5c02c86586
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>
85 lines
2.3 KiB
Python
85 lines
2.3 KiB
Python
"""
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QEMU accel module:
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This module provides utilities for discover and check the availability of
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accelerators.
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"""
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# Copyright (C) 2015-2016 Red Hat Inc.
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# Copyright (C) 2012 IBM Corp.
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#
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# Authors:
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# Fam Zheng <famz@redhat.com>
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#
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# This work is licensed under the terms of the GNU GPL, version 2. See
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# the COPYING file in the top-level directory.
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#
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import logging
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import os
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import subprocess
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from typing import List, Optional
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LOG = logging.getLogger(__name__)
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# Mapping host architecture to any additional architectures it can
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# support which often includes its 32 bit cousin.
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ADDITIONAL_ARCHES = {
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"x86_64": "i386",
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"aarch64": "armhf",
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"ppc64le": "ppc64",
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}
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def list_accel(qemu_bin: str) -> List[str]:
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"""
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List accelerators enabled in the QEMU binary.
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@param qemu_bin (str): path to the QEMU binary.
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@raise Exception: if failed to run ``qemu -accel help``
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@return a list of accelerator names.
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"""
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if not qemu_bin:
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return []
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try:
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out = subprocess.check_output([qemu_bin, '-accel', 'help'],
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universal_newlines=True)
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except:
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LOG.debug("Failed to get the list of accelerators in %s", qemu_bin)
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raise
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# Skip the first line which is the header.
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return [acc.strip() for acc in out.splitlines()[1:]]
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def kvm_available(target_arch: Optional[str] = None,
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qemu_bin: Optional[str] = None) -> bool:
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"""
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Check if KVM is available using the following heuristic:
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- Kernel module is present in the host;
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- Target and host arches don't mismatch;
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- KVM is enabled in the QEMU binary.
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@param target_arch (str): target architecture
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@param qemu_bin (str): path to the QEMU binary
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@return True if kvm is available, otherwise False.
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"""
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if not os.access("/dev/kvm", os.R_OK | os.W_OK):
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return False
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if target_arch:
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host_arch = os.uname()[4]
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if target_arch != host_arch:
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if target_arch != ADDITIONAL_ARCHES.get(host_arch):
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return False
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if qemu_bin and "kvm" not in list_accel(qemu_bin):
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return False
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return True
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def tcg_available(qemu_bin: str) -> bool:
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"""
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Check if TCG is available.
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@param qemu_bin (str): path to the QEMU binary
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"""
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return 'tcg' in list_accel(qemu_bin)
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