| # SPDX-License-Identifier: GPL-2.0-only |
| menu "Xen driver support" |
| depends on XEN |
| |
| config XEN_BALLOON |
| 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 XEN_BALLOON_MEMORY_HOTPLUG |
| bool "Memory hotplug support for Xen balloon driver" |
| depends on XEN_BALLOON && MEMORY_HOTPLUG |
| default y |
| 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. |
| |
| It's also very useful for non PV domains to obtain unpopulated physical |
| memory ranges to use in order to map foreign memory or grants. |
| |
| 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 XEN_MEMORY_HOTPLUG_LIMIT |
| int "Hotplugged memory limit (in GiB) for a PV guest" |
| default 512 |
| depends on XEN_HAVE_PVMMU |
| depends on MEMORY_HOTPLUG |
| help |
| Maxmium amount of memory (in GiB) that a PV guest can be |
| expanded to when using memory hotplug. |
| |
| A 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 XEN_SCRUB_PAGES_DEFAULT |
| bool "Scrub pages before returning them to system by default" |
| depends on XEN_BALLOON |
| 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 XEN_DEV_EVTCHN |
| 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 XEN_BACKEND |
| bool "Backend driver support" |
| default XEN_DOM0 |
| help |
| Support for backend device drivers that provide I/O services |
| to other virtual machines. |
| |
| config XENFS |
| tristate "Xen filesystem" |
| select XEN_PRIVCMD |
| 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 XEN_COMPAT_XENFS |
| bool "Create compatibility mount point /proc/xen" |
| depends on XENFS |
| 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 XEN_SYS_HYPERVISOR |
| bool "Create xen entries under /sys/hypervisor" |
| depends on SYSFS |
| select SYS_HYPERVISOR |
| 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 XEN_XENBUS_FRONTEND |
| tristate |
| |
| config XEN_GNTDEV |
| tristate "userspace grant access device driver" |
| depends on XEN |
| default m |
| select MMU_NOTIFIER |
| help |
| Allows userspace processes to use grants. |
| |
| config XEN_GNTDEV_DMABUF |
| bool "Add support for dma-buf grant access device driver extension" |
| depends on XEN_GNTDEV && XEN_GRANT_DMA_ALLOC |
| select DMA_SHARED_BUFFER |
| 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 XEN_GRANT_DEV_ALLOC |
| tristate "User-space grant reference allocator driver" |
| depends on XEN |
| 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 XEN_GRANT_DMA_ALLOC |
| bool "Allow allocating DMA capable buffers with grant reference module" |
| depends on XEN && HAS_DMA |
| 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 SWIOTLB_XEN |
| def_bool y |
| depends on XEN_PV || ARM || ARM64 |
| select DMA_OPS |
| select SWIOTLB |
| |
| config XEN_PCIDEV_BACKEND |
| tristate "Xen PCI-device backend driver" |
| depends on PCI && X86 && XEN |
| depends on XEN_BACKEND |
| default m |
| help |
| The PCI device backend driver allows the kernel to export arbitrary |
| PCI 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 PCI |
| devices to appear in the guest. You can choose the default (0) where |
| PCI topology starts at 00.00.0, or (1) for passthrough if you want |
| the PCI 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 PCI devices to this module |
| from the default device drivers. The argument is the list of PCI BDFs: |
| xen-pciback.hide=(03:00.0)(04:00.0) |
| |
| If in doubt, say m. |
| |
| config XEN_PVCALLS_FRONTEND |
| tristate "XEN PV Calls frontend driver" |
| depends on INET && XEN |
| select XEN_XENBUS_FRONTEND |
| 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 XEN_PVCALLS_BACKEND |
| tristate "XEN PV Calls backend driver" |
| depends on INET && XEN && XEN_BACKEND |
| 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 XEN_SCSI_BACKEND |
| tristate "XEN SCSI backend driver" |
| depends on XEN && XEN_BACKEND && TARGET_CORE |
| help |
| The SCSI backend driver allows the kernel to export its SCSI Devices |
| to other guests via a high-performance shared-memory interface. |
| Only needed for systems running as XEN driver domains (e.g. Dom0) and |
| if guests need generic access to SCSI devices. |
| |
| config XEN_PRIVCMD |
| tristate |
| depends on XEN |
| default m |
| |
| config XEN_ACPI_PROCESSOR |
| tristate "Xen ACPI processor" |
| depends on XEN && XEN_DOM0 && X86 && ACPI_PROCESSOR && CPU_FREQ |
| default m |
| help |
| This ACPI 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 ACPI cpufreq scaling driver) will |
| not load. |
| |
| To compile this driver as a module, choose M here: the module will be |
| called xen_acpi_processor If you do not know what to choose, select |
| M here. If the CPUFREQ drivers are built in, select Y here. |
| |
| config XEN_MCE_LOG |
| bool "Xen platform mcelog" |
| depends on XEN_DOM0 && X86_MCE |
| help |
| Allow kernel fetching MCE error from Xen platform and |
| converting it into Linux mcelog format for mcelog tools |
| |
| config XEN_HAVE_PVMMU |
| bool |
| |
| config XEN_EFI |
| def_bool y |
| depends on (ARM || ARM64 || X86_64) && EFI |
| |
| config XEN_AUTO_XLATE |
| def_bool y |
| depends on ARM || ARM64 || XEN_PVHVM |
| help |
| Support for auto-translated physmap guests. |
| |
| config XEN_ACPI |
| def_bool y |
| depends on X86 && ACPI |
| |
| config XEN_SYMS |
| bool "Xen symbols" |
| depends on X86 && XEN_DOM0 && XENFS |
| default y if KALLSYMS |
| help |
| Exports hypervisor symbols (along with their types and addresses) via |
| /proc/xen/xensyms file, similar to /proc/kallsyms |
| |
| config XEN_HAVE_VPMU |
| bool |
| |
| config XEN_FRONT_PGDIR_SHBUF |
| tristate |
| |
| config XEN_UNPOPULATED_ALLOC |
| bool "Use unpopulated memory ranges for guest mappings" |
| depends on X86 && ZONE_DEVICE |
| default XEN_BACKEND || XEN_GNTDEV || XEN_DOM0 |
| help |
| Use unpopulated memory ranges in order to create mappings for guest |
| memory regions, including grant maps and foreign pages. This avoids |
| having to balloon out RAM regions in order to obtain physical memory |
| space to create such mappings. |
| |
| endmenu |
