xref: /openbmc/linux/arch/s390/Kconfig (revision 861e10be)
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_PERF_EVENTS
82	select ARCH_HAVE_NMI_SAFE_CMPXCHG
83	select HAVE_DEBUG_KMEMLEAK
84	select HAVE_KERNEL_GZIP
85	select HAVE_KERNEL_BZIP2
86	select HAVE_KERNEL_LZMA
87	select HAVE_KERNEL_LZO
88	select HAVE_KERNEL_XZ
89	select HAVE_ARCH_MUTEX_CPU_RELAX
90	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
91	select HAVE_BPF_JIT if 64BIT && PACK_STACK
92	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
93	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
94	select HAVE_MEMBLOCK
95	select HAVE_MEMBLOCK_NODE_MAP
96	select HAVE_CMPXCHG_LOCAL
97	select HAVE_CMPXCHG_DOUBLE
98	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
99	select HAVE_VIRT_CPU_ACCOUNTING
100	select VIRT_CPU_ACCOUNTING
101	select ARCH_DISCARD_MEMBLOCK
102	select BUILDTIME_EXTABLE_SORT
103	select ARCH_INLINE_SPIN_TRYLOCK
104	select ARCH_INLINE_SPIN_TRYLOCK_BH
105	select ARCH_INLINE_SPIN_LOCK
106	select ARCH_INLINE_SPIN_LOCK_BH
107	select ARCH_INLINE_SPIN_LOCK_IRQ
108	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
109	select ARCH_INLINE_SPIN_UNLOCK
110	select ARCH_INLINE_SPIN_UNLOCK_BH
111	select ARCH_INLINE_SPIN_UNLOCK_IRQ
112	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
113	select ARCH_INLINE_READ_TRYLOCK
114	select ARCH_INLINE_READ_LOCK
115	select ARCH_INLINE_READ_LOCK_BH
116	select ARCH_INLINE_READ_LOCK_IRQ
117	select ARCH_INLINE_READ_LOCK_IRQSAVE
118	select ARCH_INLINE_READ_UNLOCK
119	select ARCH_INLINE_READ_UNLOCK_BH
120	select ARCH_INLINE_READ_UNLOCK_IRQ
121	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
122	select ARCH_INLINE_WRITE_TRYLOCK
123	select ARCH_INLINE_WRITE_LOCK
124	select ARCH_INLINE_WRITE_LOCK_BH
125	select ARCH_INLINE_WRITE_LOCK_IRQ
126	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
127	select ARCH_INLINE_WRITE_UNLOCK
128	select ARCH_INLINE_WRITE_UNLOCK_BH
129	select ARCH_INLINE_WRITE_UNLOCK_IRQ
130	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
131	select HAVE_UID16 if 32BIT
132	select ARCH_WANT_IPC_PARSE_VERSION
133	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT
134	select GENERIC_SMP_IDLE_THREAD
135	select GENERIC_TIME_VSYSCALL_OLD
136	select GENERIC_CLOCKEVENTS
137	select KTIME_SCALAR if 32BIT
138	select HAVE_ARCH_SECCOMP_FILTER
139	select HAVE_MOD_ARCH_SPECIFIC
140	select MODULES_USE_ELF_RELA
141	select CLONE_BACKWARDS2
142
143config SCHED_OMIT_FRAME_POINTER
144	def_bool y
145
146source "init/Kconfig"
147
148source "kernel/Kconfig.freezer"
149
150menu "Processor type and features"
151
152config HAVE_MARCH_Z900_FEATURES
153	def_bool n
154
155config HAVE_MARCH_Z990_FEATURES
156	def_bool n
157	select HAVE_MARCH_Z900_FEATURES
158
159config HAVE_MARCH_Z9_109_FEATURES
160	def_bool n
161	select HAVE_MARCH_Z990_FEATURES
162
163config HAVE_MARCH_Z10_FEATURES
164	def_bool n
165	select HAVE_MARCH_Z9_109_FEATURES
166
167config HAVE_MARCH_Z196_FEATURES
168	def_bool n
169	select HAVE_MARCH_Z10_FEATURES
170
171config HAVE_MARCH_ZEC12_FEATURES
172	def_bool n
173	select HAVE_MARCH_Z196_FEATURES
174
175choice
176	prompt "Processor type"
177	default MARCH_G5
178
179config MARCH_G5
180	bool "System/390 model G5 and G6"
181	depends on !64BIT
182	help
183	  Select this to build a 31 bit kernel that works
184	  on all ESA/390 and z/Architecture machines.
