|  | 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_SCRUB_PAGES | 
|  | bool "Scrub pages before returning them to system" | 
|  | 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.  Is it more | 
|  | secure, but slightly less efficient. | 
|  | 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 triger event | 
|  | channels and to receive notification of an event channel | 
|  | firing. | 
|  | If in doubt, say yes. | 
|  |  | 
|  | config XEN_BACKEND | 
|  | bool "Backend driver support" | 
|  | depends on XEN_DOM0 | 
|  | default y | 
|  | help | 
|  | Support for backend device drivers that provide I/O services | 
|  | to other virtual machines. | 
|  |  | 
|  | config XENFS | 
|  | tristate "Xen filesystem" | 
|  | 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_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_PLATFORM_PCI | 
|  | tristate "xen platform pci device driver" | 
|  | depends on XEN_PVHVM && PCI | 
|  | default m | 
|  | help | 
|  | Driver for the Xen PCI Platform device: it is responsible for | 
|  | initializing xenbus and grant_table when running in a Xen HVM | 
|  | domain. As a consequence this driver is required to run any Xen PV | 
|  | frontend on Xen HVM. | 
|  |  | 
|  | config SWIOTLB_XEN | 
|  | def_bool y | 
|  | depends on PCI | 
|  | select SWIOTLB | 
|  |  | 
|  | endmenu |