def setup_qemu_values(initial_setup=True):
"""Sets up and runs a QEMU VM in the background.
Returns a process.Popen object.
Does not block the calling process, and teardown must be handled by the
caller (use .kill()).
Fuchsia fuzzers assume a QEMU VM is running; call this routine prior to
beginning Fuchsia fuzzing tasks.
This initialization routine assumes the following layout for
fuchsia_resources_dir:
* /qemu-for-fuchsia/*
* /.ssh/*
* target/x64/fvm.blk
* target/x64/fuchsia.zbi
* target/x64/multiboot.bin
* build/out/default/fuzzers.json
* build/out/default/ids.txt
* build/out/default.zircon/tools/*
* build/zircon/prebuilt/downloads/symbolize
* build/buildtools/linux-x64/clang/bin/llvm-symbolizer"""
# First download the Fuchsia resources locally.
fuchsia_resources_dir = environment.get_value('FUCHSIA_RESOURCES_DIR')
if not fuchsia_resources_dir:
raise errors.FuchsiaConfigError('Could not find FUCHSIA_RESOURCES_DIR')
# Then, save paths for necessary commands later.
qemu_path = os.path.join(fuchsia_resources_dir, 'qemu-for-fuchsia', 'bin',
'qemu-system-x86_64')
os.chmod(qemu_path, 0o550)
kernel_path = os.path.join(fuchsia_resources_dir, 'target', 'x64',
'multiboot.bin')
os.chmod(kernel_path, 0o644)
pkey_path = os.path.join(fuchsia_resources_dir, '.ssh', 'pkey')
os.chmod(pkey_path, 0o400)
sharefiles_path = os.path.join(fuchsia_resources_dir, 'qemu-for-fuchsia',
'share', 'qemu')
drive_path = os.path.join(fuchsia_resources_dir, 'target', 'x64', 'fvm.blk')
os.chmod(drive_path, 0o644)
fuchsia_zbi = os.path.join(fuchsia_resources_dir, 'target', 'x64',
'fuchsia.zbi')
initrd_path = os.path.join(fuchsia_resources_dir, 'fuchsia-ssh.zbi')
# Perform some more initiailization steps.
# Only do these the first time you run QEMU after downloading the build.
if initial_setup:
extend_fvm(fuchsia_resources_dir, drive_path)
add_keys_to_zbi(fuchsia_resources_dir, initrd_path, fuchsia_zbi)
# Get a free port for the VM, so we can SSH in later.
tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcp.bind(('localhost', 0))
_, port = tcp.getsockname()
tcp.close()
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value('FUCHSIA_PORTNUM', port)
environment.set_value('FUCHSIA_RESOURCES_DIR', fuchsia_resources_dir)
# yapf: disable
qemu_args = [
'-m', '2048',
'-nographic',
'-kernel', kernel_path,
'-initrd', initrd_path,
'-smp', '4',
'-drive', 'file=' + drive_path + ',format=raw,if=none,id=blobstore',
'-device', 'virtio-blk-pci,drive=blobstore',
'-monitor', 'none',
'-append', '"kernel.serial=legacy TERM=dumb"',
'-machine', 'q35',
'-display', 'none',
'-netdev',
('user,id=net0,net=192.168.3.0/24,dhcpstart=192.168.3.9,'
'host=192.168.3.2,hostfwd=tcp::') + str(port) + '-:22',
'-device', 'e1000,netdev=net0,mac=52:54:00:63:5e:7b',
'-L', sharefiles_path
]
# yapf: enable
# Detecing KVM is tricky, so use an environment variable to determine whether
# to turn it on or not.
if environment.get_value('FUCHSIA_USE_KVM'):
qemu_args.extend(['-cpu', 'host,migratable=no'])
qemu_args.append('-enable-kvm')
else:
# Can't use host CPU since we don't necessarily have KVM on the machine.
# Emulate a Haswell CPU with a few feature toggles. This mirrors the most
# common configuration for Fuchsia VMs when using in-tree tools.
qemu_args.extend(['-cpu', 'Haswell,+smap,-check,-fsgsbase'])
# Get the list of fuzzers for ClusterFuzz to choose from.
host = Host.from_dir(
os.path.join(fuchsia_resources_dir, 'build', 'out', 'default'))
Device(host, 'localhost', str(port))
Fuzzer.filter(host.fuzzers, '')
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value('FUCHSIA_PKEY_PATH', pkey_path)
return qemu_path, qemu_args
def create(self):
"""Configures a QEMU process which can subsequently be `run`.
Assumes that initial_qemu_setup was already called exactly once.