185
186config MARCH_Z900
187	bool "IBM zSeries model z800 and z900"
188	select HAVE_MARCH_Z900_FEATURES if 64BIT
189	help
190	  Select this to enable optimizations for model z800/z900 (2064 and
191	  2066 series). This will enable some optimizations that are not
192	  available on older ESA/390 (31 Bit) only CPUs.
193
194config MARCH_Z990
195	bool "IBM zSeries model z890 and z990"
196	select HAVE_MARCH_Z990_FEATURES if 64BIT
197	help
198	  Select this to enable optimizations for model z890/z990 (2084 and
199	  2086 series). The kernel will be slightly faster but will not work
200	  on older machines.
201
202config MARCH_Z9_109
203	bool "IBM System z9"
204	select HAVE_MARCH_Z9_109_FEATURES if 64BIT
205	help
206	  Select this to enable optimizations for IBM System z9 (2094 and
207	  2096 series). The kernel will be slightly faster but will not work
208	  on older machines.
209
210config MARCH_Z10
211	bool "IBM System z10"
212	select HAVE_MARCH_Z10_FEATURES if 64BIT
213	help
214	  Select this to enable optimizations for IBM System z10 (2097 and
215	  2098 series). The kernel will be slightly faster but will not work
216	  on older machines.
217
218config MARCH_Z196
219	bool "IBM zEnterprise 114 and 196"
220	select HAVE_MARCH_Z196_FEATURES if 64BIT
221	help
222	  Select this to enable optimizations for IBM zEnterprise 114 and 196
223	  (2818 and 2817 series). The kernel will be slightly faster but will
224	  not work on older machines.
225
226config MARCH_ZEC12
227	bool "IBM zEC12"
228	select HAVE_MARCH_ZEC12_FEATURES if 64BIT
229	help
230	  Select this to enable optimizations for IBM zEC12 (2827 series). The
231	  kernel will be slightly faster but will not work on older machines.
232
233endchoice
234
235config 64BIT
236	def_bool y
237	prompt "64 bit kernel"
238	help
239	  Select this option if you have an IBM z/Architecture machine
240	  and want to use the 64 bit addressing mode.
241
242config 32BIT
243	def_bool y if !64BIT
244
245config COMPAT
246	def_bool y
247	prompt "Kernel support for 31 bit emulation"
248	depends on 64BIT
249	select COMPAT_BINFMT_ELF if BINFMT_ELF
250	select ARCH_WANT_OLD_COMPAT_IPC
251	help
252	  Select this option if you want to enable your system kernel to
253	  handle system-calls from ELF binaries for 31 bit ESA.  This option
254	  (and some other stuff like libraries and such) is needed for
255	  executing 31 bit applications.  It is safe to say "Y".
256
257config SYSVIPC_COMPAT
258	def_bool y if COMPAT && SYSVIPC
259
260config KEYS_COMPAT
261	def_bool y if COMPAT && KEYS
262
263config SMP
264	def_bool y
265	prompt "Symmetric multi-processing support"
266	---help---
267	  This enables support for systems with more than one CPU. If you have
268	  a system with only one CPU, like most personal computers, say N. If
269	  you have a system with more than one CPU, say Y.
270
271	  If you say N here, the kernel will run on single and multiprocessor
272	  machines, but will use only one CPU of a multiprocessor machine. If
273	  you say Y here, the kernel will run on many, but not all,
274	  singleprocessor machines. On a singleprocessor machine, the kernel
275	  will run faster if you say N here.
276
277	  See also the SMP-HOWTO available at
278	  <http://www.tldp.org/docs.html#howto>.
279
280	  Even if you don't know what to do here, say Y.
281
282config NR_CPUS
283	int "Maximum number of CPUs (2-64)"
284	range 2 64
285	depends on SMP
286	default "32" if !64BIT
287	default "64" if 64BIT
288	help
289	  This allows you to specify the maximum number of CPUs which this
290	  kernel will support.  The maximum supported value is 64 and the
291	  minimum value which makes sense is 2.
292
293	  This is purely to save memory - each supported CPU adds
294	  approximately sixteen kilobytes to the kernel image.
295
296config HOTPLUG_CPU
297	def_bool y
298	prompt "Support for hot-pluggable CPUs"
299	depends on SMP
300	select HOTPLUG
301	help
302	  Say Y here to be able to turn CPUs off and on. CPUs
303	  can be controlled through /sys/devices/system/cpu/cpu#.
