xref: /openbmc/linux/drivers/xen/Kconfig (revision 31b90347)
1menu "Xen driver support"
2	depends on XEN
3
4config XEN_BALLOON
5	bool "Xen memory balloon driver"
6	depends on !ARM
7	default y
8	help
9	  The balloon driver allows the Xen domain to request more memory from
10	  the system to expand the domain's memory allocation, or alternatively
11	  return unneeded memory to the system.
12
13config XEN_SELFBALLOONING
14	bool "Dynamically self-balloon kernel memory to target"
15	depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM
16	default n
17	help
18	  Self-ballooning dynamically balloons available kernel memory driven
19	  by the current usage of anonymous memory ("committed AS") and
20	  controlled by various sysfs-settable parameters.  Configuring
21	  FRONTSWAP is highly recommended; if it is not configured, self-
22	  ballooning is disabled by default. If FRONTSWAP is configured,
23	  frontswap-selfshrinking is enabled by default but can be disabled
24	  with the 'tmem.selfshrink=0' kernel boot parameter; and self-ballooning
25	  is enabled by default but can be disabled with the 'tmem.selfballooning=0'
26	  kernel boot parameter.  Note that systems without a sufficiently
27	  large swap device should not enable self-ballooning.
28
29config XEN_BALLOON_MEMORY_HOTPLUG
30	bool "Memory hotplug support for Xen balloon driver"
31	default n
32	depends on XEN_BALLOON && MEMORY_HOTPLUG
33	help
34	  Memory hotplug support for Xen balloon driver allows expanding memory
35	  available for the system above limit declared at system startup.
36	  It is very useful on critical systems which require long
37	  run without rebooting.
38
39	  Memory could be hotplugged in following steps:
40
41	    1) dom0: xl mem-max <domU> <maxmem>
42	       where <maxmem> is >= requested memory size,
43
44	    2) dom0: xl mem-set <domU> <memory>
45	       where <memory> is requested memory size; alternatively memory
46	       could be added by writing proper value to
47	       /sys/devices/system/xen_memory/xen_memory0/target or
48	       /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,
49
50	    3) domU: for i in /sys/devices/system/memory/memory*/state; do \
51	               [ "`cat "$i"`" = offline ] && echo online > "$i"; done
52
53	  Memory could be onlined automatically on domU by adding following line to udev rules:
54
55	  SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
56
57	  In that case step 3 should be omitted.
58
59config XEN_SCRUB_PAGES
60	bool "Scrub pages before returning them to system"
61	depends on XEN_BALLOON
62	default y
63	help
64	  Scrub pages before returning them to the system for reuse by
65	  other domains.  This makes sure that any confidential data
66	  is not accidentally visible to other domains.  Is it more
67	  secure, but slightly less efficient.
68	  If in doubt, say yes.
69
70config XEN_DEV_EVTCHN
71	tristate "Xen /dev/xen/evtchn device"
72	default y
73	help
74	  The evtchn driver allows a userspace process to trigger event
75	  channels and to receive notification of an event channel
76	  firing.
77	  If in doubt, say yes.
78
79config XEN_BACKEND
80	bool "Backend driver support"
81	depends on XEN_DOM0
82	default y
83	help
84	  Support for backend device drivers that provide I/O services
85	  to other virtual machines.
86
87config XENFS
88	tristate "Xen filesystem"
89	select XEN_PRIVCMD
90	default y
91	help
92	  The xen filesystem provides a way for domains to share
93	  information with each other and with the hypervisor.
94	  For example, by reading and writing the "xenbus" file, guests
95	  may pass arbitrary information to the initial domain.
96	  If in doubt, say yes.
97
98config XEN_COMPAT_XENFS
99       bool "Create compatibility mount point /proc/xen"
100       depends on XENFS
101       default y
102       help
103         The old xenstore userspace tools expect to find "xenbus"
104         under /proc/xen, but "xenbus" is now found at the root of the
105         xenfs filesystem.  Selecting this causes the kernel to create
106         the compatibility mount point /proc/xen if it is running on
107         a xen platform.
108         If in doubt, say yes.
109
110config XEN_SYS_HYPERVISOR
111       bool "Create xen entries under /sys/hypervisor"
112       depends on SYSFS
113       select SYS_HYPERVISOR
114       default y
115       help
116         Create entries under /sys/hypervisor describing the Xen
117	 hypervisor environment.  When running native or in another
118	 virtual environment, /sys/hypervisor will still be present,
119	 but will have no xen contents.
