ganeti.hypervisor.hv_kvm.monitor.QmpConnection

class documentation

class QmpConnection(MonitorSocket):

Connection to the QEMU Monitor using the QEMU Monitor Protocol (QMP).

Method	`__enter__`	Undocumented
Method	`__exit__`	Undocumented
Method	`__init__`	Instantiates the MonitorSocket object.
Method	`CheckDiskHotAddSupport`	Check if disk hotplug is possible
Method	`CheckNicHotAddSupport`	Check if NIC hotplug is possible
Method	`connect`	Connects to the QMP monitor.
Method	`ContinueGuestEmulation`	Continue the previously paused guest
Method	`Execute`	Executes a QMP command and returns the response of the server.
Method	`GetCpuInformation`	Retrieve CPU/thread information uses the query-cpus-fast which does not interrupt the guest
Method	`GetFreePCISlot`	Get the first available PCI slot of a running instance.
Method	`GetMigrationStatus`	Retrieve the current migration status
Method	`GetVersion`	Return the QMP/qemu version field
Method	`HasDevice`	Check if a specific device exists or not on a running instance.
Method	`HasDynamicAutoReadOnly`	Check if QEMU uses dynamic auto-read-only for block devices
Method	`HotAddDisk`	Hot-add a disk
Method	`HotAddNic`	Hot-add a NIC
Method	`HotDelDisk`	Hot-del a Disk
Method	`HotDelNic`	Hot-del a NIC
Method	`Powerdown`	Undocumented
Method	`SetBalloonMemory`	Undocumented
Method	`SetMigrationCapabilities`	Configure live migration capabilities
Method	`SetMigrationParameters`	Configute live migration parameters
Method	`SetSpicePassword`	Set Spice password of an instance
Method	`SetVNCPassword`	Set VNC password of an instance
Method	`StartMigration`	Start migration of an instance
Method	`StartPostcopyMigration`	Start postcopy-ram migration
Method	`StopGuestEmulation`	Pause the running guest
Constant	`ACTUAL_KEY`	Undocumented
Instance Variable	`package`	Undocumented
Instance Variable	`supported_commands`	Undocumented
Instance Variable	`version`	Undocumented
Method	`_AddFd`	Wrapper around add-fd qmp command
Method	`_filter_hvinfo`	Filter non valid keys of the device's hvinfo (if any).
Method	`_GetBlockDevices`	Get the block devices of a running instance.
Method	`_GetFd`	Wrapper around the getfd qmp command
Method	`_GetPCIDevices`	Get the devices of the first PCI bus of a running instance.
Method	`_GetResponse`	Parse the QMP response
Method	`_GetSupportedCommands`	Update the list of supported commands.
Method	`_HasBlockDevice`	Check if a specific device ID exists among block devices.
Method	`_HasPCIDevice`	Check if a specific device ID exists on the PCI bus.
Method	`_ParseMessage`	Extract and parse a QMP message from the given buffer.
Method	`_Recv`	Receives a message from QMP and decodes the received JSON object.
Method	`_RemoveFdset`	Wrapper around remove-fd qmp command
Method	`_Send`	Encodes and sends a message to KVM using QMP.
Constant	`_ACTUAL_KEY`	Undocumented
Constant	`_ARGUMENTS_KEY`	Undocumented
Constant	`_CAPABILITIES_COMMAND`	Undocumented
Constant	`_DEVICE_ATTRIBUTES`	Undocumented
Constant	`_ERROR_CLASS_KEY`	Undocumented
Constant	`_ERROR_DESC_KEY`	Undocumented
Constant	`_ERROR_KEY`	Undocumented
Constant	`_EVENT_KEY`	Undocumented
Constant	`_EXECUTE_KEY`	Undocumented
Constant	`_FIRST_MESSAGE_KEY`	Undocumented
Constant	`_MESSAGE_END_TOKEN`	Undocumented
Constant	`_PACKAGE_KEY`	Undocumented
Constant	`_QEMU_KEY`	Undocumented
Constant	`_QUERY_COMMANDS`	Undocumented
Constant	`_RETURN_KEY`	Undocumented
Constant	`_VERSION_KEY`	Undocumented
Instance Variable	`_buf`	Undocumented
Instance Variable	`_connected`	Undocumented

Inherited from MonitorSocket:

Method	`close`	Closes the socket
Method	`is_connected`	Return whether there is a connection to the socket or not.
Instance Variable	`monitor_filename`	Undocumented
Instance Variable	`sock`	Undocumented
Method	`_check_connection`	Make sure that the connection is established.
Method	`_check_socket`	Undocumented
Method	`_close`	Undocumented
Method	`_connect`	Connects to the monitor.
Constant	`_SOCKET_TIMEOUT`	Undocumented

def __enter__(self): ¶

Undocumented

def __exit__(self, exc_type, exc_value, tb): ¶

Undocumented

def __init__(self, monitor_filename): ¶

overrides ganeti.hypervisor.hv_kvm.monitor.MonitorSocket.__init__

Instantiates the MonitorSocket object.

