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Re: [Qemu-devel] [RFC PATCH v5 00/31] Deterministic replay and reverse e
From: |
Artyom Tarasenko |
Subject: |
Re: [Qemu-devel] [RFC PATCH v5 00/31] Deterministic replay and reverse execution |
Date: |
Thu, 27 Nov 2014 10:53:53 +0100 |
On Wed, Nov 26, 2014 at 11:47 AM, Pavel Dovgaluk
<address@hidden> wrote:
> That covermail was wrong. Here is the correct one:
>
> 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.
>
> 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.
>
> 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, and ARM hardware platforms.
This patch series is really impressive, hats off!
I wonder what would have to be done to add support for SPARC-64? Since
has a PCI bus, I guess the support in atapi and usb devices is already
there. Is anything beyond translate.c has to be adjusted?
Artyom
> * Performs deterministic replay of all operations with keyboard and mouse
> input devices.
> * Supports auto-checkpointing for convenient reverse debugging.
>
> Usage of the record/replay:
> * First, record the execution, by adding the following string to the command
> line:
> '-record fname=replay.bin -icount 7 -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: '-replay fname=replay.bin -icount 7 -net none'
> * '-net none' option should also be specified if network replay patches
> are not applied.
>
> 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:
> * 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 bottom halves execution
> * synchronization of the threads from thread pool
> * recording/replaying user input (mouse and keyboard)
> * adding internal events for cpu and io synchronization
>
> 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
>
>
>
--
Regards,
Artyom Tarasenko
SPARC and PPC PReP under qemu blog: http://tyom.blogspot.com/search/label/qemu
- [Qemu-devel] [RFC PATCH v5 24/31] replay: shutdown event, (continued)
- [Qemu-devel] [RFC PATCH v5 24/31] replay: shutdown event, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 25/31] replay: checkpoints, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 26/31] replay: bottom halves, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 27/31] replay: replay aio requests, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 28/31] replay: thread pool, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 29/31] replay: initialization and deinitialization, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 30/31] replay: command line options, Pavel Dovgalyuk, 2014/11/26
- [Qemu-devel] [RFC PATCH v5 31/31] replay: recording of the user input, Pavel Dovgalyuk, 2014/11/26
- Re: [Qemu-devel] [RFC PATCH v5 00/31] Deterministic replay and reverse execution, Pavel Dovgaluk, 2014/11/26
- Re: [Qemu-devel] [RFC PATCH v5 00/31] Deterministic replay and reverse execution, Paolo Bonzini, 2014/11/26
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