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) dom0: xl mem-max <domU> <maxmem>
  41                where <maxmem> is >= requested memory size,
  42
  43             2) dom0: xl mem-set <domU> <memory>
  44                where <memory> is requested memory size; alternatively memory
  45                could be added by writing proper value to
  46                /sys/devices/system/xen_memory/xen_memory0/target or
  47                /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,
  48
  49             3) domU: for i in /sys/devices/system/memory/memory*/state; do \
  50                        [ "`cat "$i"`" = offline ] && echo online > "$i"; done
  51
  52           Memory could be onlined automatically on domU by adding following line to udev rules:
  53
  54           SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
  55
  56           In that case step 3 should be omitted.
  57
  58 config XEN_BALLOON_MEMORY_HOTPLUG_LIMIT
  59         int "Hotplugged memory limit (in GiB) for a PV guest"
  60         default 512 if X86_64
  61         default 4 if X86_32
  62         range 0 64 if X86_32
  63         depends on XEN_HAVE_PVMMU
  64         depends on XEN_BALLOON_MEMORY_HOTPLUG
  65         help
  66           Maxmium amount of memory (in GiB) that a PV guest can be
  67           expanded to when using memory hotplug.
  68
  69           A PV guest can have more memory than this limit if is
  70           started with a larger maximum.
  71
  72           This value is used to allocate enough space in internal
  73           tables needed for physical memory administration.
  74
  75 config XEN_SCRUB_PAGES
  76         bool "Scrub pages before returning them to system"
  77         depends on XEN_BALLOON
  78         default y
  79         help
  80           Scrub pages before returning them to the system for reuse by
  81           other domains.  This makes sure that any confidential data
  82           is not accidentally visible to other domains.  Is it more
  83           secure, but slightly less efficient.
  84           If in doubt, say yes.
  85
  86 config XEN_DEV_EVTCHN
  87         tristate "Xen /dev/xen/evtchn device"
  88         default y
  89         help
  90           The evtchn driver allows a userspace process to trigger event
  91           channels and to receive notification of an event channel
  92           firing.
  93           If in doubt, say yes.
  94
  95 config XEN_BACKEND
  96         bool "Backend driver support"
  97         depends on XEN_DOM0
  98         default y
  99         help
 100           Support for backend device drivers that provide I/O services
 101           to other virtual machines.
 102
 103 config XENFS
 104         tristate "Xen filesystem"
 105         select XEN_PRIVCMD
 106         default y
 107         help
 108           The xen filesystem provides a way for domains to share
 109           information with each other and with the hypervisor.
 110           For example, by reading and writing the "xenbus" file, guests
 111           may pass arbitrary information to the initial domain.
 112           If in doubt, say yes.
 113
 114 config XEN_COMPAT_XENFS
 115        bool "Create compatibility mount point /proc/xen"
 116        depends on XENFS
 117        default y
 118        help
 119          The old xenstore userspace tools expect to find "xenbus"
 120          under /proc/xen, but "xenbus" is now found at the root of the
 121          xenfs filesystem.  Selecting this causes the kernel to create
 122          the compatibility mount point /proc/xen if it is running on
 123          a xen platform.
 124          If in doubt, say yes.
 125
 126 config XEN_SYS_HYPERVISOR
 127        bool "Create xen entries under /sys/hypervisor"
 128        depends on SYSFS
 129        select SYS_HYPERVISOR
 130        default y
 131        help
 132          Create entries under /sys/hypervisor describing the Xen
 133          hypervisor environment.  When running native or in another
 134          virtual environment, /sys/hypervisor will still be present,
 135          but will have no xen contents.
 136
 137 config XEN_XENBUS_FRONTEND
 138         tristate
 139
 140 config XEN_GNTDEV
 141         tristate "userspace grant access device driver"
 142         depends on XEN
 143         default m
 144         select MMU_NOTIFIER
 145         help
 146           Allows userspace processes to use grants.
 147
 148 config XEN_GRANT_DEV_ALLOC
 149         tristate "User-space grant reference allocator driver"
 150         depends on XEN
 151         default m
 152         help
 153           Allows userspace processes to create pages with access granted
 154           to other domains. This can be used to implement frontend drivers
 155           or as part of an inter-domain shared memory channel.
 156
 157 config SWIOTLB_XEN
 158         def_bool y
 159         select SWIOTLB
 160
 161 config XEN_TMEM
 162         tristate
 163         depends on !ARM && !ARM64
 164         default m if (CLEANCACHE || FRONTSWAP)
 165         help
 166           Shim to interface in-kernel Transcendent Memory hooks
 167           (e.g. cleancache and frontswap) to Xen tmem hypercalls.
