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 but can be enabled with the
  22           'selfballooning' kernel boot parameter.  If FRONTSWAP is configured,
  23           frontswap-selfshrinking is enabled by default but can be disabled
  24           with the 'noselfshrink' kernel boot parameter; and self-ballooning
  25           is enabled by default but can be disabled with the 'noselfballooning'
  26           kernel boot parameter.  Note that systems without a sufficiently
  27           large swap device should not enable self-ballooning.
  28
  29 config XEN_BALLOON_MEMORY_HOTPLUG
  30         bool "Memory hotplug support for Xen balloon driver"
  31         default n
  32         depends on XEN_BALLOON && MEMORY_HOTPLUG
  33         help
  34           Memory hotplug support for Xen balloon driver allows expanding memory
  35           available for the system above limit declared at system startup.
  36           It is very useful on critical systems which require long
  37           run without rebooting.
  38
  39           Memory could be hotplugged in following steps:
  40
  41             1) dom0: xl mem-max <domU> <maxmem>
  42                where <maxmem> is >= requested memory size,
  43
  44             2) dom0: xl mem-set <domU> <memory>
  45                where <memory> is requested memory size; alternatively memory
  46                could be added by writing proper value to
  47                /sys/devices/system/xen_memory/xen_memory0/target or
  48                /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,
  49
  50             3) domU: for i in /sys/devices/system/memory/memory*/state; do \
  51                        [ "`cat "$i"`" = offline ] && echo online > "$i"; done
  52
  53           Memory could be onlined automatically on domU by adding following line to udev rules:
  54
  55           SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
  56
  57           In that case step 3 should be omitted.
  58
  59 config XEN_SCRUB_PAGES
  60         bool "Scrub pages before returning them to system"
  61         depends on XEN_BALLOON
  62         default y
  63         help
  64           Scrub pages before returning them to the system for reuse by
  65           other domains.  This makes sure that any confidential data
  66           is not accidentally visible to other domains.  Is it more
  67           secure, but slightly less efficient.
  68           If in doubt, say yes.
  69
  70 config XEN_DEV_EVTCHN
  71         tristate "Xen /dev/xen/evtchn device"
  72         default y
  73         help
  74           The evtchn driver allows a userspace process to trigger event
  75           channels and to receive notification of an event channel
  76           firing.
  77           If in doubt, say yes.
  78
  79 config XEN_BACKEND
  80         bool "Backend driver support"
  81         depends on XEN_DOM0
  82         default y
  83         help
  84           Support for backend device drivers that provide I/O services
  85           to other virtual machines.
  86
  87 config XENFS
  88         tristate "Xen filesystem"
  89         select XEN_PRIVCMD
  90         default y
  91         help
  92           The xen filesystem provides a way for domains to share
  93           information with each other and with the hypervisor.
  94           For example, by reading and writing the "xenbus" file, guests
  95           may pass arbitrary information to the initial domain.
  96           If in doubt, say yes.
  97
  98 config XEN_COMPAT_XENFS
  99        bool "Create compatibility mount point /proc/xen"
 100        depends on XENFS
 101        default y
 102        help
 103          The old xenstore userspace tools expect to find "xenbus"
 104          under /proc/xen, but "xenbus" is now found at the root of the
 105          xenfs filesystem.  Selecting this causes the kernel to create
 106          the compatibility mount point /proc/xen if it is running on
 107          a xen platform.
 108          If in doubt, say yes.
 109
 110 config XEN_SYS_HYPERVISOR
 111        bool "Create xen entries under /sys/hypervisor"
 112        depends on SYSFS
 113        select SYS_HYPERVISOR
 114        default y
 115        help
 116          Create entries under /sys/hypervisor describing the Xen
 117          hypervisor environment.  When running native or in another
 118          virtual environment, /sys/hypervisor will still be present,
 119          but will have no xen contents.
 120
 121 config XEN_XENBUS_FRONTEND
 122         tristate
 123
 124 config XEN_GNTDEV
 125         tristate "userspace grant access device driver"
 126         depends on XEN
 127         default m
 128         select MMU_NOTIFIER
 129         help
 130           Allows userspace processes to use grants.
 131
 132 config XEN_GRANT_DEV_ALLOC
 133         tristate "User-space grant reference allocator driver"
 134         depends on XEN
 135         default m
 136         help
 137           Allows userspace processes to create pages with access granted
 138           to other domains. This can be used to implement frontend drivers
 139           or as part of an inter-domain shared memory channel.
 140
 141 config SWIOTLB_XEN
 142         def_bool y
 143         depends on PCI
 144         select SWIOTLB
 145
 146 config XEN_TMEM
 147         bool
 148         default y if (CLEANCACHE || FRONTSWAP)
 149         help
 150           Shim to interface in-kernel Transcendent Memory hooks
 151           (e.g. cleancache and frontswap) to Xen tmem hypercalls.
 152
 153 config XEN_PCIDEV_BACKEND
 154         tristate "Xen PCI-device backend driver"
 155         depends on PCI && X86 && XEN
 156         depends on XEN_BACKEND
 157         default m
 158         help
 159           The PCI device backend driver allows the kernel to export arbitrary
 160           PCI devices to other guests. If you select this to be a module, you
 161           will need to make sure no other driver has bound to the device(s)
 162           you want to make visible to other guests.
 163
 164           The parameter "passthrough" allows you specify how you want the PCI
 165           devices to appear in the guest. You can choose the default (0) where
 166           PCI topology starts at 00.00.0, or (1) for passthrough if you want
 167           the PCI devices topology appear the same as in the host.
 168
 169           The "hide" parameter (only applicable if backend driver is compiled
 170           into the kernel) allows you to bind the PCI devices to this module
 171           from the default device drivers. The argument is the list of PCI BDFs:
 172           xen-pciback.hide=(03:00.0)(04:00.0)
 173
 174           If in doubt, say m.
 175
 176 config XEN_PRIVCMD
 177         tristate
 178         depends on XEN
 179         default m
 180
 181 config XEN_ACPI_PROCESSOR
 182         tristate "Xen ACPI processor"
 183         depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
 184         default m
 185         help
 186           This ACPI processor uploads Power Management information to the Xen
 187           hypervisor.
 188
 189           To do that the driver parses the Power Management data and uploads
 190           said information to the Xen hypervisor. Then the Xen hypervisor can
 191           select the proper Cx and Pxx states. It also registers itslef as the
 192           SMM so that other drivers (such as ACPI cpufreq scaling driver) will
 193           not load.
 194
 195           To compile this driver as a module, choose M here: the module will be
 196           called xen_acpi_processor  If you do not know what to choose, select
 197           M here. If the CPUFREQ drivers are built in, select Y here.
 198
 199 config XEN_MCE_LOG
 200         bool "Xen platform mcelog"
 201         depends on XEN_DOM0 && X86_64 && X86_MCE
 202         default n
 203         help
 204           Allow kernel fetching MCE error from Xen platform and
 205           converting it into Linux mcelog format for mcelog tools
 206
 207 endmenu