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) target domain: ensure that memory auto online policy is in 41 effect by checking /sys/devices/system/memory/auto_online_blocks 42 file (should be 'online'). 43 44 2) control domain: xl mem-max <target-domain> <maxmem> 45 where <maxmem> is >= requested memory size, 46 47 3) control domain: xl mem-set <target-domain> <memory> 48 where <memory> is requested memory size; alternatively memory 49 could be added by writing proper value to 50 /sys/devices/system/xen_memory/xen_memory0/target or 51 /sys/devices/system/xen_memory/xen_memory0/target_kb on the 52 target domain. 53 54 Alternatively, if memory auto onlining was not requested at step 1 55 the newly added memory can be manually onlined in the target domain 56 by doing the following: 57 58 for i in /sys/devices/system/memory/memory*/state; do \ 59 [ "`cat "$i"`" = offline ] && echo online > "$i"; done 60 61 or by adding the following line to udev rules: 62 63 SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'" 64 65config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT 66 int "Hotplugged memory limit (in GiB) for a PV guest" 67 default 512 if X86_64 68 default 4 if X86_32 69 range 0 64 if X86_32 70 depends on XEN_HAVE_PVMMU 71 depends on XEN_BALLOON_MEMORY_HOTPLUG 72 help 73 Maxmium amount of memory (in GiB) that a PV guest can be 74 expanded to when using memory hotplug. 75 76 A PV guest can have more memory than this limit if is 77 started with a larger maximum. 78 79 This value is used to allocate enough space in internal 80 tables needed for physical memory administration. 81 82config XEN_SCRUB_PAGES_DEFAULT 83 bool "Scrub pages before returning them to system by default" 84 depends on XEN_BALLOON 85 default y 86 help 87 Scrub pages before returning them to the system for reuse by 88 other domains. This makes sure that any confidential data 89 is not accidentally visible to other domains. Is it more 90 secure, but slightly less efficient. This can be controlled with 91 xen_scrub_pages=0 parameter and 92 /sys/devices/system/xen_memory/xen_memory0/scrub_pages. 93 This option only sets the default value. 94 95 If in doubt, say yes. 96 97config XEN_DEV_EVTCHN 98 tristate "Xen /dev/xen/evtchn device" 99 default y 100 help 101 The evtchn driver allows a userspace process to trigger event 102 channels and to receive notification of an event channel 103 firing. 104 If in doubt, say yes. 105 106config XEN_BACKEND 107 bool "Backend driver support" 108 depends on XEN_DOM0 109 default y 110 help 111 Support for backend device drivers that provide I/O services 112 to other virtual machines. 113 114config XENFS 115 tristate "Xen filesystem" 116 select XEN_PRIVCMD 117 default y 118 help 119 The xen filesystem provides a way for domains to share 120 information with each other and with the hypervisor. 121 For example, by reading and writing the "xenbus" file, guests 122 may pass arbitrary information to the initial domain. 123 If in doubt, say yes. 124 125config XEN_COMPAT_XENFS 126 bool "Create compatibility mount point /proc/xen" 127 depends on XENFS 128 default y 129 help 130 The old xenstore userspace tools expect to find "xenbus" 131 under /proc/xen, but "xenbus" is now found at the root of the 132 xenfs filesystem. Selecting this causes the kernel to create 133 the compatibility mount point /proc/xen if it is running on 134 a xen platform. 135 If in doubt, say yes. 136 137config XEN_SYS_HYPERVISOR 138 bool "Create xen entries under /sys/hypervisor" 139 depends on SYSFS 140 select SYS_HYPERVISOR 141 default y 142 help 143 Create entries under /sys/hypervisor describing the Xen 144 hypervisor environment. When running native or in another 145 virtual environment, /sys/hypervisor will still be present, 146 but will have no xen contents. 147 148config XEN_XENBUS_FRONTEND 149 tristate 150 151config XEN_GNTDEV 152 tristate "userspace grant access device driver" 153 depends on XEN 154 default m 155 select MMU_NOTIFIER 156 help 157 Allows userspace processes to use grants. 158 159config XEN_GNTDEV_DMABUF 160 bool "Add support for dma-buf grant access device driver extension" 161 depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC && DMA_SHARED_BUFFER 162 help 163 Allows userspace processes and kernel modules to use Xen backed 164 dma-buf implementation. With this extension grant references to 165 the pages of an imported dma-buf can be exported for other domain 166 use and grant references coming from a foreign domain can be 167 converted into a local dma-buf for local export. 168 169config XEN_GRANT_DEV_ALLOC 170 tristate "User-space grant reference allocator driver" 171 depends on XEN 172 default m 173 help 174 Allows userspace processes to create pages with access granted 175 to other domains. This can be used to implement frontend drivers 176 or as part of an inter-domain shared memory channel. 177 178config XEN_GRANT_DMA_ALLOC 179 bool "Allow allocating DMA capable buffers with grant reference module" 180 depends on XEN && HAS_DMA 181 help 182 Extends grant table module API to allow allocating DMA capable 183 buffers and mapping foreign grant references on top of it. 184 The resulting buffer is similar to one allocated by the balloon 185 driver in that proper memory reservation is made by 186 ({increase|decrease}_reservation and VA mappings are updated if 187 needed). 