304	  Say N if you want to disable CPU hotplug.
305
306config SCHED_MC
307	def_bool n
308
309config SCHED_BOOK
310	def_bool y
311	prompt "Book scheduler support"
312	depends on SMP
313	select SCHED_MC
314	help
315	  Book scheduler support improves the CPU scheduler's decision making
316	  when dealing with machines that have several books.
317
318source kernel/Kconfig.preempt
319
320config MATHEMU
321	def_bool y
322	prompt "IEEE FPU emulation"
323	depends on MARCH_G5
324	help
325	  This option is required for IEEE compliant floating point arithmetic
326	  on older ESA/390 machines. Say Y unless you know your machine doesn't
327	  need this.
328
329source kernel/Kconfig.hz
330
331endmenu
332
333menu "Memory setup"
334
335config ARCH_SPARSEMEM_ENABLE
336	def_bool y
337	select SPARSEMEM_VMEMMAP_ENABLE
338	select SPARSEMEM_VMEMMAP
339	select SPARSEMEM_STATIC if !64BIT
340
341config ARCH_SPARSEMEM_DEFAULT
342	def_bool y
343
344config ARCH_SELECT_MEMORY_MODEL
345	def_bool y
346
347config ARCH_ENABLE_MEMORY_HOTPLUG
348	def_bool y if SPARSEMEM
349
350config ARCH_ENABLE_MEMORY_HOTREMOVE
351	def_bool y
352
353config FORCE_MAX_ZONEORDER
354	int
355	default "9"
356
357source "mm/Kconfig"
358
359config PACK_STACK
360	def_bool y
361	prompt "Pack kernel stack"
362	help
363	  This option enables the compiler option -mkernel-backchain if it
364	  is available. If the option is available the compiler supports
365	  the new stack layout which dramatically reduces the minimum stack
366	  frame size. With an old compiler a non-leaf function needs a
367	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
368	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
369	  and 24 byte on 64 bit.
370
371	  Say Y if you are unsure.
372
373config SMALL_STACK
374	def_bool n
375	prompt "Use 8kb for kernel stack instead of 16kb"
376	depends on PACK_STACK && 64BIT && !LOCKDEP
377	help
378	  If you say Y here and the compiler supports the -mkernel-backchain
379	  option the kernel will use a smaller kernel stack size. The reduced
380	  size is 8kb instead of 16kb. This allows to run more threads on a
381	  system and reduces the pressure on the memory management for higher
382	  order page allocations.
383
384	  Say N if you are unsure.
385
386config CHECK_STACK
387	def_bool y
388	prompt "Detect kernel stack overflow"
389	help
390	  This option enables the compiler option -mstack-guard and
391	  -mstack-size if they are available. If the compiler supports them
392	  it will emit additional code to each function prolog to trigger
393	  an illegal operation if the kernel stack is about to overflow.
394
395	  Say N if you are unsure.
396
397config STACK_GUARD
398	int "Size of the guard area (128-1024)"
399	range 128 1024
400	depends on CHECK_STACK
401	default "256"
402	help
403	  This allows you to specify the size of the guard area at the lower
404	  end of the kernel stack. If the kernel stack points into the guard
405	  area on function entry an illegal operation is triggered. The size
406	  needs to be a power of 2. Please keep in mind that the size of an
407	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
408	  The minimum size for the stack guard should be 256 for 31 bit and
409	  512 for 64 bit.
410
411config WARN_DYNAMIC_STACK
412	def_bool n
413	prompt "Emit compiler warnings for function with dynamic stack usage"
414	help
415	  This option enables the compiler option -mwarn-dynamicstack. If the
416	  compiler supports this options generates warnings for functions
417	  that dynamically allocate stack space using alloca.
418
419	  Say N if you are unsure.
420
421endmenu
422
423menu "I/O subsystem"
424
425config QDIO
426	def_tristate y
427	prompt "QDIO support"
428	---help---
429	  This driver provides the Queued Direct I/O base support for
430	  IBM System z.
431
432	  To compile this driver as a module, choose M here: the
433	  module will be called qdio.
