xref: /openbmc/linux/arch/s390/Kconfig (revision 97da55fc)
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 ARCH_DISCARD_MEMBLOCK
64	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
65	select ARCH_HAVE_NMI_SAFE_CMPXCHG
66	select ARCH_INLINE_READ_LOCK
67	select ARCH_INLINE_READ_LOCK_BH
68	select ARCH_INLINE_READ_LOCK_IRQ
69	select ARCH_INLINE_READ_LOCK_IRQSAVE
70	select ARCH_INLINE_READ_TRYLOCK
71	select ARCH_INLINE_READ_UNLOCK
72	select ARCH_INLINE_READ_UNLOCK_BH
73	select ARCH_INLINE_READ_UNLOCK_IRQ
74	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
75	select ARCH_INLINE_SPIN_LOCK
76	select ARCH_INLINE_SPIN_LOCK_BH
77	select ARCH_INLINE_SPIN_LOCK_IRQ
78	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
79	select ARCH_INLINE_SPIN_TRYLOCK
80	select ARCH_INLINE_SPIN_TRYLOCK_BH
81	select ARCH_INLINE_SPIN_UNLOCK
82	select ARCH_INLINE_SPIN_UNLOCK_BH
83	select ARCH_INLINE_SPIN_UNLOCK_IRQ
84	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
85	select ARCH_INLINE_WRITE_LOCK
86	select ARCH_INLINE_WRITE_LOCK_BH
87	select ARCH_INLINE_WRITE_LOCK_IRQ
88	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
89	select ARCH_INLINE_WRITE_TRYLOCK
90	select ARCH_INLINE_WRITE_UNLOCK
91	select ARCH_INLINE_WRITE_UNLOCK_BH
92	select ARCH_INLINE_WRITE_UNLOCK_IRQ
93	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
94	select ARCH_SAVE_PAGE_KEYS if HIBERNATION
95	select ARCH_WANT_IPC_PARSE_VERSION
96	select BUILDTIME_EXTABLE_SORT
97	select CLONE_BACKWARDS2
98	select GENERIC_CLOCKEVENTS
99	select GENERIC_CPU_DEVICES if !SMP
100	select GENERIC_KERNEL_THREAD
101	select GENERIC_SMP_IDLE_THREAD
102	select GENERIC_TIME_VSYSCALL_OLD
103	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
104	select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
105	select HAVE_ARCH_MUTEX_CPU_RELAX
106	select HAVE_ARCH_SECCOMP_FILTER
107	select HAVE_ARCH_TRACEHOOK
108	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT
109	select HAVE_BPF_JIT if 64BIT && PACK_STACK
110	select HAVE_CMPXCHG_DOUBLE
111	select HAVE_CMPXCHG_LOCAL
112	select HAVE_C_RECORDMCOUNT
113	select HAVE_DEBUG_KMEMLEAK
114	select HAVE_DYNAMIC_FTRACE
115	select HAVE_FTRACE_MCOUNT_RECORD
116	select HAVE_FUNCTION_GRAPH_TRACER
117	select HAVE_FUNCTION_TRACER
118	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
119	select HAVE_KERNEL_BZIP2
120	select HAVE_KERNEL_GZIP
121	select HAVE_KERNEL_LZMA
122	select HAVE_KERNEL_LZO
123	select HAVE_KERNEL_XZ
124	select HAVE_KPROBES
125	select HAVE_KRETPROBES
126	select HAVE_KVM if 64BIT
127	select HAVE_MEMBLOCK
128	select HAVE_MEMBLOCK_NODE_MAP
129	select HAVE_MOD_ARCH_SPECIFIC
130	select HAVE_OPROFILE
131	select HAVE_PERF_EVENTS
132	select HAVE_REGS_AND_STACK_ACCESS_API
133	select HAVE_SYSCALL_TRACEPOINTS
134	select HAVE_SYSCALL_WRAPPERS
135	select HAVE_UID16 if 32BIT
136	select HAVE_VIRT_CPU_ACCOUNTING
137	select VIRT_TO_BUS
138	select INIT_ALL_POSSIBLE
139	select KTIME_SCALAR if 32BIT
140	select MODULES_USE_ELF_RELA
141	select OLD_SIGSUSPEND3
