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1# SPDX-License-Identifier: GPL-2.0-only
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 Maximum 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 ARCH_HAS_DMA_OPS
181 depends on XEN_PV || ARM || ARM64
182 select SWIOTLB
183
184config XEN_PCI_STUB
185 bool
186
187config XEN_PCIDEV_STUB
188 tristate "Xen PCI-device stub driver"
189 depends on PCI && !X86 && XEN
190 depends on XEN_BACKEND
191 select XEN_PCI_STUB
192 default m
193 help
194 The PCI device stub driver provides limited version of the PCI
195 device backend driver without para-virtualized support for guests.
196 If you select this to be a module, you will need to make sure no
197 other driver has bound to the device(s) you want to make visible to
198 other guests.
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_PCIDEV_BACKEND
208 tristate "Xen PCI-device backend driver"
209 depends on PCI && X86 && XEN
210 depends on XEN_BACKEND
211 select XEN_PCI_STUB
212 default m
213 help
214 The PCI device backend driver allows the kernel to export arbitrary
215 PCI devices to other guests. If you select this to be a module, you
216 will need to make sure no other driver has bound to the device(s)
217 you want to make visible to other guests.
218
219 The parameter "passthrough" allows you specify how you want the PCI
220 devices to appear in the guest. You can choose the default (0) where
221 PCI topology starts at 00.00.0, or (1) for passthrough if you want
222 the PCI devices topology appear the same as in the host.
223
224 The "hide" parameter (only applicable if backend driver is compiled
225 into the kernel) allows you to bind the PCI devices to this module
226 from the default device drivers. The argument is the list of PCI BDFs:
227 xen-pciback.hide=(03:00.0)(04:00.0)
228
229 If in doubt, say m.
230
231config XEN_PVCALLS_FRONTEND
232 tristate "XEN PV Calls frontend driver"
233 depends on INET && XEN
234 select XEN_XENBUS_FRONTEND
235 help
236 Experimental frontend for the Xen PV Calls protocol
237 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
238 sends a small set of POSIX calls to the backend, which
239 implements them.
240
241config XEN_PVCALLS_BACKEND
242 tristate "XEN PV Calls backend driver"
243 depends on INET && XEN && XEN_BACKEND
244 help
245 Experimental backend for the Xen PV Calls protocol
246 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
247 allows PV Calls frontends to send POSIX calls to the backend,
248 which implements them.
249
250 If in doubt, say n.
251
252config XEN_SCSI_BACKEND
253 tristate "XEN SCSI backend driver"
254 depends on XEN && XEN_BACKEND && TARGET_CORE
255 help
256 The SCSI backend driver allows the kernel to export its SCSI Devices
257 to other guests via a high-performance shared-memory interface.
258 Only needed for systems running as XEN driver domains (e.g. Dom0) and
259 if guests need generic access to SCSI devices.
260
261config XEN_PRIVCMD
262 tristate "Xen hypercall passthrough driver"
263 depends on XEN
264 default m
265 help
266 The hypercall passthrough driver allows privileged user programs to
267 perform Xen hypercalls. This driver is normally required for systems
268 running as Dom0 to perform privileged operations, but in some
269 disaggregated Xen setups this driver might be needed for other
270 domains, too.
271
272config XEN_PRIVCMD_EVENTFD
273 bool "Xen Ioeventfd and irqfd support"
274 depends on XEN_PRIVCMD && XEN_VIRTIO && EVENTFD
275 help
276 Using the ioeventfd / irqfd mechanism a virtio backend running in a
277 daemon can speed up interrupt delivery from / to a guest.
278
279config XEN_ACPI_PROCESSOR
280 tristate "Xen ACPI processor"
281 depends on XEN && XEN_PV_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ
282 default m
283 help
284 This ACPI processor uploads Power Management information to the Xen
285 hypervisor.
286
287 To do that the driver parses the Power Management data and uploads
288 said information to the Xen hypervisor. Then the Xen hypervisor can
289 select the proper Cx and Pxx states. It also registers itself as the
290 SMM so that other drivers (such as ACPI cpufreq scaling driver) will
291 not load.
292
293 To compile this driver as a module, choose M here: the module will be
294 called xen_acpi_processor If you do not know what to choose, select
295 M here. If the CPUFREQ drivers are built in, select Y here.
296
297config XEN_MCE_LOG
298 bool "Xen platform mcelog"
299 depends on XEN_PV_DOM0 && X86_MCE
300 help
301 Allow kernel fetching MCE error from Xen platform and
302 converting it into Linux mcelog format for mcelog tools
303
304config XEN_HAVE_PVMMU
305 bool
306
307config XEN_EFI
308 def_bool y
309 depends on (ARM || ARM64 || X86_64) && EFI
310
311config XEN_AUTO_XLATE
312 def_bool y
313 depends on ARM || ARM64 || XEN_PVHVM
314 help
315 Support for auto-translated physmap guests.
316
317config XEN_ACPI
318 def_bool y
319 depends on X86 && ACPI
320
321config XEN_SYMS
322 bool "Xen symbols"
323 depends on X86 && XEN_DOM0 && XENFS
324 default y if KALLSYMS
325 help
326 Exports hypervisor symbols (along with their types and addresses) via
327 /proc/xen/xensyms file, similar to /proc/kallsyms
328
329config XEN_HAVE_VPMU
330 bool
331
332config XEN_FRONT_PGDIR_SHBUF
333 tristate
334
335config XEN_UNPOPULATED_ALLOC
336 bool "Use unpopulated memory ranges for guest mappings"
337 depends on ZONE_DEVICE
338 default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0
339 help
340 Use unpopulated memory ranges in order to create mappings for guest
341 memory regions, including grant maps and foreign pages. This avoids
342 having to balloon out RAM regions in order to obtain physical memory
343 space to create such mappings.
344
345config XEN_GRANT_DMA_IOMMU
346 bool
347 select IOMMU_API
348
349config XEN_GRANT_DMA_OPS
350 bool
351
352config XEN_VIRTIO
353 bool "Xen virtio support"
354 depends on ARCH_HAS_DMA_OPS
355 depends on VIRTIO
356 select XEN_GRANT_DMA_OPS
357 select XEN_GRANT_DMA_IOMMU if OF
358 help
359 Enable virtio support for running as Xen guest. Depending on the
360 guest type this will require special support on the backend side
361 (qemu or kernel, depending on the virtio device types used).
362
363 If in doubt, say n.
364
365config XEN_VIRTIO_FORCE_GRANT
366 bool "Require Xen virtio support to use grants"
367 depends on XEN_VIRTIO
368 help
369 Require virtio for Xen guests to use grant mappings.
370 This will avoid the need to give the backend the right to map all
371 of the guest memory. This will need support on the backend side
372 (e.g. qemu or kernel, depending on the virtio device types used).
373
374endmenu
1# SPDX-License-Identifier: GPL-2.0-only
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 select DMA_OPS
181 select SWIOTLB
182
183config XEN_PCIDEV_BACKEND
184 tristate "Xen PCI-device backend driver"
185 depends on PCI && X86 && XEN
186 depends on XEN_BACKEND
187 default m
188 help
189 The PCI device backend driver allows the kernel to export arbitrary
190 PCI devices to other guests. If you select this to be a module, you
191 will need to make sure no other driver has bound to the device(s)
192 you want to make visible to other guests.
193
194 The parameter "passthrough" allows you specify how you want the PCI
195 devices to appear in the guest. You can choose the default (0) where
196 PCI topology starts at 00.00.0, or (1) for passthrough if you want
197 the PCI devices topology appear the same as in the host.
198
199 The "hide" parameter (only applicable if backend driver is compiled
200 into the kernel) allows you to bind the PCI devices to this module
201 from the default device drivers. The argument is the list of PCI BDFs:
202 xen-pciback.hide=(03:00.0)(04:00.0)
203
204 If in doubt, say m.
205
206config XEN_PVCALLS_FRONTEND
207 tristate "XEN PV Calls frontend driver"
208 depends on INET && XEN
209 select XEN_XENBUS_FRONTEND
210 help
211 Experimental frontend for the Xen PV Calls protocol
212 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
213 sends a small set of POSIX calls to the backend, which
214 implements them.
215
216config XEN_PVCALLS_BACKEND
217 bool "XEN PV Calls backend driver"
218 depends on INET && XEN && XEN_BACKEND
219 help
220 Experimental backend for the Xen PV Calls protocol
221 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
222 allows PV Calls frontends to send POSIX calls to the backend,
223 which implements them.
224
225 If in doubt, say n.
226
227config XEN_SCSI_BACKEND
228 tristate "XEN SCSI backend driver"
229 depends on XEN && XEN_BACKEND && TARGET_CORE
230 help
231 The SCSI backend driver allows the kernel to export its SCSI Devices
232 to other guests via a high-performance shared-memory interface.
233 Only needed for systems running as XEN driver domains (e.g. Dom0) and
234 if guests need generic access to SCSI devices.
235
236config XEN_PRIVCMD
237 tristate
238 depends on XEN
239 default m
240
241config XEN_ACPI_PROCESSOR
242 tristate "Xen ACPI processor"
243 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ
244 default m
245 help
246 This ACPI processor uploads Power Management information to the Xen
247 hypervisor.
248
249 To do that the driver parses the Power Management data and uploads
250 said information to the Xen hypervisor. Then the Xen hypervisor can
251 select the proper Cx and Pxx states. It also registers itself as the
252 SMM so that other drivers (such as ACPI cpufreq scaling driver) will
253 not load.
254
255 To compile this driver as a module, choose M here: the module will be
256 called xen_acpi_processor If you do not know what to choose, select
257 M here. If the CPUFREQ drivers are built in, select Y here.
258
259config XEN_MCE_LOG
260 bool "Xen platform mcelog"
261 depends on XEN_DOM0 && X86_MCE
262 help
263 Allow kernel fetching MCE error from Xen platform and
264 converting it into Linux mcelog format for mcelog tools
265
266config XEN_HAVE_PVMMU
267 bool
268
269config XEN_EFI
270 def_bool y
271 depends on (ARM || ARM64 || X86_64) && EFI
272
273config XEN_AUTO_XLATE
274 def_bool y
275 depends on ARM || ARM64 || XEN_PVHVM
276 help
277 Support for auto-translated physmap guests.
278
279config XEN_ACPI
280 def_bool y
281 depends on X86 && ACPI
282
283config XEN_SYMS
284 bool "Xen symbols"
285 depends on X86 && XEN_DOM0 && XENFS
286 default y if KALLSYMS
287 help
288 Exports hypervisor symbols (along with their types and addresses) via
289 /proc/xen/xensyms file, similar to /proc/kallsyms
290
291config XEN_HAVE_VPMU
292 bool
293
294config XEN_FRONT_PGDIR_SHBUF
295 tristate
296
297config XEN_UNPOPULATED_ALLOC
298 bool "Use unpopulated memory ranges for guest mappings"
299 depends on X86 && ZONE_DEVICE
300 default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0
301 help
302 Use unpopulated memory ranges in order to create mappings for guest
303 memory regions, including grant maps and foreign pages. This avoids
304 having to balloon out RAM regions in order to obtain physical memory
305 space to create such mappings.
306
307endmenu