	prompt "Use 8kb for kernel stack instead of 16kb"
	depends on PACK_STACK && 64BIT && !LOCKDEP
	help
	  If you say Y here and the compiler supports the -mkernel-backchain
	  option the kernel will use a smaller kernel stack size. The reduced
	  size is 8kb instead of 16kb. This allows to run more threads on a
	  system and reduces the pressure on the memory management for higher
	  order page allocations.

	  Say N if you are unsure.

config CHECK_STACK
	def_bool y
	prompt "Detect kernel stack overflow"
	help
	  This option enables the compiler option -mstack-guard and
	  -mstack-size if they are available. If the compiler supports them
	  it will emit additional code to each function prolog to trigger
	  an illegal operation if the kernel stack is about to overflow.

	  Say N if you are unsure.

config STACK_GUARD
	int "Size of the guard area (128-1024)"
	range 128 1024
	depends on CHECK_STACK
	default "256"
	help
	  This allows you to specify the size of the guard area at the lower
	  end of the kernel stack. If the kernel stack points into the guard
	  area on function entry an illegal operation is triggered. The size
	  needs to be a power of 2. Please keep in mind that the size of an
	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
	  The minimum size for the stack guard should be 256 for 31 bit and
	  512 for 64 bit.

config WARN_DYNAMIC_STACK
	def_bool n
	prompt "Emit compiler warnings for function with dynamic stack usage"
	help
	  This option enables the compiler option -mwarn-dynamicstack. If the
	  compiler supports this options generates warnings for functions
	  that dynamically allocate stack space using alloca.

	  Say N if you are unsure.

endmenu

menu "I/O subsystem"

config QDIO
	def_tristate y
	prompt "QDIO support"
	---help---
	  This driver provides the Queued Direct I/O base support for
	  IBM System z.

	  To compile this driver as a module, choose M here: the
	  module will be called qdio.

	  If unsure, say Y.

config CHSC_SCH
	def_tristate m
	prompt "Support for CHSC subchannels"
	help
	  This driver allows usage of CHSC subchannels. A CHSC subchannel
	  is usually present on LPAR only.
	  The driver creates a device /dev/chsc, which may be used to
	  obtain I/O configuration information about the machine and
	  to issue asynchronous chsc commands (DANGEROUS).
	  You will usually only want to use this interface on a special
	  LPAR designated for system management.

	  To compile this driver as a module, choose M here: the
	  module will be called chsc_sch.

	  If unsure, say N.

config SCM_BUS
	def_bool y
	depends on 64BIT
	prompt "SCM bus driver"
	help
	  Bus driver for Storage Class Memory.

config EADM_SCH
	def_tristate m
	prompt "Support for EADM subchannels"
	depends on SCM_BUS
	help
	  This driver allows usage of EADM subchannels. EADM subchannels act
	  as a communication vehicle for SCM increments.

	  To compile this driver as a module, choose M here: the
	  module will be called eadm_sch.

endmenu

menu "Dump support"

config CRASH_DUMP
	bool "kernel crash dumps"
	depends on 64BIT && SMP
	select KEXEC
	help
	  Generate crash dump after being started by kexec.
	  Crash dump kernels are loaded in the main kernel with kexec-tools
	  into a specially reserved region and then later executed after
	  a crash by kdump/kexec.
	  For more details see Documentation/kdump/kdump.txt

config ZFCPDUMP
	def_bool n
	prompt "zfcpdump support"
	select SMP
	help
	  Select this option if you want to build an zfcpdump enabled kernel.
	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.

endmenu

menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config SECCOMP
	def_bool y
	prompt "Enable seccomp to safely compute untrusted bytecode"
	depends on PROC_FS
	help
	  This kernel feature is useful for number crunching applications
	  that may need to compute untrusted bytecode during their
	  execution. By using pipes or other transports made available to
	  the process as file descriptors supporting the read/write
	  syscalls, it's possible to isolate those applications in
	  their own address space using seccomp. Once seccomp is
	  enabled via /proc/<pid>/seccomp, it cannot be disabled
	  and the task is only allowed to execute a few safe syscalls
	  defined by each seccomp mode.

