Module libvirt-host from libvirt
Provides APIs for the management of hosts Copyright (C) 2006-2014 Red Hat, Inc. This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library. If not, see http://www.gnu.org/licenses/.
Table of Contents
Macros
#define VIR_NODEINFO_MAXCPUS #define VIR_NODE_CPU_STATS_FIELD_LENGTH #define VIR_NODE_CPU_STATS_IDLE #define VIR_NODE_CPU_STATS_INTR #define VIR_NODE_CPU_STATS_IOWAIT #define VIR_NODE_CPU_STATS_KERNEL #define VIR_NODE_CPU_STATS_USER #define VIR_NODE_CPU_STATS_UTILIZATION #define VIR_NODE_MEMORY_SHARED_FULL_SCANS #define VIR_NODE_MEMORY_SHARED_MERGE_ACROSS_NODES #define VIR_NODE_MEMORY_SHARED_PAGES_SHARED #define VIR_NODE_MEMORY_SHARED_PAGES_SHARING #define VIR_NODE_MEMORY_SHARED_PAGES_TO_SCAN #define VIR_NODE_MEMORY_SHARED_PAGES_UNSHARED #define VIR_NODE_MEMORY_SHARED_PAGES_VOLATILE #define VIR_NODE_MEMORY_SHARED_SLEEP_MILLISECS #define VIR_NODE_MEMORY_STATS_BUFFERS #define VIR_NODE_MEMORY_STATS_CACHED #define VIR_NODE_MEMORY_STATS_FIELD_LENGTH #define VIR_NODE_MEMORY_STATS_FREE #define VIR_NODE_MEMORY_STATS_TOTAL #define VIR_NODE_SEV_CBITPOS #define VIR_NODE_SEV_CERT_CHAIN #define VIR_NODE_SEV_PDH #define VIR_NODE_SEV_REDUCED_PHYS_BITS #define VIR_SECURITY_DOI_BUFLEN #define VIR_SECURITY_LABEL_BUFLEN #define VIR_SECURITY_MODEL_BUFLEN #define VIR_UUID_BUFLEN #define VIR_UUID_STRING_BUFLEN
Types
typedef enum virCPUCompareResult typedef struct _virConnect virConnect typedef struct _virConnectAuth virConnectAuth typedef virConnectAuth * virConnectAuthPtr typedef enum virConnectBaselineCPUFlags typedef enum virConnectCompareCPUFlags typedef struct _virConnectCredential virConnectCredential typedef virConnectCredential * virConnectCredentialPtr typedef enum virConnectCredentialType typedef enum virConnectFlags typedef virConnect * virConnectPtr typedef enum virNodeAllocPagesFlags typedef struct _virNodeCPUStats virNodeCPUStats typedef virNodeCPUStats * virNodeCPUStatsPtr typedef enum virNodeGetCPUStatsAllCPUs typedef enum virNodeGetMemoryStatsAllCells typedef struct _virNodeInfo virNodeInfo typedef virNodeInfo * virNodeInfoPtr typedef struct _virNodeMemoryStats virNodeMemoryStats typedef virNodeMemoryStats * virNodeMemoryStatsPtr typedef enum virNodeSuspendTarget typedef struct _virSecurityLabel virSecurityLabel typedef virSecurityLabel * virSecurityLabelPtr typedef struct _virSecurityModel virSecurityModel typedef virSecurityModel * virSecurityModelPtr typedef struct _virStream virStream typedef virStream * virStreamPtr
Functions
typedef virConnectAuthCallbackPtr int virConnectAuthCallbackPtr (virConnectCredentialPtr cred,
unsigned int ncred,
void * cbdata) char * virConnectBaselineCPU (virConnectPtr conn,
const char ** xmlCPUs,
unsigned int ncpus,
unsigned int flags) char * virConnectBaselineHypervisorCPU (virConnectPtr conn,
const char * emulator,
const char * arch,
const char * machine,
const char * virttype,
const char ** xmlCPUs,
unsigned int ncpus,
unsigned int flags) int virConnectClose (virConnectPtr conn) typedef virConnectCloseFunc void virConnectCloseFunc (virConnectPtr conn,
int reason,
void * opaque) int virConnectCompareCPU (virConnectPtr conn,
const char * xmlDesc,
unsigned int flags) int virConnectCompareHypervisorCPU (virConnectPtr conn,
const char * emulator,
const char * arch,
const char * machine,
const char * virttype,
const char * xmlCPU,
unsigned int flags) int virConnectGetCPUModelNames (virConnectPtr conn,
const char * arch,
char ** * models,
unsigned int flags) char * virConnectGetCapabilities (virConnectPtr conn) char * virConnectGetHostname (virConnectPtr conn) int virConnectGetLibVersion (virConnectPtr conn,
unsigned long * libVer) int virConnectGetMaxVcpus (virConnectPtr conn,
const char * type) char * virConnectGetSysinfo (virConnectPtr conn,
unsigned int flags) const char * virConnectGetType (virConnectPtr conn) char * virConnectGetURI (virConnectPtr conn) int virConnectGetVersion (virConnectPtr conn,
unsigned long * hvVer) int virConnectIsAlive (virConnectPtr conn) int virConnectIsEncrypted (virConnectPtr conn) int virConnectIsSecure (virConnectPtr conn) virConnectPtr virConnectOpen (const char * name) virConnectPtr virConnectOpenAuth (const char * name,
virConnectAuthPtr auth,
unsigned int flags) virConnectPtr virConnectOpenReadOnly (const char * name) int virConnectRef (virConnectPtr conn) int virConnectRegisterCloseCallback (virConnectPtr conn,
virConnectCloseFunc cb,
void * opaque,
virFreeCallback freecb) int virConnectSetKeepAlive (virConnectPtr conn,
int interval,
unsigned int count) int virConnectUnregisterCloseCallback (virConnectPtr conn,
virConnectCloseFunc cb) int virGetVersion (unsigned long * libVer,
const char * type,
unsigned long * typeVer) int virInitialize (void) int virNodeAllocPages (virConnectPtr conn,
unsigned int npages,
unsigned int * pageSizes,
unsigned long long * pageCounts,
int startCell,
unsigned int cellCount,
unsigned int flags) int virNodeGetCPUMap (virConnectPtr conn,
unsigned char ** cpumap,
unsigned int * online,
unsigned int flags) int virNodeGetCPUStats (virConnectPtr conn,
int cpuNum,
virNodeCPUStatsPtr params,
int * nparams,
unsigned int flags) int virNodeGetCellsFreeMemory (virConnectPtr conn,
unsigned long long * freeMems,
int startCell,
int maxCells) unsigned long long virNodeGetFreeMemory (virConnectPtr conn) int virNodeGetFreePages (virConnectPtr conn,
unsigned int npages,
unsigned int * pages,
int startCell,
unsigned int cellCount,
unsigned long long * counts,
unsigned int flags) int virNodeGetInfo (virConnectPtr conn,
virNodeInfoPtr info) int virNodeGetMemoryParameters (virConnectPtr conn,
virTypedParameterPtr params,
int * nparams,
unsigned int flags) int virNodeGetMemoryStats (virConnectPtr conn,
int cellNum,
virNodeMemoryStatsPtr params,
int * nparams,
unsigned int flags) int virNodeGetSEVInfo (virConnectPtr conn,
virTypedParameterPtr * params,
int * nparams,
unsigned int flags) int virNodeGetSecurityModel (virConnectPtr conn,
virSecurityModelPtr secmodel) int virNodeSetMemoryParameters (virConnectPtr conn,
virTypedParameterPtr params,
int nparams,
unsigned int flags) int virNodeSuspendForDuration (virConnectPtr conn,
unsigned int target,
unsigned long long duration,
unsigned int flags)
Description
Macros
VIR_NODEINFO_MAXCPUS
#define VIR_NODEINFO_MAXCPUS
This macro is to calculate the total number of CPUs supported but not necessary active in the host.
