# SPDX-License-Identifier: GPL-2.0-only
menu "Xen driver support"
depends on [31mCONFIG_XEN[0m
config [31mCONFIG_XEN_BALLOON[0m
bool "Xen memory balloon driver"
default y
help
The balloon driver allows the Xen domain to request more memory from
the system to expand the domain's memory allocation, or alternatively
return unneeded memory to the system.
config [31mCONFIG_XEN_BALLOON_MEMORY_HOTPLUG[0m
bool "Memory hotplug support for Xen balloon driver"
depends on [31mCONFIG_XEN_BALLOON[0m && [31mCONFIG_MEMORY_HOTPLUG[0m
help
Memory hotplug support for Xen balloon driver allows expanding memory
available for the system above limit declared at system startup.
It is very useful on critical systems which require long
run without rebooting.
Memory could be hotplugged in following steps:
1) target domain: ensure that memory auto online policy is in
effect by checking /sys/devices/system/memory/auto_online_blocks
file (should be 'online').
2) control domain: xl mem-max <target-domain> <maxmem>
where <maxmem> is >= requested memory size,
3) control domain: xl mem-set <target-domain> <memory>
where <memory> is requested memory size; alternatively memory
could be added by writing proper value to
/sys/devices/system/xen_memory/xen_memory0/target or
/sys/devices/system/xen_memory/xen_memory0/target_kb on the
target domain.
Alternatively, if memory auto onlining was not requested at step 1
the newly added memory can be manually onlined in the target domain
by doing the following:
for i in /sys/devices/system/memory/memory*/state; do \
[ "`cat "$i"`" = offline ] && echo online > "$i"; done
or by adding the following line to udev rules:
SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"
config [31mCONFIG_XEN_BALLOON_MEMORY_HOTPLUG_LIMIT[0m
int "Hotplugged memory limit (in GiB) for a PV guest"
default 512 if [31mCONFIG_X86_64[0m
default 4 if [31mCONFIG_X86_32[0m
range 0 64 if [31mCONFIG_X86_32[0m
depends on [31mCONFIG_XEN_HAVE_PVMMU[0m
depends on [31mCONFIG_XEN_BALLOON_MEMORY_HOTPLUG[0m
help
Maxmium amount of memory (in GiB) that a PV guest can be
expanded to when using memory hotplug.
[31mCONFIG_A[0m PV guest can have more memory than this limit if is
started with a larger maximum.
This value is used to allocate enough space in internal
tables needed for physical memory administration.
config [31mCONFIG_XEN_SCRUB_PAGES_DEFAULT[0m
bool "Scrub pages before returning them to system by default"
depends on [31mCONFIG_XEN_BALLOON[0m
default y
help
Scrub pages before returning them to the system for reuse by
other domains. This makes sure that any confidential data
is not accidentally visible to other domains. It is more
secure, but slightly less efficient. This can be controlled with
xen_scrub_pages=0 parameter and
/sys/devices/system/xen_memory/xen_memory0/scrub_pages.
This option only sets the default value.
If in doubt, say yes.
config [31mCONFIG_XEN_DEV_EVTCHN[0m
tristate "Xen /dev/xen/evtchn device"
default y
help
The evtchn driver allows a userspace process to trigger event
channels and to receive notification of an event channel
firing.
If in doubt, say yes.
config [31mCONFIG_XEN_BACKEND[0m
bool "Backend driver support"
default [31mCONFIG_XEN_DOM0[0m
help
Support for backend device drivers that provide I/O services
to other virtual machines.
config [31mCONFIG_XENFS[0m
tristate "Xen filesystem"
select [31mCONFIG_XEN_PRIVCMD[0m
default y
help
The xen filesystem provides a way for domains to share
information with each other and with the hypervisor.
For example, by reading and writing the "xenbus" file, guests
may pass arbitrary information to the initial domain.
If in doubt, say yes.
config [31mCONFIG_XEN_COMPAT_XENFS[0m
bool "Create compatibility mount point /proc/xen"
depends on [31mCONFIG_XENFS[0m
default y
help
The old xenstore userspace tools expect to find "xenbus"
under /proc/xen, but "xenbus" is now found at the root of the
xenfs filesystem. Selecting this causes the kernel to create
the compatibility mount point /proc/xen if it is running on
a xen platform.
