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 162 select DMA_SHARED_BUFFER 163 help 164 Allows userspace processes and kernel modules to use Xen backed 165 dma-buf implementation. With this extension grant references to 166 the pages of an imported dma-buf can be exported for other domain 167 use and grant references coming from a foreign domain can be 168 converted into a local dma-buf for local export. 169 170config XEN_GRANT_DEV_ALLOC 171 tristate "User-space grant reference allocator driver" 172 depends on XEN 173 default m 174 help 175 Allows userspace processes to create pages with access granted 176 to other domains. This can be used to implement frontend drivers 177 or as part of an inter-domain shared memory channel. 178 179config XEN_GRANT_DMA_ALLOC 180 bool "Allow allocating DMA capable buffers with grant reference module" 181 depends on XEN && HAS_DMA 182 help 183 Extends grant table module API to allow allocating DMA capable 184 buffers and mapping foreign grant references on top of it. 185 The resulting buffer is similar to one allocated by the balloon 186 driver in that proper memory reservation is made by 187 ({increase|decrease}_reservation and VA mappings are updated if 188 needed). 189 This is useful for sharing foreign buffers with HW drivers which 190 cannot work with scattered buffers provided by the balloon driver, 191 but require DMAable memory instead. 192 193config SWIOTLB_XEN 194 def_bool y 195 select SWIOTLB 196 197config XEN_TMEM 198 tristate 199 depends on !ARM && !ARM64 200 default m if (CLEANCACHE || FRONTSWAP) 201 help 202 Shim to interface in-kernel Transcendent Memory hooks 203 (e.g. cleancache and frontswap) to Xen tmem hypercalls. 204 205config XEN_PCIDEV_BACKEND 206 tristate "Xen PCI-device backend driver" 207 depends on PCI && X86 && XEN 208 depends on XEN_BACKEND 209 default m 210 help 211 The PCI device backend driver allows the kernel to export arbitrary 212 PCI devices to other guests. If you select this to be a module, you 213 will need to make sure no other driver has bound to the device(s) 214 you want to make visible to other guests. 215 216 The parameter "passthrough" allows you specify how you want the PCI 217 devices to appear in the guest. You can choose the default (0) where 218 PCI topology starts at 00.00.0, or (1) for passthrough if you want 219 the PCI devices topology appear the same as in the host. 220 221 The "hide" parameter (only applicable if backend driver is compiled 222 into the kernel) allows you to bind the PCI devices to this module 223 from the default device drivers. The argument is the list of PCI BDFs: 224 xen-pciback.hide=(03:00.0)(04:00.0) 225 226 If in doubt, say m. 227 228config XEN_PVCALLS_FRONTEND 229 tristate "XEN PV Calls frontend driver" 230 depends on INET && XEN 231 default n 232 select XEN_XENBUS_FRONTEND 233 help 234 Experimental frontend for the Xen PV Calls protocol 235 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 236 sends a small set of POSIX calls to the backend, which 237 implements them. 238 239config XEN_PVCALLS_BACKEND 240 bool "XEN PV Calls backend driver" 241 depends on INET && XEN && XEN_BACKEND 242 default n 243 help 244 Experimental backend for the Xen PV Calls protocol 245 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 246 allows PV Calls frontends to send POSIX calls to the backend, 247 which implements them. 248 249 If in doubt, say n. 250 251config XEN_SCSI_BACKEND 252 tristate "XEN SCSI backend driver" 253 depends on XEN && XEN_BACKEND && TARGET_CORE 254 help 255 The SCSI backend driver allows the kernel to export its SCSI Devices 256 to other guests via a high-performance shared-memory interface. 257 Only needed for systems running as XEN driver domains (e.g. Dom0) and 258 if guests need generic access to SCSI devices. 259 260config XEN_PRIVCMD 261 tristate 262 depends on XEN 263 default m 264 265config XEN_STUB 266 bool "Xen stub drivers" 267 depends on XEN && X86_64 && BROKEN 268 default n 269 help 270 Allow kernel to install stub drivers, to reserve space for Xen drivers, 271 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 272 so that real Xen drivers can be modular. 273 274 To enable Xen features like cpu and memory hotplug, select Y here. 275 276config XEN_ACPI_HOTPLUG_MEMORY 277 tristate "Xen ACPI memory hotplug" 278 depends on XEN_DOM0 && XEN_STUB && ACPI 279 default n 280 help 281 This is Xen ACPI memory hotplug. 282 283 Currently Xen only support ACPI memory hot-add. If you want 284 to hot-add memory at runtime (the hot-added memory cannot be 285 removed until machine stop), select Y/M here, otherwise select N. 286 287config XEN_ACPI_HOTPLUG_CPU 288 tristate "Xen ACPI cpu hotplug" 289 depends on XEN_DOM0 && XEN_STUB && ACPI 290 select ACPI_CONTAINER 291 default n 292 help 293 Xen ACPI cpu enumerating and hotplugging 294 295 For hotplugging, currently Xen only support ACPI cpu hotadd. 296 If you want to hotadd cpu at runtime (the hotadded cpu cannot 297 be removed until machine stop), select Y/M here. 298 299config XEN_ACPI_PROCESSOR 300 tristate "Xen ACPI processor" 301 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 302 default m 303 help 304 This ACPI processor uploads Power Management information to the Xen 305 hypervisor. 306 307 To do that the driver parses the Power Management data and uploads 308 said information to the Xen hypervisor. Then the Xen hypervisor can 309 select the proper Cx and Pxx states. It also registers itself as the 310 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 311 not load. 312 313 To compile this driver as a module, choose M here: the module will be 314 called xen_acpi_processor If you do not know what to choose, select 315 M here. If the CPUFREQ drivers are built in, select Y here. 316 317config XEN_MCE_LOG 318 bool "Xen platform mcelog" 319 depends on XEN_DOM0 && X86_64 && X86_MCE 320 default n 321 help 322 Allow kernel fetching MCE error from Xen platform and 323 converting it into Linux mcelog format for mcelog tools 324 325config XEN_HAVE_PVMMU 326 bool 327 328config XEN_EFI 329 def_bool y 330 depends on (ARM || ARM64 || X86_64) && EFI 331 332config XEN_AUTO_XLATE 333 def_bool y 334 depends on ARM || ARM64 || XEN_PVHVM 335 help 336 Support for auto-translated physmap guests. 337 338config XEN_ACPI 339 def_bool y 340 depends on X86 && ACPI 341 342config XEN_SYMS 343 bool "Xen symbols" 344 depends on X86 && XEN_DOM0 && XENFS 345 default y if KALLSYMS 346 help 347 Exports hypervisor symbols (along with their types and addresses) via 348 /proc/xen/xensyms file, similar to /proc/kallsyms 349 350config XEN_HAVE_VPMU 351 bool 352 353endmenu 354