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_BACKEND 200 bool "XEN PV Calls backend driver" 201 depends on INET && XEN && XEN_BACKEND 202 default n 203 help 204 Experimental backend for the Xen PV Calls protocol 205 (https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It 206 allows PV Calls frontends to send POSIX calls to the backend, 207 which implements them. 208 209 If in doubt, say n. 210 211config XEN_SCSI_BACKEND 212 tristate "XEN SCSI backend driver" 213 depends on XEN && XEN_BACKEND && TARGET_CORE 214 help 215 The SCSI backend driver allows the kernel to export its SCSI Devices 216 to other guests via a high-performance shared-memory interface. 217 Only needed for systems running as XEN driver domains (e.g. Dom0) and 218 if guests need generic access to SCSI devices. 219 220config XEN_PRIVCMD 221 tristate 222 depends on XEN 223 default m 224 225config XEN_STUB 226 bool "Xen stub drivers" 227 depends on XEN && X86_64 && BROKEN 228 default n 229 help 230 Allow kernel to install stub drivers, to reserve space for Xen drivers, 231 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded, 232 so that real Xen drivers can be modular. 233 234 To enable Xen features like cpu and memory hotplug, select Y here. 235 236config XEN_ACPI_HOTPLUG_MEMORY 237 tristate "Xen ACPI memory hotplug" 238 depends on XEN_DOM0 && XEN_STUB && ACPI 239 default n 240 help 241 This is Xen ACPI memory hotplug. 242 243 Currently Xen only support ACPI memory hot-add. If you want 244 to hot-add memory at runtime (the hot-added memory cannot be 245 removed until machine stop), select Y/M here, otherwise select N. 246 247config XEN_ACPI_HOTPLUG_CPU 248 tristate "Xen ACPI cpu hotplug" 249 depends on XEN_DOM0 && XEN_STUB && ACPI 250 select ACPI_CONTAINER 251 default n 252 help 253 Xen ACPI cpu enumerating and hotplugging 254 255 For hotplugging, currently Xen only support ACPI cpu hotadd. 256 If you want to hotadd cpu at runtime (the hotadded cpu cannot 257 be removed until machine stop), select Y/M here. 258 259config XEN_ACPI_PROCESSOR 260 tristate "Xen ACPI processor" 261 depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ 262 default m 263 help 264 This ACPI processor uploads Power Management information to the Xen 265 hypervisor. 266 267 To do that the driver parses the Power Management data and uploads 268 said information to the Xen hypervisor. Then the Xen hypervisor can 269 select the proper Cx and Pxx states. It also registers itself as the 270 SMM so that other drivers (such as ACPI cpufreq scaling driver) will 271 not load. 272 273 To compile this driver as a module, choose M here: the module will be 274 called xen_acpi_processor If you do not know what to choose, select 275 M here. If the CPUFREQ drivers are built in, select Y here. 276 277config XEN_MCE_LOG 278 bool "Xen platform mcelog" 279 depends on XEN_DOM0 && X86_64 && X86_MCE 280 default n 281 help 282 Allow kernel fetching MCE error from Xen platform and 283 converting it into Linux mcelog format for mcelog tools 284 285config XEN_HAVE_PVMMU 286 bool 287 288config XEN_EFI 289 def_bool y 290 depends on (ARM || ARM64 || X86_64) && EFI 291 292config XEN_AUTO_XLATE 293 def_bool y 294 depends on ARM || ARM64 || XEN_PVHVM 295 help 296 Support for auto-translated physmap guests. 297 298config XEN_ACPI 299 def_bool y 300 depends on X86 && ACPI 301 302config XEN_SYMS 303 bool "Xen symbols" 304 depends on X86 && XEN_DOM0 && XENFS 305 default y if KALLSYMS 306 help 307 Exports hypervisor symbols (along with their types and addresses) via 308 /proc/xen/xensyms file, similar to /proc/kallsyms 309 310config XEN_HAVE_VPMU 311 bool 312 313endmenu 314