142	select OLD_SIGACTION
143	select SYSCTL_EXCEPTION_TRACE
144	select USE_GENERIC_SMP_HELPERS if SMP
145	select VIRT_CPU_ACCOUNTING
146
147config SCHED_OMIT_FRAME_POINTER
148	def_bool y
149
150source "init/Kconfig"
151
152source "kernel/Kconfig.freezer"
153
154menu "Processor type and features"
155
156config HAVE_MARCH_Z900_FEATURES
157	def_bool n
158
159config HAVE_MARCH_Z990_FEATURES
160	def_bool n
161	select HAVE_MARCH_Z900_FEATURES
162
163config HAVE_MARCH_Z9_109_FEATURES
164	def_bool n
165	select HAVE_MARCH_Z990_FEATURES
166
167config HAVE_MARCH_Z10_FEATURES
168	def_bool n
169	select HAVE_MARCH_Z9_109_FEATURES
170
171config HAVE_MARCH_Z196_FEATURES
172	def_bool n
173	select HAVE_MARCH_Z10_FEATURES
174
175config HAVE_MARCH_ZEC12_FEATURES
176	def_bool n
177	select HAVE_MARCH_Z196_FEATURES
178
179choice
180	prompt "Processor type"
181	default MARCH_G5
182
183config MARCH_G5
184	bool "System/390 model G5 and G6"
185	depends on !64BIT
186	help
187	  Select this to build a 31 bit kernel that works
188	  on all ESA/390 and z/Architecture machines.
189
190config MARCH_Z900
191	bool "IBM zSeries model z800 and z900"
192	select HAVE_MARCH_Z900_FEATURES if 64BIT
193	help
194	  Select this to enable optimizations for model z800/z900 (2064 and
195	  2066 series). This will enable some optimizations that are not
196	  available on older ESA/390 (31 Bit) only CPUs.
197
198config MARCH_Z990
199	bool "IBM zSeries model z890 and z990"
200	select HAVE_MARCH_Z990_FEATURES if 64BIT
201	help
202	  Select this to enable optimizations for model z890/z990 (2084 and
203	  2086 series). The kernel will be slightly faster but will not work
204	  on older machines.
205
206config MARCH_Z9_109
207	bool "IBM System z9"
208	select HAVE_MARCH_Z9_109_FEATURES if 64BIT
209	help
210	  Select this to enable optimizations for IBM System z9 (2094 and
211	  2096 series). The kernel will be slightly faster but will not work
212	  on older machines.
213
214config MARCH_Z10
215	bool "IBM System z10"
216	select HAVE_MARCH_Z10_FEATURES if 64BIT
217	help
218	  Select this to enable optimizations for IBM System z10 (2097 and
219	  2098 series). The kernel will be slightly faster but will not work
220	  on older machines.
221
222config MARCH_Z196
223	bool "IBM zEnterprise 114 and 196"
224	select HAVE_MARCH_Z196_FEATURES if 64BIT
225	help
226	  Select this to enable optimizations for IBM zEnterprise 114 and 196
227	  (2818 and 2817 series). The kernel will be slightly faster but will
228	  not work on older machines.
229
230config MARCH_ZEC12
231	bool "IBM zEC12"
232	select HAVE_MARCH_ZEC12_FEATURES if 64BIT
233	help
234	  Select this to enable optimizations for IBM zEC12 (2827 series). The
235	  kernel will be slightly faster but will not work on older machines.
236
237endchoice
238
239config 64BIT
240	def_bool y
241	prompt "64 bit kernel"
242	help
243	  Select this option if you have an IBM z/Architecture machine
244	  and want to use the 64 bit addressing mode.
245
246config 32BIT
247	def_bool y if !64BIT
248
249config COMPAT
250	def_bool y
251	prompt "Kernel support for 31 bit emulation"
252	depends on 64BIT
253	select COMPAT_BINFMT_ELF if BINFMT_ELF
254	select ARCH_WANT_OLD_COMPAT_IPC
255	select COMPAT_OLD_SIGACTION
256	help
257	  Select this option if you want to enable your system kernel to
258	  handle system-calls from ELF binaries for 31 bit ESA.  This option
259	  (and some other stuff like libraries and such) is needed for
260	  executing 31 bit applications.  It is safe to say "Y".
261
262config SYSVIPC_COMPAT
263	def_bool y if COMPAT && SYSVIPC
264
265config KEYS_COMPAT
266	def_bool y if COMPAT && KEYS
267
268config SMP
269	def_bool y
270	prompt "Symmetric multi-processing support"
271	---help---
272	  This enables support for systems with more than one CPU. If you have
273	  a system with only one CPU, like most personal computers, say N. If
274	  you have a system with more than one CPU, say Y.
275
276	  If you say N here, the kernel will run on single and multiprocessor
277	  machines, but will use only one CPU of a multiprocessor machine. If
278	  you say Y here, the kernel will run on many, but not all,
279	  singleprocessor machines. On a singleprocessor machine, the kernel
280	  will run faster if you say N here.
281
282	  See also the SMP-HOWTO available at
283	  <http://www.tldp.org/docs.html#howto>.
284
285	  Even if you don't know what to do here, say Y.
286
287config NR_CPUS
288	int "Maximum number of CPUs (2-64)"
289	range 2 64
290	depends on SMP
291	default "32" if !64BIT
292	default "64" if 64BIT
293	help
294	  This allows you to specify the maximum number of CPUs which this
295	  kernel will support.  The maximum supported value is 64 and the
296	  minimum value which makes sense is 2.
297
298	  This is purely to save memory - each supported CPU adds
299	  approximately sixteen kilobytes to the kernel image.
300
301config HOTPLUG_CPU
302	def_bool y
303	prompt "Support for hot-pluggable CPUs"
304	depends on SMP
305	select HOTPLUG
306	help
307	  Say Y here to be able to turn CPUs off and on. CPUs
308	  can be controlled through /sys/devices/system/cpu/cpu#.
309	  Say N if you want to disable CPU hotplug.
310
311config SCHED_MC
312	def_bool n
313
314config SCHED_BOOK
315	def_bool y
316	prompt "Book scheduler support"
317	depends on SMP
318	select SCHED_MC
319	help
320	  Book scheduler support improves the CPU scheduler's decision making
321	  when dealing with machines that have several books.
322
323source kernel/Kconfig.preempt
324
325config MATHEMU
326	def_bool y
327	prompt "IEEE FPU emulation"
328	depends on MARCH_G5
329	help
330	  This option is required for IEEE compliant floating point arithmetic
331	  on older ESA/390 machines. Say Y unless you know your machine doesn't
332	  need this.
333
334source kernel/Kconfig.hz
335
336endmenu
337
338menu "Memory setup"
339
340config ARCH_SPARSEMEM_ENABLE
341	def_bool y
342	select SPARSEMEM_VMEMMAP_ENABLE
343	select SPARSEMEM_VMEMMAP
344	select SPARSEMEM_STATIC if !64BIT
345
346config ARCH_SPARSEMEM_DEFAULT
347	def_bool y
348
349config ARCH_SELECT_MEMORY_MODEL
350	def_bool y
351
352config ARCH_ENABLE_MEMORY_HOTPLUG
353	def_bool y if SPARSEMEM
354
355config ARCH_ENABLE_MEMORY_HOTREMOVE
356	def_bool y
357
358config FORCE_MAX_ZONEORDER
359	int
360	default "9"
361
362source "mm/Kconfig"
363
364config PACK_STACK
365	def_bool y
366	prompt "Pack kernel stack"
367	help
368	  This option enables the compiler option -mkernel-backchain if it
369	  is available. If the option is available the compiler supports
370	  the new stack layout which dramatically reduces the minimum stack
371	  frame size. With an old compiler a non-leaf function needs a
372	  minimum of 96 bytes on 31 bit and 160 bytes on 64 bit. With
373	  -mkernel-backchain the minimum size drops to 16 byte on 31 bit
374	  and 24 byte on 64 bit.
