API documentation		The virtualization API

Provides the interfaces of the libvir library to handle Xen domains from a process running in domain 0

Table of Contents

#define LIBVIR_VERSION_NUMBER

Structure virConnect
struct _virConnect
The content of this structure is not made public by the API.

Typedef virConnect * virConnectPtr

Enum virDeviceMode

Structure virDomain
struct _virDomain
The content of this structure is not made public by the API.

Enum virDomainCreateFlags

Structure virDomainInfo
struct _virDomainInfo

Typedef virDomainInfo * virDomainInfoPtr

Structure virDomainKernel
struct _virDomainKernel

Typedef virDomainKernel * virDomainKernelPtr

Typedef virDomain * virDomainPtr

Enum virDomainRestart

Enum virDomainState

int	virConnectClose			(virConnectPtr conn)

const char *	virConnectGetType	(virConnectPtr conn)

int	virConnectGetVersion		(virConnectPtr conn, 
					 unsigned long * hvVer)

int	virConnectListDomains		(virConnectPtr conn, 
					 int * ids, 
					 int maxids)

int	virConnectNumOfDomains		(virConnectPtr conn)

virConnectPtr	virConnectOpen		(const char * name)

virConnectPtr	virConnectOpenReadOnly	(const char * name)

virDomainPtr	virDomainCreateLinux	(virConnectPtr conn, 
					 const char * kernel_path, 
					 const char * initrd_path, 
					 const char * cmdline, 
					 unsigned long memory, 
					 unsigned int flags)

int	virDomainDestroy		(virDomainPtr domain)

int	virDomainFree			(virDomainPtr domain)

unsigned int	virDomainGetID		(virDomainPtr domain)

int	virDomainGetInfo		(virDomainPtr domain, 
					 virDomainInfoPtr info)

unsigned long	virDomainGetMaxMemory	(virDomainPtr domain)

const char *	virDomainGetName	(virDomainPtr domain)

char *	virDomainGetOSType		(virDomainPtr domain)

char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

virDomainPtr	virDomainLookupByName	(virConnectPtr conn, 
					 const char * name)

int	virDomainRestore		(virDomainPtr domain, 
					 const char * from)

int	virDomainResume			(virDomainPtr domain)

int	virDomainSave			(virDomainPtr domain, 
					 const char * to)

int	virDomainSetMaxMemory		(virDomainPtr domain, 
					 unsigned long memory)

int	virDomainShutdown		(virDomainPtr domain)

int	virDomainSuspend		(virDomainPtr domain)

int	virGetVersion			(unsigned long * libVer, 
					 const char * type, 
					 unsigned long * typeVer)

Description

Macro: LIBVIR_VERSION_NUMBER

#define LIBVIR_VERSION_NUMBER

Macro providing the version of the library as version * 1,000,000 + minor * 1000 + micro

Structure virConnect

Structure virConnect
struct _virConnect {
The content of this structure is not made public by the API.
}

Enum virDeviceMode

Enum virDeviceMode {
    VIR_DEVICE_DEFAULT = 0 : Default mode
    VIR_DEVICE_RO = 1 : Access read-only
    VIR_DEVICE_RW = 2 : Access read-write
    VIR_DEVICE_RW_FORCE = 3 : Forced read-write even if already used
}

Structure virDomain

Structure virDomain
struct _virDomain {
The content of this structure is not made public by the API.
}

Enum virDomainCreateFlags

Enum virDomainCreateFlags {
    VIR_DOMAIN_NONE = 0
}

Structure virDomainInfo

Structure virDomainInfo
struct _virDomainInfo {
    unsigned char	state	: the running state, one of virDomainFlag
    unsigned long	maxMem	: the maximum memory in KBytes allowed
    unsigned long	memory	: the memory in KBytes used by the domain
    unsigned short	nrVirtCpu	: * Informations below are only available
    unsigned long long	cpuTime	: * TODO: * - check what can be extracted
}

Structure virDomainKernel

Structure virDomainKernel
struct _virDomainKernel {
    const char *	kernel	: filename pointing to the kernel image
    const char *	ramdisk	: an optional init ramdisk
    const char *	root	: an optional root block device
    const char *	extra	: optional kernel command line parameters
}

Enum virDomainRestart

Enum virDomainRestart {
    VIR_DOMAIN_DESTROY = 1 : destroy the domain
    VIR_DOMAIN_RESTART = 2 : restart the domain
    VIR_DOMAIN_PRESERVE = 3 : keep as is, need manual destroy, for debug
    VIR_DOMAIN_RENAME_RESTART = 4 : restart under an new unique name
}

Enum virDomainState

Enum virDomainState {
    VIR_DOMAIN_NOSTATE = 0 : no state
    VIR_DOMAIN_RUNNING = 1 : the domain is running
    VIR_DOMAIN_BLOCKED = 2 : the domain is blocked on resource
    VIR_DOMAIN_PAUSED = 3 : the domain is paused by user
    VIR_DOMAIN_SHUTDOWN = 4 : the domain is being shut down
    VIR_DOMAIN_SHUTOFF = 5 : the domain is shut off
    VIR_DOMAIN_CRASHED = 6 : the domain is crashed
}

Function: virConnectClose

int	virConnectClose			(virConnectPtr conn)

This function closes the connection to the Hypervisor. This should not be called if further interaction with the Hypervisor are needed especially if there is running domain which need further monitoring by the application.

