python/qemu: accel: Add list_accel() method

# the COPYING file in the top-level directory.

#

import logging

import os

import subprocess

LOG = logging.getLogger(__name__)

# Mapping host architecture to any additional architectures it can

# support which often includes its 32 bit cousin.

    "aarch64" : "armhf"

}

def list_accel(qemu_bin):

    """

    List accelerators enabled in the QEMU binary.

    @param qemu_bin (str): path to the QEMU binary.

    @raise Exception: if failed to run `qemu -accel help`

    @return a list of accelerator names.

    """

    if not qemu_bin:

        return []

    try:

        out = subprocess.check_output([qemu_bin, '-accel', 'help'],

                                      universal_newlines=True)

    except:

        LOG.debug("Failed to get the list of accelerators in %s", qemu_bin)

        raise

    # Skip the first line which is the header.

    return [acc.strip() for acc in out.splitlines()[1:]]

def kvm_available(target_arch=None):

    host_arch = os.uname()[4]

    if target_arch and target_arch != host_arch: