Re: [Qemu-devel] [RFC PATCH v2 00/49] Series short description

[Frederic Konrad <fred.konrad@greensocs.com>]

On 17/07/2014 13:01, Pavel Dovgalyuk wrote:
> This set of patches is related to the reverse execution and deterministic
> replay of qemu execution  Our implementation of deterministic replay can
> be used for deterministic and reverse debugging of guest code through gdb
> remote interface.
>
> 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.
>
> Reverse execution 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, and ARM hardware platforms.
>   * Performs deterministic replay of all operations with keyboard, mouse, network adapters,
>     audio devices, serial interfaces, and physical USB devices connected to the emulator.
>   * Provides support for gdb reverse debugging commands like reverse-step and reverse-continue.
>   * Supports auto-checkpointing for convenient reverse debugging.
>
> Usage of the record/replay:
>   * First, record the execution, by adding '-record fname=replay.bin' to the
>     command line.
>   * Then you can replay it for the multiple times by using another command
>     line option: '-replay fname=replay.bin'
>   * Virtual machine should have at least one virtual disk, which is used to
>     store checkpoints. If you want to enable automatic checkpointing, simply
>     add ',period=XX' to record options, where XX is the checkpointing period
>     in seconds.
>   * Using of the network adapters in record/replay mode is possible with
>     the following command-line options:
>     - '-net user' (or another host adapter) in record mode
>     - '-net replay' in replay mode. Every host network adapter should be
>       replaced by 'replay' when replaying the execution.
>   * Reverse debugging can be used through gdb remote interface.
>     reverse-stepi and reverse-continue commands are supported. Other reverse
>     commands should also work, because they reuse these ones.
>   * Monitor is extended by the following commands:
>     - replay_info - prints information about replay mode and current step
>       (number of instructions executed)
>     - replay_break - sets "breakpoint" at the specified instructions count.
>     - replay_seek - rewinds (using the checkpoints, if possible) to the
>       specified step of replay log.
>
> Paper with short description of deterministic replay implementation:
> http://www.computer.org/csdl/proceedings/csmr/2012/4666/00/4666a553-abs.html
>
> Modifications of qemu include:
>   * adding missed fields of the virtual devices' states to the vmstate
>     structures to allow deterministic saving and restoring the VM state
>   * adding virtual clock-based timers to vmstate structures, because virtual
>     clock is the part of the virtual machine state
>   * modification of block layer to support automatic creation of the overlay
>     files to store the changes and snapshots while recording
>   * disabling of system reset while loading VM state to avoid generating of
>     interrupts by reset handlers
>   * adding warpers 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 bottom halves execution
>   * synchronization of the threads from thread pool
>   * recording/replaying user input (mouse and keyboard), input from virtual
>     serial ports, incoming network packets, input from connected USB devices
>   * adding HMP/QMP commands to monitor for controlling replay execution
>
> 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

Thanks for reshaping the patches.
We are a little busy just now, but I will review that as soon as possible.

