drivers/xen/Kconfig

   1 menu "Xen driver support"
   2         depends on XEN
   3
   4 config 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
  12 config 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
  28 config 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
  65 config 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
  82 config 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
  93 config 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
 102 config 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
 110 config 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
 121 config 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
 133 config 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
 144 config XEN_XENBUS_FRONTEND
 145         tristate
 146
 147 config 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
 155 config 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
 164 config SWIOTLB_XEN
 165         def_bool y
 166         select SWIOTLB
 167
 168 config 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
 176 config 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
 199 config 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
 210 config 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
 222 config 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
 231 config XEN_PRIVCMD
 232         tristate
 233         depends on XEN
 234         default m
 235
 236 config 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
 247 config 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
 258 config 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
 270 config XEN_ACPI_PROCESSOR
 271         tristate "Xen ACPI processor"
 272         depends on XEN && XEN_DOM0 && 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
 288 config 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
 296 config XEN_HAVE_PVMMU
 297        bool
 298
 299 config XEN_EFI
 300         def_bool y
 301         depends on (ARM || ARM64 || X86_64) && EFI
 302
 303 config XEN_AUTO_XLATE
 304         def_bool y
 305         depends on ARM || ARM64 || XEN_PVHVM
 306         help
 307           Support for auto-translated physmap guests.
 308
 309 config XEN_ACPI
 310         def_bool y
 311         depends on X86 && ACPI
 312
 313 config 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
 321 config XEN_HAVE_VPMU
 322        bool
 323
 324 endmenu