1
2menu "Xen driver support"
3 depends on XEN
4
5config XEN_BALLOON
6 bool "Xen memory balloon driver"
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_BALLOON_MEMORY_HOTPLUG
14 bool "Memory hotplug support for Xen balloon driver"
15 depends on XEN_BALLOON && MEMORY_HOTPLUG
16 default y
17 help
18 Memory hotplug support for Xen balloon driver allows expanding memory
19 available for the system above limit declared at system startup.
20 It is very useful on critical systems which require long
21 run without rebooting.
22
23 It's also very useful for non PV domains to obtain unpopulated physical
24 memory ranges to use in order to map foreign memory or grants.
25
26 Memory could be hotplugged in following steps:
27
28 1) target domain: ensure that memory auto online policy is in
29 effect by checking /sys/devices/system/memory/auto_online_blocks
30 file (should be 'online').
31
32 2) control domain: xl mem-max <target-domain> <maxmem>
33 where <maxmem> is >= requested memory size,
34
35 3) control domain: xl mem-set <target-domain> <memory>
36 where <memory> is requested memory size; alternatively memory
37 could be added by writing proper value to
38 /sys/devices/system/xen_memory/xen_memory0/target or
39 /sys/devices/system/xen_memory/xen_memory0/target_kb on the
40 target domain.
41
42 Alternatively, if memory auto onlining was not requested at step 1
43 the newly added memory can be manually onlined in the target domain
44 by doing the following:
45
46 for i in /sys/devices/system/memory/memory*/state; do \
47 [ "`cat "$i"`" = offline ] && echo online > "$i"; done
48
49 or by adding the following line to udev rules:
50
51 SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
52
53config XEN_MEMORY_HOTPLUG_LIMIT
54 int "Hotplugged memory limit (in GiB) for a PV guest"
55 default 512
56 depends on XEN_HAVE_PVMMU
57 depends on MEMORY_HOTPLUG
58 help
59 Maxmium amount of memory (in GiB) that a PV guest can be
60 expanded to when using memory hotplug.
61
62 A PV guest can have more memory than this limit if is
63 started with a larger maximum.
64
65 This value is used to allocate enough space in internal
66 tables needed for physical memory administration.
67
68config XEN_SCRUB_PAGES_DEFAULT
69 bool "Scrub pages before returning them to system by default"
70 depends on XEN_BALLOON
71 default y
72 help
73 Scrub pages before returning them to the system for reuse by
74 other domains. This makes sure that any confidential data
75 is not accidentally visible to other domains. It is more
76 secure, but slightly less efficient. This can be controlled with
77 xen_scrub_pages=0 parameter and
78 /sys/devices/system/xen_memory/xen_memory0/scrub_pages.
79 This option only sets the default value.
80
81 If in doubt, say yes.
82
83config XEN_DEV_EVTCHN
84 tristate "Xen /dev/xen/evtchn device"
85 default y
86 help
87 The evtchn driver allows a userspace process to trigger event
88 channels and to receive notification of an event channel
89 firing.
90 If in doubt, say yes.
91
92config XEN_BACKEND
93 bool "Backend driver support"
94 default XEN_DOM0
95 help
96 Support for backend device drivers that provide I/O services
97 to other virtual machines.
98
99config XENFS
100 tristate "Xen filesystem"
101 select XEN_PRIVCMD
102 default y
103 help
104 The xen filesystem provides a way for domains to share
105 information with each other and with the hypervisor.
106 For example, by reading and writing the "xenbus" file, guests
107 may pass arbitrary information to the initial domain.
108 If in doubt, say yes.
109
110config XEN_COMPAT_XENFS
111 bool "Create compatibility mount point /proc/xen"
112 depends on XENFS
113 default y
114 help
115 The old xenstore userspace tools expect to find "xenbus"
116 under /proc/xen, but "xenbus" is now found at the root of the
117 xenfs filesystem. Selecting this causes the kernel to create
118 the compatibility mount point /proc/xen if it is running on
119 a xen platform.
120 If in doubt, say yes.
121
122config XEN_SYS_HYPERVISOR
123 bool "Create xen entries under /sys/hypervisor"
124 depends on SYSFS
125 select SYS_HYPERVISOR
126 default y
127 help
128 Create entries under /sys/hypervisor describing the Xen
129 hypervisor environment. When running native or in another
130 virtual environment, /sys/hypervisor will still be present,
131 but will have no xen contents.
132
133config XEN_XENBUS_FRONTEND
134 tristate
135
136config XEN_GNTDEV
137 tristate "userspace grant access device driver"
138 depends on XEN
139 default m
140 select MMU_NOTIFIER
141 help
142 Allows userspace processes to use grants.
143
144config XEN_GNTDEV_DMABUF
145 bool "Add support for dma-buf grant access device driver extension"
146 depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC
147 select DMA_SHARED_BUFFER
148 help
149 Allows userspace processes and kernel modules to use Xen backed
150 dma-buf implementation. With this extension grant references to
151 the pages of an imported dma-buf can be exported for other domain
152 use and grant references coming from a foreign domain can be
153 converted into a local dma-buf for local export.
154
155config XEN_GRANT_DEV_ALLOC
156 tristate "User-space grant reference allocator driver"
157 depends on XEN
158 default m
159 help
160 Allows userspace processes to create pages with access granted
161 to other domains. This can be used to implement frontend drivers
162 or as part of an inter-domain shared memory channel.