VIR_NODE_CPU_STATS_FIELD_LENGTH
#define VIR_NODE_CPU_STATS_FIELD_LENGTH
Macro providing the field length of virNodeCPUStats
VIR_NODE_CPU_STATS_IDLE
#define VIR_NODE_CPU_STATS_IDLE
The cumulative idle CPU time, since the node booting up (in nanoseconds).
VIR_NODE_CPU_STATS_INTR
#define VIR_NODE_CPU_STATS_INTR
The cumulative interrupt CPU time, since the node booting up (in nanoseconds).
VIR_NODE_CPU_STATS_IOWAIT
#define VIR_NODE_CPU_STATS_IOWAIT
The cumulative I/O wait CPU time, since the node booting up (in nanoseconds).
VIR_NODE_CPU_STATS_KERNEL
#define VIR_NODE_CPU_STATS_KERNEL
Macro for the cumulative CPU time which was spent by the kernel, since the node booting up (in nanoseconds).
VIR_NODE_CPU_STATS_USER
#define VIR_NODE_CPU_STATS_USER
The cumulative CPU time which was spent by user processes, since the node booting up (in nanoseconds).
VIR_NODE_CPU_STATS_UTILIZATION
#define VIR_NODE_CPU_STATS_UTILIZATION
The CPU utilization of a node. The usage value is in percent and 100% represents all CPUs of the node.
VIR_NODE_MEMORY_SHARED_FULL_SCANS
#define VIR_NODE_MEMORY_SHARED_FULL_SCANS
Macro for typed parameter that represents how many times all mergeable areas have been scanned.
VIR_NODE_MEMORY_SHARED_MERGE_ACROSS_NODES
#define VIR_NODE_MEMORY_SHARED_MERGE_ACROSS_NODES
Macro for typed parameter that represents whether pages from different NUMA nodes can be merged. The parameter has type int, when its value is 0, only pages which physically reside in the memory area of same NUMA node are merged; When its value is 1, pages from all nodes can be merged. Other values are reserved for future use.
VIR_NODE_MEMORY_SHARED_PAGES_SHARED
#define VIR_NODE_MEMORY_SHARED_PAGES_SHARED
Macro for typed parameter that represents how many the shared memory pages are being used.
VIR_NODE_MEMORY_SHARED_PAGES_SHARING
#define VIR_NODE_MEMORY_SHARED_PAGES_SHARING
Macro for typed parameter that represents how many sites are sharing the pages i.e. how much saved.
VIR_NODE_MEMORY_SHARED_PAGES_TO_SCAN
#define VIR_NODE_MEMORY_SHARED_PAGES_TO_SCAN
Macro for typed parameter that represents how many present pages to scan before the shared memory service goes to sleep.
VIR_NODE_MEMORY_SHARED_PAGES_UNSHARED
#define VIR_NODE_MEMORY_SHARED_PAGES_UNSHARED
Macro for typed parameter that represents how many pages unique but repeatedly checked for merging.
VIR_NODE_MEMORY_SHARED_PAGES_VOLATILE
#define VIR_NODE_MEMORY_SHARED_PAGES_VOLATILE
Macro for typed parameter that represents how many pages changing too fast to be placed in a tree.
VIR_NODE_MEMORY_SHARED_SLEEP_MILLISECS
#define VIR_NODE_MEMORY_SHARED_SLEEP_MILLISECS
Macro for typed parameter that represents how many milliseconds the shared memory service should sleep before next scan.
VIR_NODE_MEMORY_STATS_BUFFERS
#define VIR_NODE_MEMORY_STATS_BUFFERS
Macro for the buffer memory: On Linux, it is only returned in case of VIR_NODE_MEMORY_STATS_ALL_CELLS.
VIR_NODE_MEMORY_STATS_CACHED
#define VIR_NODE_MEMORY_STATS_CACHED
Macro for the cached memory: On Linux, it is only returned in case of VIR_NODE_MEMORY_STATS_ALL_CELLS.
VIR_NODE_MEMORY_STATS_FIELD_LENGTH
#define VIR_NODE_MEMORY_STATS_FIELD_LENGTH
Macro providing the field length of virNodeMemoryStats
VIR_NODE_MEMORY_STATS_FREE
#define VIR_NODE_MEMORY_STATS_FREE
Macro for the free memory of specified cell: On Linux, it includes buffer and cached memory, in case of VIR_NODE_MEMORY_STATS_ALL_CELLS.
VIR_NODE_MEMORY_STATS_TOTAL
#define VIR_NODE_MEMORY_STATS_TOTAL
Macro for the total memory of specified cell: it represents the maximum memory.