If in doubt, say yes.
config [31mCONFIG_XEN_SYS_HYPERVISOR[0m
bool "Create xen entries under /sys/hypervisor"
depends on [31mCONFIG_SYSFS[0m
select [31mCONFIG_SYS_HYPERVISOR[0m
default y
help
Create entries under /sys/hypervisor describing the Xen
hypervisor environment. When running native or in another
virtual environment, /sys/hypervisor will still be present,
but will have no xen contents.
config [31mCONFIG_XEN_XENBUS_FRONTEND[0m
tristate
config [31mCONFIG_XEN_GNTDEV[0m
tristate "userspace grant access device driver"
depends on [31mCONFIG_XEN[0m
default m
select [31mCONFIG_MMU_NOTIFIER[0m
help
Allows userspace processes to use grants.
config [31mCONFIG_XEN_GNTDEV_DMABUF[0m
bool "Add support for dma-buf grant access device driver extension"
depends on [31mCONFIG_XEN_GNTDEV[0m && [31mCONFIG_XEN_GRANT_DMA_ALLOC[0m && [31mCONFIG_DMA_SHARED_BUFFER[0m
help
Allows userspace processes and kernel modules to use Xen backed
dma-buf implementation. With this extension grant references to
the pages of an imported dma-buf can be exported for other domain
use and grant references coming from a foreign domain can be
converted into a local dma-buf for local export.
config [31mCONFIG_XEN_GRANT_DEV_ALLOC[0m
tristate "User-space grant reference allocator driver"
depends on [31mCONFIG_XEN[0m
default m
help
Allows userspace processes to create pages with access granted
to other domains. This can be used to implement frontend drivers
or as part of an inter-domain shared memory channel.
config [31mCONFIG_XEN_GRANT_DMA_ALLOC[0m
bool "Allow allocating DMA capable buffers with grant reference module"
depends on [31mCONFIG_XEN[0m && [31mCONFIG_HAS_DMA[0m
help
Extends grant table module API to allow allocating DMA capable
buffers and mapping foreign grant references on top of it.
The resulting buffer is similar to one allocated by the balloon
driver in that proper memory reservation is made by
({increase|decrease}_reservation and VA mappings are updated if
needed).
This is useful for sharing foreign buffers with HW drivers which
cannot work with scattered buffers provided by the balloon driver,
but require DMAable memory instead.
config [31mCONFIG_SWIOTLB_XEN[0m
def_bool y
select [31mCONFIG_SWIOTLB[0m
config [31mCONFIG_XEN_PCIDEV_BACKEND[0m
tristate "Xen PCI-device backend driver"
depends on [31mCONFIG_PCI[0m && [31mCONFIG_X86[0m && [31mCONFIG_XEN[0m
depends on [31mCONFIG_XEN_BACKEND[0m
default m
help
The [31mCONFIG_PCI[0m device backend driver allows the kernel to export arbitrary
[31mCONFIG_PCI[0m devices to other guests. If you select this to be a module, you
will need to make sure no other driver has bound to the device(s)
you want to make visible to other guests.
The parameter "passthrough" allows you specify how you want the [31mCONFIG_PCI[0m
devices to appear in the guest. You can choose the default (0) where
[31mCONFIG_PCI[0m topology starts at 00.00.0, or (1) for passthrough if you want
the [31mCONFIG_PCI[0m devices topology appear the same as in the host.
The "hide" parameter (only applicable if backend driver is compiled
into the kernel) allows you to bind the [31mCONFIG_PCI[0m devices to this module
from the default device drivers. The argument is the list of [31mCONFIG_PCI[0m BDFs:
xen-pciback.hide=(03:00.0)(04:00.0)
If in doubt, say m.
config [31mCONFIG_XEN_PVCALLS_FRONTEND[0m
tristate "XEN PV Calls frontend driver"
depends on [31mCONFIG_INET[0m && [31mCONFIG_XEN[0m
select [31mCONFIG_XEN_XENBUS_FRONTEND[0m
help
Experimental frontend for the Xen PV Calls protocol
(https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
sends a small set of POSIX calls to the backend, which
implements them.
config [31mCONFIG_XEN_PVCALLS_BACKEND[0m
bool "XEN PV Calls backend driver"
depends on [31mCONFIG_INET[0m && [31mCONFIG_XEN[0m && [31mCONFIG_XEN_BACKEND[0m
help
Experimental backend for the Xen PV Calls protocol
(https://xenbits.xen.org/docs/unstable/misc/pvcalls.html). It
allows PV Calls frontends to send POSIX calls to the backend,
which implements them.
If in doubt, say n.
config [31mCONFIG_XEN_SCSI_BACKEND[0m
tristate "XEN SCSI backend driver"
depends on [31mCONFIG_XEN[0m && [31mCONFIG_XEN_BACKEND[0m && [31mCONFIG_TARGET_CORE[0m
help
The [31mCONFIG_SCSI[0m backend driver allows the kernel to export its [31mCONFIG_SCSI[0m Devices
to other guests via a high-performance shared-memory interface.
