+ + + + + +

+ + +

+ diff --git a/docs/examples/index.html b/docs/examples/index.html new file mode 100644 index 0000000000..8cdeed7675 --- /dev/null +++ b/docs/examples/index.html @@ -0,0 +1,7 @@ + + +Libvirt set of C code examples

Libvirt set of C code examples

The examples are stored per section depending on the main focus + of the example:

Informations :
- info1.c: Extract informations about Xen domain 0

Getting the compilation options and libraries dependancies needed +to generate binaries from the examples is best done on Linux/Unix by using +the pkg-config data which should have been installed as part of make +install step or when installing the libvirt development package:

gcc -o example example.c `pkg-config libvirt --libs`

Informations Examples

info1.c: Extract informations about Xen domain 0

Demonstrate the basic use of the library to connect to the hypervisor and extract domain informations.

Uses:

line 29: Function virConnectOpenReadOnly from libvirt.h
line 36: Function virDomainLookupByID from libvirt.h
line 43: Function virDomainGetInfo from libvirt.h
line 53: Function virDomainFree from libvirt.h
line 55: Function virConnectClose from libvirt.h

Usage:

info1

Author: Daniel Veillard

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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Reference Manual for libvir

libvir: core interfaces for the libvir library

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Module libvir from libvir

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

#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		(virConnectPtr conn, 
					 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.
-}

- 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	: * Informations below are only available
-    unsigned long long	cpuTime	: * TODO: * - check what can be extracted
-}

- 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
-}
-

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.

`conn`:	pointer to the hypervisor connection
`Returns`:	0 in case of success or -1 in case of error.

Function: virConnectGetType

const char *	virConnectGetType	(virConnectPtr conn)

-

Get the name of the Hypervisor software used.

`conn`:	pointer to the hypervisor connection
`Returns`:	NULL in case of error, a static zero terminated string otherwise.

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.

`conn`:	pointer to the hypervisor connection
`hvVer`:	return value for the version of the running hypervisor (OUT)
`Returns`:	-1 in case of error, 0 otherwise. if the version can't be extracted by lack of capacities returns 0 and @hvVer is 0, otherwise @hvVer value is major * 1,000,000 + minor * 1,000 + release

Function: virConnectListDomains

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

-

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

`conn`:	pointer to the hypervisor connection
`ids`:	array to collect the list of IDs of active domains
`maxids`:	size of @ids
`Returns`:	the number of domain found or -1 in case of error

Function: virConnectNumOfDomains

int	virConnectNumOfDomains		(virConnectPtr conn)

-

Provides the number of active domains.

`conn`:	pointer to the hypervisor connection
`Returns`:	the number of domain found or -1 in case of error

Function: virConnectOpen

virConnectPtr	virConnectOpen		(const char * name)

-

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

`name`:	optional argument currently unused, pass NULL
`Returns`:	a pointer to the hypervisor connection or NULL in case of error

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.

`name`:	optional argument currently unused, pass NULL
`Returns`:	a pointer to the hypervisor connection or NULL in case of error

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.

`conn`:	pointer to the hypervisor connection
`kernel_path`:	the file path to the kernel image
`initrd_path`:	an optional file path to an initrd
`cmdline`:	optional command line parameters for the kernel
`memory`:	the memory size in kilobytes
`flags`:	an optional set of virDomainFlags
`Returns`:	a new domain object or NULL in case of failure

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

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

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.

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

Function: virDomainGetID

unsigned int	virDomainGetID		(virDomainPtr domain)

-

Get the hypervisor ID number for the domain

`domain`:	a domain object
`Returns`:	the domain ID number or (unsigned int) -1 in case of error

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.

`domain`:	a domain object
`info`:	pointer to a virDomainInfo structure allocated by the user
`Returns`:	0 in case of success and -1 in case of failure.

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.

`domain`:	a domain object or NULL
`Returns`:	the memory size in kilobytes or 0 in case of error.

Function: virDomainGetName

const char *	virDomainGetName	(virDomainPtr domain)

-

Get the public name for that domain

`domain`:	a domain object
`Returns`:	a pointer to the name or NULL, the string need not be deallocated its lifetime will be the same as the domain object.

Function: virDomainGetOSType

char *	virDomainGetOSType		(virDomainPtr domain)

-

Get the type of domain operation system.

