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 help 16 Self-ballooning dynamically balloons available kernel memory driven 17 by the current usage of anonymous memory ("committed AS") and 18 controlled by various sysfs-settable parameters. Configuring 19 FRONTSWAP is highly recommended; if it is not configured, self- 20 ballooning is disabled by default. If FRONTSWAP is configured, 21 frontswap-selfshrinking is enabled by default but can be disabled 22 with the 'tmem.selfshrink=0' kernel boot parameter; and self-ballooning 23 is enabled by default but can be disabled with the 'tmem.selfballooning=0' 24 kernel boot parameter. Note that systems without a sufficiently 25 large swap device should not enable self-ballooning. 26 27config XEN_BALLOON_MEMORY_HOTPLUG 28 bool "Memory hotplug support for Xen balloon driver" 29 depends on XEN_BALLOON && MEMORY_HOTPLUG 30 help 31 Memory hotplug support for Xen balloon driver allows expanding memory 32 available for the system above limit declared at system startup. 33 It is very useful on critical systems which require long 34 run without rebooting. 35 36 Memory could be hotplugged in following steps: 37 38 1) target domain: ensure that memory auto online policy is in 39 effect by checking /sys/devices/system/memory/auto_online_blocks 40 file (should be 'online'). 41 42 2) control domain: xl mem-max <target-domain> <maxmem> 43 where <maxmem> is >= requested memory size, 44 45 3) control domain: xl mem-set <target-domain> <memory> 46 where <memory> is requested memory size; alternatively memory 47 could be added by writing proper value to 48 /sys/devices/system/xen_memory/xen_memory0/target or 49 /sys/devices/system/xen_memory/xen_memory0/target_kb on the 50 target domain. 51 52 Alternatively, if memory auto onlining was not requested at step 1 53 the newly added memory can be manually onlined in the target domain 54 by doing the following: 55 56 for i in /sys/devices/system/memory/memory*/state; do \ 57 [ "`cat "$i"`" = offline ] && echo online > "$i"; done 58 59 or by adding the following line to udev rules: 60 61 SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'" 62 63config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT 64 int "Hotplugged memory limit (in GiB) for a PV guest" 65 default 512 if X86_64 66 default 4 if X86_32 67 range 0 64 if X86_32 68 depends on XEN_HAVE_PVMMU 69 depends on XEN_BALLOON_MEMORY_HOTPLUG 70 help 71 Maxmium amount of memory (in GiB) that a PV guest can be 72 expanded to when using memory hotplug. 73 74 A PV guest can have more memory than this limit if is 75 started with a larger maximum. 76 77 This value is used to allocate enough space in internal 78 tables needed for physical memory administration. 79 80config XEN_SCRUB_PAGES_DEFAULT 81 bool "Scrub pages before returning them to system by default" 82 depends on XEN_BALLOON 83 default y 84 help 85 Scrub pages before returning them to the system for reuse by 86 other domains. This makes sure that any confidential data 87 is not accidentally visible to other domains. It is more 88 secure, but slightly less efficient. This can be controlled with 89 xen_scrub_pages=0 parameter and 90 /sys/devices/system/xen_memory/xen_memory0/scrub_pages. 91 This option only sets the default value. 92 93 If in doubt, say yes. 94 95config XEN_DEV_EVTCHN 96 tristate "Xen /dev/xen/evtchn device" 97 default y 98 help 99 The evtchn driver allows a userspace process to trigger event 100 channels and to receive notification of an event channel 101 firing. 102 If in doubt, say yes. 103 104config XEN_BACKEND 105 bool "Backend driver support" 106 default XEN_DOM0 107 help 108 Support for backend device drivers that provide I/O services 109 to other virtual machines. 