xref: /openbmc/linux/arch/s390/Kconfig (revision b6bec26c)
1config MMU
2	def_bool y
3
4config ZONE_DMA
5	def_bool y
6
7config LOCKDEP_SUPPORT
8	def_bool y
9
10config STACKTRACE_SUPPORT
11	def_bool y
12
13config HAVE_LATENCYTOP_SUPPORT
14	def_bool y
15
16config RWSEM_GENERIC_SPINLOCK
17	bool
18
19config RWSEM_XCHGADD_ALGORITHM
20	def_bool y
21
22config ARCH_HAS_ILOG2_U32
23	def_bool n
24
25config ARCH_HAS_ILOG2_U64
26	def_bool n
27
28config GENERIC_HWEIGHT
29	def_bool y
30
31config GENERIC_BUG
32	def_bool y if BUG
33
34config GENERIC_BUG_RELATIVE_POINTERS
35	def_bool y
36
37config ARCH_DMA_ADDR_T_64BIT
38	def_bool 64BIT
39
40config GENERIC_LOCKBREAK
41	def_bool y if SMP && PREEMPT
42
43config PGSTE
44	def_bool y if KVM
45
46config ARCH_SUPPORTS_DEBUG_PAGEALLOC
47	def_bool y
48
49config KEXEC
50	def_bool y
51
52config AUDIT_ARCH
53	def_bool y
54
55config NO_IOPORT
56	def_bool y
57
58config PCI_QUIRKS
59	def_bool n
60
61config 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 HAVE_MOD_ARCH_SPECIFIC
141	select MODULES_USE_ELF_RELA
142	select CLONE_BACKWARDS2
143
144config SCHED_OMIT_FRAME_POINTER
145	def_bool y
146
147source "init/Kconfig"
148
149source "kernel/Kconfig.freezer"
150
151menu "Processor type and features"
152
153config HAVE_MARCH_Z900_FEATURES
154	def_bool n
155
156config HAVE_MARCH_Z990_FEATURES
157	def_bool n
158	select HAVE_MARCH_Z900_FEATURES
159
160config HAVE_MARCH_Z9_109_FEATURES
161	def_bool n
162	select HAVE_MARCH_Z990_FEATURES
163
164config HAVE_MARCH_Z10_FEATURES
165	def_bool n
166	select HAVE_MARCH_Z9_109_FEATURES
167
168config HAVE_MARCH_Z196_FEATURES
169	def_bool n
170	select HAVE_MARCH_Z10_FEATURES
171
172config HAVE_MARCH_ZEC12_FEATURES
173	def_bool n
174	select HAVE_MARCH_Z196_FEATURES
175
176choice
177	prompt "Processor type"
178	default MARCH_G5
179
180config MARCH_G5
181	bool "System/390 model G5 and G6"
182	depends on !64BIT
183	help
184	  Select this to build a 31 bit kernel that works
185	  on all ESA/390 and z/Architecture machines.
186
187config MARCH_Z900
188	bool "IBM zSeries model z800 and z900"
189	select HAVE_MARCH_Z900_FEATURES if 64BIT
190	help
191	  Select this to enable optimizations for model z800/z900 (2064 and
192	  2066 series). This will enable some optimizations that are not
193	  available on older ESA/390 (31 Bit) only CPUs.
194
195config MARCH_Z990
196	bool "IBM zSeries model z890 and z990"
197	select HAVE_MARCH_Z990_FEATURES if 64BIT
198	help
199	  Select this to enable optimizations for model z890/z990 (2084 and
200	  2086 series). The kernel will be slightly faster but will not work
201	  on older machines.
202
203config MARCH_Z9_109
204	bool "IBM System z9"
205	select HAVE_MARCH_Z9_109_FEATURES if 64BIT
206	help
207	  Select this to enable optimizations for IBM System z9 (2094 and
208	  2096 series). The kernel will be slightly faster but will not work
209	  on older machines.
210
211config MARCH_Z10
212	bool "IBM System z10"
213	select HAVE_MARCH_Z10_FEATURES if 64BIT
214	help
215	  Select this to enable optimizations for IBM System z10 (2097 and
216	  2098 series). The kernel will be slightly faster but will not work
217	  on older machines.
