Re: [Qemu-devel] [PATCH v18 00/21] Deterministic replay core

["Pavel Dovgaluk" <Pavel.Dovgaluk@ispras.ru>]

Hi!

Paolo, have you reviewed these patches?

Pavel Dovgalyuk

> -----Original Message-----
> From: Pavel Dovgalyuk [mailto:Pavel.Dovgaluk@ispras.ru]
> Sent: Thursday, September 17, 2015 7:23 PM
> To: qemu-devel@nongnu.org
> Cc: edgar.iglesias@xilinx.com; peter.maydell@linaro.org; igor.rubinov@gmail.com;
> eblake@redhat.com; mark.burton@greensocs.com; real@ispras.ru; batuzovk@ispras.ru;
> maria.klimushenkova@ispras.ru; pavel.dovgaluk@ispras.ru; pbonzini@redhat.com; hines@cert.org;
> alex.bennee@linaro.org; fred.konrad@greensocs.com
> Subject: [PATCH v18 00/21] Deterministic replay core
> 
> This set of patches is related to the reverse execution and deterministic
> replay of qemu execution. This implementation of deterministic replay can
> be used for deterministic debugging of guest code through gdb remote
> interface.
> 
> Core set of patches does not include support for reverse debugging commands
> of gdb, block devices' operations, USB replay support.
> 
> These patches include only core function of the replay,
> excluding the support for replaying serial, audio, network, and USB devices'
> operations. Reverse debugging and monitor commands were also excluded to
> be submitted later as separate patches.
> 
> Execution recording writes non-deterministic events log, which can be later
> used for replaying the execution anywhere and for unlimited number of times.
> It also supports checkpointing for faster rewinding during reverse debugging.
> Execution replaying reads the log and replays all non-deterministic events
> including external input, hardware clocks, and interrupts.
> 
> Full version of deterministic replay has the following features:
>  * Deterministically replays whole system execution and all contents of the memory,
>    state of the hadrware devices, clocks, and screen of the VM.
>  * Writes execution log into the file for latter replaying for multiple times
>    on different machines.
>  * Supports i386, x86_64, ARM, PowerPC, and MIPS hardware platforms.
>  * Performs deterministic replay of all operations with keyboard and mouse
>    input devices.
>  * Supports auto-checkpointing for convenient reverse debugging.
> 
> Usage of the record/replay core:
>  * First, record the execution, by adding the following string to the command line:
>    '-icount shift=7,rr=record,rrfile=replay.bin -net none'.
>    Block devices' images are not actually changed in the recording mode,
>    because all of the changes are written to the temporary overlay file.
>  * Then you can replay it for the multiple times by using another command
>    line option: '-icount shift=7,rr=replay,rrfile=replay.bin -net none'
>  * '-net none' option should also be specified if network replay patches
>    are not applied.
>  * Do not add any disk images to VM, because they are not supported by
>    the core patches.
> 
> Papers with description of deterministic replay implementation:
> http://www.computer.org/csdl/proceedings/csmr/2012/4666/00/4666a553-abs.html
> http://dl.acm.org/citation.cfm?id=2786805.2803179
> 
> Public repository with current version of the patches:
> https://github.com/Dovgalyuk/qemu/tree/rr-17
> 
> Modifications of qemu include:
>  * wrappers for clock and time functions to save their return values in the log
>  * saving different asynchronous events (e.g. system shutdown) into the log
>  * synchronization of the threads from thread pool
>  * recording/replaying user input (mouse and keyboard)
>  * adding internal events for cpu and io synchronization
> 
> v18 changes:
>  * Patches were updated to match upstream version
>  * Added missed replay-user.c file
> 
> v17 changes:
>  * Removed useless stub functions (as suggested by Paolo Bonzini)
>  * Refined checkpoint-related code (as suggested by Paolo Bonzini)
>  * Improved icount processing (as suggested by Paolo Bonzini)
>  * Added checkpoint for suspend event (as suggested by Paolo Bonzini)
>  * Fixed linux-user configurations build
>  * Minor fixes
> 
> v16 changes:
>  * Several warnings were fixed
> 
> v15 changes:
>  * Tested record/replay with MIPS and PowerPC guests