Thanks,
Fred

>
> ---
>
> Pavel Dovgalyuk (49):
>        acpi: accurate overflow check
>        integratorcp: adding vmstate for save/restore
>        pcspk: adding vmstate for save/restore
>        fdc: adding vmstate for save/restore
>        parallel: adding vmstate for save/restore
>        serial: fixing vmstate for save/restore
>        kvmapic: fixing loading vmstate
>        hpet: fixing saving and loading process
>        pckbd: adding new fields to vmstate
>        rtl8139: adding new fields to vmstate
>        piix: do not raise irq while loading vmstate
>        mc146818rtc: add missed field to vmstate
>        pl031: add missed field to vmstate
>        ide pci: reset status field before loading the vmstate
>        softmmu: fixing usage of cpu_st/ld* from helpers
>        target: save cpu state fields
>        target-i386: update fp status fix
>        migration: add vmstate for int8 and char arrays
>        replay: global variables and function stubs
>        block: add suffix parameter to bdrv_open functions
>        sysemu: system functions for replay
>        replay: internal functions for replay log
>        cpu: invent instruction count for accurate replay
>        target-arm: instructions counting code for replay
>        target-i386: instructions counting code for replay
>        replay: interrupts and exceptions
>        vga: do not use virtual clock for blinking cursor
>        replay: asynchronous events infrastructure
>        replay: recording and replaying clock ticks
>        replay: recording and replaying different timers
>        replay: shutdown event
>        replay: checkpoints
>        replay: bottom halves
>        replay: replay aio requests
>        replay: thread pool
>        pl031: vmstate in replay mode
>        replay: initialization and deinitialization
>        replay: command line options
>        replay: snapshotting the virtual machine
>        replay: recording of the user input
>        tap-win32: destroy the thread at exit
>        replay: network packets record/replay
>        replay: audio data record/replay
>        replay: serial port
>        replay: USB passthrough
>        replay: replay_info command
>        replay: replay_break command
>        replay: replay_seek_step command
>        gdbstub: reverse debugging
>
>
>   Makefile.target                  |    1
>   arch_init.c                      |    8
>   async.c                          |   45 ++
>   audio/audio.c                    |   14 +
>   audio/audio_win_int.h            |    3
>   audio/winwaveaudio.c             |  167 +++++++--
>   block.c                          |  134 ++++++-
>   block/blkdebug.c                 |    2
>   block/blkverify.c                |    4
>   block/cow.c                      |    2
>   block/qcow.c                     |    2
>   block/qcow2.c                    |   10 -
>   block/qed.c                      |    2
>   block/raw-posix.c                |    6
>   block/raw-win32.c                |    4
>   block/sheepdog.c                 |    4
>   block/vmdk.c                     |    8
>   block/vvfat.c                    |    2
>   blockdev.c                       |   11 -
>   cpu-exec.c                       |   34 +-
>   cpus.c                           |   81 ++++
>   dma-helpers.c                    |   10 -
>   exec.c                           |   12 +
>   gdbstub.c                        |   79 +++-
>   hmp-commands.hx                  |   41 ++
>   hw/acpi/core.c                   |    7
>   hw/arm/integratorcp.c            |   38 ++
>   hw/audio/pcspk.c                 |   19 +
>   hw/block/fdc.c                   |   11 -
>   hw/block/virtio-blk.c            |   10 -
>   hw/char/parallel.c               |   22 +
>   hw/char/serial.c                 |  115 ++++--
>   hw/display/vga.c                 |    4
>   hw/i386/kvmvapic.c               |   22 +
>   hw/ide/ahci.c                    |    4
>   hw/ide/atapi.c                   |    9
>   hw/ide/core.c                    |   18 +
>   hw/ide/pci.c                     |   10 +
>   hw/input/pckbd.c                 |    3
>   hw/intc/apic_common.c            |    5
>   hw/net/rtl8139.c                 |    5
>   hw/pci-host/piix.c               |   22 +
>   hw/timer/arm_timer.c             |    2
>   hw/timer/hpet.c                  |   13 -
>   hw/timer/mc146818rtc.c           |    5
>   hw/timer/pl031.c                 |   35 +-
>   hw/usb/hcd-uhci.c                |    2
