#!/usr/bin/env python3 import os import re import shlex import shutil import subprocess import sys import time import common defaults = { 'cpus': 1, 'debug_guest': False, 'debug_vm': False, 'eval': None, 'extra_emulator_args': [], 'exec_image': None, 'gem5_exe_args': '', 'gem5_readfile': '', 'gem5_restore': None, 'gem5_script': 'fs', 'graphic': False, 'initramfs': False, 'initrd': False, 'kernel_cli': None, 'kernel_cli_after_dash': None, 'eval_busybox': None, 'kgdb': False, 'kvm': False, 'memory': '256M', 'record': False, 'replay': False, 'terminal': False, 'tmux': False, 'tmux_args': '', 'trace': None, 'vnc': False, } def main(args, extra_args=None): global defaults args = common.resolve_args(defaults, args, extra_args) # Common qemu / gem5 logic. # nokaslr: # * https://unix.stackexchange.com/questions/397939/turning-off-kaslr-to-debug-linux-kernel-using-qemu-and-gdb # * https://stackoverflow.com/questions/44612822/unable-to-debug-kernel-with-qemu-gdb/49840927#49840927 # Turned on by default since v4.12 kernel_cli = 'console_msg_format=syslog nokaslr norandmaps panic=-1 printk.devkmsg=on printk.time=y rw' if args.kernel_cli is not None: kernel_cli += ' {}'.format(args.kernel_cli) kernel_cli_after_dash = '' extra_emulator_args = [] extra_qemu_args = [] if args.debug_vm: debug_vm = ['gdb', '-q', '-ex', 'start', '--args'] else: debug_vm = [] if args.debug_guest: extra_qemu_args.append('-S') if args.eval_busybox is not None: kernel_cli_after_dash += ' lkmc_eval_base64="{}"'.format(common.base64_encode(args.eval_busybox)) if args.kernel_cli_after_dash is not None: kernel_cli_after_dash += ' {}'.format(args.kernel_cli_after_dash) if args.kgdb: kernel_cli += ' kgdbwait' if args.vnc: vnc = ['-vnc', ':0'] else: vnc = [] if args.initrd or args.initramfs: ramfs = True else: ramfs = False if args.eval is not None: if ramfs: initarg = 'rdinit' else: initarg = 'init' kernel_cli += ' {}=/eval_base64.sh'.format(initarg) kernel_cli_after_dash += ' lkmc_eval="{}"'.format(common.base64_encode(args.eval)) if not args.graphic: if args.arch == 'x86_64': kernel_cli += ' console=ttyS0' extra_qemu_args.append('-nographic') if kernel_cli_after_dash: kernel_cli += " -{}".format(kernel_cli_after_dash) extra_env = {} if args.trace is None: do_trace = False # A dummy value that is already turned on by default and does not produce large output, # just to prevent QEMU from emitting a warning that '' is not valid. trace_type = 'pr_manager_run' else: do_trace = True trace_type = args.trace def raise_rootfs_not_found(): raise Exception('Root filesystem not found. Did you build it?\n' \ 'Tried to use: ' + common.disk_image) def raise_image_not_found(): raise Exception('Executable image not found. Did you build it?\n' \ 'Tried to use: ' + common.image) if common.image is None: raise Exception('Baremetal ELF file not found. Tried:\n' + '\n'.join(paths)) if args.gem5: if args.baremetal is None: if not os.path.exists(common.rootfs_raw_file): if not os.path.exists(common.qcow2_file): raise_rootfs_not_found() common.raw_to_qcow2(prebuilt=args.prebuilt, reverse=True) else: if not os.path.exists(common.gem5_fake_iso): os.makedirs(os.path.dirname(common.gem5_fake_iso), exist_ok=True) common.write_string_to_file(common.gem5_fake_iso, 'a' * 512) if not os.path.exists(common.image): # This is to run gem5 from a prebuilt download. if (not args.baremetal is None) or (not os.path.exists(common.linux_image)): raise_image_not_found() common.run_cmd([os.path.join(common.extract_vmlinux, common.linux_image)]) os.makedirs(os.path.dirname(common.gem5_readfile), exist_ok=True) common.write_string_to_file(common.gem5_readfile, args.gem5_readfile) memory = '{}B'.format(args.memory) gem5_exe_args = shlex.split(args.gem5_exe_args) if do_trace: gem5_exe_args.append('--debug-flags={}'.format(trace_type)) extra_env['M5_PATH'] = common.gem5_system_dir # https://stackoverflow.com/questions/52312070/how-to-modify-a-file-under-src-python-and-run-it-without-rebuilding-in-gem5/52312071#52312071 extra_env['M5_OVERRIDE_PY_SOURCE'] = 'true' cmd = ( debug_vm + [ common.executable, '--debug-file=trace.txt', ] + gem5_exe_args + [ '-d', common.m5out_dir ] ) if args.gem5_script == 'fs': # TODO port if args.gem5_restore is not