From 34c18203d472c5bf969ebd87dc06c7c3a957efc4 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 17 Apr 2023 17:40:41 +0100 Subject: [PATCH] qmp: Deprecate 'singlestep' member of StatusInfo MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The 'singlestep' member of StatusInfo has never done what the QMP documentation claims it does. What it actually reports is whether TCG is working in "one guest instruction per translation block" mode. We no longer need this field for the HMP 'info status' command, as we've moved that information to 'info jit'. It seems unlikely that anybody is monitoring the state of this obscure TCG setting via QMP, especially since QMP provides no means for changing the setting. So simply deprecate the field, without providing any replacement. Until we do eventually delete the member, correct the misstatements in the QAPI documentation about it. If we do find that there are users for this, then the most likely way we would provide replacement access to the information would be to put the accelerator QOM object at a well-known path such as /machine/accel, which could then be used with the existing qom-set and qom-get commands. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Markus Armbruster Message-id: 20230417164041.684562-11-peter.maydell@linaro.org --- docs/about/deprecated.rst | 14 ++++++++++++++ qapi/run-state.json | 14 +++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 6f5e689aa4..d5eda0f566 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -199,6 +199,20 @@ accepted incorrect commands will return an error. Users should make sure that all arguments passed to ``device_add`` are consistent with the documented property types. +``StatusInfo`` member ``singlestep`` (since 8.1) +'''''''''''''''''''''''''''''''''''''''''''''''' + +The ``singlestep`` member of the ``StatusInfo`` returned from the +``query-status`` command is deprecated. This member has a confusing +name and it never did what the documentation claimed or what its name +suggests. We do not believe that anybody is actually using the +information provided in this member. + +The information it reports is whether the TCG JIT is in "one +instruction per translated block" mode (which can be set on the +command line or via the HMP, but not via QMP). The information remains +available via the HMP 'info jit' command. + Human Monitor Protocol (HMP) commands ------------------------------------- diff --git a/qapi/run-state.json b/qapi/run-state.json index 09ea120292..db3cf52c62 100644 --- a/qapi/run-state.json +++ b/qapi/run-state.json @@ -104,16 +104,24 @@ # # @running: true if all VCPUs are runnable, false if not runnable # -# @singlestep: true if VCPUs are in single-step mode +# @singlestep: true if using TCG with one guest instruction +# per translation block # # @status: the virtual machine @RunState # +# Features: +# @deprecated: Member 'singlestep' is deprecated (with no replacement). +# # Since: 0.14 # -# Notes: @singlestep is enabled through the GDB stub +# Notes: @singlestep is enabled on the command line with +# '-accel tcg,one-insn-per-tb=on', or with the HMP +# 'one-insn-per-tb' command. ## { 'struct': 'StatusInfo', - 'data': {'running': 'bool', 'singlestep': 'bool', 'status': 'RunState'} } + 'data': {'running': 'bool', + 'singlestep': { 'type': 'bool', 'features': [ 'deprecated' ]}, + 'status': 'RunState'} } ## # @query-status: