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 help 17 Memory hotplug support for Xen balloon driver allows expanding memory 18 available for the system above limit declared at system startup. 19 It is very useful on critical systems which require long 20 run without rebooting. 21 22 Memory could be hotplugged in following steps: 23 24 1) target domain: ensure that memory auto online policy is in 25 effect by checking /sys/devices/system/memory/auto_online_blocks 26 file (should be 'online'). 27 28 2) control domain: xl mem-max <target-domain> <maxmem> 29 where <maxmem> is >= requested memory size, 30 31 3) control domain: xl mem-set <target-domain> <memory> 32 where <memory> is requested memory size; alternatively memory 33 could be added by writing proper value to 34 /sys/devices/system/xen_memory/xen_memory0/target or 35 /sys/devices/system/xen_memory/xen_memory0/target_kb on the 36 target domain. 37 38 Alternatively, if memory auto onlining was not requested at step 1 39 the newly added memory can be manually onlined in the target domain 40 by doing the following: 41 42 for i in /sys/devices/system/memory/memory*/state; do \ 43 [ "`cat "$i"`" = offline ] && echo online > "$i"; done 44 45 or by adding the following line to udev rules: 46 47 SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'" 48 49config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT 50 int "Hotplugged memory limit (in GiB) for a PV guest" 51 default 512 if X86_64 52 default 4 if X86_32 53 range 0 64 if X86_32 54 depends on XEN_HAVE_PVMMU 55 depends on XEN_BALLOON_MEMORY_HOTPLUG 56 help 57 Maxmium amount of memory (in GiB) that a PV guest can be 58 expanded to when using memory hotplug. 59 60 A PV guest can have more memory than this limit if is 61 started with a larger maximum. 62 63 This value is used to allocate enough space in internal 64 tables needed for physical memory administration. 65 66config XEN_SCRUB_PAGES_DEFAULT 67 bool "Scrub pages before returning them to system by default" 68 depends on XEN_BALLOON 69 default y 70 help 71 Scrub pages before returning them to the system for reuse by 72 other domains. This makes sure that any confidential data 73 is not accidentally visible to other domains. It is more 74 secure, but slightly less efficient. This can be controlled with 75 xen_scrub_pages=0 parameter and 76 /sys/devices/system/xen_memory/xen_memory0/scrub_pages. 77 This option only sets the default value. 78 79 If in doubt, say yes. 80 81config XEN_DEV_EVTCHN 82 tristate "Xen /dev/xen/evtchn device" 83 default y 84 help 85 The evtchn driver allows a userspace process to trigger event 86 channels and to receive notification of an event channel 87 firing. 88 If in doubt, say yes. 89 90config XEN_BACKEND 91 bool "Backend driver support" 92 default XEN_DOM0 93 help 94 Support for backend device drivers that provide I/O services 95 to other virtual machines. 96 97config XENFS 98 tristate "Xen filesystem" 99 select XEN_PRIVCMD 100 default y 101 help 102 The xen filesystem provides a way for domains to share 103 information with each other and with the hypervisor. 104 For example, by reading and writing the "xenbus" file, guests 105 may pass arbitrary information to the initial domain. 106 If in doubt, say yes. 107 108config XEN_COMPAT_XENFS 109 bool "Create compatibility mount point /proc/xen" 110 depends on XENFS 111 default y 112 help 113 The old xenstore userspace tools expect to find "xenbus" 114 under /proc/xen, but "xenbus" is now found at the root of the 115 xenfs filesystem. Selecting this causes the kernel to create 116 the compatibility mount point /proc/xen if it is running on 117 a xen platform. 118 If in doubt, say yes. 119 120config XEN_SYS_HYPERVISOR 121 bool "Create xen entries under /sys/hypervisor" 122 depends on SYSFS 123 select SYS_HYPERVISOR 124 default y 125 help 126 Create entries under /sys/hypervisor describing the Xen 127 hypervisor environment. When running native or in another 128 virtual environment, /sys/hypervisor will still be present, 129 but will have no xen contents. 130 131config XEN_XENBUS_FRONTEND 132 tristate 133 134config XEN_GNTDEV 135 tristate "userspace grant access device driver" 136 depends on XEN 137 default m 138 select MMU_NOTIFIER 139 help 140 Allows userspace processes to use grants. 141 142config XEN_GNTDEV_DMABUF 143 bool "Add support for dma-buf grant access device driver extension" 144 depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC 145 select DMA_SHARED_BUFFER 146 help 147 Allows userspace processes and kernel modules to use Xen backed 148 dma-buf implementation. With this extension grant references to 149 the pages of an imported dma-buf can be exported for other domain 150 use and grant references coming from a foreign domain can be 151 converted into a local dma-buf for local export. 152 153config XEN_GRANT_DEV_ALLOC 154 tristate "User-space grant reference allocator driver" 155 depends on XEN 156 default m 157 help 158 Allows userspace processes to create pages with access granted 159 to other domains. This can be used to implement frontend drivers 160 or as part of an inter-domain shared memory channel. 