None: cpt_dirs = common.gem_list_checkpoint_dirs() cpt_dir = cpt_dirs[-args.gem5_restore] extra_emulator_args.extend(['-r', str(sorted(cpt_dirs).index(cpt_dir) + 1)]) cmd += [ common.gem5_fs_file, '--disk-image', common.disk_image, '--kernel', common.image, '--mem-size', memory, '--num-cpus', str(args.cpus), '--script', common.gem5_readfile, ] if args.arch == 'x86_64': if args.kvm: cmd += ['--cpu-type', 'X86KvmCPU'] cmd += ['--command-line', 'earlyprintk=ttyS0 console=ttyS0 lpj=7999923 root=/dev/sda {}'.format(kernel_cli)] elif args.arch == 'arm' or args.arch == 'aarch64': # TODO why is it mandatory to pass mem= here? Not true for QEMU. # Anything smaller than physical blows up as expected, but why can't it auto-detect the right value? cmd += [ '--command-line', 'earlyprintk=pl011,0x1c090000 console=ttyAMA0 lpj=19988480 rw loglevel=8 mem={} root=/dev/sda {}'.format(memory, kernel_cli), '--dtb-filename', os.path.join(common.gem5_system_dir, 'arm', 'dt', 'armv{}_gem5_v1_{}cpu.dtb'.format(common.armv, args.cpus)), '--machine-type', common.machine, ] if not args.baremetal is None: cmd.append('--bare-metal') elif args.gem5_script == 'biglittle': if args.gem5_restore is not None: cpt_dir = common.gem_list_checkpoint_dirs()[-args.gem5_restore] extra_emulator_args.extend(['--restore-from', os.path.join(common.m5out_dir, cpt_dir)]) cmd += [ os.path.join(common.gem5_src_dir, 'configs', 'example', 'arm', 'fs_bigLITTLE.py'), '--big-cpus', '2', '--cpu-type', 'atomic', '--disk', common.disk_image, '--dtb', os.path.join(common.gem5_system_dir, 'arm', 'dt', 'armv8_gem5_v1_big_little_2_2.dtb'), '--kernel', common.image, '--little-cpus', '2' ] elif args.gem5_script == 'se': assert(args.exec_image is not None) cmd += [common.gem5_se_file, '-c', args.exec_image] else: if not os.path.exists(common.image): raise_image_not_found() extra_emulator_args.extend(extra_qemu_args) common.make_run_dirs() if args.prebuilt: qemu_executable = common.qemu_executable_basename qemu_found = shutil.which(qemu_executable) is not None else: qemu_executable = common.qemu_executable qemu_found = os.path.exists(qemu_executable) if not qemu_found: raise Exception('QEMU executable not found, did you forget to build or install it?\n' \ 'Tried to use: ' + qemu_executable) if args.debug_vm: serial_monitor = [] else: serial_monitor = ['-serial', 'mon:stdio'] if args.kvm: extra_emulator_args.append('-enable-kvm') if args.kgdb: extra_emulator_args.extend(['-serial', 'tcp::{},server,nowait'.format(common.gdb_port)]) cmd = ( debug_vm + [ qemu_executable, '-device', 'rtl8139,netdev=net0', '-gdb', 'tcp::{}'.format(common.gdb_port), '-kernel', common.image, '-m', args.memory, '-monitor', 'telnet::{},server,nowait'.format(common.qemu_monitor_port), '-netdev', 'user,hostfwd=tcp::{}-:{},hostfwd=tcp::{}-:22,id=net0'.format(common.qemu_hostfwd_generic_port, common.qemu_hostfwd_generic_port, common.qemu_hostfwd_ssh_port), '-no-reboot', '-smp', str(args.cpus), '-trace', 'enable={},file={}'.format(trace_type, common.qemu_trace_file), '-virtfs', 'local,path={},mount_tag=host_data,security_model=mapped,id=host_data'.format(common.p9_dir), '-virtfs', 'local,path={},mount_tag=host_out,security_model=mapped,id=host_out'.format(common.out_dir), '-virtfs', 'local,path={},mount_tag=host_out_rootfs_overlay,security_model=mapped,id=host_out_rootfs_overlay'.format(common.out_rootfs_overlay_dir), '-virtfs', 'local,path={},mount_tag=host_rootfs_overlay,security_model=mapped,id=host_rootfs_overlay'.format(common.rootfs_overlay_dir), ] + serial_monitor + vnc ) if args.initrd: extra_emulator_args.extend(['-initrd', os.path.join(common.buildroot_images_dir, 'rootfs.cpio')]) rr = args.record or args.replay if ramfs: # TODO why is this needed, and why any string works. root = 'root=/dev/anything' else: if rr: driveif = 'none' rrid = ',id=img-direct' root = 'root=/dev/sda' snapshot = '' else: driveif = 'virtio' root = 'root=/dev/vda' rrid = '' snapshot = ',snapshot' if args.baremetal is None: if not os.path.exists(common.qcow2_file): if not os.path.exists(common.rootfs_raw_file): raise_rootfs_not_found() common.raw_to_qcow2(prebuilt=args.prebuilt) extra_emulator_args.extend([ '-drive', 'file={},format=qcow2,if={}{}{}'.format(common.disk_image, driveif, snapshot, rrid) ]) if