# 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