218
219config MARCH_Z196
220	bool "IBM zEnterprise 114 and 196"
221	select HAVE_MARCH_Z196_FEATURES if 64BIT
222	help
223	  Select this to enable optimizations for IBM zEnterprise 114 and 196
224	  (2818 and 2817 series). The kernel will be slightly faster but will
225	  not work on older machines.
226
227config MARCH_ZEC12
228	bool "IBM zEC12"
229	select HAVE_MARCH_ZEC12_FEATURES if 64BIT
230	help
231	  Select this to enable optimizations for IBM zEC12 (2827 series). The
232	  kernel will be slightly faster but will not work on older machines.
233
234endchoice
235
236config 64BIT
237	def_bool y
238	prompt "64 bit kernel"
239	help
240	  Select this option if you have an IBM z/Architecture machine
241	  and want to use the 64 bit addressing mode.
242
243config 32BIT
244	def_bool y if !64BIT
245
246config COMPAT
247	def_bool y
248	prompt "Kernel support for 31 bit emulation"
249	depends on 64BIT
250	select COMPAT_BINFMT_ELF if BINFMT_ELF
251	select ARCH_WANT_OLD_COMPAT_IPC
252	help
253	  Select this option if you want to enable your system kernel to
254	  handle system-calls from ELF binaries for 31 bit ESA.  This option
255	  (and some other stuff like libraries and such) is needed for
256	  executing 31 bit applications.  It is safe to say "Y".
257
258config SYSVIPC_COMPAT
259	def_bool y if COMPAT && SYSVIPC
260
261config KEYS_COMPAT
262	def_bool y if COMPAT && KEYS
263
264config SMP
265	def_bool y
266	prompt "Symmetric multi-processing support"
267	---help---
268	  This enables support for systems with more than one CPU. If you have
269	  a system with only one CPU, like most personal computers, say N. If
270	  you have a system with more than one CPU, say Y.
271
272	  If you say N here, the kernel will run on single and multiprocessor
273	  machines, but will use only one CPU of a multiprocessor machine. If
274	  you say Y here, the kernel will run on many, but not all,
275	  singleprocessor machines. On a singleprocessor machine, the kernel
276	  will run faster if you say N here.
277
278	  See also the SMP-HOWTO available at
279	  <http://www.tldp.org/docs.html#howto>.
280
281	  Even if you don't know what to do here, say Y.
282
283config NR_CPUS
284	int "Maximum number of CPUs (2-64)"
285	range 2 64
286	depends on SMP
287	default "32" if !64BIT
288	default "64" if 64BIT
289	help
290	  This allows you to specify the maximum number of CPUs which this
291	  kernel will support.  The maximum supported value is 64 and the
292	  minimum value which makes sense is 2.
293
294	  This is purely to save memory - each supported CPU adds
295	  approximately sixteen kilobytes to the kernel image.
296
297config HOTPLUG_CPU
298	def_bool y
299	prompt "Support for hot-pluggable CPUs"
300	depends on SMP
301	select HOTPLUG
302	help
303	  Say Y here to be able to turn CPUs off and on. CPUs
304	  can be controlled through /sys/devices/system/cpu/cpu#.
305	  Say N if you want to disable CPU hotplug.
306
307config SCHED_MC
308	def_bool n
309
310config SCHED_BOOK
311	def_bool y
312	prompt "Book scheduler support"
313	depends on SMP
314	select SCHED_MC
315	help
316	  Book scheduler support improves the CPU scheduler's decision making
317	  when dealing with machines that have several books.
318
319source kernel/Kconfig.preempt
320
321config MATHEMU
322	def_bool y
323	prompt "IEEE FPU emulation"
324	depends on MARCH_G5
325	help
326	  This option is required for IEEE compliant floating point arithmetic
327	  on older ESA/390 machines. Say Y unless you know your machine doesn't
328	  need this.
329
330source kernel/Kconfig.hz
331
332endmenu
333
334menu "Memory setup"
335
336config ARCH_SPARSEMEM_ENABLE
337	def_bool y
338	select SPARSEMEM_VMEMMAP_ENABLE
339	select SPARSEMEM_VMEMMAP
340	select SPARSEMEM_STATIC if !64BIT
341
342config ARCH_SPARSEMEM_DEFAULT
343	def_bool y
344
345config ARCH_SELECT_MEMORY_MODEL
346	def_bool y
347
348config ARCH_ENABLE_MEMORY_HOTPLUG
349	def_bool y if SPARSEMEM
350
351config ARCH_ENABLE_MEMORY_HOTREMOVE
352	def_bool y
353
354config FORCE_MAX_ZONEORDER
355	int
356	default "9"
357
358source "mm/Kconfig"
359
360config PACK_STACK
361	def_bool y
362	prompt "Pack kernel stack"
363	help
364	  This option enables the compiler option -mkernel-backchain if it
365	  is available. If the option is available the compiler supports
366	  the new stack layout which dramatically reduces the minimum stack
367	  frame size. With an old compiler a non-leaf function needs a
368	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
369	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
370	  and 24 byte on 64 bit.
371
372	  Say Y if you are unsure.
373
374config SMALL_STACK
375	def_bool n
376	prompt "Use 8kb for kernel stack instead of 16kb"
377	depends on PACK_STACK && 64BIT && !LOCKDEP
378	help
379	  If you say Y here and the compiler supports the -mkernel-backchain
380	  option the kernel will use a smaller kernel stack size. The reduced
381	  size is 8kb instead of 16kb. This allows to run more threads on a
382	  system and reduces the pressure on the memory management for higher
383	  order page allocations.
384
385	  Say N if you are unsure.
386
387config CHECK_STACK
388	def_bool y
389	prompt "Detect kernel stack overflow"
390	help
391	  This option enables the compiler option -mstack-guard and
392	  -mstack-size if they are available. If the compiler supports them
393	  it will emit additional code to each function prolog to trigger
394	  an illegal operation if the kernel stack is about to overflow.
395
396	  Say N if you are unsure.
397
398config STACK_GUARD
399	int "Size of the guard area (128-1024)"
400	range 128 1024
401	depends on CHECK_STACK
402	default "256"
403	help
404	  This allows you to specify the size of the guard area at the lower
405	  end of the kernel stack. If the kernel stack points into the guard
406	  area on function entry an illegal operation is triggered. The size
407	  needs to be a power of 2. Please keep in mind that the size of an
408	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
409	  The minimum size for the stack guard should be 256 for 31 bit and
410	  512 for 64 bit.
411
412config WARN_DYNAMIC_STACK
413	def_bool n
414	prompt "Emit compiler warnings for function with dynamic stack usage"
415	help
416	  This option enables the compiler option -mwarn-dynamicstack. If the
417	  compiler supports this options generates warnings for functions
418	  that dynamically allocate stack space using alloca.
419
420	  Say N if you are unsure.
421
422endmenu
423
424menu "I/O subsystem"
425
426config QDIO
427	def_tristate y
428	prompt "QDIO support"
429	---help---
430	  This driver provides the Queued Direct I/O base support for
431	  IBM System z.
432
433	  To compile this driver as a module, choose M here: the
434	  module will be called qdio.
435
436	  If unsure, say Y.
437
438menuconfig PCI
439	bool "PCI support"
440	default n
441	depends on 64BIT
442	select ARCH_SUPPORTS_MSI
443	select PCI_MSI
444	help
445	  Enable PCI support.
446
447if PCI
448
449config PCI_NR_FUNCTIONS
450	int "Maximum number of PCI functions (1-4096)"
451	range 1 4096
452	default "64"
453	help
454	  This allows you to specify the maximum number of PCI functions which
455	  this kernel will support.
