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         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
  27 config 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
  63 config 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
  80 config 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
  95 config 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
 104 config 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
 111 config 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
 122 config 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
 134 config 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
 145 config XEN_XENBUS_FRONTEND
 146         tristate
 147
 148 config 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
 156 config 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
 166 config 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
 175 config 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
 189 config SWIOTLB_XEN
 190         def_bool y
 191         select SWIOTLB
 192
 193 config 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
 201 config 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
 224 config 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
 234 config 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
 245 config 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
 254 config XEN_PRIVCMD
 255         tristate
 256         depends on XEN
 257         default m
 258
 259 config 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
 269 config 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
 279 config 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
 290 config 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
 308 config 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
 315 config XEN_HAVE_PVMMU
 316        bool
 317
 318 config XEN_EFI
 319         def_bool y
 320         depends on (ARM || ARM64 || X86_64) && EFI
 321
 322 config XEN_AUTO_XLATE
 323         def_bool y
 324         depends on ARM || ARM64 || XEN_PVHVM
 325         help
 326           Support for auto-translated physmap guests.
 327
 328 config XEN_ACPI
 329         def_bool y
 330         depends on X86 && ACPI
 331
 332 config 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
 340 config XEN_HAVE_VPMU
 341        bool
 342
 343 config XEN_FRONT_PGDIR_SHBUF
 344         tristate
 345
 346 endmenu