Function: virConnectGetType

const char *	virConnectGetType	(virConnectPtr conn)

Get the name of the Hypervisor software used.

Function: virConnectGetVersion

int	virConnectGetVersion		(virConnectPtr conn, 
					 unsigned long * hvVer)

Get the version level of the Hypervisor running. This may work only with hypervisor call, i.e. with priviledged access to the hypervisor, not with a Read-Only connection.

Function: virConnectListDomains

int	virConnectListDomains		(virConnectPtr conn, 
					 int * ids, 
					 int maxids)

Collect the list of active domains, and store their ID in @maxids

Function: virConnectNumOfDomains

int	virConnectNumOfDomains		(virConnectPtr conn)

Provides the number of active domains.

Function: virConnectOpen

virConnectPtr	virConnectOpen		(const char * name)

This function should be called first to get a connection to the Hypervisor and xen store

Function: virConnectOpenReadOnly

virConnectPtr	virConnectOpenReadOnly	(const char * name)

This function should be called first to get a read-only connection to the xen store. The set of APIs usable are then restricted.

Function: virDomainCreateLinux

virDomainPtr	virDomainCreateLinux	(virConnectPtr conn, 
					 const char * kernel_path, 
					 const char * initrd_path, 
					 const char * cmdline, 
					 unsigned long memory, 
					 unsigned int flags)

Launch a new Linux guest domain, unimplemented yet, API to be defined. This would function requires priviledged access to the hypervisor.

Function: virDomainDestroy

int	virDomainDestroy		(virDomainPtr domain)

Destroy the domain object. The running instance is shutdown if not down already and all resources used by it are given back to the hypervisor. The data structure is freed and should not be used thereafter if the call does not return an error. This function may requires priviledged access

Function: virDomainFree

int	virDomainFree			(virDomainPtr domain)

Free the domain object. The running instance is kept alive. The data structure is freed and should not be used thereafter.

Function: virDomainGetID

unsigned int	virDomainGetID		(virDomainPtr domain)

Get the hypervisor ID number for the domain

Function: virDomainGetInfo

int	virDomainGetInfo		(virDomainPtr domain, 
					 virDomainInfoPtr info)

Extract information about a domain. Note that if the connection used to get the domain is limited only a partial set of the informations can be extracted.

Function: virDomainGetMaxMemory

unsigned long	virDomainGetMaxMemory	(virDomainPtr domain)

Retrieve the maximum amount of physical memory allocated to a domain. If domain is NULL, then this get the amount of memory reserved to Domain0 i.e. the domain where the application runs.

Function: virDomainGetName

const char *	virDomainGetName	(virDomainPtr domain)

Get the public name for that domain

Function: virDomainGetOSType

char *	virDomainGetOSType		(virDomainPtr domain)

Get the type of domain operation system.

Function: virDomainGetXMLDesc

char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

Provide an XML description of the domain. NOTE: this API is subject to changes.

Function: virDomainLookupByID

virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

Try to find a domain based on the hypervisor ID number

Function: virDomainLookupByName

virDomainPtr	virDomainLookupByName	(virConnectPtr conn, 
					 const char * name)

Try to lookup a domain on the given hypervisor based on its name.

Function: virDomainRestore

int	virDomainRestore		(virDomainPtr domain, 
					 const char * from)

This method will restore a domain saved to disk by virDomainSave().

Function: virDomainResume

int	virDomainResume			(virDomainPtr domain)

Resume an suspended domain, the process is restarted from the state where it was frozen by calling virSuspendDomain(). This function may requires priviledged access

Function: virDomainSave

int	virDomainSave			(virDomainPtr domain, 
					 const char * to)

This method will suspend a domain and save its memory contents to a file on disk. Use virDomainRestore() to restore a domain after saving.

Function: virDomainSetMaxMemory

int	virDomainSetMaxMemory		(virDomainPtr domain, 
					 unsigned long memory)

Dynamically change the maximum amount of physical memory allocated to a domain. If domain is NULL, then this change the amount of memory reserved to Domain0 i.e. the domain where the application runs. This function requires priviledged access to the hypervisor.

Function: virDomainShutdown

int	virDomainShutdown		(virDomainPtr domain)

Shutdown a domain, the domain object is still usable there after but the domain OS is being stopped. Note that the guest OS may ignore the request. TODO: should we add an option for reboot, knowing it may not be doable in the general case ?

Function: virDomainSuspend

int	virDomainSuspend		(virDomainPtr domain)

Suspends an active domain, the process is frozen without further access to CPU resources and I/O but the memory used by the domain at the hypervisor level will stay allocated. Use virDomainResume() to reactivate the domain. This function may requires priviledged access.

Function: virGetVersion

int	virGetVersion			(unsigned long * libVer, 
					 const char * type, 
					 unsigned long * typeVer)

Provides two information back, @libVer is the version of the library while @typeVer will be the version of the hypervisor type @type against which the library was compiled. If @type is NULL, "Xen" is assumed, if @type is unknown or not availble, an error code will be returned and @typeVer will be 0.

Daniel Veillard