456
457source "drivers/pci/Kconfig"
458source "drivers/pci/pcie/Kconfig"
459source "drivers/pci/hotplug/Kconfig"
460
461endif	# PCI
462
463config PCI_DOMAINS
464	def_bool PCI
465
466config HAS_IOMEM
467	def_bool PCI
468
469config IOMMU_HELPER
470	def_bool PCI
471
472config HAS_DMA
473	def_bool PCI
474	select HAVE_DMA_API_DEBUG
475
476config NEED_SG_DMA_LENGTH
477	def_bool PCI
478
479config HAVE_DMA_ATTRS
480	def_bool PCI
481
482config NEED_DMA_MAP_STATE
483	def_bool PCI
484
485config CHSC_SCH
486	def_tristate m
487	prompt "Support for CHSC subchannels"
488	help
489	  This driver allows usage of CHSC subchannels. A CHSC subchannel
490	  is usually present on LPAR only.
491	  The driver creates a device /dev/chsc, which may be used to
492	  obtain I/O configuration information about the machine and
493	  to issue asynchronous chsc commands (DANGEROUS).
494	  You will usually only want to use this interface on a special
495	  LPAR designated for system management.
496
497	  To compile this driver as a module, choose M here: the
498	  module will be called chsc_sch.
499
500	  If unsure, say N.
501
502config SCM_BUS
503	def_bool y
504	depends on 64BIT
505	prompt "SCM bus driver"
506	help
507	  Bus driver for Storage Class Memory.
508
509config EADM_SCH
510	def_tristate m
511	prompt "Support for EADM subchannels"
512	depends on SCM_BUS
513	help
514	  This driver allows usage of EADM subchannels. EADM subchannels act
515	  as a communication vehicle for SCM increments.
516
517	  To compile this driver as a module, choose M here: the
518	  module will be called eadm_sch.
519
520endmenu
521
522menu "Dump support"
523
524config CRASH_DUMP
525	bool "kernel crash dumps"
526	depends on 64BIT && SMP
527	select KEXEC
528	help
529	  Generate crash dump after being started by kexec.
530	  Crash dump kernels are loaded in the main kernel with kexec-tools
531	  into a specially reserved region and then later executed after
532	  a crash by kdump/kexec.
533	  For more details see Documentation/kdump/kdump.txt
534
535config ZFCPDUMP
536	def_bool n
537	prompt "zfcpdump support"
538	select SMP
539	help
540	  Select this option if you want to build an zfcpdump enabled kernel.
541	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
542
543endmenu
544
545menu "Executable file formats / Emulations"
546
547source "fs/Kconfig.binfmt"
548
549config SECCOMP
550	def_bool y
551	prompt "Enable seccomp to safely compute untrusted bytecode"
552	depends on PROC_FS
553	help
554	  This kernel feature is useful for number crunching applications
555	  that may need to compute untrusted bytecode during their
556	  execution. By using pipes or other transports made available to
557	  the process as file descriptors supporting the read/write
558	  syscalls, it's possible to isolate those applications in
559	  their own address space using seccomp. Once seccomp is
560	  enabled via /proc/<pid>/seccomp, it cannot be disabled
561	  and the task is only allowed to execute a few safe syscalls
562	  defined by each seccomp mode.
563
564	  If unsure, say Y.
565
566endmenu
567
568menu "Power Management"
569
570config ARCH_HIBERNATION_POSSIBLE
571	def_bool y if 64BIT
572
573source "kernel/power/Kconfig"
574
575endmenu
576
577source "net/Kconfig"
578
579config PCMCIA
580	def_bool n
581
582config CCW
583	def_bool y
584
585source "drivers/Kconfig"
586
587source "fs/Kconfig"
588
589source "arch/s390/Kconfig.debug"
590
591source "security/Kconfig"
592
593source "crypto/Kconfig"
594
595source "lib/Kconfig"
596
597menu "Virtualization"
598
599config PFAULT
600	def_bool y
601	prompt "Pseudo page fault support"
602	help
603	  Select this option, if you want to use PFAULT pseudo page fault
604	  handling under VM. If running native or in LPAR, this option
605	  has no effect. If your VM does not support PFAULT, PAGEEX
606	  pseudo page fault handling will be used.
607	  Note that VM 4.2 supports PFAULT but has a bug in its
608	  implementation that causes some problems.
609	  Everybody who wants to run Linux under VM != VM4.2 should select
610	  this option.
611
612config SHARED_KERNEL
613	bool "VM shared kernel support"
614	depends on !JUMP_LABEL
615	help
616	  Select this option, if you want to share the text segment of the
617	  Linux kernel between different VM guests. This reduces memory
618	  usage with lots of guests but greatly increases kernel size.
619	  Also if a kernel was IPL'ed from a shared segment the kexec system
620	  call will not work.
621	  You should only select this option if you know what you are
622	  doing and want to exploit this feature.
623
624config CMM
625	def_tristate n
626	prompt "Cooperative memory management"
627	help
628	  Select this option, if you want to enable the kernel interface
629	  to reduce the memory size of the system. This is accomplished
630	  by allocating pages of memory and put them "on hold". This only
631	  makes sense for a system running under VM where the unused pages
632	  will be reused by VM for other guest systems. The interface
633	  allows an external monitor to balance memory of many systems.
634	  Everybody who wants to run Linux under VM should select this
635	  option.
636
637config CMM_IUCV
638	def_bool y
639	prompt "IUCV special message interface to cooperative memory management"
640	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
641	help
642	  Select this option to enable the special message interface to
643	  the cooperative memory management.
644
645config APPLDATA_BASE
646	def_bool n
647	prompt "Linux - VM Monitor Stream, base infrastructure"
648	depends on PROC_FS
649	help
650	  This provides a kernel interface for creating and updating z/VM APPLDATA
651	  monitor records. The monitor records are updated at certain time
652	  intervals, once the timer is started.
653	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
654	  i.e. enables or disables monitoring on the Linux side.
655	  A custom interval value (in seconds) can be written to
656	  /proc/appldata/interval.
657
658	  Defaults are 60 seconds interval and timer off.
659	  The /proc entries can also be read from, showing the current settings.
660
661config APPLDATA_MEM
662	def_tristate m
663	prompt "Monitor memory management statistics"
664	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
665	help
666	  This provides memory management related data to the Linux - VM Monitor
667	  Stream, like paging/swapping rate, memory utilisation, etc.
668	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
669	  APPLDATA monitor record, i.e. enables or disables monitoring this record
670	  on the z/VM side.
671
672	  Default is disabled.
673	  The /proc entry can also be read from, showing the current settings.
674
675	  This can also be compiled as a module, which will be called
676	  appldata_mem.o.
677
678config APPLDATA_OS
679	def_tristate m
680	prompt "Monitor OS statistics"
681	depends on APPLDATA_BASE
682	help
683	  This provides OS related data to the Linux - VM Monitor Stream, like
684	  CPU utilisation, etc.
685	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
686	  APPLDATA monitor record, i.e. enables or disables monitoring this record
687	  on the z/VM side.
688
689	  Default is disabled.
690	  This can also be compiled as a module, which will be called
691	  appldata_os.o.
692
693config APPLDATA_NET_SUM
694	def_tristate m
695	prompt "Monitor overall network statistics"
696	depends on APPLDATA_BASE && NET
697	help
698	  This provides network related data to the Linux - VM Monitor Stream,
699	  currently there is only a total sum of network I/O statistics, no
700	  per-interface data.
701	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
702	  APPLDATA monitor record, i.e. enables or disables monitoring this record
703	  on the z/VM side.
704
705	  Default is disabled.
706	  This can also be compiled as a module, which will be called
707	  appldata_net_sum.o.
708
709config S390_HYPFS_FS
710	def_bool y
711	prompt "s390 hypervisor file system support"
712	select SYS_HYPERVISOR
713	help
714	  This is a virtual file system intended to provide accounting
715	  information in an s390 hypervisor environment.
716
717source "arch/s390/kvm/Kconfig"
718
719config S390_GUEST
720	def_bool y
721	prompt "s390 support for virtio devices (EXPERIMENTAL)"
722	depends on 64BIT && EXPERIMENTAL
723	select VIRTUALIZATION
724	select VIRTIO
725	select VIRTIO_CONSOLE
726	help
727	  Enabling this option adds support for virtio based paravirtual device
728	  drivers on s390.
729
730	  Select this option if you want to run the kernel as a guest under
731	  the KVM hypervisor.
732
733endmenu
734