375
376	  Say Y if you are unsure.
377
378config SMALL_STACK
379	def_bool n
380	prompt "Use 8kb for kernel stack instead of 16kb"
381	depends on PACK_STACK && 64BIT && !LOCKDEP
382	help
383	  If you say Y here and the compiler supports the -mkernel-backchain
384	  option the kernel will use a smaller kernel stack size. The reduced
385	  size is 8kb instead of 16kb. This allows to run more threads on a
386	  system and reduces the pressure on the memory management for higher
387	  order page allocations.
388
389	  Say N if you are unsure.
390
391config CHECK_STACK
392	def_bool y
393	prompt "Detect kernel stack overflow"
394	help
395	  This option enables the compiler option -mstack-guard and
396	  -mstack-size if they are available. If the compiler supports them
397	  it will emit additional code to each function prolog to trigger
398	  an illegal operation if the kernel stack is about to overflow.
399
400	  Say N if you are unsure.
401
402config STACK_GUARD
403	int "Size of the guard area (128-1024)"
404	range 128 1024
405	depends on CHECK_STACK
406	default "256"
407	help
408	  This allows you to specify the size of the guard area at the lower
409	  end of the kernel stack. If the kernel stack points into the guard
410	  area on function entry an illegal operation is triggered. The size
411	  needs to be a power of 2. Please keep in mind that the size of an
412	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
413	  The minimum size for the stack guard should be 256 for 31 bit and
414	  512 for 64 bit.
415
416config WARN_DYNAMIC_STACK
417	def_bool n
418	prompt "Emit compiler warnings for function with dynamic stack usage"
419	help
420	  This option enables the compiler option -mwarn-dynamicstack. If the
421	  compiler supports this options generates warnings for functions
422	  that dynamically allocate stack space using alloca.
423
424	  Say N if you are unsure.
425
426endmenu
427
428menu "I/O subsystem"
429
430config QDIO
431	def_tristate y
432	prompt "QDIO support"
433	---help---
434	  This driver provides the Queued Direct I/O base support for
435	  IBM System z.
436
437	  To compile this driver as a module, choose M here: the
438	  module will be called qdio.
439
440	  If unsure, say Y.
441
442menuconfig PCI
443	bool "PCI support"
444	default n
445	depends on 64BIT
446	select ARCH_SUPPORTS_MSI
447	select PCI_MSI
448	help
449	  Enable PCI support.
450
451if PCI
452
453config PCI_NR_FUNCTIONS
454	int "Maximum number of PCI functions (1-4096)"
455	range 1 4096
456	default "64"
457	help
458	  This allows you to specify the maximum number of PCI functions which
459	  this kernel will support.
460
461source "drivers/pci/Kconfig"
462source "drivers/pci/pcie/Kconfig"
463source "drivers/pci/hotplug/Kconfig"
464
465endif	# PCI
466
467config PCI_DOMAINS
468	def_bool PCI
469
470config HAS_IOMEM
471	def_bool PCI
472
473config IOMMU_HELPER
474	def_bool PCI
475
476config HAS_DMA
477	def_bool PCI
478	select HAVE_DMA_API_DEBUG
479
480config NEED_SG_DMA_LENGTH
481	def_bool PCI
482
483config HAVE_DMA_ATTRS
484	def_bool PCI
485
486config NEED_DMA_MAP_STATE
487	def_bool PCI
488
489config CHSC_SCH
490	def_tristate m
491	prompt "Support for CHSC subchannels"
492	help
493	  This driver allows usage of CHSC subchannels. A CHSC subchannel
494	  is usually present on LPAR only.
