Module hv_kvm

KVM hypervisor

Classes

QmpMessage
QEMU Messaging Protocol (QMP) message.

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

KVMHypervisor
KVM hypervisor interface

Functions

_ProbeTapVnetHdr(fd)
Check whether to enable the IFF_VNET_HDR flag.

source code

tuple

_OpenTap(vnet_hdr=True)
Open a new tap device and return its file descriptor.

source code

Variables

affinity = None

_KVM_NETWORK_SCRIPT = constants.SYSCONFDIR+ "/ganeti/kvm-vif-b...

_KVM_START_PAUSED_FLAG = "-S"

TUNSETIFF = 0x400454ca

TUNGETIFF = 0x800454d2

TUNGETFEATURES = 0x800454cf

IFF_TAP = 0x0002

IFF_NO_PI = 0x1000

IFF_VNET_HDR = 0x4000

Imports: errno, os, re, tempfile, time, logging, pwd, struct, fcntl, shutil, socket, stat, StringIO, utils, constants, errors, serializer, objects, uidpool, ssconf, hv_base, netutils, utils_wrapper

Function Details

Check whether to enable the IFF_VNET_HDR flag.

To do this, _all_ of the following conditions must be met:

TUNGETFEATURES ioctl() *must* be implemented
TUNGETFEATURES ioctl() result *must* contain the IFF_VNET_HDR flag
TUNGETIFF ioctl() *must* be implemented; reading the kernel code in drivers/net/tun.c there is no way to test this until after the tap device has been created using TUNSETIFF, and there is no way to change the IFF_VNET_HDR flag after creating the interface, catch-22! However both TUNGETIFF and TUNGETFEATURES were introduced in kernel version 2.6.27, thus we can expect TUNGETIFF to be present if TUNGETFEATURES is.

Parameters:

Open a new tap device and return its file descriptor.

This is intended to be used by a qemu-type hypervisor together with the -net tap,fd=<fd> command line parameter.

Parameters:

Returns: tuple

(ifname, tapfd)

Variables Details

Value:

constants.SYSCONFDIR+ "/ganeti/kvm-vif-bridge"