On Fri, Sep 17, 2021 at 9:21 AM Hanna Reitz <hreitz@redhat.com> wrote:
On 17.09.21 07:40, John Snow wrote:
> It turns out you can do this directly from Python ... and because of
> this, you don't need to worry about setting the inheritability of the
> fds or spawning another process.
>
> Doing this is helpful because it allows QEMUMonitorProtocol to keep its
> file descriptor and socket object as private implementation details.
>
> *that* is helpful in turn because it allows me to write a compatible,
>   alternative implementation.

Bit of a weird indentation here.

> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>   python/qemu/machine/machine.py | 44 +++++++---------------------------
>   python/qemu/qmp/__init__.py    | 21 +++++++---------
>   2 files changed, 18 insertions(+), 47 deletions(-)
>
> diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
> index ae945ca3c9..1c6532a3d6 100644
> --- a/python/qemu/machine/machine.py
> +++ b/python/qemu/machine/machine.py
> @@ -213,48 +213,22 @@ def add_fd(self: _T, fd: int, fdset: int,
>       def send_fd_scm(self, fd: Optional[int] = None,
>                       file_path: Optional[str] = None) -> int:

[...]

>           if file_path is not None:
>               assert fd is None
> -            fd_param.append(file_path)
> +            with open(file_path, "rb") as passfile:
> +                fd = passfile.fileno()
> +                self._qmp.send_fd_scm(fd)

Seems a bit strange to send an fd that is then immediately closed, but
that’s what socket_scm_helper did, and so it looks like the fd is
effectively duplicated.  OK then.


Same boat. It's weird, but it seems to work, and it's how the old interface (ultimately) behaved, so ... https://i.imgur.com/O0CQXoh.png
 
Reviewed-by: Hanna Reitz <hreitz@redhat.com>