434
435	  If unsure, say Y.
436
437menuconfig PCI
438	bool "PCI support"
439	default n
440	depends on 64BIT
441	select ARCH_SUPPORTS_MSI
442	select PCI_MSI
443	help
444	  Enable PCI support.
445
446if PCI
447
448config PCI_NR_FUNCTIONS
449	int "Maximum number of PCI functions (1-4096)"
450	range 1 4096
451	default "64"
452	help
453	  This allows you to specify the maximum number of PCI functions which
454	  this kernel will support.
455
456source "drivers/pci/Kconfig"
457source "drivers/pci/pcie/Kconfig"
458source "drivers/pci/hotplug/Kconfig"
459
460endif	# PCI
461
462config PCI_DOMAINS
463	def_bool PCI
464
465config HAS_IOMEM
466	def_bool PCI
467
468config IOMMU_HELPER
469	def_bool PCI
470
471config HAS_DMA
472	def_bool PCI
473	select HAVE_DMA_API_DEBUG
474
475config NEED_SG_DMA_LENGTH
476	def_bool PCI
477
478config HAVE_DMA_ATTRS
479	def_bool PCI
480
481config NEED_DMA_MAP_STATE
482	def_bool PCI
483
484config CHSC_SCH
485	def_tristate m
486	prompt "Support for CHSC subchannels"
487	help
488	  This driver allows usage of CHSC subchannels. A CHSC subchannel
489	  is usually present on LPAR only.
490	  The driver creates a device /dev/chsc, which may be used to
491	  obtain I/O configuration information about the machine and
492	  to issue asynchronous chsc commands (DANGEROUS).
493	  You will usually only want to use this interface on a special
494	  LPAR designated for system management.
495
496	  To compile this driver as a module, choose M here: the
497	  module will be called chsc_sch.
498
499	  If unsure, say N.
500
501config SCM_BUS
502	def_bool y
503	depends on 64BIT
504	prompt "SCM bus driver"
505	help
506	  Bus driver for Storage Class Memory.
507
508config EADM_SCH
509	def_tristate m
510	prompt "Support for EADM subchannels"
511	depends on SCM_BUS
512	help
513	  This driver allows usage of EADM subchannels. EADM subchannels act
514	  as a communication vehicle for SCM increments.
515
516	  To compile this driver as a module, choose M here: the
517	  module will be called eadm_sch.
518
519endmenu
520
521menu "Dump support"
522
523config CRASH_DUMP
524	bool "kernel crash dumps"
525	depends on 64BIT && SMP
526	select KEXEC
527	help
528	  Generate crash dump after being started by kexec.
529	  Crash dump kernels are loaded in the main kernel with kexec-tools
530	  into a specially reserved region and then later executed after
531	  a crash by kdump/kexec.
532	  For more details see Documentation/kdump/kdump.txt
533
534config ZFCPDUMP
535	def_bool n
536	prompt "zfcpdump support"
537	select SMP
538	help
539	  Select this option if you want to build an zfcpdump enabled kernel.
540	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
541
542endmenu
543
544menu "Executable file formats / Emulations"
545
546source "fs/Kconfig.binfmt"
547
548config SECCOMP
549	def_bool y
550	prompt "Enable seccomp to safely compute untrusted bytecode"
551	depends on PROC_FS
552	help
553	  This kernel feature is useful for number crunching applications
554	  that may need to compute untrusted bytecode during their
555	  execution. By using pipes or other transports made available to
556	  the process as file descriptors supporting the read/write
557	  syscalls, it's possible to isolate those applications in
558	  their own address space using seccomp. Once seccomp is
559	  enabled via /proc/<pid>/seccomp, it cannot be disabled
560	  and the task is only allowed to execute a few safe syscalls
561	  defined by each seccomp mode.
562
563	  If unsure, say Y.
564
565endmenu
566
567menu "Power Management"
568
569config ARCH_HIBERNATION_POSSIBLE
570	def_bool y if 64BIT
571
572source "kernel/power/Kconfig"
573
574endmenu
575
576source "net/Kconfig"
577
578config PCMCIA
579	def_bool n
580
581config CCW
582	def_bool y
583
584source "drivers/Kconfig"
585
586source "fs/Kconfig"
587
588source "arch/s390/Kconfig.debug"
589
590source "security/Kconfig"
591
592source "crypto/Kconfig"
593
594source "lib/Kconfig"
595
596menu "Virtualization"
597
598config PFAULT
599	def_bool y
600	prompt "Pseudo page fault support"
601	help
602	  Select this option, if you want to use PFAULT pseudo page fault
603	  handling under VM. If running native or in LPAR, this option
604	  has no effect. If your VM does not support PFAULT, PAGEEX
605	  pseudo page fault handling will be used.
