Package ganeti :: Package hypervisor :: Module hv_kvm
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Module hv_kvm

source code

KVM hypervisor

Classes [hide private]
QEMU Messaging Protocol (QMP) message.
Connection to the QEMU Monitor using the QEMU Monitor Protocol (QMP).
KVM hypervisor interface
Functions [hide private]
Check whether to enable the IFF_VNET_HDR flag.
source code
Open a new tap device and return its file descriptor.
source code
Variables [hide private]
  affinity = None
  _KVM_NETWORK_SCRIPT = constants.SYSCONFDIR+ "/ganeti/kvm-vif-b...
  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 [hide private]


source code 

Check whether to enable the IFF_VNET_HDR flag.

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

  1. TUNGETFEATURES ioctl() *must* be implemented
  2. TUNGETFEATURES ioctl() result *must* contain the IFF_VNET_HDR flag
  3. 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.
  • fd (int) - the file descriptor of /dev/net/tun


source code 

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.

  • vnet_hdr (boolean) - Enable the VNET Header
Returns: tuple
(ifname, tapfd)

Variables Details [hide private]


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