Module libvirt from libvirt

	API documentation		The virtualization API	virterror

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

Table of Contents

#define LIBVIR_VERSION_NUMBER

#define VIR_COPY_CPUMAP

#define VIR_CPU_MAPLEN

#define VIR_CPU_USABLE

#define VIR_GET_CPUMAP

#define VIR_NODEINFO_MAXCPUS

#define VIR_UNUSE_CPU

#define VIR_USE_CPU

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

Structure virNodeInfo
struct _virNodeInfo

Typedef virNodeInfo * virNodeInfoPtr

Structure virVcpuInfo
struct _virVcpuInfo

Typedef virVcpuInfo * virVcpuInfoPtr

Enum virVcpuState

int	virConnectClose			(virConnectPtr conn)

const char *	virConnectGetType	(virConnectPtr conn)

int	virConnectGetVersion		(virConnectPtr conn, 
					 unsigned long * hvVer)

int	virConnectListDefinedDomains	(virConnectPtr conn, 
					 const char ** names, 
					 int maxnames)

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

int	virConnectNumOfDomains		(virConnectPtr conn)

virConnectPtr	virConnectOpen		(const char * name)

virConnectPtr	virConnectOpenReadOnly	(const char * name)

int	virDomainCreate			(virDomainPtr domain)

virDomainPtr	virDomainCreateLinux	(virConnectPtr conn, 
					 const char * xmlDesc, 
					 unsigned int flags)

virDomainPtr	virDomainDefineXML	(virConnectPtr conn, 
					 const char * xml)

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)

int	virDomainGetUUID		(virDomainPtr domain, 
					 unsigned char * uuid)

int	virDomainGetUUIDString		(virDomainPtr domain, 
					 char * buf)

int	virDomainGetVcpus		(virDomainPtr domain, 
					 virVcpuInfoPtr info, 
					 int maxinfo, 
					 unsigned char * cpumaps, 
					 int maplen)

char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

virDomainPtr	virDomainLookupByName	(virConnectPtr conn, 
					 const char * name)

virDomainPtr	virDomainLookupByUUID	(virConnectPtr conn, 
					 const unsigned char * uuid)

virDomainPtr	virDomainLookupByUUIDString	(virConnectPtr conn, 
						 const char * uuidstr)

int	virDomainPinVcpu		(virDomainPtr domain, 
					 unsigned int vcpu, 
					 unsigned char * cpumap, 
					 int maplen)

int	virDomainReboot			(virDomainPtr domain, 
					 unsigned int flags)

int	virDomainRestore		(virConnectPtr conn, 
					 const char * from)

int	virDomainResume			(virDomainPtr domain)

int	virDomainSave			(virDomainPtr domain, 
					 const char * to)

int	virDomainSetMaxMemory		(virDomainPtr domain, 
					 unsigned long memory)

int	virDomainSetMemory		(virDomainPtr domain, 
					 unsigned long memory)

int	virDomainSetVcpus		(virDomainPtr domain, 
					 unsigned int nvcpus)

int	virDomainShutdown		(virDomainPtr domain)

int	virDomainSuspend		(virDomainPtr domain)

int	virDomainUndefine		(virDomainPtr domain)

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

int	virInitialize			(void)

int	virNodeGetInfo			(virConnectPtr conn, 
					 virNodeInfoPtr info)

Description

Macro: LIBVIR_VERSION_NUMBER

#define LIBVIR_VERSION_NUMBER

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

Macro: VIR_COPY_CPUMAP

#define VIR_COPY_CPUMAP

This macro is to be used in conjonction with virDomainGetVcpus() and virDomainPinVcpu() APIs. VIR_COPY_CPUMAP macro extract the cpumap of the specified vcpu from cpumaps array and copy it into cpumap to be used later by virDomainPinVcpu() API.

Macro: VIR_CPU_MAPLEN

#define VIR_CPU_MAPLEN

This macro is to be used in conjonction with virDomainPinVcpu() API. It returns the length (in bytes) required to store the complete CPU map between a single virtual & all physical CPUs of a domain.

Macro: VIR_CPU_USABLE

#define VIR_CPU_USABLE

This macro is to be used in conjonction with virDomainGetVcpus() API. VIR_CPU_USABLE macro returns a non zero value (true) if the cpu is usable by the vcpu, and 0 otherwise.

Macro: VIR_GET_CPUMAP

#define VIR_GET_CPUMAP

This macro is to be used in conjonction with virDomainGetVcpus() and virDomainPinVcpu() APIs. VIR_GET_CPUMAP macro returns a pointer to the cpumap of the specified vcpu from cpumaps array.

Macro: VIR_NODEINFO_MAXCPUS

#define VIR_NODEINFO_MAXCPUS

This macro is to calculate the total number of CPUs supported but not neccessarily active in the host.

Macro: VIR_UNUSE_CPU

#define VIR_UNUSE_CPU

This macro is to be used in conjonction with virDomainPinVcpu() API. USE_CPU macro reset the bit (CPU not usable) of the related cpu in cpumap.

Macro: VIR_USE_CPU

#define VIR_USE_CPU

This macro is to be used in conjonction with virDomainPinVcpu() API. USE_CPU macro set the bit (CPU usable) of the related cpu in cpumap.