VIR_NODE_SEV_CBITPOS
#define VIR_NODE_SEV_CBITPOS
Macro represents the CBit Position used by hypervisor when SEV is enabled.
VIR_NODE_SEV_CERT_CHAIN
#define VIR_NODE_SEV_CERT_CHAIN
Macro represents the platform certificate chain that includes the platform endorsement key (PEK), owner certificate authority (OCD) and chip endorsement key (CEK), as VIR_TYPED_PARAMS_STRING.
VIR_NODE_SEV_PDH
#define VIR_NODE_SEV_PDH
Macro represents the Platform Diffie-Hellman key, as VIR_TYPED_PARAMS_STRING.
VIR_NODE_SEV_REDUCED_PHYS_BITS
#define VIR_NODE_SEV_REDUCED_PHYS_BITS
Macro represents the number of bits we lose in physical address space when SEV is enabled in the guest.
VIR_SECURITY_DOI_BUFLEN
#define VIR_SECURITY_DOI_BUFLEN
Macro providing the maximum length of the virSecurityModel doi string.
VIR_SECURITY_LABEL_BUFLEN
#define VIR_SECURITY_LABEL_BUFLEN
Macro providing the maximum length of the virSecurityLabel label string. Note that this value is based on that used by Labeled NFS.
VIR_SECURITY_MODEL_BUFLEN
#define VIR_SECURITY_MODEL_BUFLEN
Macro providing the maximum length of the virSecurityModel model string.
VIR_UUID_BUFLEN
#define VIR_UUID_BUFLEN
This macro provides the length of the buffer required for virDomainGetUUID()
VIR_UUID_STRING_BUFLEN
#define VIR_UUID_STRING_BUFLEN
This macro provides the length of the buffer required for virDomainGetUUIDString()
Types
virCPUCompareResult
enum virCPUCompareResult {
VIR_CPU_COMPARE_ERROR | = | -1 (-0x1) | |
VIR_CPU_COMPARE_INCOMPATIBLE | = | 0 (0x0) | |
VIR_CPU_COMPARE_IDENTICAL | = | 1 (0x1) | |
VIR_CPU_COMPARE_SUPERSET | = | 2 (0x2) | |
VIR_CPU_COMPARE_LAST | = | 3 (0x3) |
}
virConnect
struct virConnect {
}
virConnectAuth
struct virConnectAuth {
int * | credtype |
List of supported virConnectCredentialType values
|
unsigned int | ncredtype | |
virConnectAuthCallbackPtr | cb |
Callback used to collect credentials
|
void * | cbdata |
}
virConnectBaselineCPUFlags
enum virConnectBaselineCPUFlags {
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES | = | 1 (0x1; 1 << 0) |
show all features
|
VIR_CONNECT_BASELINE_CPU_MIGRATABLE | = | 2 (0x2; 1 << 1) |
filter out non-migratable features
|
}
virConnectCompareCPUFlags
enum virConnectCompareCPUFlags {
VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE | = | 1 (0x1; 1 << 0) |
treat incompatible CPUs as failure
|
}
virConnectCredential
struct virConnectCredential {
int | type |
One of virConnectCredentialType constants
|
const char * | prompt |
Prompt to show to user
|
const char * | challenge |
Additional challenge to show
|
const char * | defresult |
Optional default result
|
char * | result |
Result to be filled with user response (or defresult)
|
unsigned int | resultlen |
Length of the result
|
}
virConnectCredentialType
enum virConnectCredentialType {
VIR_CRED_USERNAME | = | 1 (0x1) |
Identity to act as
|
VIR_CRED_AUTHNAME | = | 2 (0x2) |
Identify to authorize as
|
VIR_CRED_LANGUAGE | = | 3 (0x3) |
RFC 1766 languages, comma separated
|
VIR_CRED_CNONCE | = | 4 (0x4) |
client supplies a nonce
|
VIR_CRED_PASSPHRASE | = | 5 (0x5) |
Passphrase secret
|
VIR_CRED_ECHOPROMPT | = | 6 (0x6) |
Challenge response
|
VIR_CRED_NOECHOPROMPT | = | 7 (0x7) |
Challenge response
|
VIR_CRED_REALM | = | 8 (0x8) |
Authentication realm
|
VIR_CRED_EXTERNAL | = | 9 (0x9) |
Externally managed credential
|
VIR_CRED_LAST | = | 10 (0xa) |
More may be added - expect the unexpected
|
}
virConnectFlags
enum virConnectFlags {
VIR_CONNECT_RO | = | 1 (0x1; 1 << 0) |
A readonly connection
|
VIR_CONNECT_NO_ALIASES | = | 2 (0x2; 1 << 1) |
Don't try to resolve URI aliases
|
}
virNodeAllocPagesFlags
enum virNodeAllocPagesFlags {
VIR_NODE_ALLOC_PAGES_ADD | = | 0 (0x0) |
Add @pageCounts to the pages pool. This can be used only to size up the pool.
|
VIR_NODE_ALLOC_PAGES_SET | = | 1 (0x1; 1 << 0) |
Don't add @pageCounts, instead set passed number of pages. This can be used to free allocated pages.
|
}
virNodeCPUStats
struct virNodeCPUStats {
char field[VIR_NODE_CPU_STATS_FIELD_LENGTH] | field |
unsigned long long | value |
}
virNodeGetCPUStatsAllCPUs
virNodeGetMemoryStatsAllCells
virNodeInfo
struct virNodeInfo {
char model[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, 0 if not known or on unusual architectures
|
unsigned int | nodes |
the number of NUMA cell, 1 for unusual NUMA topologies or uniform memory access; check capabilities XML for the actual NUMA topology
|
unsigned int | sockets |
number of CPU sockets per node if nodes > 1, 1 in case of unusual NUMA topology
|
unsigned int | cores |
number of cores per socket, total number of processors in case of unusual NUMA topolog
|
unsigned int | threads |
number of threads per core, 1 in case of unusual numa topology
|
}
virNodeMemoryStats
struct virNodeMemoryStats {
char field[VIR_NODE_MEMORY_STATS_FIELD_LENGTH] | field |
unsigned long long | value |
}
virNodeSuspendTarget
enum virNodeSuspendTarget {
VIR_NODE_SUSPEND_TARGET_MEM | = | 0 (0x0) | |
VIR_NODE_SUSPEND_TARGET_DISK | = | 1 (0x1) | |
VIR_NODE_SUSPEND_TARGET_HYBRID | = | 2 (0x2) | |
VIR_NODE_SUSPEND_TARGET_LAST | = | 3 (0x3) |
This constant is subject to change
|
}
virSecurityLabel
struct virSecurityLabel {
char label[VIR_SECURITY_LABEL_BUFLEN] | label |
security label string
|
int | enforcing |
1 if security policy is being enforced for domain
|
}
virSecurityModel
struct virSecurityModel {
char model[VIR_SECURITY_MODEL_BUFLEN] | model |
security model string
|
char doi[VIR_SECURITY_DOI_BUFLEN] | doi |
domain of interpretation
|
}
virStream
struct virStream {
}
Functions
virConnectAuthCallbackPtr
typedef int (*virConnectAuthCallbackPtr) (virConnectCredentialPtr cred, unsigned int ncred, void * cbdata)
When authentication requires one or more interactions, this callback is invoked. For each interaction supplied, data must be gathered from the user and filled in to the 'result' and 'resultlen' fields. If an interaction cannot be filled, fill in NULL and 0.
