From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59026) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZbD4-0001oG-22 for qemu-devel@nongnu.org; Wed, 19 Dec 2018 07:44:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZbCy-00085d-9b for qemu-devel@nongnu.org; Wed, 19 Dec 2018 07:44:20 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55484) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gZbCx-000844-7J for qemu-devel@nongnu.org; Wed, 19 Dec 2018 07:44:16 -0500 From: Markus Armbruster References: <20181218112056.11727.96529.stgit@pasha-VirtualBox> <20181218112154.11727.4557.stgit@pasha-VirtualBox> Date: Wed, 19 Dec 2018 13:43:52 +0100 In-Reply-To: <20181218112154.11727.4557.stgit@pasha-VirtualBox> (Pavel Dovgalyuk's message of "Tue, 18 Dec 2018 14:21:54 +0300") Message-ID: <87y38lit4n.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH v8 10/20] replay: introduce info hmp/qmp command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk Cc: qemu-devel@nongnu.org, kwolf@redhat.com, peter.maydell@linaro.org, war2jordan@live.com, pbonzini@redhat.com, crosthwaite.peter@gmail.com, ciro.santilli@gmail.com, jasowang@redhat.com, quintela@redhat.com, mreitz@redhat.com, alex.bennee@linaro.org, maria.klimushenkova@ispras.ru, mst@redhat.com, kraxel@redhat.com, boost.lists@gmail.com, thomas.dullien@googlemail.com, dovgaluk@ispras.ru, artem.k.pisarenko@gmail.com, dgilbert@redhat.com, rth@twiddle.net Pavel Dovgalyuk writes: > This patch introduces 'info replay' monitor command and > corresponding qmp request. > These commands request the current record/replay mode, replay log file name, > and the execution step (number or recorded/replayed instructions). > User may use step number for replay_seek/replay_break commands and > for controlling the execution of replay. > > Signed-off-by: Pavel Dovgalyuk > Acked-by: Dr. David Alan Gilbert > > -- > > v2: > - renamed info_replay qmp into query-replay (suggested by Eric Blake) > v7: > - added empty line (suggested by Markus Armbruster) > --- > hmp-commands-info.hx | 14 ++++++++++++++ > hmp.h | 1 + > qapi/misc.json | 35 +++++++++++++++++++++++++++++++++++ > replay/Makefile.objs | 3 ++- > replay/replay-debugging.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 94 insertions(+), 1 deletion(-) > create mode 100644 replay/replay-debugging.c > > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx > index cbee8b9..9f2f35e 100644 > --- a/hmp-commands-info.hx > +++ b/hmp-commands-info.hx > @@ -918,6 +918,20 @@ STEXI > Show SEV information. > ETEXI > > + { > + .name = "replay", > + .args_type = "", > + .params = "", > + .help = "show parameters of the record/replay", > + .cmd = hmp_info_replay, > + }, > + > +STEXI > +@item info replay > +@findex info replay > +Display the current record/replay mode and the currently executing step. > +ETEXI > + > STEXI > @end table > ETEXI > diff --git a/hmp.h b/hmp.h > index 5f1addc..d792149 100644 > --- a/hmp.h > +++ b/hmp.h > @@ -148,5 +148,6 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict); > void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict); > void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict); > void hmp_info_sev(Monitor *mon, const QDict *qdict); > +void hmp_info_replay(Monitor *mon, const QDict *qdict); > > #endif > diff --git a/qapi/misc.json b/qapi/misc.json > index 8325e0d..e47aea6 100644 > --- a/qapi/misc.json > +++ b/qapi/misc.json > @@ -3113,6 +3113,41 @@ > 'data': [ 'none', 'record', 'play' ] } > > ## > +# @ReplayInfo: > +# > +# Status of the record/replay mode. > +# > +# @mode: current mode. > +# > +# @filename: name of the record/replay log file. > +# > +# @step: current step number. > +# > +# Since: 4.0 > +# > +## > +{ 