Structure virConnect

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

a virConnectPtr is pointer to a virConnect private structure, this is the type used to reference a connection to the Xen Hypervisor in 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	: the number of virtual CPUs for the doma
    unsigned long long	cpuTime	: the CPU time used in nanoseconds
}

a virDomainInfoPtr is a pointer to a virDomainInfo structure.

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
}

a virDomainKernelPtr is a pointer to a virDomainKernel structure. a virDomainPtr is pointer to a virDomain private structure, this is the type used to reference a Xen domain in the API.

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
}

Structure virNodeInfo

Structure virNodeInfo
struct _virNodeInfo {
    charmodel[32]	model	: string indicating the CPU model
    unsigned long	memory	: memory size in kilobytes
    unsigned int	cpus	: the number of active CPUs
    unsigned int	mhz	: expected CPU frequency
    unsigned int	nodes	: the number of NUMA cell, 1 for uniform
    unsigned int	sockets	: number of CPU socket per node
    unsigned int	cores	: number of core per socket
    unsigned int	threads	: number of threads per core
}

a virNodeInfoPtr is a pointer to a virNodeInfo structure.

Structure virVcpuInfo

Structure virVcpuInfo
struct _virVcpuInfo {
    unsigned int	number	: virtual CPU number
    int	state	: value from virVcpuState
    unsigned long long	cpuTime	: CPU time used, in nanoseconds
    int	cpu	: real CPU number, or -1 if offline
}

Enum virVcpuState

Enum virVcpuState {
    VIR_VCPU_OFFLINE = 0 : the virtual CPU is offline
    VIR_VCPU_RUNNING = 1 : the virtual CPU is running
    VIR_VCPU_BLOCKED = 2 : the virtual CPU is blocked on resource
}

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: virConnectListDefinedDomains

int	virConnectListDefinedDomains	(virConnectPtr conn, 
					 const char ** names, 
					 int maxnames)

list the defined domains, stores the pointers to the names in @names

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 restricted connection to the libbrary functionalities. The set of APIs usable are then restricted on the available methods to control the domains.

Function: virDomainCreate

int	virDomainCreate			(virDomainPtr domain)

launch a defined domain. If the call succeed the domain moves from the defined to the running domains pools.

Function: virDomainCreateLinux

virDomainPtr	virDomainCreateLinux	(virConnectPtr conn, 
					 const char * xmlDesc, 
					 unsigned int flags)

Launch a new Linux guest domain, based on an XML description similar to the one returned by virDomainGetXMLDesc() This function may requires priviledged access to the hypervisor.

Function: virDomainDefineXML

virDomainPtr	virDomainDefineXML	(virConnectPtr conn, 
					 const char * xml)

define a domain, but does not start it

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 information 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: virDomainGetUUID

int	virDomainGetUUID		(virDomainPtr domain, 
					 unsigned char * uuid)

Get the UUID for a domain

Function: virDomainGetUUIDString

int	virDomainGetUUIDString		(virDomainPtr domain, 
					 char * buf)

Get the UUID for a domain as string. For more information about UUID see RFC4122.

Function: virDomainGetVcpus

int	virDomainGetVcpus		(virDomainPtr domain, 
					 virVcpuInfoPtr info, 
					 int maxinfo, 
					 unsigned char * cpumaps, 
					 int maplen)

Extract information about virtual CPUs of domain, store it in info array and also in cpumaps if this pointer is'nt NULL.

Function: virDomainGetXMLDesc

char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

Provide an XML description of the domain. The description may be reused later to relaunch the domain with virDomainCreateLinux().

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: virDomainLookupByUUID

virDomainPtr	virDomainLookupByUUID	(virConnectPtr conn, 
					 const unsigned char * uuid)

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

Function: virDomainLookupByUUIDString

virDomainPtr	virDomainLookupByUUIDString	(virConnectPtr conn, 
						 const char * uuidstr)

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

Function: virDomainPinVcpu

int	virDomainPinVcpu		(virDomainPtr domain, 
					 unsigned int vcpu, 
					 unsigned char * cpumap, 
					 int maplen)

Dynamically change the real CPUs which can be allocated to a virtual CPU. This function requires priviledged access to the hypervisor.

Function: virDomainReboot

int	virDomainReboot			(virDomainPtr domain, 
					 unsigned int flags)

Reboot a domain, the domain object is still usable there after but the domain OS is being stopped for a restart. Note that the guest OS may ignore the request.

Function: virDomainRestore

int	virDomainRestore		(virConnectPtr conn, 
					 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. After the call, if successful, the domain is not listed as running anymore (this may be a problem). 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: virDomainSetMemory

int	virDomainSetMemory		(virDomainPtr domain, 
					 unsigned long memory)

Dynamically change the target 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 may requires priviledged access to the hypervisor.

Function: virDomainSetVcpus

int	virDomainSetVcpus		(virDomainPtr domain, 
					 unsigned int nvcpus)

Dynamically change the number of virtual CPUs used by the domain. Note that this call may fail if the underlying virtualization hypervisor does not support it or if growing the number is arbitrary limited. 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: virDomainUndefine

int	virDomainUndefine		(virDomainPtr domain)

undefine a domain but does not stop it if it is running

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.

Function: virInitialize

int	virInitialize			(void)

Initialize the library. It's better to call this routine at startup in multithreaded applications to avoid potential race when initializing the library.

Function: virNodeGetInfo

int	virNodeGetInfo			(virConnectPtr conn, 
					 virNodeInfoPtr info)

Extract hardware information about the node.