1 menu "Xen driver support"
5 bool "Xen memory balloon driver"
9 The balloon driver allows the Xen domain to request more memory from
10 the system to expand the domain's memory allocation, or alternatively
11 return unneeded memory to the system.
13 config XEN_SELFBALLOONING
14 bool "Dynamically self-balloon kernel memory to target"
15 depends on XEN && XEN_BALLOON && CLEANCACHE && SWAP && XEN_TMEM
18 Self-ballooning dynamically balloons available kernel memory driven
19 by the current usage of anonymous memory ("committed AS") and
20 controlled by various sysfs-settable parameters. Configuring
21 FRONTSWAP is highly recommended; if it is not configured, self-
22 ballooning is disabled by default but can be enabled with the
23 'selfballooning' kernel boot parameter. If FRONTSWAP is configured,
24 frontswap-selfshrinking is enabled by default but can be disabled
25 with the 'noselfshrink' kernel boot parameter; and self-ballooning
26 is enabled by default but can be disabled with the 'noselfballooning'
27 kernel boot parameter. Note that systems without a sufficiently
28 large swap device should not enable self-ballooning.
30 config XEN_BALLOON_MEMORY_HOTPLUG
31 bool "Memory hotplug support for Xen balloon driver"
33 depends on XEN_BALLOON && MEMORY_HOTPLUG
35 Memory hotplug support for Xen balloon driver allows expanding memory
36 available for the system above limit declared at system startup.
37 It is very useful on critical systems which require long
38 run without rebooting.
40 Memory could be hotplugged in following steps:
42 1) dom0: xl mem-max <domU> <maxmem>
43 where <maxmem> is >= requested memory size,
45 2) dom0: xl mem-set <domU> <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 dumU,
51 3) domU: for i in /sys/devices/system/memory/memory*/state; do \
52 [ "`cat "$i"`" = offline ] && echo online > "$i"; done
54 Memory could be onlined automatically on domU by adding following line to udev rules:
56 SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
58 In that case step 3 should be omitted.
60 config XEN_SCRUB_PAGES
61 bool "Scrub pages before returning them to system"
62 depends on XEN_BALLOON
65 Scrub pages before returning them to the system for reuse by
66 other domains. This makes sure that any confidential data
67 is not accidentally visible to other domains. Is it more
68 secure, but slightly less efficient.
72 tristate "Xen /dev/xen/evtchn device"
75 The evtchn driver allows a userspace process to trigger event
76 channels and to receive notification of an event channel
81 bool "Backend driver support"
85 Support for backend device drivers that provide I/O services
86 to other virtual machines.
89 tristate "Xen filesystem"
93 The xen filesystem provides a way for domains to share
94 information with each other and with the hypervisor.
95 For example, by reading and writing the "xenbus" file, guests
96 may pass arbitrary information to the initial domain.
99 config XEN_COMPAT_XENFS
100 bool "Create compatibility mount point /proc/xen"
104 The old xenstore userspace tools expect to find "xenbus"
105 under /proc/xen, but "xenbus" is now found at the root of the
106 xenfs filesystem. Selecting this causes the kernel to create
107 the compatibility mount point /proc/xen if it is running on
109 If in doubt, say yes.
111 config XEN_SYS_HYPERVISOR
112 bool "Create xen entries under /sys/hypervisor"
114 select SYS_HYPERVISOR
117 Create entries under /sys/hypervisor describing the Xen
118 hypervisor environment. When running native or in another
119 virtual environment, /sys/hypervisor will still be present,
120 but will have no xen contents.
122 config XEN_XENBUS_FRONTEND
126 tristate "userspace grant access device driver"
131 Allows userspace processes to use grants.
133 config XEN_GRANT_DEV_ALLOC
134 tristate "User-space grant reference allocator driver"
138 Allows userspace processes to create pages with access granted
139 to other domains. This can be used to implement frontend drivers
140 or as part of an inter-domain shared memory channel.
150 default y if (CLEANCACHE || FRONTSWAP)
152 Shim to interface in-kernel Transcendent Memory hooks
153 (e.g. cleancache and frontswap) to Xen tmem hypercalls.
155 config XEN_PCIDEV_BACKEND
156 tristate "Xen PCI-device backend driver"
157 depends on PCI && X86 && XEN
158 depends on XEN_BACKEND
161 The PCI device backend driver allows the kernel to export arbitrary
162 PCI devices to other guests. If you select this to be a module, you
163 will need to make sure no other driver has bound to the device(s)
164 you want to make visible to other guests.
166 The parameter "passthrough" allows you specify how you want the PCI
167 devices to appear in the guest. You can choose the default (0) where
168 PCI topology starts at 00.00.0, or (1) for passthrough if you want
169 the PCI devices topology appear the same as in the host.
171 The "hide" parameter (only applicable if backend driver is compiled
172 into the kernel) allows you to bind the PCI devices to this module
173 from the default device drivers. The argument is the list of PCI BDFs:
174 xen-pciback.hide=(03:00.0)(04:00.0)
184 bool "Xen stub drivers"
185 depends on XEN && X86_64
188 Allow kernel to install stub drivers, to reserve space for Xen drivers,
189 i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
190 so that real Xen drivers can be modular.
192 To enable Xen features like cpu and memory hotplug, select Y here.
194 config XEN_ACPI_HOTPLUG_MEMORY
195 tristate "Xen ACPI memory hotplug"
196 depends on XEN_DOM0 && XEN_STUB && ACPI
199 This is Xen ACPI memory hotplug.
201 Currently Xen only support ACPI memory hot-add. If you want
202 to hot-add memory at runtime (the hot-added memory cannot be
203 removed until machine stop), select Y/M here, otherwise select N.
205 config XEN_ACPI_HOTPLUG_CPU
206 tristate "Xen ACPI cpu hotplug"
207 depends on XEN_DOM0 && XEN_STUB && ACPI
208 select ACPI_CONTAINER
211 Xen ACPI cpu enumerating and hotplugging
213 For hotplugging, currently Xen only support ACPI cpu hotadd.
214 If you want to hotadd cpu at runtime (the hotadded cpu cannot
215 be removed until machine stop), select Y/M here.
217 config XEN_ACPI_PROCESSOR
218 tristate "Xen ACPI processor"
219 depends on XEN && X86 && ACPI_PROCESSOR && CPU_FREQ
222 This ACPI processor uploads Power Management information to the Xen
225 To do that the driver parses the Power Management data and uploads
226 said information to the Xen hypervisor. Then the Xen hypervisor can
227 select the proper Cx and Pxx states. It also registers itslef as the
228 SMM so that other drivers (such as ACPI cpufreq scaling driver) will
231 To compile this driver as a module, choose M here: the module will be
232 called xen_acpi_processor If you do not know what to choose, select
233 M here. If the CPUFREQ drivers are built in, select Y here.
236 bool "Xen platform mcelog"
237 depends on XEN_DOM0 && X86_64 && X86_MCE
240 Allow kernel fetching MCE error from Xen platform and
241 converting it into Linux mcelog format for mcelog tools
243 config XEN_HAVE_PVMMU