120
121config XEN_XENBUS_FRONTEND
122	tristate
123
124config XEN_GNTDEV
125	tristate "userspace grant access device driver"
126	depends on XEN
127	default m
128	select MMU_NOTIFIER
129	help
130	  Allows userspace processes to use grants.
131
132config XEN_GRANT_DEV_ALLOC
133	tristate "User-space grant reference allocator driver"
134	depends on XEN
135	default m
136	help
137	  Allows userspace processes to create pages with access granted
138	  to other domains. This can be used to implement frontend drivers
139	  or as part of an inter-domain shared memory channel.
140
141config SWIOTLB_XEN
142	def_bool y
143	select SWIOTLB
144
145config XEN_TMEM
146	tristate
147	depends on !ARM && !ARM64
148	default m if (CLEANCACHE || FRONTSWAP)
149	help
150	  Shim to interface in-kernel Transcendent Memory hooks
151	  (e.g. cleancache and frontswap) to Xen tmem hypercalls.
152
153config XEN_PCIDEV_BACKEND
154	tristate "Xen PCI-device backend driver"
155	depends on PCI && X86 && XEN
156	depends on XEN_BACKEND
157	default m
158	help
159	  The PCI device backend driver allows the kernel to export arbitrary
160	  PCI devices to other guests. If you select this to be a module, you
161	  will need to make sure no other driver has bound to the device(s)
162	  you want to make visible to other guests.
163
164	  The parameter "passthrough" allows you specify how you want the PCI
165	  devices to appear in the guest. You can choose the default (0) where
166	  PCI topology starts at 00.00.0, or (1) for passthrough if you want
167	  the PCI devices topology appear the same as in the host.
168
169	  The "hide" parameter (only applicable if backend driver is compiled
170	  into the kernel) allows you to bind the PCI devices to this module
171	  from the default device drivers. The argument is the list of PCI BDFs:
172	  xen-pciback.hide=(03:00.0)(04:00.0)
173
174	  If in doubt, say m.
175
176config XEN_PRIVCMD
177	tristate
178	depends on XEN
179	default m
180
181config XEN_STUB
182	bool "Xen stub drivers"
183	depends on XEN && X86_64 && BROKEN
184	default n
185	help
186	  Allow kernel to install stub drivers, to reserve space for Xen drivers,
187	  i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
188	  so that real Xen drivers can be modular.
189
190	  To enable Xen features like cpu and memory hotplug, select Y here.
191
192config XEN_ACPI_HOTPLUG_MEMORY
193	tristate "Xen ACPI memory hotplug"
194	depends on XEN_DOM0 && XEN_STUB && ACPI
195	default n
196	help
197	  This is Xen ACPI memory hotplug.
198
199	  Currently Xen only support ACPI memory hot-add. If you want
200	  to hot-add memory at runtime (the hot-added memory cannot be
201	  removed until machine stop), select Y/M here, otherwise select N.
202
203config XEN_ACPI_HOTPLUG_CPU
204	tristate "Xen ACPI cpu hotplug"
205	depends on XEN_DOM0 && XEN_STUB && ACPI
206	select ACPI_CONTAINER
207	default n
208	help
209	  Xen ACPI cpu enumerating and hotplugging
210
211	  For hotplugging, currently Xen only support ACPI cpu hotadd.
212	  If you want to hotadd cpu at runtime (the hotadded cpu cannot
213	  be removed until machine stop), select Y/M here.
214
215config XEN_ACPI_PROCESSOR
216	tristate "Xen ACPI processor"
217	depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
218	default m
219	help
220          This ACPI processor uploads Power Management information to the Xen
221	  hypervisor.
222
223	  To do that the driver parses the Power Management data and uploads
224	  said information to the Xen hypervisor. Then the Xen hypervisor can
225	  select the proper Cx and Pxx states. It also registers itslef as the
226	  SMM so that other drivers (such as ACPI cpufreq scaling driver) will
227	  not load.
228
229          To compile this driver as a module, choose M here: the module will be
230	  called xen_acpi_processor  If you do not know what to choose, select
231	  M here. If the CPUFREQ drivers are built in, select Y here.
232
233config XEN_MCE_LOG
234	bool "Xen platform mcelog"
235	depends on XEN_DOM0 && X86_64 && X86_MCE
236	default n
237	help
238	  Allow kernel fetching MCE error from Xen platform and
239	  converting it into Linux mcelog format for mcelog tools
240
241config XEN_HAVE_PVMMU
242       bool
243
244endmenu
245