| # 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 | |
| Maximum 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 | |
| select FIND_NORMAL_PAGE | |
| 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 ARCH_HAS_DMA_OPS | |
| depends on XEN_PV || ARM || ARM64 | |
| select SWIOTLB | |
| config XEN_PCI_STUB | |
| bool | |
| config XEN_PCIDEV_STUB | |
| tristate "Xen PCI-device stub driver" | |
| depends on PCI && !X86 && XEN | |
| depends on XEN_BACKEND | |
| select XEN_PCI_STUB | |
| default m | |
| help | |
| The PCI device stub driver provides limited version of the PCI | |
| device backend driver without para-virtualized support for 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 "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_PCIDEV_BACKEND | |
| tristate "Xen PCI-device backend driver" | |
| depends on PCI && X86 && XEN | |
| depends on XEN_BACKEND | |
| select XEN_PCI_STUB | |
| 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 "Xen hypercall passthrough driver" | |
| depends on XEN | |
| default m | |
| help | |
| The hypercall passthrough driver allows privileged user programs to | |
| perform Xen hypercalls. This driver is normally required for systems | |
| running as Dom0 to perform privileged operations, but in some | |
| disaggregated Xen setups this driver might be needed for other | |
| domains, too. | |
| config XEN_PRIVCMD_EVENTFD | |
| bool "Xen Ioeventfd and irqfd support" | |
| depends on XEN_PRIVCMD && XEN_VIRTIO && EVENTFD | |
| help | |
| Using the ioeventfd / irqfd mechanism a virtio backend running in a | |
| daemon can speed up interrupt delivery from / to a guest. | |
| 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_PV_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_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 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. | |
| config XEN_GRANT_DMA_IOMMU | |
| bool | |
| select IOMMU_API | |
| config XEN_GRANT_DMA_OPS | |
| bool | |
| config XEN_VIRTIO | |
| bool "Xen virtio support" | |
| depends on ARCH_HAS_DMA_OPS | |
| depends on VIRTIO | |
| select XEN_GRANT_DMA_OPS | |
| select XEN_GRANT_DMA_IOMMU if OF | |
| help | |
| Enable virtio support for running as Xen guest. Depending on the | |
| guest type this will require special support on the backend side | |
| (qemu or kernel, depending on the virtio device types used). | |
| If in doubt, say n. | |
| config XEN_VIRTIO_FORCE_GRANT | |
| bool "Require Xen virtio support to use grants" | |
| depends on XEN_VIRTIO | |
| help | |
| Require virtio for Xen guests to use grant mappings. | |
| This will avoid the need to give the backend the right to map all | |
| of the guest memory. This will need support on the backend side | |
| (e.g. qemu or kernel, depending on the virtio device types used). | |
| endmenu |