>   hw/usb/host-libusb.c             |  525 ++++++++++++++++++---------
>   include/block/aio.h              |   17 +
>   include/block/block.h            |   21 +
>   include/block/thread-pool.h      |    4
>   include/exec/cpu-defs.h          |    1
>   include/exec/cpu_ldst_template.h |   28 +
>   include/exec/exec-all.h          |   31 ++
>   include/hw/host-libusb.h         |  105 +++++
>   include/migration/vmstate.h      |   13 +
>   include/qemu-common.h            |    3
>   include/qemu/main-loop.h         |    1
>   include/qemu/timer.h             |   48 ++
>   include/qom/cpu.h                |    4
>   include/sysemu/char.h            |   25 +
>   include/sysemu/cpus.h            |    1
>   include/sysemu/sysemu.h          |    2
>   include/ui/input.h               |    2
>   main-loop.c                      |    5
>   monitor.c                        |   49 +++
>   net/Makefile.objs                |    1
>   net/clients.h                    |    3
>   net/dump.c                       |    6
>   net/hub.c                        |    1
>   net/net-replay.c                 |   66 +++
>   net/net.c                        |    7
>   net/slirp.c                      |   14 +
>   net/socket.c                     |   35 ++
>   net/tap-win32.c                  |   25 +
>   net/tap.c                        |   23 +
>   net/vde.c                        |   14 +
>   qapi-schema.json                 |   62 +++
>   qemu-char.c                      |   55 +++
>   qemu-img.c                       |    6
>   qemu-io-cmds.c                   |    2
>   qemu-io.c                        |    4
>   qemu-nbd.c                       |    2
>   qemu-options.hx                  |   28 +
>   qemu-timer.c                     |   45 ++
>   qmp-commands.hx                  |   60 +++
>   replay/Makefile.objs             |   11 +
>   replay/replay-audio.c            |  228 ++++++++++++
>   replay/replay-char.c             |   99 +++++
>   replay/replay-debug.c            |  148 ++++++++
>   replay/replay-events.c           |  381 ++++++++++++++++++++
>   replay/replay-input.c            |  107 ++++++
>   replay/replay-internal.c         |  159 ++++++++
>   replay/replay-internal.h         |  224 ++++++++++++
>   replay/replay-net.c              |  190 ++++++++++
>   replay/replay-qmp.c              |   57 +++
>   replay/replay-time.c             |  181 +++++++++
>   replay/replay-usb.c              |  188 ++++++++++
>   replay/replay.c                  |  735 ++++++++++++++++++++++++++++++++++++++
>   replay/replay.h                  |  218 +++++++++++
>   savevm.c                         |   32 +-
>   slirp/slirp.c                    |    9
>   softmmu_template.h               |   18 +
>   stubs/Makefile.objs              |    1
>   stubs/replay.c                   |   42 ++
>   target-arm/Makefile.objs         |    1
>   target-arm/helper.h              |    3
>   target-arm/machine.c             |    5
>   target-arm/replay_helper.c       |   38 ++
>   target-arm/translate.c           |   62 +++
>   target-i386/Makefile.objs        |    1
>   target-i386/cpu.c                |    1
>   target-i386/cpu.h                |    8
>   target-i386/fpu_helper.c         |    5
>   target-i386/helper.h             |    3
>   target-i386/machine.c            |    7
>   target-i386/replay_helper.c      |   38 ++
>   target-i386/translate.c          |   91 ++++-
>   tests/test-thread-pool.c         |    7
>   thread-pool.c                    |   53 ++-
>   trace-events                     |    2
>   translate-all.c                  |   15 +
>   ui/input.c                       |   79 +++-
>   util/iov.c                       |    4
>   vl.c                             |  108 +++++-
>   vmstate.c                        |    6
>   126 files changed, 5433 insertions(+), 543 deletions(-)
>   create mode 100755 include/hw/host-libusb.h
>   create mode 100755 net/net-replay.c
>   create mode 100755 replay/Makefile.objs
>   create mode 100755 replay/replay-audio.c
>   create mode 100755 replay/replay-char.c
>   create mode 100755 replay/replay-debug.c
>   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-net.c
>   create mode 100755 replay/replay-qmp.c
>   create mode 100755 replay/replay-time.c
>   create mode 100755 replay/replay-usb.c
>   create mode 100755 replay/replay.c
>   create mode 100755 replay/replay.h
>   create mode 100755 stubs/replay.c
>   create mode 100755 target-arm/replay_helper.c
>   create mode 100755 target-i386/replay_helper.c
>