qemu-patch-raspberry4/python/qemu/utils/accel.py
John Snow 5c02c86586 python: Fix broken ReST docstrings
This patch *doesn't* update all of the docstring standards across the
QEMU package directory to make our docstring usage consistent. It
*doesn't* fix the formatting to make it look pretty or reasonable in
generated output. It *does* fix a few small instances where Sphinx would
emit a build warning because of malformed ReST -- If we built our Python
docs with Sphinx.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-id: 20210629214323.1329806-16-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2021-06-30 21:57:08 -04:00

85 lines
2.3 KiB
Python

"""
QEMU accel module:
This module provides utilities for discover and check the availability of
accelerators.
"""
# Copyright (C) 2015-2016 Red Hat Inc.
# Copyright (C) 2012 IBM Corp.
#
# Authors:
# Fam Zheng <famz@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2. See
# the COPYING file in the top-level directory.
#
import logging
import os
import subprocess
from typing import List, Optional
LOG = logging.getLogger(__name__)
# Mapping host architecture to any additional architectures it can
# support which often includes its 32 bit cousin.
ADDITIONAL_ARCHES = {
"x86_64": "i386",
"aarch64": "armhf",
"ppc64le": "ppc64",
}
def list_accel(qemu_bin: str) -> List[str]:
"""
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: Optional[str] = None,
qemu_bin: Optional[str] = None) -> bool:
"""
Check if KVM is available using the following heuristic:
- Kernel module is present in the host;
- Target and host arches don't mismatch;
- KVM is enabled in the QEMU binary.
@param target_arch (str): target architecture
@param qemu_bin (str): path to the QEMU binary
@return True if kvm is available, otherwise False.
"""
if not os.access("/dev/kvm", os.R_OK | os.W_OK):
return False
if target_arch:
host_arch = os.uname()[4]
if target_arch != host_arch:
if target_arch != ADDITIONAL_ARCHES.get(host_arch):
return False
if qemu_bin and "kvm" not in list_accel(qemu_bin):
return False
return True
def tcg_available(qemu_bin: str) -> bool:
"""
Check if TCG is available.
@param qemu_bin (str): path to the QEMU binary
"""
return 'tcg' in list_accel(qemu_bin)