`domain`:	a domain object
`Returns`:	the new string or NULL in case of error

Function: virDomainGetXMLDesc

char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

-

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

`domain`:	a domain object
`flags`:	and OR'ed set of extraction flags, not used yet
`Returns`:	a 0 terminated UTF-8 encoded XML instance, or NULL in case of error. the caller must free() the returned value.

Function: virDomainLookupByID

virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

-

Try to find a domain based on the hypervisor ID number

`conn`:	pointer to the hypervisor connection
`id`:	the domain ID number
`Returns`:	a new domain object or NULL in case of failure

Function: virDomainLookupByName

virDomainPtr	virDomainLookupByName	(virConnectPtr conn, 
					 const char * name)

-

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

`conn`:	pointer to the hypervisor connection
`name`:	name for the domain
`Returns`:	a new domain object or NULL in case of failure

Function: virDomainRestore

int	virDomainRestore		(virConnectPtr conn, 
					 const char * from)

-

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

`conn`:	pointer to the hypervisor connection
`from`:	path to the
`Returns`:	0 in case of success and -1 in case of failure.

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

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

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.

`domain`:	a domain object
`to`:	path for the output file
`Returns`:	0 in case of success and -1 in case of failure.

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.

`domain`:	a domain object or NULL
`memory`:	the memory size in kilobytes
`Returns`:	0 in case of success and -1 in case of failure.

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 ?

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

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.

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

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.

`libVer`:	return value for the library version (OUT)
`type`:	hypervisor type
`typeVer`:	return value for the version of the hypervisor (OUT)
`Returns`:	-1 in case of failure, 0 otherwise, and values for @libVer and @typeVer have the format major * 1,000,000 + minor * 1,000 + release.

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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Reference Manual for libvirt

libvirt: core interfaces for the libvirt library

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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.

`name`:	optional argument currently unused, pass NULL
`Returns`:	a pointer to the hypervisor connection or NULL in case of error

Function: virDomainCreateLinux

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

-

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

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

`conn`:	pointer to the hypervisor connection
`xmlDesc`:	an XML description of the domain
`flags`:	an optional set of virDomainFlags
`Returns`:	a new domain object or NULL in case of failure

Function: virDomainDestroy

int	virDomainDestroy		(virDomainPtr domain)

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

Function: virDomainFree

int	virDomainFree			(virDomainPtr domain)

@@ -119,8 +119,8 @@ The content of this structure is not made public by the API.
 domain: a domain object
Returns: a pointer to the name or NULL, the string need not be deallocated its lifetime will be the same as the domain object.
Function: virDomainGetOSType
char *	virDomainGetOSType		(virDomainPtr domain)

 
Get the type of domain operation system.
 domain: a domain object
Returns: the new string or NULL in case of error
Function: virDomainGetXMLDesc
char *	virDomainGetXMLDesc		(virDomainPtr domain, 
					 int flags)

-
Provide an XML description of the domain. NOTE: this API is subject to changes.
-domain: a domain object
flags: and OR'ed set of extraction flags, not used yet
Returns: a 0 terminated UTF-8 encoded XML instance, or NULL in case of error. the caller must free() the returned value.
Function: virDomainLookupByID
virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

+

+domain: 
flags: 
Returns: 
Function: virDomainLookupByID
virDomainPtr	virDomainLookupByID	(virConnectPtr conn, 
					 int id)

 
Try to find a domain based on the hypervisor ID number
 conn: pointer to the hypervisor connection
id: the domain ID number
Returns: a new domain object or NULL in case of failure
Function: virDomainLookupByName
virDomainPtr	virDomainLookupByName	(virConnectPtr conn, 
					 const char * name)

 
Try to lookup a domain on the given hypervisor based on its name.
@@ -138,4 +138,4 @@ The content of this structure is not made public by the API.

`domain`:	a domain object
`Returns`:	0 in case of success and -1 in case of failure.

Function: virGetVersion

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

`libVer`:	return value for the library version (OUT)
`type`:	hypervisor type
`typeVer`:	return value for the version of the hypervisor (OUT)
`Returns`:	-1 in case of failure, 0 otherwise, and values for @libVer and @typeVer have the format major * 1,000,000 + minor * 1,000 + release.

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Type virDomainPtr:

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:

Libvirt set of C code examples

Informations Examples

info1.c: Extract informations about Xen domain 0

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Reference Manual for libvirt

Table of Contents

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