xref: /linux/drivers/xen/Kconfig (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1menu "Xen driver support"
2	depends on XEN
3
4config XEN_BALLOON
5	bool "Xen memory balloon driver"
6	default y
7	help
8	  The balloon driver allows the Xen domain to request more memory from
9	  the system to expand the domain's memory allocation, or alternatively
10	  return unneeded memory to the system.
11
12config XEN_SELFBALLOONING
13	bool "Dynamically self-balloon kernel memory to target"
14	depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM
15	default n
16	help
17	  Self-ballooning dynamically balloons available kernel memory driven
18	  by the current usage of anonymous memory ("committed AS") and
19	  controlled by various sysfs-settable parameters.  Configuring
20	  FRONTSWAP is highly recommended; if it is not configured, self-
21	  ballooning is disabled by default. If FRONTSWAP is configured,
22	  frontswap-selfshrinking is enabled by default but can be disabled
23	  with the 'tmem.selfshrink=0' kernel boot parameter; and self-ballooning
24	  is enabled by default but can be disabled with the 'tmem.selfballooning=0'
25	  kernel boot parameter.  Note that systems without a sufficiently
26	  large swap device should not enable self-ballooning.
27
28config XEN_BALLOON_MEMORY_HOTPLUG
29	bool "Memory hotplug support for Xen balloon driver"
30	default n
31	depends on XEN_BALLOON && MEMORY_HOTPLUG
32	help
33	  Memory hotplug support for Xen balloon driver allows expanding memory
34	  available for the system above limit declared at system startup.
35	  It is very useful on critical systems which require long
36	  run without rebooting.
37
38	  Memory could be hotplugged in following steps:
39
40	    1) dom0: xl mem-max <domU> <maxmem>
41	       where <maxmem> is >= requested memory size,
42
43	    2) dom0: xl mem-set <domU> <memory>
44	       where <memory> is requested memory size; alternatively memory
45	       could be added by writing proper value to
46	       /sys/devices/system/xen_memory/xen_memory0/target or
47	       /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,
48
49	    3) domU: for i in /sys/devices/system/memory/memory*/state; do \
50	               [ "`cat "$i"`" = offline ] && echo online > "$i"; done
51
52	  Memory could be onlined automatically on domU by adding following line to udev rules:
53
54	  SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
55
56	  In that case step 3 should be omitted.
57
58config XEN_SCRUB_PAGES
59	bool "Scrub pages before returning them to system"
60	depends on XEN_BALLOON
61	default y
62	help
63	  Scrub pages before returning them to the system for reuse by
64	  other domains.  This makes sure that any confidential data
65	  is not accidentally visible to other domains.  Is it more
66	  secure, but slightly less efficient.
67	  If in doubt, say yes.
68
69config XEN_DEV_EVTCHN
70	tristate "Xen /dev/xen/evtchn device"
71	default y
72	help
73	  The evtchn driver allows a userspace process to trigger event
74	  channels and to receive notification of an event channel
75	  firing.
76	  If in doubt, say yes.
77
78config XEN_BACKEND
79	bool "Backend driver support"
80	depends on XEN_DOM0
81	default y
82	help
83	  Support for backend device drivers that provide I/O services
84	  to other virtual machines.
85
86config XENFS
87	tristate "Xen filesystem"
88	select XEN_PRIVCMD
89	default y
90	help
91	  The xen filesystem provides a way for domains to share
92	  information with each other and with the hypervisor.
93	  For example, by reading and writing the "xenbus" file, guests
94	  may pass arbitrary information to the initial domain.
95	  If in doubt, say yes.
96
97config XEN_COMPAT_XENFS
98       bool "Create compatibility mount point /proc/xen"
99       depends on XENFS
100       default y
101       help
102         The old xenstore userspace tools expect to find "xenbus"
103         under /proc/xen, but "xenbus" is now found at the root of the
104         xenfs filesystem.  Selecting this causes the kernel to create
105         the compatibility mount point /proc/xen if it is running on
106         a xen platform.
107         If in doubt, say yes.
108
109config XEN_SYS_HYPERVISOR
110       bool "Create xen entries under /sys/hypervisor"
111       depends on SYSFS
112       select SYS_HYPERVISOR
113       default y
114       help
115         Create entries under /sys/hypervisor describing the Xen
116	 hypervisor environment.  When running native or in another
117	 virtual environment, /sys/hypervisor will still be present,
118	 but will have no xen contents.
119
120config XEN_XENBUS_FRONTEND
121	tristate
122
123config XEN_GNTDEV
124	tristate "userspace grant access device driver"
125	depends on XEN
126	default m
127	select MMU_NOTIFIER
128	help
129	  Allows userspace processes to use grants.
130
131config XEN_GRANT_DEV_ALLOC
132	tristate "User-space grant reference allocator driver"
133	depends on XEN
134	default m
135	help
136	  Allows userspace processes to create pages with access granted
137	  to other domains. This can be used to implement frontend drivers
138	  or as part of an inter-domain shared memory channel.