110 111config XENFS 112 tristate "Xen filesystem" 113 select XEN_PRIVCMD 114 default y 115 help 116 The xen filesystem provides a way for domains to share 117 information with each other and with the hypervisor. 118 For example, by reading and writing the "xenbus" file, guests 119 may pass arbitrary information to the initial domain. 120 If in doubt, say yes. 121 122config XEN_COMPAT_XENFS 123 bool "Create compatibility mount point /proc/xen" 124 depends on XENFS 125 default y 126 help 127 The old xenstore userspace tools expect to find "xenbus" 128 under /proc/xen, but "xenbus" is now found at the root of the 129 xenfs filesystem. Selecting this causes the kernel to create 130 the compatibility mount point /proc/xen if it is running on 131 a xen platform. 132 If in doubt, say yes. 133 134config XEN_SYS_HYPERVISOR 135 bool "Create xen entries under /sys/hypervisor" 136 depends on SYSFS 137 select SYS_HYPERVISOR 138 default y 139 help 140 Create entries under /sys/hypervisor describing the Xen 141 hypervisor environment. When running native or in another 142 virtual environment, /sys/hypervisor will still be present, 143 but will have no xen contents. 144 145config XEN_XENBUS_FRONTEND 146 tristate 147 148config XEN_GNTDEV 149 tristate "userspace grant access device driver" 150 depends on XEN 151 default m 152 select MMU_NOTIFIER 153 help 154 Allows userspace processes to use grants. 155 156config XEN_GNTDEV_DMABUF 157 bool "Add support for dma-buf grant access device driver extension" 158 depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC && DMA_SHARED_BUFFER 159 help 160 Allows userspace processes and kernel modules to use Xen backed 161 dma-buf implementation. With this extension grant references to 162 the pages of an imported dma-buf can be exported for other domain 163 use and grant references coming from a foreign domain can be 164 converted into a local dma-buf for local export. 165 166config XEN_GRANT_DEV_ALLOC 167 tristate "User-space grant reference allocator driver" 168 depends on XEN 169 default m 170 help 171 Allows userspace processes to create pages with access granted 172 to other domains. This can be used to implement frontend drivers 173 or as part of an inter-domain shared memory channel. 174 175config XEN_GRANT_DMA_ALLOC 176 bool "Allow allocating DMA capable buffers with grant reference module" 177 depends on XEN && HAS_DMA 178 help 179 Extends grant table module API to allow allocating DMA capable 180 buffers and mapping foreign grant references on top of it. 181 The resulting buffer is similar to one allocated by the balloon 182 driver in that proper memory reservation is made by 183 ({increase|decrease}_reservation and VA mappings are updated if 184 needed). 185 This is useful for sharing foreign buffers with HW drivers which 186 cannot work with scattered buffers provided by the balloon driver, 187 but require DMAable memory instead. 188 189config SWIOTLB_XEN 190 def_bool y 191 select SWIOTLB 192 193config XEN_TMEM 194 tristate 195 depends on !ARM && !ARM64 196 default m if (CLEANCACHE || FRONTSWAP) 197 help 198 Shim to interface in-kernel Transcendent Memory hooks 199 (e.g. cleancache and frontswap) to Xen tmem hypercalls. 200 201config XEN_PCIDEV_BACKEND 202 tristate "Xen PCI-device backend driver" 203 depends on PCI && X86 && XEN 204 depends on XEN_BACKEND 205 default m 206 help 207 The PCI device backend driver allows the kernel to export arbitrary 208 PCI devices to other guests. If you select this to be a module, you 209 will need to make sure no other driver has bound to the device(s) 210 you want to make visible to other guests. 