>  * Published the patches on github
>  * Fixed replay mutex operation in icount mode
>  * Fixed timers processing in record/replay mode
> 
> v14 changes:
>  * Minor fixes
> 
> v13 changes:
>  * Introduced "ptimer trigger" event (as suggested by Paolo Bonzini)
> 
> v12 changes:
>  * Removed block patches from the core patches set.
> 
> v11 changes:
>  * Fixed instructions event processing.
>  * Added some mutex protection calls for replay.
>  * Fixed replaying read operations for qcow2.
>  * Fixed rtc reads on initializations stage.
>  * Eliminated some warnings in replay module.
>  * Fixed misprints in documentation for replay (as suggested by Eric Blake)
> 
> v10 changes:
>  * Fixed queue processing for bottom halves (as suggested by Paolo Bonzini)
>  * Rewritten several replay functions (as suggested by Paolo Bonzini)
>  * Some minor fixes.
> 
> v9 changes:
>  * Replaced fwrite/fread with putc/getc (as suggested by Paolo Bonzini)
>  * Stopping virtual machine in case of replay file end (as suggested by Paolo Bonzini)
>  * Removed one of the replay mutexes (as suggested by Paolo Bonzini)
>  * Fixed RCU queue for bottom halves (as suggested by Paolo Bonzini)
>  * Updated command line options' names (as suggested by Paolo Bonzini)
>  * Added design document for record/replay (as suggested by Paolo Bonzini)
>  * Simplified checkpoints for the timers
>  * Added cloning InputEvent objects for replay (as suggested by Paolo Bonzini)
>  * Added replay blockers instead of checking the command line (as suggested by Paolo Bonzini)
>  * Some functions renaming and extracting.
> 
> v8 changes:
>  * Simplified processing of the shutdown event (as suggested by Paolo Bonzini)
>  * Replaced stack of bottom halves in AIO context with QSIMPLEQ (as suggested by Paolo
> Bonzini)
>  * Moved replay_submode out of the series (as suggested by Paolo Bonzini)
>  * Moved suffix option out of the series
>  * Converted some of the defines into enums (as suggested by Paolo Bonzini)
>  * Encapsulated save_tm/read_tm calls into the single function (as suggested by Paolo Bonzini)
>  * Moved record/replay options to icount group (as suggested by Paolo Bonzini)
>  * Updated mutex protection for the events queue (as suggested by Paolo Bonzini)
>  * Added mutex to protect replay log file (as suggested by Paolo Bonzini)
>  * Minor cleanups
> 
> v7 changes:
>  * Removed patches that were applied to upstream.
> 
> v6 changes:
>  * Fixed replay stub return value (as suggested by Eric Blake)
>  * Fixed icount warping.
>  * Virtual rt clock now uses cpu_get_clock() (as suggested by Paolo Bonzini)
>  * Replated get_clock_realtime and get_clock calls with qemu clock requests (as suggested by
> Paolo Bonzini)
>  * Modified can_do_io logic to allow requesting icount from cpu_exec function (as suggested by
> Paolo Bonzini)
>  * Removed applied patches.
> 
> v5 changes:
>  * Minor changes.
>  * Used fixed-width integer types for read/write functions (as suggested by Alex Bennee)
>  * Moved savevm-related code out of the core.
>  * Added new traced clock for deterministic virtual clock warping (as suggested by Paolo
> Bonzini)
>  * Fixed exception_index reset for user mode (as suggested by Paolo Bonzini)
>  * Adopted Paolo's icount patches
>  * Fixed hardware interrupts replaying
> 
> v4 changes:
>  * Updated block drivers to support new bdrv_open interface.
>  * Moved migration patches into separate series (as suggested by Paolo Bonzini)
>  * Fixed a bug in replay_break operation.
>  * Fixed rtl8139 migration for replay.
>  * Fixed 'period' parameter processing for record mode.
>  * Fixed bug in 'reverse-stepi' implementation.
>  * Fixed replay without making any snapshots (even the starting one).
>  * Moved core replay patches into the separate series.
>  * Fixed reverse step and reverse continue support.
>  * Fixed several bugs in icount subsystem.
>  * Reusing native qemu icount for replay instructions counting.
>  * Separated core patches into their own series.
> 
> v3 changes:
>  * Fixed bug with replay of the aio write operations.
>  * Added virtual clock based on replay icount.
>  * Removed duplicated saving of interrupt_request CPU field.
>  * Fixed some coding style issues.
>  * Renamed QMP commands for controlling reverse execution (as suggested by Eric Blake)
>  * Replay mode and submode implemented as QAPI enumerations (as suggested by Eric Blake)
>  * Added description and example for replay-info command (as suggested by Eric Blake)
>  * Added information about the current breakpoint to the output of replay-info (as suggested
> by Eric Blake)
>  * Updated version id for HPET vmstate (as suggested by Paolo Bonzini)
>  * Removed static fields from parallel vmstate (as suggested by Paolo Bonzini)
>  * New vmstate fields for mc146818rtc, pckbd, kvmapic, serial, fdc, rtl8139 moved to
> subsection (as suggested by Paolo Bonzini)
>  * Disabled textmode cursor blinking, when virtual machine is stopped (as suggested by Paolo
> Bonzini)
>  * Extracted saving of exception_index to separate patch (as suggested by Paolo Bonzini)
> 
> v2 changes:
>  * Patches are split to be reviewable and bisectable (as suggested by Kirill Batuzov)
>  * Added QMP versions of replay commands (as suggested by Eric Blake)
>  * Removed some optional features of replay to make patches cleaner
>  * Minor changes and code cleanup were made
> 
> ---
> 
> Pavel Dovgalyuk (21):
>       i386: partial revert of interrupt poll fix
>       replay: global variables and function stubs
>       replay: internal functions for replay log
>       replay: introduce mutex to protect the replay log
>       replay: introduce icount event
>       cpu-exec: allow temporary disabling icount
>       cpu: replay instructions sequence
>       i386: interrupt poll processing
>       replay: interrupts and exceptions
>       replay: asynchronous events infrastructure
>       replay: recording and replaying clock ticks
>       replay: shutdown event
>       icount: improve counting for record/replay
>       replay: checkpoints
>       bottom halves: introduce bh call function
>       replay: ptimer
>       typedef: add typedef for QemuOpts
>       replay: initialization and deinitialization
>       replay: replay blockers for devices
>       replay: command line options
>       replay: recording of the user input
> 
> 
>  Makefile.target           |    1
>  async.c                   |    7 +
>  cpu-exec.c                |   62 +++++++-
>  cpus.c                    |   57 +++++---
>  docs/replay.txt           |  168 ++++++++++++++++++++++
>  exec.c                    |    2
>  hw/bt/hci.c               |    7 +
>  hw/core/ptimer.c          |    7 +
>  include/block/aio.h       |    5 +
>  include/exec/exec-all.h   |    1
>  include/qapi/qmp/qerror.h |    3
>  include/qemu/option.h     |    5 -
>  include/qemu/typedefs.h   |    3
>  include/ui/input.h        |    2
>  main-loop.c               |    3
>  qapi-schema.json          |   18 ++
>  qapi/common.json          |    6 +
>  qemu-options.hx           |    8 +
>  qemu-timer.c              |   48 +++++-
>  replay/Makefile.objs      |    6 +
>  replay/replay-events.c    |  274 ++++++++++++++++++++++++++++++++++++
>  replay/replay-input.c     |  160 +++++++++++++++++++++
>  replay/replay-internal.c  |  206 +++++++++++++++++++++++++++
>  replay/replay-internal.h  |  140 ++++++++++++++++++
>  replay/replay-time.c      |   64 ++++++++
>  replay/replay-user.c      |   36 +++++
>  replay/replay.c           |  342 +++++++++++++++++++++++++++++++++++++++++++++
>  replay/replay.h           |  120 ++++++++++++++++
>  stubs/Makefile.objs       |    1
>  stubs/replay.c            |   32 ++++
>  target-i386/cpu.c         |   10 -
>  target-i386/seg_helper.c  |    3
>  translate-all.c           |    2
>  ui/input.c                |   27 +++-
>  vl.c                      |   53 ++++++-
>  35 files changed, 1820 insertions(+), 69 deletions(-)
>  create mode 100755 docs/replay.txt
>  create mode 100755 replay/Makefile.objs
>  create mode 100755 replay/replay-events.c
>  create mode 100755 replay/replay-input.c
>  create mode 100755 replay/replay-internal.c
>  create mode 100755 replay/replay-internal.h
>  create mode 100755 replay/replay-time.c
>  create mode 100755 replay/replay-user.c
>  create mode 100755 replay/replay.c
>  create mode 100755 replay/replay.h
>  create mode 100755 stubs/replay.c
> 
> --
> Pavel Dovgalyuk