"""
qemu_vars = _fetch_qemu_vars()
# Get a free port for the VM, so we can SSH in later.
tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcp.bind(('localhost', 0))
_, port = tcp.getsockname()
tcp.close()
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value('FUCHSIA_PORTNUM', port)
environment.set_value('FUCHSIA_RESOURCES_DIR',
qemu_vars['fuchsia_resources_dir'])
# yapf: disable
qemu_args = [
'-m', '3072',
'-nographic',
'-kernel', qemu_vars['kernel_path'],
'-initrd', qemu_vars['initrd_path'],
'-smp', '4',
'-drive',
('file=' + qemu_vars['drive_path'] + ',format=raw,if=none,'
'id=blobstore'),
'-device', 'virtio-blk-pci,drive=blobstore',
'-monitor', 'none',
'-append', 'kernel.serial=legacy TERM=dumb',
'-machine', 'q35',
'-display', 'none',
'-netdev',
('user,id=net0,net=192.168.3.0/24,dhcpstart=192.168.3.9,'
'host=192.168.3.2,hostfwd=tcp::') + str(port) + '-:22',
'-device', 'e1000,netdev=net0,mac=52:54:00:63:5e:7b',
'-L', qemu_vars['sharefiles_path']
]
# yapf: enable
# Detecting KVM is tricky, so use an environment variable to determine
# whether to turn it on or not.
if environment.get_value('FUCHSIA_USE_KVM'):
# In builds before fxrev.dev/375343, a bug prevents booting with newer
# versions of KVM. On some of these older builds,
# `kernel.x86.disable-spec-mitigations` also doesn't work as
# expected, so we work around this by selecting a CPU type where the
# speculation mitigation will not applied.
if environment.get_value('APP_REVISION') < 20200414210423:
qemu_args.extend(['-cpu', 'Opteron_G5,+invtsc'])
else:
qemu_args.extend(['-cpu', 'host,migratable=no,+invtsc'])
qemu_args.append('-enable-kvm')
else:
# Can't use host CPU since we don't necessarily have KVM on the machine.
# Emulate a Haswell CPU with a few feature toggles. This mirrors the most
# common configuration for Fuchsia VMs when using in-tree tools.
qemu_args.extend(['-cpu', 'Haswell,+smap,-check,-fsgsbase'])
# Get the list of fuzzers for ClusterFuzz to choose from.
host = Host.from_dir(
os.path.join(qemu_vars['fuchsia_resources_dir'], 'build', 'out',
'default'))
Device(host, 'localhost', str(port))
Fuzzer.filter(host.fuzzers, '')
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value('FUCHSIA_PKEY_PATH', qemu_vars['pkey_path'])
logs.log('Ready to run QEMU. Command: ' + qemu_vars['qemu_path'] +
' ' + ' '.join(shlex.quote(arg) for arg in qemu_args))
self.process_runner = new_process.ProcessRunner(
qemu_vars['qemu_path'], qemu_args)
def create(self):
"""Configures a QEMU process which can subsequently be `run`.
Assumes that initial_qemu_setup was already called exactly once.
"""
qemu_vars = _fetch_qemu_vars()
# Get a free port for the VM, so we can SSH in later.
tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcp.bind(("localhost", 0))
_, port = tcp.getsockname()
tcp.close()
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value("FUCHSIA_PORTNUM", port)
environment.set_value("FUCHSIA_RESOURCES_DIR",
qemu_vars["fuchsia_resources_dir"])
# yapf: disable
qemu_args = [
'-m', '3072',
'-nographic',
'-kernel', qemu_vars['kernel_path'],
'-initrd', qemu_vars['initrd_path'],
'-smp', '4',
'-drive',
('file=' + qemu_vars['drive_path'] + ',format=raw,if=none,'
'id=blobstore'),
'-device', 'virtio-blk-pci,drive=blobstore',
'-monitor', 'none',
'-append', 'kernel.serial=legacy TERM=dumb',
'-machine', 'q35',
'-display', 'none',
'-netdev',
('user,id=net0,net=192.168.3.0/24,dhcpstart=192.168.3.9,'
'host=192.168.3.2,hostfwd=tcp::') + str(port) + '-:22',
'-device', 'e1000,netdev=net0,mac=52:54:00:63:5e:7b',
'-L', qemu_vars['sharefiles_path']
]
# yapf: enable
# Detecing KVM is tricky, so use an environment variable to determine
# whether to turn it on or not.
if environment.get_value("FUCHSIA_USE_KVM"):
qemu_args.extend(["-cpu", "host,migratable=no"])
qemu_args.append("-enable-kvm")
else:
# Can't use host CPU since we don't necessarily have KVM on the machine.
# Emulate a Haswell CPU with a few feature toggles. This mirrors the most
# common configuration for Fuchsia VMs when using in-tree tools.
qemu_args.extend(["-cpu", "Haswell,+smap,-check,-fsgsbase"])
# Get the list of fuzzers for ClusterFuzz to choose from.
host = Host.from_dir(
os.path.join(qemu_vars["fuchsia_resources_dir"], "build", "out",
"default"))
Device(host, "localhost", str(port))
Fuzzer.filter(host.fuzzers, "")
# Fuzzing jobs that SSH into the QEMU VM need access to this env var.
environment.set_value("FUCHSIA_PKEY_PATH", qemu_vars["pkey_path"])
logs.log("Ready to run QEMU. Command: " + qemu_vars["qemu_path"] +
" " + str(qemu_args))
self.process_runner = new_process.ProcessRunner(
qemu_vars["qemu_path"], qemu_args)