Source code
Revision control
Copy as Markdown
Other Tools
# Copyright 2018 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Implements commands for running and interacting with Fuchsia on QEMU."""
import boot_data
import common
import emu_target
import hashlib
import logging
import os
import platform
import qemu_image
import shutil
import subprocess
import sys
import tempfile
from common import GetHostArchFromPlatform, GetEmuRootForPlatform
from common import EnsurePathExists
from qemu_image import ExecQemuImgWithRetry
from target import FuchsiaTargetException
# Virtual networking configuration data for QEMU.
HOST_IP_ADDRESS = '10.0.2.2'
GUEST_MAC_ADDRESS = '52:54:00:63:5e:7b'
# Capacity of the system's blobstore volume.
EXTENDED_BLOBSTORE_SIZE = 1073741824 # 1GB
def GetTargetType():
return QemuTarget
class QemuTarget(emu_target.EmuTarget):
EMULATOR_NAME = 'qemu'
def __init__(self, out_dir, target_cpu, system_log_file, cpu_cores,
require_kvm, ram_size_mb):
super(QemuTarget, self).__init__(out_dir, target_cpu, system_log_file)
self._cpu_cores=cpu_cores
self._require_kvm=require_kvm
self._ram_size_mb=ram_size_mb
@staticmethod
def CreateFromArgs(args):
return QemuTarget(args.out_dir, args.target_cpu, args.system_log_file,
args.cpu_cores, args.require_kvm, args.ram_size_mb)
def _IsKvmEnabled(self):
kvm_supported = sys.platform.startswith('linux') and \
os.access('/dev/kvm', os.R_OK | os.W_OK)
same_arch = \
(self._target_cpu == 'arm64' and platform.machine() == 'aarch64') or \
(self._target_cpu == 'x64' and platform.machine() == 'x86_64')
if kvm_supported and same_arch:
return True
elif self._require_kvm:
if same_arch:
if not os.path.exists('/dev/kvm'):
kvm_error = 'File /dev/kvm does not exist. Please install KVM first.'
else:
kvm_error = 'To use KVM acceleration, add user to the kvm group '\
'with "sudo usermod -a -G kvm $USER". Log out and back '\
'in for the change to take effect.'
raise FuchsiaTargetException(kvm_error)
else:
raise FuchsiaTargetException('KVM unavailable when CPU architecture '\
'of host is different from that of'\
' target. See --allow-no-kvm.')
else:
return False
def _BuildQemuConfig(self):
boot_data.AssertBootImagesExist(self._GetTargetSdkArch(), 'qemu')
emu_command = [
'-kernel',
EnsurePathExists(
boot_data.GetTargetFile('qemu-kernel.kernel',
self._GetTargetSdkArch(),
boot_data.TARGET_TYPE_QEMU)),
'-initrd',
EnsurePathExists(
boot_data.GetBootImage(self._out_dir, self._GetTargetSdkArch(),
boot_data.TARGET_TYPE_QEMU)),
'-m',
str(self._ram_size_mb),
'-smp',
str(self._cpu_cores),
# Attach the blobstore and data volumes. Use snapshot mode to discard
# any changes.
'-snapshot',
'-drive',
'file=%s,format=qcow2,if=none,id=blobstore,snapshot=on' %
_EnsureBlobstoreQcowAndReturnPath(self._out_dir,
self._GetTargetSdkArch()),
'-device',
'virtio-blk-pci,drive=blobstore',
# Use stdio for the guest OS only; don't attach the QEMU interactive
# monitor.
'-serial',
'stdio',
'-monitor',
'none',
]
# Configure the machine to emulate, based on the target architecture.
if self._target_cpu == 'arm64':
emu_command.extend([
'-machine','virt,gic_version=3',
])
else:
emu_command.extend([
'-machine', 'q35',
])
# Configure virtual network.
netdev_type = 'virtio-net-pci'
netdev_config = 'type=user,id=net0,restrict=off'
self._host_ssh_port = common.GetAvailableTcpPort()
netdev_config += ",hostfwd=tcp::%s-:22" % self._host_ssh_port
emu_command.extend([
'-netdev', netdev_config,
'-device', '%s,netdev=net0,mac=%s' % (netdev_type, GUEST_MAC_ADDRESS),
])