495	  The driver creates a device /dev/chsc, which may be used to
496	  obtain I/O configuration information about the machine and
497	  to issue asynchronous chsc commands (DANGEROUS).
498	  You will usually only want to use this interface on a special
499	  LPAR designated for system management.
500
501	  To compile this driver as a module, choose M here: the
502	  module will be called chsc_sch.
503
504	  If unsure, say N.
505
506config SCM_BUS
507	def_bool y
508	depends on 64BIT
509	prompt "SCM bus driver"
510	help
511	  Bus driver for Storage Class Memory.
512
513config EADM_SCH
514	def_tristate m
515	prompt "Support for EADM subchannels"
516	depends on SCM_BUS
517	help
518	  This driver allows usage of EADM subchannels. EADM subchannels act
519	  as a communication vehicle for SCM increments.
520
521	  To compile this driver as a module, choose M here: the
522	  module will be called eadm_sch.
523
524endmenu
525
526menu "Dump support"
527
528config CRASH_DUMP
529	bool "kernel crash dumps"
530	depends on 64BIT && SMP
531	select KEXEC
532	help
533	  Generate crash dump after being started by kexec.
534	  Crash dump kernels are loaded in the main kernel with kexec-tools
535	  into a specially reserved region and then later executed after
536	  a crash by kdump/kexec.
537	  For more details see Documentation/kdump/kdump.txt
538
539config ZFCPDUMP
540	def_bool n
541	prompt "zfcpdump support"
542	select SMP
543	help
544	  Select this option if you want to build an zfcpdump enabled kernel.
545	  Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
546
547endmenu
548
549menu "Executable file formats / Emulations"
550
551source "fs/Kconfig.binfmt"
552
553config SECCOMP
554	def_bool y
555	prompt "Enable seccomp to safely compute untrusted bytecode"
556	depends on PROC_FS
557	help
558	  This kernel feature is useful for number crunching applications
559	  that may need to compute untrusted bytecode during their
560	  execution. By using pipes or other transports made available to
561	  the process as file descriptors supporting the read/write
562	  syscalls, it's possible to isolate those applications in
563	  their own address space using seccomp. Once seccomp is
564	  enabled via /proc/<pid>/seccomp, it cannot be disabled
565	  and the task is only allowed to execute a few safe syscalls
566	  defined by each seccomp mode.
567
568	  If unsure, say Y.
569
570endmenu
571
572menu "Power Management"
573
574config ARCH_HIBERNATION_POSSIBLE
575	def_bool y if 64BIT
576
577source "kernel/power/Kconfig"
578
579endmenu
580
581source "net/Kconfig"
582
583config PCMCIA
584	def_bool n
585
586config CCW
587	def_bool y
588
589source "drivers/Kconfig"
590
591source "fs/Kconfig"
592
593source "arch/s390/Kconfig.debug"
594
595source "security/Kconfig"
596
597source "crypto/Kconfig"
598
599source "lib/Kconfig"
600
601menu "Virtualization"
602
603config PFAULT
604	def_bool y
605	prompt "Pseudo page fault support"
606	help
607	  Select this option, if you want to use PFAULT pseudo page fault
608	  handling under VM. If running native or in LPAR, this option
609	  has no effect. If your VM does not support PFAULT, PAGEEX
610	  pseudo page fault handling will be used.
611	  Note that VM 4.2 supports PFAULT but has a bug in its
612	  implementation that causes some problems.
613	  Everybody who wants to run Linux under VM != VM4.2 should select
614	  this option.
615
616config SHARED_KERNEL
617	bool "VM shared kernel support"
618	depends on !JUMP_LABEL
619	help
620	  Select this option, if you want to share the text segment of the
621	  Linux kernel between different VM guests. This reduces memory
622	  usage with lots of guests but greatly increases kernel size.
