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_SCRUB_PAGES
  59         bool "Scrub pages before returning them to system"
  60         depends on XEN_BALLOON
  61         default y
  62         help
  63           Scrub pages before returning them to the system for reuse by
  64           other domains.  This makes sure that any confidential data
  65           is not accidentally visible to other domains.  Is it more
  66           secure, but slightly less efficient.
  67           If in doubt, say yes.
  68
  69 config XEN_DEV_EVTCHN
  70         tristate "Xen /dev/xen/evtchn device"
  71         default y
  72         help
  73           The evtchn driver allows a userspace process to trigger event
  74           channels and to receive notification of an event channel
  75           firing.
  76           If in doubt, say yes.
  77
  78 config XEN_BACKEND
  79         bool "Backend driver support"
  80         depends on XEN_DOM0
  81         default y
  82         help
  83           Support for backend device drivers that provide I/O services
  84           to other virtual machines.
  85
  86 config XENFS
  87         tristate "Xen filesystem"
  88         select XEN_PRIVCMD
  89         default y
  90         help
  91           The xen filesystem provides a way for domains to share
  92           information with each other and with the hypervisor.
  93           For example, by reading and writing the "xenbus" file, guests
  94           may pass arbitrary information to the initial domain.
  95           If in doubt, say yes.
  96
  97 config XEN_COMPAT_XENFS
  98        bool "Create compatibility mount point /proc/xen"
  99        depends on XENFS
 100        default y
 101        help
 102          The old xenstore userspace tools expect to find "xenbus"
 103          under /proc/xen, but "xenbus" is now found at the root of the
 104          xenfs filesystem.  Selecting this causes the kernel to create
 105          the compatibility mount point /proc/xen if it is running on
 106          a xen platform.
 107          If in doubt, say yes.
 108
 109 config XEN_SYS_HYPERVISOR
 110        bool "Create xen entries under /sys/hypervisor"
 111        depends on SYSFS
 112        select SYS_HYPERVISOR
 113        default y
 114        help
 115          Create entries under /sys/hypervisor describing the Xen
 116          hypervisor environment.  When running native or in another
 117          virtual environment, /sys/hypervisor will still be present,
 118          but will have no xen contents.
 119
 120 config XEN_XENBUS_FRONTEND
 121         tristate
 122
 123 config XEN_GNTDEV
 124         tristate "userspace grant access device driver"
 125         depends on XEN
 126         default m
 127         select MMU_NOTIFIER
 128         help
 129           Allows userspace processes to use grants.
 130
 131 config XEN_GRANT_DEV_ALLOC
 132         tristate "User-space grant reference allocator driver"
 133         depends on XEN
 134         default m
 135         help
 136           Allows userspace processes to create pages with access granted
 137           to other domains. This can be used to implement frontend drivers
 138           or as part of an inter-domain shared memory channel.
 139
 140 config SWIOTLB_XEN
 141         def_bool y
 142         select SWIOTLB
 143
 144 config XEN_TMEM
 145         tristate
 146         depends on !ARM && !ARM64
 147         default m if (CLEANCACHE || FRONTSWAP)
 148         help
 149           Shim to interface in-kernel Transcendent Memory hooks
 150           (e.g. cleancache and frontswap) to Xen tmem hypercalls.
 151
 152 config XEN_PCIDEV_BACKEND
 153         tristate "Xen PCI-device backend driver"
 154         depends on PCI && X86 && XEN
 155         depends on XEN_BACKEND
 156         default m
 157         help
 158           The PCI device backend driver allows the kernel to export arbitrary
 159           PCI devices to other guests. If you select this to be a module, you
 160           will need to make sure no other driver has bound to the device(s)
 161           you want to make visible to other guests.
 162
 163           The parameter "passthrough" allows you specify how you want the PCI
 164           devices to appear in the guest. You can choose the default (0) where
 165           PCI topology starts at 00.00.0, or (1) for passthrough if you want
 166           the PCI devices topology appear the same as in the host.
 167
 168           The "hide" parameter (only applicable if backend driver is compiled
 169           into the kernel) allows you to bind the PCI devices to this module
 170           from the default device drivers. The argument is the list of PCI BDFs:
 171           xen-pciback.hide=(03:00.0)(04:00.0)
 172
 173           If in doubt, say m.
 174
 175 config XEN_PRIVCMD
 176         tristate
 177         depends on XEN
 178         default m
 179
 180 config XEN_STUB
 181         bool "Xen stub drivers"
 182         depends on XEN && X86_64 && BROKEN
 183         default n
 184         help
 185           Allow kernel to install stub drivers, to reserve space for Xen drivers,
 186           i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
 187           so that real Xen drivers can be modular.
 188
 189           To enable Xen features like cpu and memory hotplug, select Y here.
 190
 191 config XEN_ACPI_HOTPLUG_MEMORY
 192         tristate "Xen ACPI memory hotplug"
 193         depends on XEN_DOM0 && XEN_STUB && ACPI
 194         default n
 195         help
 196           This is Xen ACPI memory hotplug.
 197
 198           Currently Xen only support ACPI memory hot-add. If you want
 199           to hot-add memory at runtime (the hot-added memory cannot be
 200           removed until machine stop), select Y/M here, otherwise select N.
 201
 202 config XEN_ACPI_HOTPLUG_CPU
 203         tristate "Xen ACPI cpu hotplug"
 204         depends on XEN_DOM0 && XEN_STUB && ACPI
 205         select ACPI_CONTAINER
 206         default n
 207         help
 208           Xen ACPI cpu enumerating and hotplugging
 209
 210           For hotplugging, currently Xen only support ACPI cpu hotadd.
 211           If you want to hotadd cpu at runtime (the hotadded cpu cannot
 212           be removed until machine stop), select Y/M here.
 213
 214 config XEN_ACPI_PROCESSOR
 215         tristate "Xen ACPI processor"
 216         depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
 217         default m
 218         help
 219           This ACPI processor uploads Power Management information to the Xen
 220           hypervisor.
 221
 222           To do that the driver parses the Power Management data and uploads
 223           said information to the Xen hypervisor. Then the Xen hypervisor can
 224           select the proper Cx and Pxx states. It also registers itself as the
 225           SMM so that other drivers (such as ACPI cpufreq scaling driver) will
 226           not load.
 227
 228           To compile this driver as a module, choose M here: the module will be
 229           called xen_acpi_processor  If you do not know what to choose, select
 230           M here. If the CPUFREQ drivers are built in, select Y here.
 231
 232 config XEN_MCE_LOG
 233         bool "Xen platform mcelog"
 234         depends on XEN_DOM0 && X86_64 && X86_MCE
 235         default n
 236         help
 237           Allow kernel fetching MCE error from Xen platform and
 238           converting it into Linux mcelog format for mcelog tools
 239
 240 config XEN_HAVE_PVMMU
 241        bool
 242
 243 config XEN_EFI
 244         def_bool y
 245         depends on X86_64 && EFI
 246
 247 endmenu