- cred
- list of virConnectCredential object to fetch from user
- ncred
- size of cred list
- cbdata
- opaque data passed to virConnectOpenAuth
- Returns
- 0 if all interactions were filled, or -1 upon error
virConnectBaselineCPU
char * virConnectBaselineCPU (virConnectPtr conn, const char ** xmlCPUs, unsigned int ncpus, unsigned int flags)
Computes the most feature-rich CPU which is compatible with all given host CPUs.
See virConnectBaselineHypervisorCPU() to get a CPU which can be provided by the hypervisor.
If @flags includes VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES then libvirt will explicitly list all CPU features that are part of the host CPU, without this flag features that are part of the CPU model will not be listed.
If @flags includes VIR_CONNECT_BASELINE_CPU_MIGRATABLE, the resulting CPU will not include features that block migration.
- conn
- virConnect connection
- xmlCPUs
- array of XML descriptions of host CPUs
- ncpus
- number of CPUs in xmlCPUs
- flags
- bitwise-OR of virConnectBaselineCPUFlags
- Returns
- XML description of the computed CPU (caller frees) or NULL on error.
virConnectBaselineHypervisorCPU
char * virConnectBaselineHypervisorCPU (virConnectPtr conn, const char * emulator, const char * arch, const char * machine, const char * virttype, const char ** xmlCPUs, unsigned int ncpus, unsigned int flags)
Computes the most feature-rich CPU which is compatible with all given CPUs and can be provided by the specified hypervisor. For best results the host-model CPUs as advertised by virConnectGetDomainCapabilities() should be passed in @xmlCPUs. Any of @emulator, @arch, @machine, and @virttype parameters may be NULL; libvirt will choose sensible defaults tailored to the host and its current configuration.
This is different from virConnectBaselineCPU() which doesn't consider any hypervisor abilities when computing the best CPU.
If @flags includes VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES then libvirt will explicitly list all CPU features that are part of the computed CPU, without this flag features that are part of the CPU model will not be listed.
If @flags includes VIR_CONNECT_BASELINE_CPU_MIGRATABLE, the resulting CPU will not include features that block migration.
- conn
- pointer to the hypervisor connection
- emulator
- path to the emulator binary
- arch
- CPU architecture
- machine
- machine type
- virttype
- virtualization type
- xmlCPUs
- array of XML descriptions of CPUs
- ncpus
- number of CPUs in xmlCPUs
- flags
- bitwise-OR of virConnectBaselineCPUFlags
- Returns
- XML description of the computed CPU (caller frees) or NULL on error.
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.
Connections are reference counted; the count is explicitly increased by the initial open (virConnectOpen, virConnectOpenAuth, and the like) as well as virConnectRef; it is also temporarily increased by other API that depend on the connection remaining alive. The open and every virConnectRef call should have a matching virConnectClose, and all other references will be released after the corresponding operation completes.
- conn
- pointer to the hypervisor connection
- Returns
- a positive number if at least 1 reference remains on success. The returned value should not be assumed to be the total reference count. A return of 0 implies no references remain and the connection is closed and memory has been freed. A return of -1 implies a failure. It is possible for the last virConnectClose to return a positive value if some other object still has a temporary reference to the connection, but the application should not try to further use a connection after the virConnectClose that matches the initial open.
virConnectCloseFunc
typedef void (*virConnectCloseFunc ) (virConnectPtr conn, int reason, void * opaque)
A callback function to be registered, and called when the connection is closed.
- conn
- virConnect connection
- reason
- reason why the connection was closed (one of virConnectCloseReason)
- opaque
- opaque user data
virConnectCompareCPU
int virConnectCompareCPU (virConnectPtr conn, const char * xmlDesc, unsigned int flags)
Compares the given CPU description with the host CPU.
See virConnectCompareHypervisorCPU() if you want to consider hypervisor abilities and compare the CPU to the CPU which a hypervisor is able to provide on the host.
- conn
- virConnect connection
- xmlDesc
- XML describing the CPU to compare with host CPU
- flags
- bitwise-OR of virConnectCompareCPUFlags
- Returns
- comparison result according to enum virCPUCompareResult. If VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE is used and @xmlDesc CPU is incompatible with host CPU, this function will return VIR_CPU_COMPARE_ERROR (instead of VIR_CPU_COMPARE_INCOMPATIBLE) and the error will use the VIR_ERR_CPU_INCOMPATIBLE code with a message providing more details about the incompatibility.
virConnectCompareHypervisorCPU
int virConnectCompareHypervisorCPU (virConnectPtr conn, const char * emulator, const char * arch, const char * machine, const char * virttype, const char * xmlCPU, unsigned int flags)
Compares the given CPU description with the CPU the specified hypervisor is able to provide on the host. Any of @emulator, @arch, @machine, and @virttype parameters may be NULL; libvirt will choose sensible defaults tailored to the host and its current configuration.
This is different from virConnectCompareCPU() which compares the CPU definition with the host CPU without considering any specific hypervisor and its abilities.
