albatross/src/vmm_resources.mli
Hannes Mehnert a9c32d7801 vmmd: actually, first check resources, then exec VM, then insert VM
in case the insertion fails, raise Invalid_argument

this leads to more sane failure behaviour, and also cleans up resources in case
 vmm_resources.insert_vm fails (or cpuset/open of the fifo, create_process)
2019-01-27 17:20:24 +01:00

70 lines
2.7 KiB
OCaml

(* (c) 2017 Hannes Mehnert, all rights reserved *)
(** A tree data structure including policies and dynamic usage.
Considering delegation of resources to someone, and further delegation
to others - using a process which is not controlled by the authority -
requires runtime tracking of these delegations and the actual usage:
If Alice may create 2 virtual machines, and she delegates the same
capability further to both Bob and Charlie, the authority must still enforce
that Alice, Bob, and Charlie are able to run 2 virtual machines in total,
rather than 2 each. *)
open Vmm_core
(** The type of the resource tree. *)
type t = private {
policies : Policy.t Vmm_trie.t ;
block_devices : (int * bool) Vmm_trie.t ;
unikernels : Unikernel.t Vmm_trie.t ;
}
(** [empty] is the empty tree. *)
val empty : t
(** [find_vm t id] is either [Some vm] or [None]. *)
val find_vm : t -> Name.t -> Unikernel.t option
(** [find_policy t Name.t] is either [Some policy] or [None]. *)
val find_policy : t -> Name.t -> Policy.t option
(** [find_block t Name.t] is either [Some (size, active)] or [None]. *)
val find_block : t -> Name.t -> (int * bool) option
(** [check_vm t Name.t vm] checks whether [vm] under [Name.t] in [t] would be
allowed under the current policies. *)
val check_vm : t -> Name.t -> Unikernel.config -> (unit, [> `Msg of string ]) result
(** [insert_vm t Name.t vm] inserts [vm] under [Name.t] in [t], and returns the
new [t]. The caller has to ensure (using {!check_vm}) that a VM with the
same name does not yet exist, and the block device is not in use.
@raise Invalid_argument if block device is already in use, or VM already
exists. *)
val insert_vm : t -> Name.t -> Unikernel.t -> t
(** [insert_policy t Name.t policy] inserts [policy] under [Name.t] in [t], and returns
the new [t] or an error. *)
val insert_policy : t -> Name.t -> Policy.t -> (t, [> `Msg of string]) result
(** [check_block t Name.t size] checks whether [size] under [Name.t] in [t] would be
allowed under the current policies. *)
val check_block : t -> Name.t -> int -> (unit, [> `Msg of string ]) result
(** [insert_block t Name.t size] inserts [size] under [Name.t] in [t], and returns the new [t] or
an error. *)
val insert_block : t -> Name.t -> int -> (t, [> `Msg of string]) result
(** [remove_vm t Name.t] removes vm [Name.t] from [t]. *)
val remove_vm : t -> Name.t -> (t, [> `Msg of string ]) result
(** [remove_policy t Name.t] removes policy [Name.t] from [t]. *)
val remove_policy : t -> Name.t -> (t, [> `Msg of string ]) result
(** [remove_block t Name.t] removes block [Name.t] from [t]. *)
val remove_block : t -> Name.t -> (t, [> `Msg of string ]) result
(** [pp] is a pretty printer for [t]. *)
val pp : t Fmt.t