Module `Gnt.Gntshr`Source

Sourcetype interface

A connection to the gntshr device, needed for sharing/unmapping

Sourceval interface_open : unit -> interface

Open a connection to the gntshr device. This must be done before any calls to share or unmap.

Sourceval interface_close : interface -> unit

Close a connection to the gntshr device. Any future calls to share or unmap will fail.

Sourcetype share = {

refs : gntref list;
(*
List of grant references which have been shared with a foreign domain.
*)
mapping : Io_page.t;
(*
Mapping of the shared memory.
*)

}

When sharing a number of pages with another domain, we receive back both the list of grant references shared and actually mapped page(s). The foreign domain can map the same shared memory, after being notified (e.g. via xenstore) of our domid and list of references.

Sourceval share_pages_exn : interface -> int -> int -> bool -> share

share_pages_exn if domid count writable shares count pages with foreign domain domid. writable determines whether or not the foreign domain can write to the shared memory.

Sourceval share_pages : interface -> int -> int -> bool -> share option

share_pages if domid count writable shares count pages with foreign domain domid. writable determines whether or not the foreign domain can write to the shared memory. On error this function returns None. Diagnostic details will be logged.

Sourceval munmap_exn : interface -> share -> unit

Unmap a single mapping (which may involve multiple grants)

Low-level interface

This is is only available in kernelspace and is deprecated. For low-level access, use mirage-xen's OS.Xen API instead.

Sourceexception Interface_unavailable

Raised when the low-level grant table interface is not available

Sourceval get : unit -> gntref Lwt.t

Allocate a single grant table index

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval get_n : int -> gntref list Lwt.t

Allocate a block of n grant table indices

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval put : gntref -> unit

Deallocate a grant table index

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval get_nonblock : unit -> gntref option

get_nonblock () is Some idx is the grant table is not full, or None otherwise.

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval get_n_nonblock : int -> gntref list

get_n_nonblock count is a list of grant table indices of length count, or [] if there if the table is too full to accomodate count new grant references.

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval num_free_grants : unit -> int

num_free_grants () returns the number of instantaneously free grant table indices

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval with_ref : (gntref -> 'a Lwt.t) -> 'a Lwt.t

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval with_refs : int -> (gntref list -> 'a Lwt.t) -> 'a Lwt.t

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval grant_access : domid:int -> writable:bool -> gntref -> Io_page.t -> unit

grant_access ~domid ~writable gntref page adds a grant table entry at index gntref to the grant table, granting access to domid to read page, and write to is as well if writable is true.

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval end_access : gntref -> unit

end_access gntref removes entry index gntref from the grant table.

deprecated Use mirage-xen's OS.Xen API instead.

Source

val with_grant : 
  domid:int ->
  writable:bool ->
  gntref ->
  Io_page.t ->
  (unit -> 'a Lwt.t) ->
  'a Lwt.t

deprecated Use mirage-xen's OS.Xen API instead.

Source

val with_grants : 
  domid:int ->
  writable:bool ->
  gntref list ->
  Io_page.t list ->
  (unit -> 'a Lwt.t) ->
  'a Lwt.t

deprecated Use mirage-xen's OS.Xen API instead.

Sourceval with_gntshr : (interface -> 'a) -> 'a

with_gntshr f opens an interface to gntshr, passes it to f, then returns the result of f (or re-raises any exceptions) ensuring that the gntshr interface is closed before returning.

package xen-gnt

Module Gnt.GntshrSource

Low-level interface

Module `Gnt.Gntshr`Source