xref: /openbmc/linux/drivers/xen/Kconfig (revision 8e9356c6)
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_PRIVCMD
176	tristate
177	depends on XEN
178	default m
179
180config XEN_STUB
181	bool "Xen stub drivers"
182	depends on XEN && X86_64 && BROKEN
183	default n
184	help
185	  Allow kernel to install stub drivers, to reserve space for Xen drivers,
186	  i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
187	  so that real Xen drivers can be modular.
188
189	  To enable Xen features like cpu and memory hotplug, select Y here.
190
191config XEN_ACPI_HOTPLUG_MEMORY
192	tristate "Xen ACPI memory hotplug"
193	depends on XEN_DOM0 && XEN_STUB && ACPI
194	default n
195	help
196	  This is Xen ACPI memory hotplug.
197
198	  Currently Xen only support ACPI memory hot-add. If you want
199	  to hot-add memory at runtime (the hot-added memory cannot be
200	  removed until machine stop), select Y/M here, otherwise select N.
201
202config XEN_ACPI_HOTPLUG_CPU
203	tristate "Xen ACPI cpu hotplug"
204	depends on XEN_DOM0 && XEN_STUB && ACPI
205	select ACPI_CONTAINER
206	default n
207	help
208	  Xen ACPI cpu enumerating and hotplugging
209
210	  For hotplugging, currently Xen only support ACPI cpu hotadd.
211	  If you want to hotadd cpu at runtime (the hotadded cpu cannot
212	  be removed until machine stop), select Y/M here.
213
214config XEN_ACPI_PROCESSOR
215	tristate "Xen ACPI processor"
216	depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
217	default m
218	help
219          This ACPI processor uploads Power Management information to the Xen
220	  hypervisor.
221
222	  To do that the driver parses the Power Management data and uploads
223	  said information to the Xen hypervisor. Then the Xen hypervisor can
224	  select the proper Cx and Pxx states. It also registers itself as the
225	  SMM so that other drivers (such as ACPI cpufreq scaling driver) will
226	  not load.
227
228          To compile this driver as a module, choose M here: the module will be
229	  called xen_acpi_processor  If you do not know what to choose, select
230	  M here. If the CPUFREQ drivers are built in, select Y here.
231
232config XEN_MCE_LOG
233	bool "Xen platform mcelog"
234	depends on XEN_DOM0 && X86_64 && X86_MCE
235	default n
236	help
237	  Allow kernel fetching MCE error from Xen platform and
238	  converting it into Linux mcelog format for mcelog tools
239
240config XEN_HAVE_PVMMU
241       bool
242
243endmenu
244