Commit Graph

23 Commits

Author SHA1 Message Date
John Snow 39cf73c349 python/qemu/qmp.py: Fix settimeout operation
We enabled callers to interface directly with settimeout, but this
reacts poorly with blocking/nonblocking operation; as they are using the
same internal mechanism.

1. Whenever we change the blocking mechanism temporarily, always set it
back to what it was afterwards.

2. Disallow callers from setting a timeout of "0", which means
Non-blocking mode. This is going to create more weird problems than
anybody wants, so just forbid it.

I opt not to coerce '0' to 'None' to maintain the principal of least
surprise in mirroring the semantics of Python's interface.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20201009175123.249009-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2020-10-20 15:00:06 -04:00
John Snow d5cca076c3 python/qemu/qmp.py: re-raise OSError when encountered
Nested if conditions don't change when the exception block fires; we
need to explicitly re-raise the error if we didn't intend to capture and
suppress it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20201009175123.249009-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2020-10-20 14:58:47 -04:00
John Snow d2b08b79b0 python/qemu/qmp.py: Preserve error context on re-raise
Use the "from ..." phrasing when re-raising errors to preserve their
initial context, to help aid debugging when things go wrong.

This also silences a pylint 2.6.0+ error.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20201006235817.3280413-18-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2020-10-20 09:37:57 -04:00
John Snow f12a282ff4 python/qemu: Add mypy type annotations
These should all be purely annotations with no changes in behavior at
all. You need to be in the python folder, but you should be able to
confirm that these annotations are correct (or at least self-consistent)
by running `mypy --strict qemu`.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20201006235817.3280413-12-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2020-10-20 09:37:57 -04:00
John Snow 932ca4bbde python/qemu: use isort to lay out imports
Borrowed from the QAPI cleanup series, use the same configuration to
standardize the way we write and sort imports.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20201006235817.3280413-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2020-10-20 09:37:57 -04:00
John Snow 84dcdf0887 python/qmp.py: add QMPProtocolError
In the case that we receive a reply but are unable to understand it,
use this exception name to indicate that case.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-7-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-14 22:22:22 +02:00
John Snow 2e2d930517 python/qmp.py: add casts to JSON deserialization
mypy and python type hints are not powerful enough to properly describe
JSON messages in Python 3.6. The best we can do, generally, is describe
them as Dict[str, Any].

Add casts to coerce this type for static analysis; but do NOT enforce
this type at runtime in any way.

Note: Python 3.8 adds a TypedDict construct which allows for the
description of more arbitrary Dictionary shapes. There is a third-party
module, "Pydantic", which is compatible with 3.6 that can be used
instead of the JSON library that parses JSON messages to fully-typed
Python objects, and may be preferable in some cases.

(That is well beyond the scope of this commit or series.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-6-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-14 22:22:22 +02:00
John Snow ef5d474472 python/qmp.py: Do not return None from cmd_obj
This makes typing the qmp library difficult, as it necessitates wrapping
Optional[] around the type for every return type up the stack. At some
point, it becomes difficult to discern or remember why it's None instead
of the expected object.

Use the python exception system to tell us exactly why we didn't get an
object. Remove this special-cased return.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-5-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-14 22:22:22 +02:00
John Snow e3a23b4803 python/qmp.py: re-absorb MonitorResponseError
When I initially split this out, I considered this more of a machine
error than a QMP protocol error, but I think that's misguided.

Move this back to qmp.py and name it QMPResponseError. Convert
qmp.command() to use this exception type.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-4-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-14 22:22:22 +02:00
John Snow a5d76376d6 python/qmp.py: Define common types
Define some common types that we'll need to annotate a lot of other
functions going forward.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710052220.3306-2-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-14 22:22:22 +02:00
John Snow de210ec53c python/qemu/qmp: assert sockfile is not None
In truth, if you don't do this, you'll just get a TypeError
exception. Now, you'll get an AssertionError.

Is this tangibly better? No.
Does mypy complain less? Yes.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-21-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 18:25:31 +02:00
John Snow 7af67d694e python/qemu/qmp: use True/False for non/blocking modes
The type system doesn't want integers.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-15-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 18:25:31 +02:00
John Snow 1dda0404d8 python/qemu: Adjust traceback typing
mypy considers it incorrect to use `bool` to statically return false,
because it will assume that it could conceivably return True, and gives
different analysis in that case. Use a None return to achieve the same
effect, but make mypy happy.