161 162config XEN_GRANT_DMA_ALLOC 163 bool "Allow allocating DMA capable buffers with grant reference module" 164 depends on XEN && HAS_DMA 165 help 166 Extends grant table module API to allow allocating DMA capable 167 buffers and mapping foreign grant references on top of it. 168 The resulting buffer is similar to one allocated by the balloon 169 driver in that proper memory reservation is made by 170 ({increase|decrease}_reservation and VA mappings are updated if 171 needed). 172 This is useful for sharing foreign buffers with HW drivers which 173 cannot work with scattered buffers provided by the balloon driver, 174 but require DMAable memory instead. 175 176config SWIOTLB_XEN 177 def_bool y 178 select SWIOTLB 179 180config XEN_PCIDEV_BACKEND 181 tristate "Xen PCI-device backend driver" 182 depends on PCI && X86 && XEN 183 depends on XEN_BACKEND 184 default m 185 help 186 The PCI device backend driver allows the kernel to export arbitrary 187 PCI devices to other guests. If you select this to be a module, you 188 will need to make sure no other driver has bound to the device(s) 189 you want to make visible to other guests. 190 191 The parameter "passthrough" allows you specify how you want the PCI 192 devices to appear in the guest. You can choose the default (0) where 193 PCI topology starts at 00.00.0, or (1) for passthrough if you want 194 the PCI devices topology appear the same as in the host. 195 196 The "hide" parameter (only applicable if backend driver is compiled 197 into the kernel) allows you to bind the PCI devices to this module 198 from the default device drivers. The argument is the list of PCI BDFs: 199 xen-pciback.hide=(03:00.0)(04:00.0) 200 201 If in doubt, say m. 202 203config XEN_PVCALLS_FRONTEND 204 tristate "XEN PV Calls frontend driver" 205 depends on INET && XEN 206 select XEN_XENBUS_FRONTEND 207 help 208 Experimental frontend for the Xen PV Calls protocol 209 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 210 sends a small set of POSIX calls to the backend, which 211 implements them. 212 213config XEN_PVCALLS_BACKEND 214 bool "XEN PV Calls backend driver" 215 depends on INET && XEN && XEN_BACKEND 216 help 217 Experimental backend for the Xen PV Calls protocol 218 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 219 allows PV Calls frontends to send POSIX calls to the backend, 220 which implements them. 221 222 If in doubt, say n. 223 224config XEN_SCSI_BACKEND 225 tristate "XEN SCSI backend driver" 226 depends on XEN && XEN_BACKEND && TARGET_CORE 227 help 228 The SCSI backend driver allows the kernel to export its SCSI Devices 229 to other guests via a high-performance shared-memory interface. 230 Only needed for systems running as XEN driver domains (e.g. Dom0) and 231 if guests need generic access to SCSI devices. 232 233config XEN_PRIVCMD 234 tristate 235 depends on XEN 236 default m 237 238config XEN_STUB 239 bool "Xen stub drivers" 240 depends on XEN && X86_64 && BROKEN 241 help 242 Allow kernel to install stub drivers, to reserve space for Xen drivers, 243 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 244 so that real Xen drivers can be modular. 245 246 To enable Xen features like cpu and memory hotplug, select Y here. 247 248config XEN_ACPI_HOTPLUG_MEMORY 249 tristate "Xen ACPI memory hotplug" 250 depends on XEN_DOM0 && XEN_STUB && ACPI 251 help 252 This is Xen ACPI memory hotplug. 253 254 Currently Xen only support ACPI memory hot-add. If you want 255 to hot-add memory at runtime (the hot-added memory cannot be 256 removed until machine stop), select Y/M here, otherwise select N. 257 258config XEN_ACPI_HOTPLUG_CPU 259 tristate "Xen ACPI cpu hotplug" 260 depends on XEN_DOM0 && XEN_STUB && ACPI 261 select ACPI_CONTAINER 262 help 263 Xen ACPI cpu enumerating and hotplugging 264 265 For hotplugging, currently Xen only support ACPI cpu hotadd. 266 If you want to hotadd cpu at runtime (the hotadded cpu cannot 267 be removed until machine stop), select Y/M here. 268 269config XEN_ACPI_PROCESSOR 270 tristate "Xen ACPI processor" 271 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 272 default m 273 help 274 This ACPI processor uploads Power Management information to the Xen 275 hypervisor. 276 277 To do that the driver parses the Power Management data and uploads 278 said information to the Xen hypervisor. Then the Xen hypervisor can 279 select the proper Cx and Pxx states. It also registers itself as the 280 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 281 not load. 282 283 To compile this driver as a module, choose M here: the module will be 284 called xen_acpi_processor If you do not know what to choose, select 285 M here. If the CPUFREQ drivers are built in, select Y here. 286 287config XEN_MCE_LOG 288 bool "Xen platform mcelog" 289 depends on XEN_DOM0 && X86_MCE 290 help 291 Allow kernel fetching MCE error from Xen platform and 292 converting it into Linux mcelog format for mcelog tools 293 294config XEN_HAVE_PVMMU 295 bool 296 297config XEN_EFI 298 def_bool y 299 depends on (ARM || ARM64 || X86_64) && EFI 300 301config XEN_AUTO_XLATE 302 def_bool y 303 depends on ARM || ARM64 || XEN_PVHVM 304 help 305 Support for auto-translated physmap guests. 306 307config XEN_ACPI 308 def_bool y 309 depends on X86 && ACPI 310 311config XEN_SYMS 312 bool "Xen symbols" 313 depends on X86 && XEN_DOM0 && XENFS 314 default y if KALLSYMS 315 help 316 Exports hypervisor symbols (along with their types and addresses) via 317 /proc/xen/xensyms file, similar to /proc/kallsyms 318 319config XEN_HAVE_VPMU 320 bool 321 322config XEN_FRONT_PGDIR_SHBUF 323 tristate 324 325endmenu 326