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2024-04-18stubs: split record/replay stubs furtherPaolo Bonzini
replay.c symbols are only needed by user mode emulation, with the exception of replay_mode that is needed by both user mode emulation (by way of qemu_guest_getrandom) and block layer tools (by way of util/qemu-timer.c). Since it is needed by libqemuutil rather than specific files that are part of the tools and emulators, split the replay_mode stub into its own file. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-ID: <20240408155330.522792-17-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-02-27replay: Extract core API to 'exec/replay-core.h'Philippe Mathieu-Daudé
replay API is used deeply within TCG common code (common to user and system emulation). Unfortunately "sysemu/replay.h" requires some QAPI headers for few system-specific declarations, example: void replay_input_event(QemuConsole *src, InputEvent *evt); Since commit c2651c0eaa ("qapi/meson: Restrict UI module to system emulation and tools") the QAPI header defining the InputEvent is not generated anymore. To keep it simple, extract the 'core' replay prototypes to a new "exec/replay-core.h" header which we include in the TCG code that doesn't need the rest of the replay API. Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Message-Id: <20221219170806.60580-5-philmd@linaro.org> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2020-10-22replay: do not build if TCG is not availableClaudio Fontana
this fixes non-TCG builds broken recently by replay reverse debugging. Stub the needed functions in stub/, splitting roughly between functions needed only by system emulation, by system emulation and tools, and by everyone. This includes duplicating some code in replay/, and puts the logic for non-replay related events in the replay/ module (+ the stubs), so this should be revisited in the future. Surprisingly, only _one_ qtest was affected by this, ide-test.c, which resulted in a buzz as the bh events were never delivered, and the bh never executed. Many other subsystems _should_ have been affected. This fixes the immediate issue, however a better way to group replay functionality to TCG-only code could be developed in the long term. Signed-off-by: Claudio Fontana <cfontana@suse.de> Message-Id: <20201013192123.22632-4-cfontana@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06gdbstub: add reverse continue support in replay modePavel Dovgalyuk
This patch adds support of the reverse continue operation for gdbstub. Reverse continue finds the last breakpoint that would happen in normal execution from the beginning to the current moment. Implementation of the reverse continue replays the execution twice: to find the breakpoints that were hit and to seek to the last breakpoint. Reverse continue loads the previous snapshot and tries to find the breakpoint since that moment. If there are no such breakpoints, it proceeds to the earlier snapshot, and so on. When no breakpoints or watchpoints were hit at all, execution stops at the beginning of the replay log. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Message-Id: <160174522930.12451.6994758004725016836.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06gdbstub: add reverse step support in replay modePavel Dovgalyuk
GDB remote protocol supports two reverse debugging commands: reverse step and reverse continue. This patch adds support of the first one to the gdbstub. Reverse step is intended to step one instruction in the backwards direction. This is not possible in regular execution. But replayed execution is deterministic, therefore we can load one of the prior snapshots and proceed to the desired step. It is equivalent to stepping one instruction back. There should be at least one snapshot preceding the debugged part of the replay log. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> -- v4 changes: - inverted condition in cpu_handle_guest_debug (suggested by Alex Bennée) Message-Id: <160174522341.12451.1498758422543765253.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06migration: introduce icount field for snapshotsPavel Dovgalyuk
Saving icount as a parameters of the snapshot allows navigation between them in the execution replay scenario. This information can be used for finding a specific snapshot for proceeding the recorded execution to the specific moment of the time. E.g., 'reverse step' action (introduced in one of the following patches) needs to load the nearest snapshot which is prior to the current moment of time. This patch also updates snapshot test which verifies qemu monitor output. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Acked-by: Markus Armbruster <armbru@redhat.com> Acked-by: Kevin Wolf <kwolf@redhat.com> -- v4 changes: - squashed format update with test output update v7 changes: - introduced the spaces between the fields in snapshot info output - updated the test to match new field widths Message-Id: <160174518865.12451.14327573383978752463.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-07replay: record and replay random number sourcesPavel Dovgalyuk
Record/replay feature of icount allows deterministic running of execution scenarios. Some CPUs and peripheral devices read random numbers from external sources making deterministic execution impossible. This patch adds recording and replaying of random read operations into guest-random module, which is used by the virtual hardware. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Message-Id: <157675984852.14505.15709141760677102489.stgit@pasha-Precision-3630-Tower> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-16Clean up inclusion of sysemu/sysemu.hMarkus Armbruster