Note: Pylint considers function signatures as code that might trip the
duplicate-code checker. I'd rather not disable this as it does not
trigger often in practice, so I'm disabling it as a one-off and filed a
change request; see https://github.com/PyCQA/pylint/issues/3619

Signed-off-by: John Snow <jsnow@redhat.com>
Acked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-14-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 18:25:31 +02:00
John Snow 0add048fbd python/qemu: fix socket.makefile() typing
Note:

A bug in typeshed (https://github.com/python/typeshed/issues/3977)
misinterprets the type of makefile(). Work around this by explicitly
stating that we are opening a text-mode file.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200514055403.18902-13-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 18:25:31 +02:00
John Snow 8dfac2edb2 python/qemu: delint; add flake8 config
Mostly, ignore the "no bare except" rule, because flake8 is not
contextual and cannot determine if we re-raise. Pylint can, though, so
always prefer pylint for that.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200528222129.23826-5-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-31 18:25:30 +02:00
Oksana Vohchana 566054a0bc python/qemu/qmp.py: QMP debug with VM label
QEMUMachine writes some messages to the default logger.
But it sometimes hard to read the output if we have requests to
more than one VM.
This patch adds a label to the logger in the debug mode.

Signed-off-by: Oksana Vohchana <ovoshcha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20200316103203.10046-1-ovoshcha@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>
2020-03-17 17:55:57 -04:00
Lukáš Doktor 52c68b8abb python: Treat None-return of greeting cmd
In case qemu process dies the "monitor.cmd" returns None which gets
passed to the "__negotiate_capabilities" and leads to unhandled
exception. Let's only check the resp in case it has a value.

Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20200120071202.30646-1-ldoktor@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Wainer dos Santos Moschetta 50d189c97a python/qemu: qmp: Remove unnused attributes
The `error` and `timeout` attributes in QEMUMonitorProtocol are
not used, so this delete them.

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191227134101.244496-6-wainersm@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Wainer dos Santos Moschetta 07608e807d python/qemu: qmp: Make QEMUMonitorProtocol a context manager
This implement the __enter__ and __exit__ functions on
QEMUMonitorProtocol class so that it can be used on 'with'
statement and the resources will be free up on block end:

with QEMUMonitorProtocol(socket_path) as qmp:
    qmp.connect()
    qmp.command('query-status')

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20200204141111.3207-5-wainersm@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Wainer dos Santos Moschetta 54aafc2fc6 python/qemu: qmp: Make accept()'s timeout configurable
Currently the timeout of QEMUMonitorProtocol.accept() is
hard-coded to 15.0 seconds. This added the parameter `timeout`
so the value can be configured by the user.

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20200204141111.3207-4-wainersm@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Wainer dos Santos Moschetta a0a261e472 python/qemu: Delint the qmp module
This clean up the pylint-3 report on qmp:

************* Module qemu.qmp
python/qemu/qmp.py:1:0: C0111: Missing module docstring (missing-docstring)
python/qemu/qmp.py:17:0: C0111: Missing class docstring (missing-docstring)
python/qemu/qmp.py:21:0: C0111: Missing class docstring (missing-docstring)
python/qemu/qmp.py:25:0: C0111: Missing class docstring (missing-docstring)
python/qemu/qmp.py:29:0: C0111: Missing class docstring (missing-docstring)
python/qemu/qmp.py:33:0: C0111: Missing class docstring (missing-docstring)
python/qemu/qmp.py:33:0: R0205: Class 'QEMUMonitorProtocol' inherits from object, can be safely removed from bases in python3 (useless-object-inheritance)
python/qemu/qmp.py:80:4: R1710: Either all return statements in a function should return an expression, or none of them should. (inconsistent-return-statements)
python/qemu/qmp.py:131:4: R1710: Either all return statements in a function should return an expression, or none of them should. (inconsistent-return-statements)
python/qemu/qmp.py:159:4: R1710: Either all return statements in a function should return an expression, or none of them should. (inconsistent-return-statements)
python/qemu/qmp.py:245:4: C0111: Missing method docstring (missing-docstring)
python/qemu/qmp.py:249:4: C0111: Missing method docstring (missing-docstring)
python/qemu/qmp.py:252:4: C0111: Missing method docstring (missing-docstring)
python/qemu/qmp.py:255:4: C0111: Missing method docstring (missing-docstring)

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191227134101.244496-3-wainersm@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Wainer dos Santos Moschetta 10e163c039 python/qemu: qmp: Replace socket.error with OSError
The socket.error is deprecated from Python 3.3, instead it is
made a link to OSError. This change replaces the occurences
of socket.error with OSError.

Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20191227134101.244496-2-wainersm@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-02-07 15:12:48 +01:00
Cleber Rosa 8f8fd9edba Introduce a Python module structure
This is a simple move of Python code that wraps common QEMU
functionality, and are used by a number of different tests
and scripts.

By treating that code as a real Python module, we can more easily:
 * reuse code
 * have a proper place for the module's own unittests
 * apply a more consistent style
 * generate documentation

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Caio Carrara <ccarrara@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20190206162901.19082-2-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>
2019-02-22 14:07:01 -05:00