Only needed for systems running as [31mCONFIG_XEN[0m driver domains (e.g. Dom0) and
if guests need generic access to [31mCONFIG_SCSI[0m devices.
config [31mCONFIG_XEN_PRIVCMD[0m
tristate
depends on [31mCONFIG_XEN[0m
default m
config [31mCONFIG_XEN_STUB[0m
bool "Xen stub drivers"
depends on [31mCONFIG_XEN[0m && [31mCONFIG_X86_64[0m && [31mCONFIG_BROKEN[0m
help
Allow kernel to install stub drivers, to reserve space for Xen drivers,
i.e. memory hotplug and cpu hotplug, and to block native drivers loaded,
so that real Xen drivers can be modular.
To enable Xen features like cpu and memory hotplug, select Y here.
config [31mCONFIG_XEN_ACPI_HOTPLUG_MEMORY[0m
tristate "Xen ACPI memory hotplug"
depends on [31mCONFIG_XEN_DOM0[0m && [31mCONFIG_XEN_STUB[0m && [31mCONFIG_ACPI[0m
help
This is Xen [31mCONFIG_ACPI[0m memory hotplug.
Currently Xen only support [31mCONFIG_ACPI[0m memory hot-add. If you want
to hot-add memory at runtime (the hot-added memory cannot be
removed until machine stop), select Y/[31mCONFIG_M[0m here, otherwise select N.
config [31mCONFIG_XEN_ACPI_HOTPLUG_CPU[0m
tristate "Xen ACPI cpu hotplug"
depends on [31mCONFIG_XEN_DOM0[0m && [31mCONFIG_XEN_STUB[0m && [31mCONFIG_ACPI[0m
select [31mCONFIG_ACPI_CONTAINER[0m
help
Xen [31mCONFIG_ACPI[0m cpu enumerating and hotplugging
For hotplugging, currently Xen only support [31mCONFIG_ACPI[0m cpu hotadd.
If you want to hotadd cpu at runtime (the hotadded cpu cannot
be removed until machine stop), select Y/[31mCONFIG_M[0m here.
config [31mCONFIG_XEN_ACPI_PROCESSOR[0m
tristate "Xen ACPI processor"
depends on [31mCONFIG_XEN[0m && [31mCONFIG_XEN_DOM0[0m && [31mCONFIG_X86[0m && [31mCONFIG_ACPI_PROCESSOR[0m && [31mCONFIG_CPU_FREQ[0m
default m
help
This [31mCONFIG_ACPI[0m processor uploads Power Management information to the Xen
hypervisor.
To do that the driver parses the Power Management data and uploads
said information to the Xen hypervisor. Then the Xen hypervisor can
select the proper Cx and Pxx states. It also registers itself as the
SMM so that other drivers (such as [31mCONFIG_ACPI[0m cpufreq scaling driver) will
not load.
To compile this driver as a module, choose [31mCONFIG_M[0m here: the module will be
called xen_acpi_processor If you do not know what to choose, select
[31mCONFIG_M[0m here. If the CPUFREQ drivers are built in, select Y here.
config [31mCONFIG_XEN_MCE_LOG[0m
bool "Xen platform mcelog"
depends on [31mCONFIG_XEN_DOM0[0m && [31mCONFIG_X86_64[0m && [31mCONFIG_X86_MCE[0m
help
Allow kernel fetching MCE error from Xen platform and
converting it into Linux mcelog format for mcelog tools
config [31mCONFIG_XEN_HAVE_PVMMU[0m
bool
config [31mCONFIG_XEN_EFI[0m
def_bool y
depends on ([31mCONFIG_ARM[0m || [31mCONFIG_ARM64[0m || [31mCONFIG_X86_64[0m) && [31mCONFIG_EFI[0m
config [31mCONFIG_XEN_AUTO_XLATE[0m
def_bool y
depends on [31mCONFIG_ARM[0m || [31mCONFIG_ARM64[0m || [31mCONFIG_XEN_PVHVM[0m
help
Support for auto-translated physmap guests.
config [31mCONFIG_XEN_ACPI[0m
def_bool y
depends on [31mCONFIG_X86[0m && [31mCONFIG_ACPI[0m
config [31mCONFIG_XEN_SYMS[0m
bool "Xen symbols"
depends on [31mCONFIG_X86[0m && [31mCONFIG_XEN_DOM0[0m && [31mCONFIG_XENFS[0m
default y if [31mCONFIG_KALLSYMS[0m
help
Exports hypervisor symbols (along with their types and addresses) via
/proc/xen/xensyms file, similar to /proc/kallsyms
config [31mCONFIG_XEN_HAVE_VPMU[0m
bool
config [31mCONFIG_XEN_FRONT_PGDIR_SHBUF[0m
tristate
endmenu