In my "build everything" tree, changing sysemu/sysemu.h triggers a recompile of some 5400 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). Almost a third of its inclusions are actually superfluous. Delete them. Downgrade two more to qapi/qapi-types-run-state.h, and move one from char/serial.h to char/serial.c. hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and stubs/semihost.c define variables declared in sysemu/sysemu.h without including it. The compiler is cool with that, but include it anyway. This doesn't reduce actual use much, as it's still included into widely included headers. The next commit will tackle that. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190812052359.30071-27-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2018-10-19replay: pass raw icount value to replay_save_clockPaolo Bonzini
This avoids lock recursion when REPLAY_CLOCK is called inside the timers spinlock. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-12replay: make locking visible outside replay codeAlex Bennée
The replay_mutex_lock/unlock/locked functions are now going to be used for ensuring lock-step behaviour between the two threads. Make them public API functions and also provide stubs for non-QEMU builds on common paths. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20180227095242.1060.16601.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-27char: rename CharDriverState ChardevMarc-André Lureau
Pick a uniform chardev type name. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-27replay: allow replay stopping and restartingPavel Dovgalyuk
This patch fixes bug with stopping and restarting replay through monitor. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20160926080815.6992.71818.stgit@PASHA-ISP> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-30replay: introduce block devices record/replayPavel Dovgalyuk
This patch introduces block driver that implement recording and replaying of block devices' operations. All block completion operations are added to the queue. Queue is flushed at checkpoints and information about processed requests is recorded to the log. In replay phase the queue is matched with events read from the log. Therefore block devices requests are processed deterministically. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> [ kwolf: Rebased onto modified and already applied part of the series ] Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-03-15replay: character devicesPavel Dovgalyuk
This patch implements record and replay of character devices. It records chardevs communication in replay mode. Recorded information include data read from backend and counter of bytes written from frontend to backend to preserve frontend internal state. If character device was configured through the command line in record mode, then in replay mode it should be also added to command line. Backend of the character device could be changed in replay mode. Replaying of devices that perform ioctl and get_msgfd operations is not supported. gdbstub which also acts as a backend is not recorded to allow controlling the replaying through gdb. Monitor backends are also not recorded. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20160314074436.4980.83856.stgit@PASHA-ISP> [Add stubs. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-04stubs: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-3-git-send-email-peter.maydell@linaro.org
2015-11-06replay: initialization and deinitializationPavel Dovgalyuk
This patch introduces the functions for enabling the record/replay and for freeing the resources when simulator closes. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20150917162507.8676.90232.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2015-11-06replay: checkpointsPavel Dovgalyuk
This patch introduces checkpoints that synchronize cpu thread and iothread. When checkpoint is met in the code all asynchronous events from the queue are executed. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20150917162444.8676.52916.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2015-11-06replay: recording and replaying clock ticksPavel Dovgalyuk
Clock ticks are considered as the sources of non-deterministic data for virtual machine. This patch implements saving the clock values when they are acquired (virtual, host clock). When replaying the execution corresponding values are read from log and transfered to the module, which wants to read the values. Such a design required the clock polling to be synchronized. Sometimes it is not true - e.g. when timeouts for timer lists are checked. In this case we use a cached value of the clock, passing it to the client code. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20150917162427.8676.36558.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2015-11-05replay: global variables and function stubsPavel Dovgalyuk
This patch adds global variables, defines, function declarations, and function stubs for deterministic VM replay used by external modules. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20150917162337.8676.41538.stgit@PASHA-ISP.def.inno> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>