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_GNTDEV_DMABUF 156 bool "Add support for dma-buf grant access device driver extension" 157 depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC && DMA_SHARED_BUFFER 158 help 159 Allows userspace processes and kernel modules to use Xen backed 160 dma-buf implementation. With this extension grant references to 161 the pages of an imported dma-buf can be exported for other domain 162 use and grant references coming from a foreign domain can be 163 converted into a local dma-buf for local export. 164 165config XEN_GRANT_DEV_ALLOC 166 tristate "User-space grant reference allocator driver" 167 depends on XEN 168 default m 169 help 170 Allows userspace processes to create pages with access granted 171 to other domains. This can be used to implement frontend drivers 172 or as part of an inter-domain shared memory channel. 173 174config XEN_GRANT_DMA_ALLOC 175 bool "Allow allocating DMA capable buffers with grant reference module" 176 depends on XEN && HAS_DMA 177 help 178 Extends grant table module API to allow allocating DMA capable 179 buffers and mapping foreign grant references on top of it. 180 The resulting buffer is similar to one allocated by the balloon 181 driver in that proper memory reservation is made by 182 ({increase|decrease}_reservation and VA mappings are updated if 183 needed). 184 This is useful for sharing foreign buffers with HW drivers which 185 cannot work with scattered buffers provided by the balloon driver, 186 but require DMAable memory instead. 187 188config SWIOTLB_XEN 189 def_bool y 190 select SWIOTLB 191 192config XEN_TMEM 193 tristate 194 depends on !ARM && !ARM64 195 default m if (CLEANCACHE || FRONTSWAP) 196 help 197 Shim to interface in-kernel Transcendent Memory hooks 198 (e.g. cleancache and frontswap) to Xen tmem hypercalls. 199 200config XEN_PCIDEV_BACKEND 201 tristate "Xen PCI-device backend driver" 202 depends on PCI && X86 && XEN 203 depends on XEN_BACKEND 204 default m 205 help 206 The PCI device backend driver allows the kernel to export arbitrary 207 PCI devices to other guests. If you select this to be a module, you 208 will need to make sure no other driver has bound to the device(s) 209 you want to make visible to other guests. 210 211 The parameter "passthrough" allows you specify how you want the PCI 212 devices to appear in the guest. You can choose the default (0) where 213 PCI topology starts at 00.00.0, or (1) for passthrough if you want 214 the PCI devices topology appear the same as in the host. 215 216 The "hide" parameter (only applicable if backend driver is compiled 217 into the kernel) allows you to bind the PCI devices to this module 218 from the default device drivers. The argument is the list of PCI BDFs: 219 xen-pciback.hide=(03:00.0)(04:00.0) 220 221 If in doubt, say m. 222 223config XEN_PVCALLS_FRONTEND 224 tristate "XEN PV Calls frontend driver" 225 depends on INET && XEN 226 default n 227 select XEN_XENBUS_FRONTEND 228 help 229 Experimental frontend for the Xen PV Calls protocol 230 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 231 sends a small set of POSIX calls to the backend, which 232 implements them. 233 234config XEN_PVCALLS_BACKEND 235 bool "XEN PV Calls backend driver" 236 depends on INET && XEN && XEN_BACKEND 237 default n 238 help 239 Experimental backend for the Xen PV Calls protocol 240 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 241 allows PV Calls frontends to send POSIX calls to the backend, 242 which implements them. 243 244 If in doubt, say n. 245 246config XEN_SCSI_BACKEND 247 tristate "XEN SCSI backend driver" 248 depends on XEN && XEN_BACKEND && TARGET_CORE 249 help 250 The SCSI backend driver allows the kernel to export its SCSI Devices 251 to other guests via a high-performance shared-memory interface. 252 Only needed for systems running as XEN driver domains (e.g. Dom0) and 253 if guests need generic access to SCSI devices. 254 255config XEN_PRIVCMD 256 tristate 257 depends on XEN 258 default m 259 260config XEN_STUB 261 bool "Xen stub drivers" 262 depends on XEN && X86_64 && BROKEN 263 default n 264 help 265 Allow kernel to install stub drivers, to reserve space for Xen drivers, 266 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 267 so that real Xen drivers can be modular. 268 269 To enable Xen features like cpu and memory hotplug, select Y here. 270 271config XEN_ACPI_HOTPLUG_MEMORY 272 tristate "Xen ACPI memory hotplug" 273 depends on XEN_DOM0 && XEN_STUB && ACPI 274 default n 275 help 276 This is Xen ACPI memory hotplug. 277 278 Currently Xen only support ACPI memory hot-add. If you want 279 to hot-add memory at runtime (the hot-added memory cannot be 280 removed until machine stop), select Y/M here, otherwise select N. 281 282config XEN_ACPI_HOTPLUG_CPU 283 tristate "Xen ACPI cpu hotplug" 284 depends on XEN_DOM0 && XEN_STUB && ACPI 285 select ACPI_CONTAINER 286 default n 287 help 288 Xen ACPI cpu enumerating and hotplugging 289 290 For hotplugging, currently Xen only support ACPI cpu hotadd. 291 If you want to hotadd cpu at runtime (the hotadded cpu cannot 292 be removed until machine stop), select Y/M here. 293 294config XEN_ACPI_PROCESSOR 295 tristate "Xen ACPI processor" 296 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 297 default m 298 help 299 This ACPI processor uploads Power Management information to the Xen 300 hypervisor. 301 302 To do that the driver parses the Power Management data and uploads 303 said information to the Xen hypervisor. Then the Xen hypervisor can 304 select the proper Cx and Pxx states. It also registers itself as the 305 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 306 not load. 307 308 To compile this driver as a module, choose M here: the module will be 309 called xen_acpi_processor If you do not know what to choose, select 310 M here. If the CPUFREQ drivers are built in, select Y here. 311 312config XEN_MCE_LOG 313 bool "Xen platform mcelog" 314 depends on XEN_DOM0 && X86_64 && X86_MCE 315 default n 316 help 317 Allow kernel fetching MCE error from Xen platform and 318 converting it into Linux mcelog format for mcelog tools 319 320config XEN_HAVE_PVMMU 321 bool 322 323config XEN_EFI 324 def_bool y 325 depends on (ARM || ARM64 || X86_64) && EFI 326 327config XEN_AUTO_XLATE 328 def_bool y 329 depends on ARM || ARM64 || XEN_PVHVM 330 help 331 Support for auto-translated physmap guests. 332 333config XEN_ACPI 334 def_bool y 335 depends on X86 && ACPI 336 337config XEN_SYMS 338 bool "Xen symbols" 339 depends on X86 && XEN_DOM0 && XENFS 340 default y if KALLSYMS 341 help 342 Exports hypervisor symbols (along with their types and addresses) via 343 /proc/xen/xensyms file, similar to /proc/kallsyms 344 345config XEN_HAVE_VPMU 346 bool 347 348endmenu 349