- conn
- pointer to the hypervisor connection
- emulator
- path to the emulator binary
- arch
- CPU architecture
- machine
- machine type
- virttype
- virtualization type
- xmlCPU
- XML describing the CPU to be compared
- flags
- bitwise-OR of virConnectCompareCPUFlags
- Returns
- comparison result according to enum virCPUCompareResult. If VIR_CONNECT_COMPARE_CPU_FAIL_INCOMPATIBLE is used and @xmlCPU is incompatible with the CPU the specified hypervisor is able to provide on the host, this function will return VIR_CPU_COMPARE_ERROR (instead of VIR_CPU_COMPARE_INCOMPATIBLE) and the error will use the VIR_ERR_CPU_INCOMPATIBLE code with a message providing more details about the incompatibility.
virConnectGetCPUModelNames
int virConnectGetCPUModelNames (virConnectPtr conn, const char * arch, char ** * models, unsigned int flags)
Get the list of CPU models supported by libvirt for a specific architecture.
The returned list limits CPU models usable with libvirt (empty list means there's no limit imposed by libvirt) and it does not reflect capabilities of any particular hypervisor. See the XML returned by virConnectGetDomainCapabilities() for a list of CPU models supported by libvirt for domains created on a specific hypervisor.
- conn
- virConnect connection
- arch
- Architecture
- models
- Pointer to a variable to store the NULL-terminated array of the CPU models supported for the specified architecture. Each element and the array itself must be freed by the caller with free. Pass NULL if only the list length is needed.
- flags
- extra flags; not used yet, so callers should always pass 0.
- Returns
- -1 on error, number of elements in @models on success (0 means libvirt accepts any CPU model).
virConnectGetCapabilities
char * virConnectGetCapabilities (virConnectPtr conn)
Provides capabilities of the hypervisor / driver.
- conn
- pointer to the hypervisor connection
- Returns
- NULL in case of error, or an XML string defining the capabilities. The client must free the returned string after use.
virConnectGetHostname
char * virConnectGetHostname (virConnectPtr conn)
This returns a system hostname on which the hypervisor is running (based on the result of the gethostname system call, but possibly expanded to a fully-qualified domain name via getaddrinfo). If we are connected to a remote system, then this returns the hostname of the remote system.
- conn
- pointer to a hypervisor connection
- Returns
- the hostname which must be freed by the caller, or NULL if there was an error.
virConnectGetLibVersion
int virConnectGetLibVersion (virConnectPtr conn, unsigned long * libVer)
Provides @libVer, which is the version of libvirt used by the daemon running on the @conn host
- conn
- pointer to the hypervisor connection
- libVer
- returns the libvirt library version used on the connection (OUT)
- Returns
- -1 in case of failure, 0 otherwise, and values for @libVer have the format major * 1,000,000 + minor * 1,000 + release.
virConnectGetMaxVcpus
int virConnectGetMaxVcpus (virConnectPtr conn, const char * type)
Provides the maximum number of virtual CPUs supported for a guest VM of a specific type. The 'type' parameter here corresponds to the 'type' attribute in the <domain> element of the XML. This API doesn't take emulator limits into consideration, hence the returned value is not guaranteed to be usable. It is recommended to use virConnectGetDomainCapabilities() and look for "<vcpu max='...'>" in its output instead.
- conn
- pointer to the hypervisor connection
- type
- value of the 'type' attribute in the <domain> element
- Returns
- the maximum of virtual CPU or -1 in case of error.
virConnectGetSysinfo
char * virConnectGetSysinfo (virConnectPtr conn, unsigned int flags)
This returns the XML description of the sysinfo details for the host on which the hypervisor is running, in the same format as the <sysinfo> element of a domain XML. This information is generally available only for hypervisors running with root privileges.
- conn
- pointer to a hypervisor connection
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- the XML string which must be freed by the caller, or NULL if there was an error.
virConnectGetType
const char * virConnectGetType (virConnectPtr conn)
Get the name of the Hypervisor driver used. This is merely the driver name; for example, both KVM and QEMU guests are serviced by the driver for the qemu:// URI, so a return of "QEMU" does not indicate whether KVM acceleration is present. For more details about the hypervisor, use virConnectGetCapabilities().
- conn
- pointer to the hypervisor connection
- Returns
- NULL in case of error, a static zero terminated string otherwise.
virConnectGetURI
char * virConnectGetURI (virConnectPtr conn)
This returns the URI (name) of the hypervisor connection. Normally this is the same as or similar to the string passed to the virConnectOpen/virConnectOpenReadOnly call, but the driver may make the URI canonical. If name == NULL was passed to virConnectOpen, then the driver will return a non-NULL URI which can be used to connect to the same hypervisor later.
- conn
- pointer to a hypervisor connection
- Returns
- the URI string which must be freed by the caller, or NULL if there was an error.
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 privileged 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
virConnectIsAlive
int virConnectIsAlive (virConnectPtr conn)
Determine if the connection to the hypervisor is still alive
A connection will be classed as alive if it is either local, or running over a channel (TCP or UNIX socket) which is not closed.
- conn
- pointer to the connection object
- Returns
- 1 if alive, 0 if dead, -1 on error
virConnectIsEncrypted
int virConnectIsEncrypted (virConnectPtr conn)
Determine if the connection to the hypervisor is encrypted
- conn
- pointer to the connection object
- Returns
- 1 if encrypted, 0 if not encrypted, -1 on error
virConnectIsSecure
int virConnectIsSecure (virConnectPtr conn)
Determine if the connection to the hypervisor is secure
A connection will be classed as secure if it is either encrypted, or running over a channel which is not exposed to eavesdropping (eg a UNIX domain socket, or pipe)
- conn
- pointer to the connection object
- Returns
- 1 if secure, 0 if not secure, -1 on error
virConnectOpen
virConnectPtr virConnectOpen (const char * name)
This function should be called first to get a connection to the Hypervisor and xen store
If @name is NULL, if the LIBVIRT_DEFAULT_URI environment variable is set, then it will be used. Otherwise if the client configuration file has the "uri_default" parameter set, then it will be used. Finally probing will be done to determine a suitable default driver to activate. This involves trying each hypervisor in turn until one successfully opens.
If connecting to an unprivileged hypervisor driver which requires the libvirtd daemon to be active, it will automatically be launched if not already running. This can be prevented by setting the environment variable LIBVIRT_AUTOSTART=0
URIs are documented at https://libvirt.org/uri.html
virConnectClose should be used to release the resources after the connection is no longer needed.