 168
 169 config XEN_PCIDEV_BACKEND
 170         tristate "Xen PCI-device backend driver"
 171         depends on PCI && X86 && XEN
 172         depends on XEN_BACKEND
 173         default m
 174         help
 175           The PCI device backend driver allows the kernel to export arbitrary
 176           PCI devices to other guests. If you select this to be a module, you
 177           will need to make sure no other driver has bound to the device(s)
 178           you want to make visible to other guests.
 179
 180           The parameter "passthrough" allows you specify how you want the PCI
 181           devices to appear in the guest. You can choose the default (0) where
 182           PCI topology starts at 00.00.0, or (1) for passthrough if you want
 183           the PCI devices topology appear the same as in the host.
 184
 185           The "hide" parameter (only applicable if backend driver is compiled
 186           into the kernel) allows you to bind the PCI devices to this module
 187           from the default device drivers. The argument is the list of PCI BDFs:
 188           xen-pciback.hide=(03:00.0)(04:00.0)
 189
 190           If in doubt, say m.
 191
 192 config XEN_SCSI_BACKEND
 193         tristate "XEN SCSI backend driver"
 194         depends on XEN && XEN_BACKEND && TARGET_CORE
 195         help
 196           The SCSI backend driver allows the kernel to export its SCSI Devices
 197           to other guests via a high-performance shared-memory interface.
 198           Only needed for systems running as XEN driver domains (e.g. Dom0) and
 199           if guests need generic access to SCSI devices.
 200
 201 config XEN_PRIVCMD
 202         tristate
 203         depends on XEN
 204         default m
 205
 206 config XEN_STUB
 207         bool "Xen stub drivers"
 208         depends on XEN && X86_64 && BROKEN
 209         default n
 210         help
 211           Allow kernel to install stub drivers, to reserve space for Xen drivers,
 212           i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
 213           so that real Xen drivers can be modular.
 214
 215           To enable Xen features like cpu and memory hotplug, select Y here.
 216
 217 config XEN_ACPI_HOTPLUG_MEMORY
 218         tristate "Xen ACPI memory hotplug"
 219         depends on XEN_DOM0 && XEN_STUB && ACPI
 220         default n
 221         help
 222           This is Xen ACPI memory hotplug.
 223
 224           Currently Xen only support ACPI memory hot-add. If you want
 225           to hot-add memory at runtime (the hot-added memory cannot be
 226           removed until machine stop), select Y/M here, otherwise select N.
 227
 228 config XEN_ACPI_HOTPLUG_CPU
 229         tristate "Xen ACPI cpu hotplug"
 230         depends on XEN_DOM0 && XEN_STUB && ACPI
 231         select ACPI_CONTAINER
 232         default n
 233         help
 234           Xen ACPI cpu enumerating and hotplugging
 235
 236           For hotplugging, currently Xen only support ACPI cpu hotadd.
 237           If you want to hotadd cpu at runtime (the hotadded cpu cannot
 238           be removed until machine stop), select Y/M here.
 239
 240 config XEN_ACPI_PROCESSOR
 241         tristate "Xen ACPI processor"
 242         depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
 243         default m
 244         help
 245           This ACPI processor uploads Power Management information to the Xen
 246           hypervisor.
 247
 248           To do that the driver parses the Power Management data and uploads
 249           said information to the Xen hypervisor. Then the Xen hypervisor can
 250           select the proper Cx and Pxx states. It also registers itself as the
 251           SMM so that other drivers (such as ACPI cpufreq scaling driver) will
 252           not load.
 253
 254           To compile this driver as a module, choose M here: the module will be
 255           called xen_acpi_processor  If you do not know what to choose, select
 256           M here. If the CPUFREQ drivers are built in, select Y here.
 257
 258 config XEN_MCE_LOG
 259         bool "Xen platform mcelog"
 260         depends on XEN_DOM0 && X86_64 && X86_MCE
 261         default n
 262         help
 263           Allow kernel fetching MCE error from Xen platform and
 264           converting it into Linux mcelog format for mcelog tools
 265
 266 config XEN_HAVE_PVMMU
 267        bool
 268
 269 config XEN_EFI
 270         def_bool y
 271         depends on X86_64 && EFI
 272
 273 config XEN_AUTO_XLATE
 274         def_bool y
 275         depends on ARM || ARM64 || XEN_PVHVM
 276         help
 277           Support for auto-translated physmap guests.
 278
 279 config XEN_ACPI
 280         def_bool y
 281         depends on X86 && ACPI
 282
 283 config XEN_SYMS
 284        bool "Xen symbols"
 285        depends on X86 && XEN_DOM0 && XENFS
 286        default y if KALLSYMS
 287        help
 288           Exports hypervisor symbols (along with their types and addresses) via
 289           /proc/xen/xensyms file, similar to /proc/kallsyms
 290
 291 config XEN_HAVE_VPMU
 292        bool
 293
 294 endmenu