	  If unsure, say Y.

endmenu

menu "Power Management"

config ARCH_HIBERNATION_POSSIBLE
	def_bool y if 64BIT

source "kernel/power/Kconfig"

endmenu

source "net/Kconfig"

config PCMCIA
	def_bool n

config CCW
	def_bool y

source "drivers/Kconfig"

source "fs/Kconfig"

source "arch/s390/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "lib/Kconfig"

menu "Virtualization"

config PFAULT
	def_bool y
	prompt "Pseudo page fault support"
	help
	  Select this option, if you want to use PFAULT pseudo page fault
	  handling under VM. If running native or in LPAR, this option
	  has no effect. If your VM does not support PFAULT, PAGEEX
	  pseudo page fault handling will be used.
	  Note that VM 4.2 supports PFAULT but has a bug in its
	  implementation that causes some problems.
	  Everybody who wants to run Linux under VM != VM4.2 should select
	  this option.

config SHARED_KERNEL
	bool "VM shared kernel support"
	depends on !JUMP_LABEL
	help
	  Select this option, if you want to share the text segment of the
	  Linux kernel between different VM guests. This reduces memory
	  usage with lots of guests but greatly increases kernel size.
	  Also if a kernel was IPL'ed from a shared segment the kexec system
	  call will not work.
	  You should only select this option if you know what you are
	  doing and want to exploit this feature.

config CMM
	def_tristate n
	prompt "Cooperative memory management"
	help
	  Select this option, if you want to enable the kernel interface
	  to reduce the memory size of the system. This is accomplished
	  by allocating pages of memory and put them "on hold". This only
	  makes sense for a system running under VM where the unused pages
	  will be reused by VM for other guest systems. The interface
	  allows an external monitor to balance memory of many systems.
	  Everybody who wants to run Linux under VM should select this
	  option.

config CMM_IUCV
	def_bool y
	prompt "IUCV special message interface to cooperative memory management"
	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
	help
	  Select this option to enable the special message interface to
	  the cooperative memory management.

config APPLDATA_BASE
	def_bool n
	prompt "Linux - VM Monitor Stream, base infrastructure"
	depends on PROC_FS
	help
	  This provides a kernel interface for creating and updating z/VM APPLDATA
	  monitor records. The monitor records are updated at certain time
	  intervals, once the timer is started.
	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
	  i.e. enables or disables monitoring on the Linux side.
	  A custom interval value (in seconds) can be written to
	  /proc/appldata/interval.

	  Defaults are 60 seconds interval and timer off.
	  The /proc entries can also be read from, showing the current settings.

config APPLDATA_MEM
	def_tristate m
	prompt "Monitor memory management statistics"
	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
	help
	  This provides memory management related data to the Linux - VM Monitor
	  Stream, like paging/swapping rate, memory utilisation, etc.
	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
	  APPLDATA monitor record, i.e. enables or disables monitoring this record
	  on the z/VM side.

	  Default is disabled.
	  The /proc entry can also be read from, showing the current settings.

	  This can also be compiled as a module, which will be called
	  appldata_mem.o.

config APPLDATA_OS
	def_tristate m
	prompt "Monitor OS statistics"
	depends on APPLDATA_BASE
	help
	  This provides OS related data to the Linux - VM Monitor Stream, like
	  CPU utilisation, etc.
	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
	  APPLDATA monitor record, i.e. enables or disables monitoring this record
	  on the z/VM side.

	  Default is disabled.
	  This can also be compiled as a module, which will be called
	  appldata_os.o.

config APPLDATA_NET_SUM
	def_tristate m
	prompt "Monitor overall network statistics"
	depends on APPLDATA_BASE && NET
	help
	  This provides network related data to the Linux - VM Monitor Stream,
	  currently there is only a total sum of network I/O statistics, no
	  per-interface data.
	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
	  APPLDATA monitor record, i.e. enables or disables monitoring this record
	  on the z/VM side.

	  Default is disabled.
	  This can also be compiled as a module, which will be called
	  appldata_net_sum.o.

config S390_HYPFS_FS
	def_bool y
	prompt "s390 hypervisor file system support"
	select SYS_HYPERVISOR
	help
	  This is a virtual file system intended to provide accounting
	  information in an s390 hypervisor environment.

source "arch/s390/kvm/Kconfig"

config S390_GUEST
	def_bool y
	prompt "s390 support for virtio devices (EXPERIMENTAL)"
	depends on 64BIT && EXPERIMENTAL
	select VIRTUALIZATION
	select VIRTIO
	select VIRTIO_CONSOLE
	help
	  Enabling this option adds support for virtio based paravirtual device
	  drivers on s390.

	  Select this option if you want to run the kernel as a guest under
	  the KVM hypervisor.

endmenu