- name
- (optional) URI of the hypervisor
- Returns
- a pointer to the hypervisor connection or NULL in case of error
virConnectOpenAuth
virConnectPtr virConnectOpenAuth (const char * name, virConnectAuthPtr auth, unsigned int flags)
This function should be called first to get a connection to the Hypervisor. If necessary, authentication will be performed fetching credentials via the callback
See virConnectOpen for notes about environment variables which can have an effect on opening drivers and freeing the connection resources
URIs are documented at https://libvirt.org/uri.html
- name
- (optional) URI of the hypervisor
- auth
- Authenticate callback parameters
- flags
- bitwise-OR of virConnectFlags
- Returns
- a pointer to the hypervisor connection or NULL in case of error
virConnectOpenReadOnly
virConnectPtr virConnectOpenReadOnly (const char * name)
This function should be called first to get a restricted connection to the library functionalities. The set of APIs usable are then restricted on the available methods to control the domains.
See virConnectOpen for notes about environment variables which can have an effect on opening drivers and freeing the connection resources
URIs are documented at https://libvirt.org/uri.html
- name
- (optional) URI of the hypervisor
- Returns
- a pointer to the hypervisor connection or NULL in case of error
virConnectRef
int virConnectRef (virConnectPtr conn)
Increment the reference count on the connection. For each additional call to this method, there shall be a corresponding call to virConnectClose to release the reference count, once the caller no longer needs the reference to this object.
This method is typically useful for applications where multiple threads are using a connection, and it is required that the connection remain open until all threads have finished using it. ie, each new thread using a connection would increment the reference count.
- conn
- the connection to hold a reference on
- Returns
- 0 in case of success, -1 in case of failure
virConnectRegisterCloseCallback
int virConnectRegisterCloseCallback (virConnectPtr conn, virConnectCloseFunc cb, void * opaque, virFreeCallback freecb)
Registers a callback to be invoked when the connection is closed. This callback is invoked when there is any condition that causes the socket connection to the hypervisor to be closed.
This function is only applicable to hypervisor drivers which maintain a persistent open connection. Drivers which open a new connection for every operation will not invoke this.
The @freecb must not invoke any other libvirt public APIs, since it is not called from a re-entrant safe context.
- conn
- pointer to connection object
- cb
- callback to invoke upon close
- opaque
- user data to pass to @cb
- freecb
- callback to free @opaque
- Returns
- 0 on success, -1 on error
virConnectSetKeepAlive
int virConnectSetKeepAlive (virConnectPtr conn, int interval, unsigned int count)
Start sending keepalive messages after @interval seconds of inactivity and consider the connection to be broken when no response is received after @count keepalive messages sent in a row. In other words, sending count + 1 keepalive message results in closing the connection. When @interval is <= 0, no keepalive messages will be sent. When @count is 0, the connection will be automatically closed after @interval seconds of inactivity without sending any keepalive messages.
Note: The client has to implement and run an event loop with virEventRegisterImpl() or virEventRegisterDefaultImpl() to be able to use keepalive messages. Failure to do so may result in connections being closed unexpectedly.
Note: This API function controls only keepalive messages sent by the client. If the server is configured to use keepalive you still need to run the event loop to respond to them, even if you disable keepalives by this function.
- conn
- pointer to a hypervisor connection
- interval
- number of seconds of inactivity before a keepalive message is sent
- count
- number of messages that can be sent in a row
- Returns
- -1 on error, 0 on success, 1 when remote party doesn't support keepalive messages.
virConnectUnregisterCloseCallback
int virConnectUnregisterCloseCallback (virConnectPtr conn, virConnectCloseFunc cb)
Unregisters the callback previously set with the virConnectRegisterCloseCallback method. The callback will no longer receive notifications when the connection closes. If a virFreeCallback was provided at time of registration, it will be invoked
- conn
- pointer to connection object
- cb
- pointer to the current registered callback
- Returns
- 0 on success, -1 on error
virGetVersion
int virGetVersion (unsigned long * libVer, const char * type, unsigned long * typeVer)
Provides version information. @libVer is the version of the library and will always be set unless an error occurs, in which case an error code will be returned. @typeVer exists for historical compatibility; if it is not NULL it will duplicate @libVer (it was originally intended to return hypervisor information based on @type, but due to the design of remote clients this is not reliable). To get the version of the running hypervisor use the virConnectGetVersion() function instead. To get the libvirt library version used by a connection use the virConnectGetLibVersion() instead.
This function includes a call to virInitialize() when necessary.
- libVer
- return value for the library version (OUT)
- type
- ignored; pass NULL
- typeVer
- pass NULL; for historical purposes duplicates @libVer if non-NULL
- 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.
virInitialize
int virInitialize (void)
Initialize the library.
This method is invoked automatically by any of the virConnectOpen() API calls, and by virGetVersion(). Since release 1.0.0, there is no need to call this method even in a multithreaded application, since initialization is performed in a thread safe manner; but applications using an older version of the library should manually call this before setting up competing threads that attempt virConnectOpen in parallel.
The only other time it would be necessary to call virInitialize is if the application did not invoke virConnectOpen as its first API call, such as when calling virEventRegisterImpl() before setting up connections, or when using virSetErrorFunc() to alter error reporting of the first connection attempt.
- Returns
- 0 in case of success, -1 in case of error
virNodeAllocPages
int virNodeAllocPages (virConnectPtr conn, unsigned int npages, unsigned int * pageSizes, unsigned long long * pageCounts, int startCell, unsigned int cellCount, unsigned int flags)
Sometimes, when trying to start a new domain, it may be necessary to reserve some huge pages in the system pool which can be then allocated by the domain. This API serves that purpose. On its input, @pageSizes and @pageCounts are arrays of the same cardinality of @npages. The @pageSizes contains page sizes which are to be allocated in the system (the size unit is kibibytes), and @pageCounts then contains the number of pages to reserve. If @flags is 0 (VIR_NODE_ALLOC_PAGES_ADD), each pool corresponding to @pageSizes grows by the number of pages specified in the corresponding @pageCounts. If @flags contains VIR_NODE_ALLOC_PAGES_SET, each pool mentioned is resized to the given number of pages. The pages pool can be allocated over several NUMA nodes at once, just point at @startCell and tell how many subsequent NUMA nodes should be taken in. As a special case, if @startCell is equal to negative one, then kernel is instructed to allocate the pages over all NUMA nodes proportionally.