211 212 The parameter "passthrough" allows you specify how you want the PCI 213 devices to appear in the guest. You can choose the default (0) where 214 PCI topology starts at 00.00.0, or (1) for passthrough if you want 215 the PCI devices topology appear the same as in the host. 216 217 The "hide" parameter (only applicable if backend driver is compiled 218 into the kernel) allows you to bind the PCI devices to this module 219 from the default device drivers. The argument is the list of PCI BDFs: 220 xen-pciback.hide=(03:00.0)(04:00.0) 221 222 If in doubt, say m. 223 224config XEN_PVCALLS_FRONTEND 225 tristate "XEN PV Calls frontend driver" 226 depends on INET && XEN 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 help 238 Experimental backend for the Xen PV Calls protocol 239 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 240 allows PV Calls frontends to send POSIX calls to the backend, 241 which implements them. 242 243 If in doubt, say n. 244 245config XEN_SCSI_BACKEND 246 tristate "XEN SCSI backend driver" 247 depends on XEN && XEN_BACKEND && TARGET_CORE 248 help 249 The SCSI backend driver allows the kernel to export its SCSI Devices 250 to other guests via a high-performance shared-memory interface. 251 Only needed for systems running as XEN driver domains (e.g. Dom0) and 252 if guests need generic access to SCSI devices. 253 254config XEN_PRIVCMD 255 tristate 256 depends on XEN 257 default m 258 259config XEN_STUB 260 bool "Xen stub drivers" 261 depends on XEN && X86_64 && BROKEN 262 help 263 Allow kernel to install stub drivers, to reserve space for Xen drivers, 264 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 265 so that real Xen drivers can be modular. 266 267 To enable Xen features like cpu and memory hotplug, select Y here. 268 269config XEN_ACPI_HOTPLUG_MEMORY 270 tristate "Xen ACPI memory hotplug" 271 depends on XEN_DOM0 && XEN_STUB && ACPI 272 help 273 This is Xen ACPI memory hotplug. 274 275 Currently Xen only support ACPI memory hot-add. If you want 276 to hot-add memory at runtime (the hot-added memory cannot be 277 removed until machine stop), select Y/M here, otherwise select N. 278 279config XEN_ACPI_HOTPLUG_CPU 280 tristate "Xen ACPI cpu hotplug" 281 depends on XEN_DOM0 && XEN_STUB && ACPI 282 select ACPI_CONTAINER 283 help 284 Xen ACPI cpu enumerating and hotplugging 285 286 For hotplugging, currently Xen only support ACPI cpu hotadd. 287 If you want to hotadd cpu at runtime (the hotadded cpu cannot 288 be removed until machine stop), select Y/M here. 289 290config XEN_ACPI_PROCESSOR 291 tristate "Xen ACPI processor" 292 depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ 293 default m 294 help 295 This ACPI processor uploads Power Management information to the Xen 296 hypervisor. 297 298 To do that the driver parses the Power Management data and uploads 299 said information to the Xen hypervisor. Then the Xen hypervisor can 300 select the proper Cx and Pxx states. It also registers itself as the 301 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 302 not load. 303 304 To compile this driver as a module, choose M here: the module will be 305 called xen_acpi_processor If you do not know what to choose, select 306 M here. If the CPUFREQ drivers are built in, select Y here. 307 308config XEN_MCE_LOG 309 bool "Xen platform mcelog" 310 depends on XEN_DOM0 && X86_64 && X86_MCE 311 help 312 Allow kernel fetching MCE error from Xen platform and 313 converting it into Linux mcelog format for mcelog tools 314 315config XEN_HAVE_PVMMU 316 bool 317 318config XEN_EFI 319 def_bool y 320 depends on (ARM || ARM64 || X86_64) && EFI 321 322config XEN_AUTO_XLATE 323 def_bool y 324 depends on ARM || ARM64 || XEN_PVHVM 325 help 326 Support for auto-translated physmap guests. 327 328config XEN_ACPI 329 def_bool y 330 depends on X86 && ACPI 331 332config XEN_SYMS 333 bool "Xen symbols" 334 depends on X86 && XEN_DOM0 && XENFS 335 default y if KALLSYMS 336 help 337 Exports hypervisor symbols (along with their types and addresses) via 338 /proc/xen/xensyms file, similar to /proc/kallsyms 339 340config XEN_HAVE_VPMU 341 bool 342 343endmenu 344