'struct': 'ReplayInfo', > + 'data': { 'mode': 'ReplayMode', '*filename': 'str', 'step': 'int' } } @filename is optional. For each ReplayMode: is @filename always absent, always present, or can it be either? > + > +## > +# @query-replay: > +# > +# Retrieves the status of the execution record/replay. > +# > +# Returns: structure with the properties of the record/replay. You've used "parameters of the record/replay" (in HMP help info), "status of the record/replay mode" (QMP ReplayInfo doc), "the status of the execution record/replay" (QMP query-replay doc), and "structure with the properties of the record/replay". Please pick one. I think I'd pick "record/replay information". In my (superficial) review of v6, I asked what a client would do with @step. You gave two use cases: 1. Control current step to be sure that replay is not stalled due to the bug. 2. Requesting the step for some moment of execution to use it as a parameter of replay_seek/replay_break operations. I.e., for returning to the same point later. The first one is a bit vague. The second one sounds plausible enough to me at least for stopped VMs (for running VMs, it feels too imprecise to be useful, but what do I know). replay-break is in PATCH 11, replay-seek in PATCH 12. Would it make sense add a suitable reference to ReplayInfo's documentation then? > +# > +# Since: 4.0 > +# > +# Example: > +# > +# -> { "execute": "query-replay" } > +# <- { "return": { "mode": "play", "filename": "log.rr", "step": 220414 } } > +# > +## > +{ 'command': 'query-replay', > + 'returns': 'ReplayInfo' } > + > +## > # @xen-load-devices-state: > # > # Load the state of all devices from file. The RAM and the block devices At the end of this series, record/replay takes almost 100 non-blank lines in misc.json. Let's create a separate QAPI schema module qapi/replay.json, so we can have MAINTAINERS cover this stuff properly. > diff --git a/replay/Makefile.objs b/replay/Makefile.objs > index cee6539..6694e3e 100644 > --- a/replay/Makefile.objs > +++ b/replay/Makefile.objs > @@ -6,4 +6,5 @@ common-obj-y += replay-input.o > common-obj-y += replay-char.o > common-obj-y += replay-snapshot.o > common-obj-y += replay-net.o > -common-obj-y += replay-audio.o > \ No newline at end of file > +common-obj-y += replay-audio.o > +common-obj-y += replay-debugging.o > diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c > new file mode 100644 > index 0000000..1d7e75d > --- /dev/null > +++ b/replay/replay-debugging.c > @@ -0,0 +1,42 @@ > +/* > + * replay-debugging.c > + * > + * Copyright (c) 2010-2018 Institute for System Programming > + * of the Russian Academy of Sciences. > + * > + * This work is licensed under the terms of the GNU GPL, version 2 or later. > + * See the COPYING file in the top-level directory. > + * > + */ > + > +#include "qemu/osdep.h" > +#include "qapi/error.h" > +#include "sysemu/replay.h" > +#include "replay-internal.h" > +#include "hmp.h" > +#include "monitor/monitor.h" > +#include "qapi/qapi-commands-misc.h" > + > +void hmp_info_replay(Monitor *mon, const QDict *qdict) > +{ > + if (replay_mode == REPLAY_MODE_NONE) { > + monitor_printf(mon, "No record/replay\n"); > + } else { > + monitor_printf(mon, "%s execution '%s': current step = %"PRId64"\n", > + replay_mode == REPLAY_MODE_RECORD ? "Recording" : "Replaying", > + replay_get_filename(), replay_get_current_step()); > + } > +} > + > +ReplayInfo *qmp_query_replay(Error **errp) > +{ > + ReplayInfo *retval = g_new0(ReplayInfo, 1); > + > + retval->mode = replay_mode; > + if (replay_get_filename()) { > + retval->filename = g_strdup(replay_get_filename()); > + retval->has_filename = true; > + } > + retval->step = replay_get_current_step(); > + return retval; > +}