139
140config SWIOTLB_XEN
141	def_bool y
142	select SWIOTLB
143
144config XEN_TMEM
145	tristate
146	depends on !ARM && !ARM64
147	default m if (CLEANCACHE || FRONTSWAP)
148	help
149	  Shim to interface in-kernel Transcendent Memory hooks
150	  (e.g. cleancache and frontswap) to Xen tmem hypercalls.
151
152config XEN_PCIDEV_BACKEND
153	tristate "Xen PCI-device backend driver"
154	depends on PCI && X86 && XEN
155	depends on XEN_BACKEND
156	default m
157	help
158	  The PCI device backend driver allows the kernel to export arbitrary
159	  PCI devices to other guests. If you select this to be a module, you
160	  will need to make sure no other driver has bound to the device(s)
161	  you want to make visible to other guests.
162
163	  The parameter "passthrough" allows you specify how you want the PCI
164	  devices to appear in the guest. You can choose the default (0) where
165	  PCI topology starts at 00.00.0, or (1) for passthrough if you want
166	  the PCI devices topology appear the same as in the host.
167
168	  The "hide" parameter (only applicable if backend driver is compiled
169	  into the kernel) allows you to bind the PCI devices to this module
170	  from the default device drivers. The argument is the list of PCI BDFs:
171	  xen-pciback.hide=(03:00.0)(04:00.0)
172
173	  If in doubt, say m.
174
175config XEN_SCSI_BACKEND
176	tristate "XEN SCSI backend driver"
177	depends on XEN && XEN_BACKEND && TARGET_CORE
178	help
179	  The SCSI backend driver allows the kernel to export its SCSI Devices
180	  to other guests via a high-performance shared-memory interface.
181	  Only needed for systems running as XEN driver domains (e.g. Dom0) and
182	  if guests need generic access to SCSI devices.
183
184config XEN_PRIVCMD
185	tristate
186	depends on XEN
187	default m
188
189config XEN_STUB
190	bool "Xen stub drivers"
191	depends on XEN && X86_64 && BROKEN
192	default n
193	help
194	  Allow kernel to install stub drivers, to reserve space for Xen drivers,
195	  i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
196	  so that real Xen drivers can be modular.
197
198	  To enable Xen features like cpu and memory hotplug, select Y here.
199
200config XEN_ACPI_HOTPLUG_MEMORY
201	tristate "Xen ACPI memory hotplug"
202	depends on XEN_DOM0 && XEN_STUB && ACPI
203	default n
204	help
205	  This is Xen ACPI memory hotplug.
206
207	  Currently Xen only support ACPI memory hot-add. If you want
208	  to hot-add memory at runtime (the hot-added memory cannot be
209	  removed until machine stop), select Y/M here, otherwise select N.
210
211config XEN_ACPI_HOTPLUG_CPU
212	tristate "Xen ACPI cpu hotplug"
213	depends on XEN_DOM0 && XEN_STUB && ACPI
214	select ACPI_CONTAINER
215	default n
216	help
217	  Xen ACPI cpu enumerating and hotplugging
218
219	  For hotplugging, currently Xen only support ACPI cpu hotadd.
220	  If you want to hotadd cpu at runtime (the hotadded cpu cannot
221	  be removed until machine stop), select Y/M here.
222
223config XEN_ACPI_PROCESSOR
224	tristate "Xen ACPI processor"
225	depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
226	default m
227	help
228          This ACPI processor uploads Power Management information to the Xen
229	  hypervisor.
230
231	  To do that the driver parses the Power Management data and uploads
232	  said information to the Xen hypervisor. Then the Xen hypervisor can
233	  select the proper Cx and Pxx states. It also registers itself as the
234	  SMM so that other drivers (such as ACPI cpufreq scaling driver) will
235	  not load.
236
237          To compile this driver as a module, choose M here: the module will be
238	  called xen_acpi_processor  If you do not know what to choose, select
239	  M here. If the CPUFREQ drivers are built in, select Y here.
240
241config XEN_MCE_LOG
242	bool "Xen platform mcelog"
243	depends on XEN_DOM0 && X86_64 && X86_MCE
244	default n
245	help
246	  Allow kernel fetching MCE error from Xen platform and
247	  converting it into Linux mcelog format for mcelog tools
248
249config XEN_HAVE_PVMMU
250       bool
251
252config XEN_EFI
253	def_bool y
254	depends on X86_64 && EFI
255
256endmenu
257