Parameters
monitor_filename:string	the filename of the UNIX raw socket on which the monitor (QMP or simple one) is listening

@_ensure_connection
def CheckDiskHotAddSupport(self): ¶

Check if disk hotplug is possible

Hotplug is *not* supported in case the add-fd and blockdev-add qmp commands are not supported

@_ensure_connection
def CheckNicHotAddSupport(self): ¶

Check if NIC hotplug is possible

Hotplug is *not* supported in case the getfd and netdev_add qmp commands are not supported

def connect(self): ¶

overrides ganeti.hypervisor.hv_kvm.monitor.MonitorSocket.connect

Connects to the QMP monitor.

Connects to the UNIX socket and makes sure that we can actually send and receive data to the kvm instance via QMP.

Raises
`errors.HypervisorError`	when there are communication errors
`errors.ProgrammerError`	when there are data serialization errors

@_ensure_connection
def ContinueGuestEmulation(self): ¶

Continue the previously paused guest

def Execute(self, command, arguments=None): ¶

Executes a QMP command and returns the response of the server.

Parameters
command:str	the command to execute
arguments:dict	dictionary of arguments to be passed to the command
Returns
dict	dictionary representing the received JSON object
Raises
`errors.HypervisorError`	when there are communication errors
`errors.ProgrammerError`	when there are data serialization errors

@_ensure_connection
def GetCpuInformation(self): ¶

Retrieve CPU/thread information uses the query-cpus-fast which does not interrupt the guest

@_ensure_connection
def GetFreePCISlot(self): ¶

Get the first available PCI slot of a running instance.

@_ensure_connection
def GetMigrationStatus(self): ¶

Retrieve the current migration status

@_ensure_connection
def GetVersion(self): ¶

Return the QMP/qemu version field

Accessing the version attribute directly might result in an error since the socket might not be yet connected. This getter method uses the @_ensure_connection decorator to work around this problem.

@_ensure_connection
def HasDevice(self, devid): ¶

Check if a specific device exists or not on a running instance.

It first checks the PCI devices and then the block devices.

@_ensure_connection
def HasDynamicAutoReadOnly(self): ¶

Check if QEMU uses dynamic auto-read-only for block devices

Use QMP schema introspection (QEMU 2.5+) to check for the dynamic-auto-read-only feature.

@_ensure_connection
def HotAddDisk(self, disk, devid, uri, drive_add_fn=None): ¶

Hot-add a disk

Try opening the device to obtain a fd and pass it with SCM_RIGHTS. This will be omitted in case of userspace access mode (open will fail). Then use blockdev-add QMP command or drive_add_fn() callback if any. The add the guest device.

@_ensure_connection
def HotAddNic(self, nic, devid, tapfds=None, vhostfds=None, features=None, is_chrooted=False): ¶

Hot-add a NIC

First pass the tapfds, then netdev_add and then device_add

@_ensure_connection
def HotDelDisk(self, devid): ¶

Hot-del a Disk

Note that drive_del is not supported yet in qmp and thus should be invoked from HMP.

@_ensure_connection
def HotDelNic(self, devid): ¶

Hot-del a NIC

@_ensure_connection
def Powerdown(self): ¶

Undocumented

@_ensure_connection
def SetBalloonMemory(self, memory): ¶

Undocumented

@_ensure_connection
def SetMigrationCapabilities(self, capabilities, state): ¶

Configure live migration capabilities

@_ensure_connection
def SetMigrationParameters(self, max_bandwidth, downtime_limit): ¶

Configute live migration parameters

@_ensure_connection
def SetSpicePassword(self, spice_pwd): ¶

Set Spice password of an instance

@_ensure_connection
def SetVNCPassword(self, vnc_pwd): ¶

Set VNC password of an instance

@_ensure_connection
def StartMigration(self, target, port): ¶

Start migration of an instance

@_ensure_connection
def StartPostcopyMigration(self): ¶

Start postcopy-ram migration

@_ensure_connection
def StopGuestEmulation(self): ¶

Pause the running guest

ACTUAL_KEY: str = ¶

Undocumented

Value

'actual'

package = ¶

Undocumented

supported_commands = ¶

Undocumented

version = ¶

Undocumented

def _AddFd(self, fd): ¶

Wrapper around add-fd qmp command

Send fd to a running process via SCM_RIGHTS and then add-fd qmp command to add it to an fdset so that it can be used later by disk hotplugging.

