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