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 triger 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         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         depends on PCI
 143         select SWIOTLB
 144
 145 config XEN_TMEM
 146         bool
 147         default y 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 endmenu