hen-0.1.1: Haskell bindings to Xen hypervisor interface

Safe HaskellNone

System.Xen

Contents

Description

Haskell bidings to Xen hypervisor interface. There are three interface levels in this library:

  • Low-level interface. System.Xen.Low. It just provides bindings to c-calls.
  • Mid-level interface. System.Xen.Mid. Contains helper functions and allow to use your favorite Monad.
  • High-level interface. System.Xen.High. Contains Xen monad and provides a safe way to run any Xen computation.

Last one is also re-exported by current module and intend for common usage. Usage example: 

 module Main (main) where

 import System.Xen (runXenT, domainGetInfo)

 main :: IO ()
 main = print =<< runXenT domainGetInfo

Synopsis

Errors

data XcHandleOpenError Source

This error can be raised if handle can not be opened, insufficient rights for example.

Constructors

XcHandleOpenError Errno 

Instances

data InvalidDomainShutdownReason Source

This error can be raised if peecked value of DomainShutdownReason is not expected.

Constructors

InvalidDomainShutdownReason CInt

Peeked value

Instances

data DomainGetInfoError Source

This error can be raised if any error occured during receiving the list, for example: try to to fetch a list in domU.

Constructors

DomainGetInfoError Errno 

Instances

Domain info

newtype DomId Source

Domain id, wrapper around Word32.

Constructors

DomId 

Fields

unDomId :: Word32
 

Instances

data DomainFlag Source

Domain flags. It's translated from xc_dominfo structure, so it's possible to be mutual exclusion flags in one domain, e.g. DomainFlagShutdown and DomainFlagRunning.

Constructors

DomainFlagDying 
DomainFlagCrashed 
DomainFlagShutdown 
DomainFlagPaused 
DomainFlagBlocked 
DomainFlagRunning 
DomainFlagHVM 
DomainFlagDebugged 

Instances

data DomainShutdownReason Source

Domain shutdown reason it's only meaningful if domain has DomainFlagShutdown flag.

Constructors

DomainShutdownReasonPoweroff 
DomainShutdownReasonReboot 
DomainShutdownReasonSuspend 
DomainShutdownReasonCrash 
DomainShutdownReasonWatchdog 

Instances

data DomainInfo Source

Information about a single domain.

Constructors

DomainInfo 

Fields

domainInfoId :: !DomId
 
domainInfoSsidRef :: !Word32
 
domainInfoFlags :: !(BitSet DomainFlag)
 
domainInfoShutdownReason :: !(Maybe DomainShutdownReason)
 
domainInfoNumberOfPages :: !Word32
 
domainInfoNumberOfSharedPages :: !Word32
 
domainInfoSharedInfoFrame :: !Word32
 
domainInfoCpuTime :: !Word64
 
domainInfoMaxMemKb :: !Word32
 
domainInfoNubmerOfOnlineVcpus :: !Word32
 
domainInfoMaxVcpuId :: !Word32
 
domainInfoDomHandle :: !UUID
 
domainInfoCpuPool :: !Word32
 

Instances

High-level API

Monad stuff

data XenT m a Source

A Xen transformer. This transformers keeps connection to the Xen hypervisor interface.

Instances

MonadTrans XenT 
MonadRWS r w s m => MonadRWS r w s (XenT m) 
MonadReader r m => MonadReader r (XenT m) 
MonadState s m => MonadState s (XenT m) 
MonadWriter w m => MonadWriter w (XenT m) 
Monad m => Monad (XenT m) 
Functor m => Functor (XenT m) 
Applicative m => Applicative (XenT m) 
MonadCatch m => MonadCatch (XenT m) 
MonadIO m => MonadIO (XenT m) 
(Functor m, MonadIO m, MonadCatch m) => MonadXen (XenT m) 

type Xen = XenT IOSource

Most simple XenT implementation.

runXenT :: (Functor m, MonadIO m, MonadCatch m) => XenT m a -> m (Either SomeException a)Source

Open new connection to the hypervisor, run any Xen action and close connection if nessesary. This function can fail with Either SomeException with XcHandleOpenError and any error of providing Xen action.

Domain

domainGetInfo :: MonadXen m => m [DomainInfo]Source

Returns a lift of domains, this function can fail with InvalidDomainShutdownReason and DomainGetInfoError.

Domain pause

domainPause :: MonadXen m => DomId -> m BoolSource

Pause domain. A paused domain still exists in memory however it does not receive any timeslices from the hypervisor.

domainUnpause :: MonadXen m => DomId -> m BoolSource

Unpause a domain. The domain should have been previously paused.

Domain powerstate

domainShutdown :: MonadXen m => DomId -> DomainShutdownReason -> m BoolSource

Shutdown domain. This is intended for use in fully-virtualized domains where this operation is analogous to the sched_op operations in a paravirtualized domain.

domainDestroy :: MonadXen m => DomId -> m BoolSource

Destroy a domain. Destroying a domain removes the domain completely from memory. This function should be called after domainShutdown to free up the domain resources.