- conn
- pointer to the hypervisor connection
- npages
- number of items in the @pageSizes and @pageCounts arrays
- pageSizes
- which huge page sizes to allocate
- pageCounts
- how many pages should be allocated
- startCell
- index of first cell to allocate pages on
- cellCount
- number of consecutive cells to allocate pages on
- flags
- extra flags; binary-OR of virNodeAllocPagesFlags
- Returns
- the number of nodes successfully adjusted or -1 in case of an error.
virNodeGetCPUMap
int virNodeGetCPUMap (virConnectPtr conn, unsigned char ** cpumap, unsigned int * online, unsigned int flags)
Get CPU map of host node CPUs.
- conn
- pointer to the hypervisor connection
- cpumap
- optional pointer to a bit map of real CPUs on the host node (in 8-bit bytes) (OUT) In case of success each bit set to 1 means that corresponding CPU is online. Bytes are stored in little-endian order: CPU0-7, 8-15... In each byte, lowest CPU number is least significant bit. The bit map is allocated by virNodeGetCPUMap and needs to be released using free() by the caller.
- online
- optional number of online CPUs in cpumap (OUT) Contains the number of online CPUs if the call was successful.
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- number of CPUs present on the host node, or -1 if there was an error.
virNodeGetCPUStats
int virNodeGetCPUStats (virConnectPtr conn, int cpuNum, virNodeCPUStatsPtr params, int * nparams, unsigned int flags)
This function provides individual cpu statistics of the node. If you want to get total cpu statistics of the node, you must specify VIR_NODE_CPU_STATS_ALL_CPUS to @cpuNum. The @params array will be filled with the values equal to the number of parameters suggested by @nparams
As the value of @nparams is dynamic, call the API setting @nparams to 0 and @params as NULL, the API returns the number of parameters supported by the HV by updating @nparams on SUCCESS. The caller should then allocate @params array, i.e. (sizeof(@virNodeCPUStats) * @nparams) bytes and call the API again.
Here is a sample code snippet:
if (virNodeGetCPUStats(conn, cpuNum, NULL, &nparams, 0) == 0 && nparams != 0) { if ((params = malloc(sizeof(virNodeCPUStats) * nparams)) == NULL) goto error; memset(params, 0, sizeof(virNodeCPUStats) * nparams); if (virNodeGetCPUStats(conn, cpuNum, params, &nparams, 0)) goto error; }
This function doesn't require privileged access to the hypervisor. This function expects the caller to allocate the @params.
CPU time Statistics:
VIR_NODE_CPU_STATS_KERNEL: The cumulative CPU time which spends by kernel, when the node booting up.(nanoseconds) VIR_NODE_CPU_STATS_USER: The cumulative CPU time which spends by user processes, when the node booting up.(nanoseconds) VIR_NODE_CPU_STATS_IDLE: The cumulative idle CPU time, when the node booting up.(nanoseconds) VIR_NODE_CPU_STATS_IOWAIT: The cumulative I/O wait CPU time, when the node booting up.(nanoseconds) VIR_NODE_CPU_STATS_UTILIZATION: The CPU utilization. The usage value is in percent and 100% represents all CPUs on the server.
- conn
- pointer to the hypervisor connection.
- cpuNum
- number of node cpu. (VIR_NODE_CPU_STATS_ALL_CPUS means total cpu statistics)
- params
- pointer to node cpu time parameter objects
- nparams
- number of node cpu time parameter (this value should be same or less than the number of parameters supported)
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- -1 in case of error, 0 in case of success.
virNodeGetCellsFreeMemory
int virNodeGetCellsFreeMemory (virConnectPtr conn, unsigned long long * freeMems, int startCell, int maxCells)
This call returns the amount of free memory in one or more NUMA cells. The @freeMems array must be allocated by the caller and will be filled with the amount of free memory in bytes for each cell requested, starting with startCell (in freeMems[0]), up to either (startCell + maxCells), or the number of additional cells in the node, whichever is smaller.
- conn
- pointer to the hypervisor connection
- freeMems
- pointer to the array of unsigned long long
- startCell
- index of first cell to return freeMems info on.
- maxCells
- Maximum number of cells for which freeMems information can be returned.
- Returns
- the number of entries filled in freeMems, or -1 in case of error.
virNodeGetFreeMemory
unsigned long long virNodeGetFreeMemory (virConnectPtr conn)
provides the free memory available on the Node Note: most libvirt APIs provide memory sizes in kibibytes, but in this function the returned value is in bytes. Divide by 1024 as necessary.
- conn
- pointer to the hypervisor connection
- Returns
- the available free memory in bytes or 0 in case of error
virNodeGetFreePages
int virNodeGetFreePages (virConnectPtr conn, unsigned int npages, unsigned int * pages, int startCell, unsigned int cellCount, unsigned long long * counts, unsigned int flags)
This calls queries the host system on free pages of specified size. For the input, @pages is expected to be filled with pages that caller is interested in (the size unit is kibibytes, so e.g. pass 2048 for 2MB), then @startcell refers to the first NUMA node that info should be collected from, and @cellcount tells how many consecutive nodes should be queried. On the function output, @counts is filled with desired information, where items are grouped by NUMA node. So from @counts[0] till @counts[@npages - 1] you'll find count for the first node (@startcell), then from @counts[@npages] till @count[2 * @npages - 1] you'll find info for the (@startcell + 1) node, and so on. It's callers responsibility to allocate the @counts array.
Example how to use this API:
unsigned int pages[] = { 4, 2048, 1048576} unsigned int npages = ARRAY_CARDINALITY(pages); int startcell = 0; unsigned int cellcount = 2; unsigned long long counts = malloc(sizeof(long long) * npages * cellcount); virNodeGetFreePages(conn, pages, npages, startcell, cellcount, counts, 0); for (i = 0 ; i < cellcount ; i++) { fprintf(stdout, "Cell %d\n", startcell + i); for (j = 0 ; j < npages ; j++) { fprintf(stdout, " Page size=%d count=%d bytes=%llu\n", pages[j], counts[(i * npages) + j], pages[j] * counts[(i * npages) + j]); } } This little code snippet will produce something like this: Cell 0 Page size=4096 count=300 bytes=1228800 Page size=2097152 count=0 bytes=0 Page size=1073741824 count=1 bytes=1073741824 Cell 1 Page size=4096 count=0 bytes=0 Page size=2097152 count=20 bytes=41943040 Page size=1073741824 count=0 bytes=0
- conn
- pointer to the hypervisor connection
- npages
- number of items in the @pages array
- pages
- page sizes to query
- startCell
- index of first cell to return free pages info on.