rr: extra_emulator_args.extend([ '-drive', 'driver=blkreplay,if=none,image=img-direct,id=img-blkreplay', '-device', 'ide-hd,drive=img-blkreplay' ]) if rr: extra_emulator_args.extend([ '-object', 'filter-replay,id=replay,netdev=net0', '-icount', 'shift=7,rr={},rrfile={}'.format('record' if args.record else 'replay', common.qemu_rrfile), ]) virtio_gpu_pci = [] else: virtio_gpu_pci = ['-device', 'virtio-gpu-pci'] if args.arch == 'x86_64': if args.kgdb: kernel_cli += ' kgdboc=ttyS0,115200' append = ['-append', '{} nopat {}'.format(root, kernel_cli)] cmd.extend([ '-M', common.machine, '-device', 'edu', ]) elif args.arch == 'arm' or args.arch == 'aarch64': extra_emulator_args.append('-semihosting') if args.kgdb: kernel_cli += ' kgdboc=ttyAMA0,115200' if args.arch == 'arm': cpu = 'cortex-a15' else: cpu = 'cortex-a57' append = ['-append', '{} {}'.format(root, kernel_cli)] cmd = ( cmd + [ # highmem=off needed since v3.0.0 due to: # http://lists.nongnu.org/archive/html/qemu-discuss/2018-08/msg00034.html '-M', '{},highmem=off'.format(common.machine), '-cpu', cpu, ] + virtio_gpu_pci ) if args.baremetal is None: cmd.extend(append) if args.tmux: if args.gem5: subprocess.Popen([os.path.join(common.root_dir, 'tmu'), 'sleep 2;./gem5-shell -n {} {}' \ .format(args.run_id, args.tmux_args) ]) elif args.debug_guest: # TODO find a nicer way to forward all those args automatically. # Part of me wants to: https://github.com/jonathanslenders/pymux # but it cannot be used as a library properly it seems, and it is # slower than tmux. subprocess.Popen([os.path.join(common.root_dir, 'tmu'), "sleep 2;./run-gdb -a '{}' -L '{}' -n '{}' {}" \ .format(args.arch, args.linux_build_id, args.run_id, args.tmux_args) ]) cmd.extend(extra_emulator_args) cmd.extend(args.extra_emulator_args) if debug_vm or args.terminal: out_file = None else: out_file = common.termout_file common.run_cmd(cmd, cmd_file=common.run_cmd_file, out_file=out_file, extra_env=extra_env) # Check if guest panicked. if args.gem5: # We have to do some parsing here because gem5 exits with status 0 even when panic happens. # Grepping for '^panic: ' does not work because some errors don't show that message. panic_msg = b'--- BEGIN LIBC BACKTRACE ---$' else: panic_msg = b'Kernel panic - not syncing' panic_re = re.compile(panic_msg) with open(common.termout_file, 'br') as logfile: for line in logfile: if panic_re.search(line): common.log_error('simulation error detected by parsing logs') return 1 return 0 def get_argparse(): parser = common.get_argparse(argparse_args={'description':'Run Linux on an emulator'}) init_group = parser.add_mutually_exclusive_group() kvm_group = parser.add_mutually_exclusive_group() parser.add_argument( '-c', '--cpus', default=defaults['cpus'], type=int, help='Number of guest CPUs to emulate. Default: %(default)s' ) parser.add_argument( '-D', '--debug-vm', default=defaults['debug_vm'], action='store_true', help='Run GDB on the emulator itself.' ) kvm_group.add_argument( '-d', '--debug-guest', default=defaults['debug_guest'], action='store_true', help='Wait for GDB to connect before starting execution' ) parser.add_argument( '-E', '--eval', help='''\ Replace the normal init with a minimal init that just evals the given string. See: https://github.com/cirosantilli/linux-kernel-module-cheat#replace-init ''' ) parser.add_argument( '--exec-image', default=defaults['gem5_script'], help='''\ Set which executable image to use. Currently only used for gem5 se.py which has no sensible default. Maybe we could also select the --baremetal executable with this, might be a nicer interface. We could definitely use this to override the default Linux kernel image. ''' ) parser.add_argument( '-e', '--kernel-cli', help='''\ Pass an extra Linux kernel command line options, and place them before the dash separator `-`. Only options that come before the `-`, i.e. "standard" options, should be passed with this option. Example: `./run -a arm -e 'init=/poweroff.out'` ''' ) parser.add_argument( '-F', '--eval-busybox', help='''\ Pass a base64 encoded command line parameter that gets evalled by the Busybox init. See: https://github.com/cirosantilli/linux-kernel-module-cheat#init-busybox ''' ) parser.add_argument( '-f', '--kernel-cli-after-dash', help='''\ Pass an extra Linux kernel command line options, add a dash `-` separator, and place the options after the dash. Intended for custom options understood by our `init` scripts, most of which are prefixed by `lkmc_`. Example: `./run -f 'lkmc_eval="wget google.com" lkmc_lala=y'` Mnenomic: `-f` comes after `-e`. ''' ) parser.add_argument( '-G', '--gem5-exe-args', default=defaults['gem5_exe_args'], help='''\ Pass extra options to the gem5 executable. Do not confuse with the arguments passed to config scripts, like `fs.py`. Example: ./run -G '--debug-flags=Exec --debug' --gem5 -- --cpu-type=HPI --caches will run: gem.op5 --debug-flags=Exec fs.py --cpu-type=HPI --caches ''' ) parser.add_argument( '--gem5-script', default=defaults['gem5_script'], choices=['fs', 'se', 'biglittle'], help='Which gem5 script to use' ) parser.add_argument( '--gem5-readfile', default=defaults['gem5_readfile'], help='Set the contents of m5 readfile to this string.' ) init_group.add_argument( '-I', '--initramfs', default=defaults['initramfs'], action='store_true', help='Use initramfs instead of a root filesystem' ) init_group.add_argument( '-i', '--initrd', default=defaults['initrd'], action='store_true', help='Use initrd instead of a root filesystem' ) kvm_group.add_argument( '-K', '--kvm', default=defaults['kvm'], action='store_true', help='Use KVM. Only works if guest arch == host arch' ) parser.add_argument( '-k', '--kgdb', default=defaults['kgdb'], action='store_true' ) parser.add_argument( '-l', '--gem5-restore', type=int, help='''\ Restore the nth most recently taken gem5 checkpoint according to directory timestamps. ''' ) parser.add_argument( '-m', '--memory', default=defaults['memory'], help='''\ Set the memory size of the guest. E.g.: `-m 512M`. We try to keep the default at the minimal ammount amount that boots all archs. Anything lower could lead some arch to fail to boot. Default: %(default)s ''' ) group = parser.add_mutually_exclusive_group() group.add_argument( '-R', '--replay', default=defaults['replay'], action='store_true', help='Replay a QEMU run record deterministically' ) group.add_argument( '-r', '--record', default=defaults['record'], action='store_true', help='Record a QEMU run record for later replay with `-R`' ) parser.add_argument( '-T', '--trace', help='''\ Set trace events to be enabled. If not given, gem5 tracing is completely disabled, while QEMU tracing is enabled but uses default traces that are very rare and don't affect performance, because `./configure --enable-trace-backends=simple` seems to enable some traces by default, e.g. `pr_manager_run`, and I don't know how to get rid of them. ''' ) init_group.add_argument( '--terminal', default=defaults['terminal'], action='store_true', help='''Output to the terminal, don't pipe to tee as the default. Does not save the output to a file, but allows you to use debuggers. Set automatically by --debug-vm, but you still need this option to debug gem5 Python scripts. ''' ) parser.add_argument( '-U', '--tmux-args', default=defaults['tmux_args'], help='Pass extra parameters to the program running on the `-u` tmux split' ) parser.add_argument( '-u', '--tmux', default=defaults['tmux'], action='store_true', help='''\ Create a tmUx split the window. You must already be inside of a `tmux` session to use this option: * on the main window, run the emulator as usual * on the split: ** if on QEMU and `-d` is given, GDB ** if on gem5, the gem5 terminal ''' ) parser.add_argument( '-x', '--graphic', default=defaults['graphic'], action='store_true', help='Run in graphic mode. Mnemonic: X11' ) parser.add_argument( '-V', '--vnc', default=defaults['vnc'], action='store_true', help='''\ Run QEMU with VNC instead of the default SDL. Connect to it with: `vinagre localhost:5900`. ''' ) parser.add_argument( 'extra_emulator_args', nargs='*', default=defaults['extra_emulator_args'], help='Extra options to append at the end of the emulator command line' ) return parser if __name__ == '__main__': parser = get_argparse() args = common.setup(parser) start_time = time.time() exit_status = main(args) end_time = time.time() common.print_time(end_time - start_time) sys.exit(exit_status)