Parameters
fd:int	The file descriptor to pass
Returns
The fdset ID that the fd has been added to
Raises
`errors.HypervisorError`	If add-fd fails for some reason

def _filter_hvinfo(self, hvinfo): ¶

Filter non valid keys of the device's hvinfo (if any).

def _GetBlockDevices(self): ¶

Get the block devices of a running instance.

The query-block QMP command returns a list of dictionaries including information for each virtual disk. For example:

[{"device": "disk-049f140d", "inserted": {"file": ..., "image": ...}}]

Returns
list of dicts	Info about the virtual disks of the instance.

def _GetFd(self, fd, fdname): ¶

Wrapper around the getfd qmp command

Send an fd to a running process via SCM_RIGHTS and then use the getfd qmp command to name it properly so that it can be used later by NIC hotplugging.

Parameters
fd:int	The file descriptor to pass
fdname	Undocumented
Raises
`errors.HypervisorError`	If getfd fails for some reason

def _GetPCIDevices(self): ¶

Get the devices of the first PCI bus of a running instance.

def _GetResponse(self, command): ¶

Parse the QMP response

If error key found in the response message raise HypervisorError. Ignore any async event and thus return the response message related to command.

def _GetSupportedCommands(self): ¶

Update the list of supported commands.

def _HasBlockDevice(self, devid): ¶

Check if a specific device ID exists among block devices.

def _HasPCIDevice(self, devid): ¶

Check if a specific device ID exists on the PCI bus.

def _ParseMessage(self, buf): ¶

Extract and parse a QMP message from the given buffer.

Seeks for a QMP message in the given buf. If found, it parses it and returns it together with the rest of the characters in the buf. If no message is found, returns None and the whole buffer.

Raises
`errors.ProgrammerError`	when there are data serialization errors

def _Recv(self): ¶

Receives a message from QMP and decodes the received JSON object.

Returns
QmpMessage	the received message
Raises
`errors.HypervisorError`	when there are communication errors
`errors.ProgrammerError`	when there are data serialization errors

def _RemoveFdset(self, fdset): ¶

Wrapper around remove-fd qmp command

Remove the file descriptor previously passed. After qemu has dup'd the fd (e.g. during disk hotplug), it can be safely removed.

def _Send(self, message): ¶

Encodes and sends a message to KVM using QMP.

Parameters
message:QmpMessage	message to send to KVM
Raises
`errors.HypervisorError`	when there are communication errors
`errors.ProgrammerError`	when there are data serialization errors

_ACTUAL_KEY: str = ¶

Undocumented

Value

'actual'

_ARGUMENTS_KEY: str = ¶

Undocumented

Value

'arguments'

_CAPABILITIES_COMMAND: str = ¶

Undocumented

Value

'qmp_capabilities'

_DEVICE_ATTRIBUTES: list[str] = ¶

Undocumented

Value

['driver', 'id', 'bus', 'addr', 'channel', 'scsi-id', 'lun']

_ERROR_CLASS_KEY: str = ¶

Undocumented

Value

'class'

_ERROR_DESC_KEY: str = ¶

Undocumented

Value

'desc'

_ERROR_KEY: str = ¶

Undocumented

Value

'error'

_EVENT_KEY: str = ¶

Undocumented

Value

'event'

_EXECUTE_KEY: str = ¶

Undocumented

Value

'execute'

_FIRST_MESSAGE_KEY: str = ¶

Undocumented

Value

'QMP'

_MESSAGE_END_TOKEN: bytes = ¶

Undocumented

Value

b'''\r
'''

_PACKAGE_KEY: str = ¶

Undocumented

Value

'package'

_QEMU_KEY: str = ¶

Undocumented

Value

'qemu'

_QUERY_COMMANDS: str = ¶

Undocumented

Value

'query-commands'

_RETURN_KEY: str = ¶

Undocumented

Value

'return'

_VERSION_KEY: str = ¶

Undocumented

Value

'version'

_buf = ¶

Undocumented

_connected: bool = ¶

overrides ganeti.hypervisor.hv_kvm.monitor.MonitorSocket._connected

Undocumented