188 This is useful for sharing foreign buffers with HW drivers which 189 cannot work with scattered buffers provided by the balloon driver, 190 but require DMAable memory instead. 191 192config SWIOTLB_XEN 193 def_bool y 194 select SWIOTLB 195 196config XEN_TMEM 197 tristate 198 depends on !ARM && !ARM64 199 default m if (CLEANCACHE || FRONTSWAP) 200 help 201 Shim to interface in-kernel Transcendent Memory hooks 202 (e.g. cleancache and frontswap) to Xen tmem hypercalls. 203 204config XEN_PCIDEV_BACKEND 205 tristate "Xen PCI-device backend driver" 206 depends on PCI && X86 && XEN 207 depends on XEN_BACKEND 208 default m 209 help 210 The PCI device backend driver allows the kernel to export arbitrary 211 PCI devices to other guests. If you select this to be a module, you 212 will need to make sure no other driver has bound to the device(s) 213 you want to make visible to other guests. 214 215 The parameter "passthrough" allows you specify how you want the PCI 216 devices to appear in the guest. You can choose the default (0) where 217 PCI topology starts at 00.00.0, or (1) for passthrough if you want 218 the PCI devices topology appear the same as in the host. 219 220 The "hide" parameter (only applicable if backend driver is compiled 221 into the kernel) allows you to bind the PCI devices to this module 222 from the default device drivers. The argument is the list of PCI BDFs: 223 xen-pciback.hide=(03:00.0)(04:00.0) 224 225 If in doubt, say m. 226 227config XEN_PVCALLS_FRONTEND 228 tristate "XEN PV Calls frontend driver" 229 depends on INET && XEN 230 default n 231 select XEN_XENBUS_FRONTEND 232 help 233 Experimental frontend for the Xen PV Calls protocol 234 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 235 sends a small set of POSIX calls to the backend, which 236 implements them. 237 238config XEN_PVCALLS_BACKEND 239 bool "XEN PV Calls backend driver" 240 depends on INET && XEN && XEN_BACKEND 241 default n 242 help 243 Experimental backend for the Xen PV Calls protocol 244 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 245 allows PV Calls frontends to send POSIX calls to the backend, 246 which implements them. 247 248 If in doubt, say n. 249 250config XEN_SCSI_BACKEND 251 tristate "XEN SCSI backend driver" 252 depends on XEN && XEN_BACKEND && TARGET_CORE 253 help 254 The SCSI backend driver allows the kernel to export its SCSI Devices 255 to other guests via a high-performance shared-memory interface. 256 Only needed for systems running as XEN driver domains (e.g. Dom0) and 257 if guests need generic access to SCSI devices. 258 259config XEN_PRIVCMD 260 tristate 261 depends on XEN 262 default m 263 264config XEN_STUB 265 bool "Xen stub drivers" 266 depends on XEN && X86_64 && BROKEN 267 default n 268 help 269 Allow kernel to install stub drivers, to reserve space for Xen drivers, 270 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 271 so that real Xen drivers can be modular. 272 273 To enable Xen features like cpu and memory hotplug, select Y here. 274 275config XEN_ACPI_HOTPLUG_MEMORY 276 tristate "Xen ACPI memory hotplug" 277 depends on XEN_DOM0 && XEN_STUB && ACPI 278 default n 279 help 280 This is Xen ACPI memory hotplug. 281 282 Currently Xen only support ACPI memory hot-add. If you want 283 to hot-add memory at runtime (the hot-added memory cannot be 284 removed until machine stop), select Y/M here, otherwise select N. 285 286config XEN_ACPI_HOTPLUG_CPU 287 tristate "Xen ACPI cpu hotplug" 288 depends on XEN_DOM0 && XEN_STUB && ACPI 289 select ACPI_CONTAINER 290 default n 291 help 292 Xen ACPI cpu enumerating and hotplugging 293 294 For hotplugging, currently Xen only support ACPI cpu hotadd. 295 If you want to hotadd cpu at runtime (the hotadded cpu cannot 296 be removed until machine stop), select Y/M here. 297 298config XEN_ACPI_PROCESSOR 299 tristate "Xen ACPI processor" 300 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 301 default m 302 help 303 This ACPI processor uploads Power Management information to the Xen 304 hypervisor. 305 306 To do that the driver parses the Power Management data and uploads 307 said information to the Xen hypervisor. Then the Xen hypervisor can 308 select the proper Cx and Pxx states. It also registers itself as the 309 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 310 not load. 311 312 To compile this driver as a module, choose M here: the module will be 313 called xen_acpi_processor If you do not know what to choose, select 314 M here. If the CPUFREQ drivers are built in, select Y here. 315 316config XEN_MCE_LOG 317 bool "Xen platform mcelog" 318 depends on XEN_DOM0 && X86_64 && X86_MCE 319 default n 320 help 321 Allow kernel fetching MCE error from Xen platform and 322 converting it into Linux mcelog format for mcelog tools 323 324config XEN_HAVE_PVMMU 325 bool 326 327config XEN_EFI 328 def_bool y 329 depends on (ARM || ARM64 || X86_64) && EFI 330 331config XEN_AUTO_XLATE 332 def_bool y 333 depends on ARM || ARM64 || XEN_PVHVM 334 help 335 Support for auto-translated physmap guests. 336 337config XEN_ACPI 338 def_bool y 339 depends on X86 && ACPI 340 341config XEN_SYMS 342 bool "Xen symbols" 343 depends on X86 && XEN_DOM0 && XENFS 344 default y if KALLSYMS 345 help 346 Exports hypervisor symbols (along with their types and addresses) via 347 /proc/xen/xensyms file, similar to /proc/kallsyms 348 349config XEN_HAVE_VPMU 350 bool 351 352endmenu 353