# Configure the CPU to emulate.
# On Linux, we can enable lightweight virtualization (KVM) if the host and
# guest architectures are the same.
if self._IsKvmEnabled():
kvm_command = ['-enable-kvm', '-cpu']
if self._target_cpu == 'arm64':
kvm_command.append('host')
else:
kvm_command.append('host,migratable=no,+invtsc')
else:
logging.warning('Unable to launch %s with KVM acceleration. '
'The guest VM will be slow.' % (self.EMULATOR_NAME))
if self._target_cpu == 'arm64':
kvm_command = ['-cpu', 'cortex-a53']
else:
kvm_command = ['-cpu', 'Haswell,+smap,-check,-fsgsbase']
emu_command.extend(kvm_command)
kernel_args = boot_data.GetKernelArgs(self._out_dir)
# TERM=dumb tells the guest OS to not emit ANSI commands that trigger
# noisy ANSI spew from the user's terminal emulator.
kernel_args.append('TERM=dumb')
# Construct kernel cmd line
kernel_args.append('kernel.serial=legacy')
# Don't 'reboot' the emulator if the kernel crashes
kernel_args.append('kernel.halt-on-panic=true')
emu_command.extend(['-append', ' '.join(kernel_args)])
return emu_command
def _BuildCommand(self):
if self._target_cpu == 'arm64':
qemu_exec = 'qemu-system-' + 'aarch64'
elif self._target_cpu == 'x64':
qemu_exec = 'qemu-system-' + 'x86_64'
else:
raise Exception('Unknown target_cpu %s:' % self._target_cpu)
qemu_command = [
os.path.join(GetEmuRootForPlatform(self.EMULATOR_NAME), 'bin',
qemu_exec)
]
qemu_command.extend(self._BuildQemuConfig())
qemu_command.append('-nographic')
return qemu_command
def _ComputeFileHash(filename):
hasher = hashlib.md5()
with open(filename, 'rb') as f:
buf = f.read(4096)
while buf:
hasher.update(buf)
buf = f.read(4096)
return hasher.hexdigest()
def _EnsureBlobstoreQcowAndReturnPath(out_dir, target_arch):
"""Returns a file containing the Fuchsia blobstore in a QCOW format,
with extra buffer space added for growth."""
qimg_tool = os.path.join(common.GetEmuRootForPlatform('qemu'),
'bin', 'qemu-img')
fvm_tool = common.GetHostToolPathFromPlatform('fvm')
blobstore_path = boot_data.GetTargetFile('storage-full.blk', target_arch,
'qemu')
qcow_path = os.path.join(out_dir, 'gen', 'blobstore.qcow')
# Check a hash of the blobstore to determine if we can re-use an existing
# extended version of it.
blobstore_hash_path = os.path.join(out_dir, 'gen', 'blobstore.hash')
current_blobstore_hash = _ComputeFileHash(blobstore_path)
if os.path.exists(blobstore_hash_path) and os.path.exists(qcow_path):
if current_blobstore_hash == open(blobstore_hash_path, 'r').read():
return qcow_path
# Add some extra room for growth to the Blobstore volume.
# Fuchsia is unable to automatically extend FVM volumes at runtime so the
# volume enlargement must be performed prior to QEMU startup.
# The 'fvm' tool only supports extending volumes in-place, so make a
# temporary copy of 'blobstore.bin' before it's mutated.
extended_blobstore = tempfile.NamedTemporaryFile()
shutil.copyfile(blobstore_path, extended_blobstore.name)
subprocess.check_call([fvm_tool, extended_blobstore.name, 'extend',
'--length', str(EXTENDED_BLOBSTORE_SIZE),
blobstore_path])
# Construct a QCOW image from the extended, temporary FVM volume.
# The result will be retained in the build output directory for re-use.
qemu_img_cmd = [qimg_tool, 'convert', '-f', 'raw', '-O', 'qcow2',
'-c', extended_blobstore.name, qcow_path]
# TODO(crbug.com/1046861): Remove arm64 call with retries when bug is fixed.
if common.GetHostArchFromPlatform() == 'arm64':
qemu_image.ExecQemuImgWithRetry(qemu_img_cmd)
else:
subprocess.check_call(qemu_img_cmd)
# Write out a hash of the original blobstore file, so that subsequent runs
# can trivially check if a cached extended FVM volume is available for reuse.
with open(blobstore_hash_path, 'w') as blobstore_hash_file:
blobstore_hash_file.write(current_blobstore_hash)
return qcow_path