606	  Note that VM 4.2 supports PFAULT but has a bug in its
607	  implementation that causes some problems.
608	  Everybody who wants to run Linux under VM != VM4.2 should select
609	  this option.
610
611config SHARED_KERNEL
612	bool "VM shared kernel support"
613	depends on !JUMP_LABEL
614	help
615	  Select this option, if you want to share the text segment of the
616	  Linux kernel between different VM guests. This reduces memory
617	  usage with lots of guests but greatly increases kernel size.
618	  Also if a kernel was IPL'ed from a shared segment the kexec system
619	  call will not work.
620	  You should only select this option if you know what you are
621	  doing and want to exploit this feature.
622
623config CMM
624	def_tristate n
625	prompt "Cooperative memory management"
626	help
627	  Select this option, if you want to enable the kernel interface
628	  to reduce the memory size of the system. This is accomplished
629	  by allocating pages of memory and put them "on hold". This only
630	  makes sense for a system running under VM where the unused pages
631	  will be reused by VM for other guest systems. The interface
632	  allows an external monitor to balance memory of many systems.
633	  Everybody who wants to run Linux under VM should select this
634	  option.
635
636config CMM_IUCV
637	def_bool y
638	prompt "IUCV special message interface to cooperative memory management"
639	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
640	help
641	  Select this option to enable the special message interface to
642	  the cooperative memory management.
643
644config APPLDATA_BASE
645	def_bool n
646	prompt "Linux - VM Monitor Stream, base infrastructure"
647	depends on PROC_FS
648	help
649	  This provides a kernel interface for creating and updating z/VM APPLDATA
650	  monitor records. The monitor records are updated at certain time
651	  intervals, once the timer is started.
652	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
653	  i.e. enables or disables monitoring on the Linux side.
654	  A custom interval value (in seconds) can be written to
655	  /proc/appldata/interval.
656
657	  Defaults are 60 seconds interval and timer off.
658	  The /proc entries can also be read from, showing the current settings.
659
660config APPLDATA_MEM
661	def_tristate m
662	prompt "Monitor memory management statistics"
663	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
664	help
665	  This provides memory management related data to the Linux - VM Monitor
666	  Stream, like paging/swapping rate, memory utilisation, etc.
667	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
668	  APPLDATA monitor record, i.e. enables or disables monitoring this record
669	  on the z/VM side.
670
671	  Default is disabled.
672	  The /proc entry can also be read from, showing the current settings.
673
674	  This can also be compiled as a module, which will be called
675	  appldata_mem.o.
676
677config APPLDATA_OS
678	def_tristate m
679	prompt "Monitor OS statistics"
680	depends on APPLDATA_BASE
681	help
682	  This provides OS related data to the Linux - VM Monitor Stream, like
683	  CPU utilisation, etc.
684	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
685	  APPLDATA monitor record, i.e. enables or disables monitoring this record
686	  on the z/VM side.
687
688	  Default is disabled.
689	  This can also be compiled as a module, which will be called
690	  appldata_os.o.
691
692config APPLDATA_NET_SUM
693	def_tristate m
694	prompt "Monitor overall network statistics"
695	depends on APPLDATA_BASE && NET
696	help
697	  This provides network related data to the Linux - VM Monitor Stream,
698	  currently there is only a total sum of network I/O statistics, no
699	  per-interface data.
700	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
701	  APPLDATA monitor record, i.e. enables or disables monitoring this record
702	  on the z/VM side.
703
704	  Default is disabled.
705	  This can also be compiled as a module, which will be called
706	  appldata_net_sum.o.
707
708config S390_HYPFS_FS
709	def_bool y
710	prompt "s390 hypervisor file system support"
711	select SYS_HYPERVISOR
712	help
713	  This is a virtual file system intended to provide accounting
714	  information in an s390 hypervisor environment.
715
716source "arch/s390/kvm/Kconfig"
717
718config S390_GUEST
719	def_bool y
720	prompt "s390 support for virtio devices (EXPERIMENTAL)"
721	depends on 64BIT && EXPERIMENTAL
722	select VIRTUALIZATION
723	select VIRTIO
724	select VIRTIO_CONSOLE
725	help
726	  Enabling this option adds support for virtio based paravirtual device
727	  drivers on s390.
728
729	  Select this option if you want to run the kernel as a guest under
730	  the KVM hypervisor.
731
732endmenu
733