- cellCount
- maximum number of cells for which free pages information can be returned.
- counts
- returned counts of free pages
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- the number of entries filled in @counts or -1 in case of error.
virNodeGetInfo
int virNodeGetInfo (virConnectPtr conn, virNodeInfoPtr info)
Extract hardware information about the node.
- conn
- pointer to the hypervisor connection
- info
- pointer to a virNodeInfo structure allocated by the user
- Returns
- 0 in case of success and -1 in case of failure.
virNodeGetMemoryParameters
int virNodeGetMemoryParameters (virConnectPtr conn, virTypedParameterPtr params, int * nparams, unsigned int flags)
Get all node memory parameters (parameters unsupported by OS will be omitted). On input, @nparams gives the size of the @params array; on output, @nparams gives how many slots were filled with parameter information, which might be less but will not exceed the input value.
As a special case, calling with @params as NULL and @nparams as 0 on input will cause @nparams on output to contain the number of parameters supported by the hypervisor. The caller should then allocate @params array, i.e. (sizeof(@virTypedParameter) * @nparams) bytes and call the API again. See virDomainGetMemoryParameters() for an equivalent usage example.
- conn
- pointer to the hypervisor connection
- params
- pointer to memory parameter object (return value, allocated by the caller)
- nparams
- pointer to number of memory parameters; input and output
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- 0 in case of success, and -1 in case of failure.
virNodeGetMemoryStats
int virNodeGetMemoryStats (virConnectPtr conn, int cellNum, virNodeMemoryStatsPtr params, int * nparams, unsigned int flags)
This function provides memory stats of the node. If you want to get total memory statistics of the node, you must specify VIR_NODE_MEMORY_STATS_ALL_CELLS to @cellNum. The @params array will be filled with the values equal to the number of stats suggested by @nparams
As the value of @nparams is dynamic, call the API setting @nparams to 0 and @params as NULL, the API returns the number of parameters supported by the HV by updating @nparams on SUCCESS. The caller should then allocate @params array, i.e. (sizeof(@virNodeMemoryStats) * @nparams) bytes and call the API again.
Here is the sample code snippet:
if (virNodeGetMemoryStats(conn, cellNum, NULL, &nparams, 0) == 0 && nparams != 0) { if ((params = malloc(sizeof(virNodeMemoryStats) * nparams)) == NULL) goto error; memset(params, cellNum, 0, sizeof(virNodeMemoryStats) * nparams); if (virNodeGetMemoryStats(conn, params, &nparams, 0)) goto error; }
This function doesn't require privileged access to the hypervisor. This function expects the caller to allocate the @params.
Memory Stats:
VIR_NODE_MEMORY_STATS_TOTAL: The total memory usage.(KB) VIR_NODE_MEMORY_STATS_FREE: The free memory usage.(KB) On linux, this usage includes buffers and cached. VIR_NODE_MEMORY_STATS_BUFFERS: The buffers memory usage.(KB) VIR_NODE_MEMORY_STATS_CACHED: The cached memory usage.(KB)
- conn
- pointer to the hypervisor connection.
- cellNum
- number of node cell. (VIR_NODE_MEMORY_STATS_ALL_CELLS means total cell statistics)
- params
- pointer to node memory stats objects
- nparams
- number of node memory stats (this value should be same or less than the number of stats supported)
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- -1 in case of error, 0 in case of success.
virNodeGetSEVInfo
int virNodeGetSEVInfo (virConnectPtr conn, virTypedParameterPtr * params, int * nparams, unsigned int flags)
If hypervisor supports AMD's SEV feature, then @params will contain various platform specific information like PDH and certificate chain. Caller is responsible for freeing @params.
- conn
- pointer to the hypervisor connection
- params
- where to store SEV information
- nparams
- pointer to number of SEV parameters returned in @params
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- 0 in case of success, and -1 in case of failure.
virNodeGetSecurityModel
int virNodeGetSecurityModel (virConnectPtr conn, virSecurityModelPtr secmodel)
Extract the security model of a hypervisor. The 'model' field in the @secmodel argument may be initialized to the empty string if the driver has not activated a security model.
- conn
- a connection object
- secmodel
- pointer to a virSecurityModel structure
- Returns
- 0 in case of success, -1 in case of failure
virNodeSetMemoryParameters
int virNodeSetMemoryParameters (virConnectPtr conn, virTypedParameterPtr params, int nparams, unsigned int flags)
Change all or a subset of the node memory tunables. The function fails if not all of the tunables are supported.
Note that it's not recommended to use this function while the outside tuning program is running (such as ksmtuned under Linux), as they could change the tunables in parallel, which could cause conflicts.
This function may require privileged access to the hypervisor.
- conn
- pointer to the hypervisor connection
- params
- pointer to scheduler parameter objects
- nparams
- number of scheduler parameter objects (this value can be the same or less than the returned value nparams of virDomainGetSchedulerType)
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- 0 in case of success, -1 in case of failure.
virNodeSuspendForDuration
int virNodeSuspendForDuration (virConnectPtr conn, unsigned int target, unsigned long long duration, unsigned int flags)
Attempt to suspend the node (host machine) for the given duration of time in the specified state (Suspend-to-RAM, Suspend-to-Disk or Hybrid-Suspend). Schedule the node's Real-Time-Clock interrupt to resume the node after the duration is complete.
- conn
- pointer to the hypervisor connection
- target
- the state to which the host must be suspended to, such as: VIR_NODE_SUSPEND_TARGET_MEM (Suspend-to-RAM) VIR_NODE_SUSPEND_TARGET_DISK (Suspend-to-Disk) VIR_NODE_SUSPEND_TARGET_HYBRID (Hybrid-Suspend, which is a combination of the former modes).
- duration
- the time duration in seconds for which the host has to be suspended
- flags
- extra flags; not used yet, so callers should always pass 0
- Returns
- 0 on success (i.e., the node will be suspended after a short delay), -1 on failure (the operation is not supported, or an attempted suspend is already underway).