• Daniel Latypov's avatar
    kunit: tool: stop using a shell to run kernel under QEMU · 3f0a50f3
    Daniel Latypov authored
    Note: this potentially breaks custom qemu_configs if people are using
    them! But the fix for them is simple, don't specify multiple arguments
    in one string and don't add on a redundant ''.
    
    It feels a bit iffy to be using a shell in the first place.
    
    There's the usual shenanigans where people could pass in arbitrary shell
    commands via --kernel_arg (since we're just adding '' around the
    kernel_cmdline) or via a custom qemu_config.
    This isn't too much of a concern given the nature of this script (and
    the qemu_config file is in python, you can do w/e you want already).
    
    But it does have some other drawbacks.
    
    One example of a kunit-specific pain point:
    If the relevant qemu binary is missing, we get output like this:
    > /bin/sh: line 1: qemu-system-aarch64: command not found
    This in turn results in our KTAP parser complaining about
    missing/invalid KTAP, but we don't directly show the error!
    It's even more annoying to debug when you consider --raw_output only
    shows KUnit output by default, i.e. you need --raw_output=all to see it.
    
    Whereas directly invoking the binary, Python will raise a
    FileNotFoundError for us, which is a noisier but more clear.
    
    Making this change requires
    * splitting parameters like ['-m 256'] into ['-m', '256'] in
      kunit/qemu_configs/*.py
    * change [''] to [] in kunit/qemu_configs/*.py since otherwise
      QEMU fails w/ 'Device needs media, but drive is empty'
    * dropping explicit quoting of the kernel cmdline
    * using shlex.quote() when we print what command we're running
      so the user can copy-paste and run it
    Signed-off-by: default avatarDaniel Latypov <dlatypov@google.com>
    Reviewed-by: default avatarBrendan Higgins <brendanhiggins@google.com>
    Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
    3f0a50f3
powerpc.py 357 Bytes