163
164config XEN_GRANT_DMA_ALLOC
165 bool "Allow allocating DMA capable buffers with grant reference module"
166 depends on XEN && HAS_DMA
167 help
168 Extends grant table module API to allow allocating DMA capable
169 buffers and mapping foreign grant references on top of it.
170 The resulting buffer is similar to one allocated by the balloon
171 driver in that proper memory reservation is made by
172 ({increase|decrease}_reservation and VA mappings are updated if
173 needed).
174 This is useful for sharing foreign buffers with HW drivers which
175 cannot work with scattered buffers provided by the balloon driver,
176 but require DMAable memory instead.
177
178config SWIOTLB_XEN
179 def_bool y
180 depends on XEN_PV || ARM || ARM64
181 select DMA_OPS
182 select SWIOTLB
183
184config XEN_PCIDEV_BACKEND
185 tristate "Xen PCI-device backend driver"
186 depends on PCI && X86 && XEN
187 depends on XEN_BACKEND
188 default m
189 help
190 The PCI device backend driver allows the kernel to export arbitrary
191 PCI devices to other guests. If you select this to be a module, you
192 will need to make sure no other driver has bound to the device(s)
193 you want to make visible to other guests.
194
195 The parameter "passthrough" allows you specify how you want the PCI
196 devices to appear in the guest. You can choose the default (0) where
197 PCI topology starts at 00.00.0, or (1) for passthrough if you want
198 the PCI devices topology appear the same as in the host.
199
200 The "hide" parameter (only applicable if backend driver is compiled
201 into the kernel) allows you to bind the PCI devices to this module
202 from the default device drivers. The argument is the list of PCI BDFs:
203 xen-pciback.hide=(03:00.0)(04:00.0)
204
205 If in doubt, say m.
206
207config XEN_PVCALLS_FRONTEND
208 tristate "XEN PV Calls frontend driver"
209 depends on INET && XEN
210 select XEN_XENBUS_FRONTEND
211 help
212 Experimental frontend for the Xen PV Calls protocol
213 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
214 sends a small set of POSIX calls to the backend, which
215 implements them.
216
217config XEN_PVCALLS_BACKEND
218 tristate "XEN PV Calls backend driver"
219 depends on INET && XEN && XEN_BACKEND
220 help
221 Experimental backend for the Xen PV Calls protocol
222 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
223 allows PV Calls frontends to send POSIX calls to the backend,
224 which implements them.
225
226 If in doubt, say n.
227
228config XEN_SCSI_BACKEND
229 tristate "XEN SCSI backend driver"
230 depends on XEN && XEN_BACKEND && TARGET_CORE
231 help
232 The SCSI backend driver allows the kernel to export its SCSI Devices
233 to other guests via a high-performance shared-memory interface.
234 Only needed for systems running as XEN driver domains (e.g. Dom0) and
235 if guests need generic access to SCSI devices.
236
237config XEN_PRIVCMD
238 tristate
239 depends on XEN
240 default m
241
242config XEN_ACPI_PROCESSOR
243 tristate "Xen ACPI processor"
244 depends on XEN && XEN_PV_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ
245 default m
246 help
247 This ACPI processor uploads Power Management information to the Xen
248 hypervisor.
249
250 To do that the driver parses the Power Management data and uploads
251 said information to the Xen hypervisor. Then the Xen hypervisor can
252 select the proper Cx and Pxx states. It also registers itself as the
253 SMM so that other drivers (such as ACPI cpufreq scaling driver) will
254 not load.
255
256 To compile this driver as a module, choose M here: the module will be
257 called xen_acpi_processor If you do not know what to choose, select
258 M here. If the CPUFREQ drivers are built in, select Y here.
259
260config XEN_MCE_LOG
261 bool "Xen platform mcelog"
262 depends on XEN_PV_DOM0 && X86_MCE
263 help
264 Allow kernel fetching MCE error from Xen platform and
265 converting it into Linux mcelog format for mcelog tools
266
267config XEN_HAVE_PVMMU
268 bool
269
270config XEN_EFI
271 def_bool y
272 depends on (ARM || ARM64 || X86_64) && EFI
273
274config XEN_AUTO_XLATE
275 def_bool y
276 depends on ARM || ARM64 || XEN_PVHVM
277 help
278 Support for auto-translated physmap guests.
279
280config XEN_ACPI
281 def_bool y
282 depends on X86 && ACPI
283
284config XEN_SYMS
285 bool "Xen symbols"
286 depends on X86 && XEN_DOM0 && XENFS
287 default y if KALLSYMS
288 help
289 Exports hypervisor symbols (along with their types and addresses) via
290 /proc/xen/xensyms file, similar to /proc/kallsyms
291
292config XEN_HAVE_VPMU
293 bool
294
295config XEN_FRONT_PGDIR_SHBUF
296 tristate
297
298config XEN_UNPOPULATED_ALLOC
299 bool "Use unpopulated memory ranges for guest mappings"
300 depends on X86 && ZONE_DEVICE
301 default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0
302 help
303 Use unpopulated memory ranges in order to create mappings for guest
304 memory regions, including grant maps and foreign pages. This avoids
305 having to balloon out RAM regions in order to obtain physical memory
306 space to create such mappings.
307
308endmenu
309
