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 83 bool "Scrub pages before returning them to system" 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. 91 If in doubt, say yes. 92 93config XEN_DEV_EVTCHN 94 tristate "Xen /dev/xen/evtchn device" 95 default y 96 help 97 The evtchn driver allows a userspace process to trigger event 98 channels and to receive notification of an event channel 99 firing. 100 If in doubt, say yes. 101 102config XEN_BACKEND 103 bool "Backend driver support" 104 depends on XEN_DOM0 105 default y 106 help 107 Support for backend device drivers that provide I/O services 108 to other virtual machines. 109 110config XENFS 111 tristate "Xen filesystem" 112 select XEN_PRIVCMD 113 default y 114 help 115 The xen filesystem provides a way for domains to share 116 information with each other and with the hypervisor. 117 For example, by reading and writing the "xenbus" file, guests 118 may pass arbitrary information to the initial domain. 119 If in doubt, say yes. 120 121config XEN_COMPAT_XENFS 122 bool "Create compatibility mount point /proc/xen" 123 depends on XENFS 124 default y 125 help 126 The old xenstore userspace tools expect to find "xenbus" 127 under /proc/xen, but "xenbus" is now found at the root of the 128 xenfs filesystem. Selecting this causes the kernel to create 129 the compatibility mount point /proc/xen if it is running on 130 a xen platform. 131 If in doubt, say yes. 132 133config XEN_SYS_HYPERVISOR 134 bool "Create xen entries under /sys/hypervisor" 135 depends on SYSFS 136 select SYS_HYPERVISOR 137 default y 138 help 139 Create entries under /sys/hypervisor describing the Xen 140 hypervisor environment. When running native or in another 141 virtual environment, /sys/hypervisor will still be present, 142 but will have no xen contents. 143 144config XEN_XENBUS_FRONTEND 145 tristate 146 147config XEN_GNTDEV 148 tristate "userspace grant access device driver" 149 depends on XEN 150 default m 151 select MMU_NOTIFIER 152 help 153 Allows userspace processes to use grants. 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 SWIOTLB 181 182config XEN_TMEM 183 tristate 184 depends on !ARM && !ARM64 185 default m if (CLEANCACHE || FRONTSWAP) 186 help 187 Shim to interface in-kernel Transcendent Memory hooks 188 (e.g. cleancache and frontswap) to Xen tmem hypercalls. 189 190config XEN_PCIDEV_BACKEND 191 tristate "Xen PCI-device backend driver" 192 depends on PCI && X86 && XEN 193 depends on XEN_BACKEND 194 default m 195 help 196 The PCI device backend driver allows the kernel to export arbitrary 197 PCI devices to other guests. If you select this to be a module, you 198 will need to make sure no other driver has bound to the device(s) 199 you want to make visible to other guests. 200 201 The parameter "passthrough" allows you specify how you want the PCI 202 devices to appear in the guest. You can choose the default (0) where 203 PCI topology starts at 00.00.0, or (1) for passthrough if you want 204 the PCI devices topology appear the same as in the host. 205 206 The "hide" parameter (only applicable if backend driver is compiled 207 into the kernel) allows you to bind the PCI devices to this module 208 from the default device drivers. The argument is the list of PCI BDFs: 209 xen-pciback.hide=(03:00.0)(04:00.0) 210 211 If in doubt, say m. 212 213config XEN_PVCALLS_FRONTEND 214 tristate "XEN PV Calls frontend driver" 215 depends on INET && XEN 216 default n 217 select XEN_XENBUS_FRONTEND 218 help 219 Experimental frontend for the Xen PV Calls protocol 220 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 221 sends a small set of POSIX calls to the backend, which 222 implements them. 223 224config XEN_PVCALLS_BACKEND 225 bool "XEN PV Calls backend driver" 226 depends on INET && XEN && XEN_BACKEND 227 default n 228 help 229 Experimental backend for the Xen PV Calls protocol 230 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 231 allows PV Calls frontends to send POSIX calls to the backend, 232 which implements them. 233 234 If in doubt, say n. 235 236config XEN_SCSI_BACKEND 237 tristate "XEN SCSI backend driver" 238 depends on XEN && XEN_BACKEND && TARGET_CORE 239 help 240 The SCSI backend driver allows the kernel to export its SCSI Devices 241 to other guests via a high-performance shared-memory interface. 242 Only needed for systems running as XEN driver domains (e.g. Dom0) and 243 if guests need generic access to SCSI devices. 244 245config XEN_PRIVCMD 246 tristate 247 depends on XEN 248 default m 249 250config XEN_STUB 251 bool "Xen stub drivers" 252 depends on XEN && X86_64 && BROKEN 253 default n 254 help 255 Allow kernel to install stub drivers, to reserve space for Xen drivers, 256 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 257 so that real Xen drivers can be modular. 258 259 To enable Xen features like cpu and memory hotplug, select Y here. 260 261config XEN_ACPI_HOTPLUG_MEMORY 262 tristate "Xen ACPI memory hotplug" 263 depends on XEN_DOM0 && XEN_STUB && ACPI 264 default n 265 help 266 This is Xen ACPI memory hotplug. 267 268 Currently Xen only support ACPI memory hot-add. If you want 269 to hot-add memory at runtime (the hot-added memory cannot be 270 removed until machine stop), select Y/M here, otherwise select N. 271 272config XEN_ACPI_HOTPLUG_CPU 273 tristate "Xen ACPI cpu hotplug" 274 depends on XEN_DOM0 && XEN_STUB && ACPI 275 select ACPI_CONTAINER 276 default n 277 help 278 Xen ACPI cpu enumerating and hotplugging 279 280 For hotplugging, currently Xen only support ACPI cpu hotadd. 281 If you want to hotadd cpu at runtime (the hotadded cpu cannot 282 be removed until machine stop), select Y/M here. 283 284config XEN_ACPI_PROCESSOR 285 tristate "Xen ACPI processor" 286 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 287 default m 288 help 289 This ACPI processor uploads Power Management information to the Xen 290 hypervisor. 291 292 To do that the driver parses the Power Management data and uploads 293 said information to the Xen hypervisor. Then the Xen hypervisor can 294 select the proper Cx and Pxx states. It also registers itself as the 295 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 296 not load. 297 298 To compile this driver as a module, choose M here: the module will be 299 called xen_acpi_processor If you do not know what to choose, select 300 M here. If the CPUFREQ drivers are built in, select Y here. 301 302config XEN_MCE_LOG 303 bool "Xen platform mcelog" 304 depends on XEN_DOM0 && X86_64 && X86_MCE 305 default n 306 help 307 Allow kernel fetching MCE error from Xen platform and 308 converting it into Linux mcelog format for mcelog tools 309 310config XEN_HAVE_PVMMU 311 bool 312 313config XEN_EFI 314 def_bool y 315 depends on (ARM || ARM64 || X86_64) && EFI 316 317config XEN_AUTO_XLATE 318 def_bool y 319 depends on ARM || ARM64 || XEN_PVHVM 320 help 321 Support for auto-translated physmap guests. 322 323config XEN_ACPI 324 def_bool y 325 depends on X86 && ACPI 326 327config XEN_SYMS 328 bool "Xen symbols" 329 depends on X86 && XEN_DOM0 && XENFS 330 default y if KALLSYMS 331 help 332 Exports hypervisor symbols (along with their types and addresses) via 333 /proc/xen/xensyms file, similar to /proc/kallsyms 334 335config XEN_HAVE_VPMU 336 bool 337 338endmenu 339