623	  Also if a kernel was IPL'ed from a shared segment the kexec system
624	  call will not work.
625	  You should only select this option if you know what you are
626	  doing and want to exploit this feature.
627
628config CMM
629	def_tristate n
630	prompt "Cooperative memory management"
631	help
632	  Select this option, if you want to enable the kernel interface
633	  to reduce the memory size of the system. This is accomplished
634	  by allocating pages of memory and put them "on hold". This only
635	  makes sense for a system running under VM where the unused pages
636	  will be reused by VM for other guest systems. The interface
637	  allows an external monitor to balance memory of many systems.
638	  Everybody who wants to run Linux under VM should select this
639	  option.
640
641config CMM_IUCV
642	def_bool y
643	prompt "IUCV special message interface to cooperative memory management"
644	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
645	help
646	  Select this option to enable the special message interface to
647	  the cooperative memory management.
648
649config APPLDATA_BASE
650	def_bool n
651	prompt "Linux - VM Monitor Stream, base infrastructure"
652	depends on PROC_FS
653	help
654	  This provides a kernel interface for creating and updating z/VM APPLDATA
655	  monitor records. The monitor records are updated at certain time
656	  intervals, once the timer is started.
657	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
658	  i.e. enables or disables monitoring on the Linux side.
659	  A custom interval value (in seconds) can be written to
660	  /proc/appldata/interval.
661
662	  Defaults are 60 seconds interval and timer off.
663	  The /proc entries can also be read from, showing the current settings.
664
665config APPLDATA_MEM
666	def_tristate m
667	prompt "Monitor memory management statistics"
668	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
669	help
670	  This provides memory management related data to the Linux - VM Monitor
671	  Stream, like paging/swapping rate, memory utilisation, etc.
672	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
673	  APPLDATA monitor record, i.e. enables or disables monitoring this record
674	  on the z/VM side.
675
676	  Default is disabled.
677	  The /proc entry can also be read from, showing the current settings.
678
679	  This can also be compiled as a module, which will be called
680	  appldata_mem.o.
681
682config APPLDATA_OS
683	def_tristate m
684	prompt "Monitor OS statistics"
685	depends on APPLDATA_BASE
686	help
687	  This provides OS related data to the Linux - VM Monitor Stream, like
688	  CPU utilisation, etc.
689	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
690	  APPLDATA monitor record, i.e. enables or disables monitoring this record
691	  on the z/VM side.
692
693	  Default is disabled.
694	  This can also be compiled as a module, which will be called
695	  appldata_os.o.
696
697config APPLDATA_NET_SUM
698	def_tristate m
699	prompt "Monitor overall network statistics"
700	depends on APPLDATA_BASE && NET
701	help
702	  This provides network related data to the Linux - VM Monitor Stream,
703	  currently there is only a total sum of network I/O statistics, no
704	  per-interface data.
705	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
706	  APPLDATA monitor record, i.e. enables or disables monitoring this record
707	  on the z/VM side.
708
709	  Default is disabled.
710	  This can also be compiled as a module, which will be called
711	  appldata_net_sum.o.
712
713config S390_HYPFS_FS
714	def_bool y
715	prompt "s390 hypervisor file system support"
716	select SYS_HYPERVISOR
717	help
718	  This is a virtual file system intended to provide accounting
719	  information in an s390 hypervisor environment.
720
721source "arch/s390/kvm/Kconfig"
722
723config S390_GUEST
724	def_bool y
725	prompt "s390 support for virtio devices"
726	depends on 64BIT
727	select VIRTUALIZATION
728	select VIRTIO
729	select VIRTIO_CONSOLE
730	help
731	  Enabling this option adds support for virtio based paravirtual device
732	  drivers on s390.
733
734	  Select this option if you want to run the kernel as a guest under
735	  the KVM hypervisor.
736
737endmenu
738