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>
Replay is capable of recording normal BH events, but sometimes
there are single use callbacks scheduled with aio_bh_schedule_oneshot
function. This patch enables recording and replaying such callbacks.
Block layer uses these events for calling the completion function.
Replaying these calls makes the execution deterministic.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch renames replay_get_current_step() and related variables
to make these names consistent with existing 'icount' command line
option and future record/replay hmp/qmp commands.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <156404428377.18669.15476429889039912070.stgit@pasha-Precision-3630-Tower>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds events processing when emulation finishes instead
of just cleaning the queue. Now the bdrv coroutines will be in consistent
state when emulator closes. It allows correct polling of the block layer
at exit.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180912081859.3228.79735.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch fixes saving and loading the snapshots in the replay mode.
It is required for the snapshots created in the moment when the header
of the asynchronous event is read. This information was not saved in
the snapshot. After loading the vmstate replay continued with the file offset
passed the event header. The event header is lost in this case and replay
hangs.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180227095322.1060.53929.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Replay mutex is held by vCPU thread and destroy function is called
from atexit of the main thread. Therefore we cannot destroy it safely.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180227095254.1060.96971.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
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>
This time commit 802f045a5f broke the
replay file format. Also add a comment about this to
replay-internal.h.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180227095231.1060.91180.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds saving/restoring of the host clock field 'last'.
It is used in host clock calculation and therefore clock may
become incorrect when using restored vmstate.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180227095226.1060.50975.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
With the recent addition of ShutdownCause, we want to be able to pass
a cause through any shutdown request, and then faithfully replay that
cause when later replaying the same sequence. The easiest way is to
expand the reply event mechanism to track a series of values for
EVENT_SHUTDOWN, one corresponding to each value of ShutdownCause.
We are free to change the replay stream as needed, since there are
already no guarantees about being able to use a replay stream by
any other version of qemu than the one that generated it.
The cause is not actually fed back until the next patch changes the
signature for requesting a shutdown; a TODO marks that upcoming change.
Yes, this uses the gcc/clang extension of a ranged case label,
but this is not the first time we've used non-C99 constructs.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20170515214114.15442-4-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch adds recording and replaying audio data. Is saves synchronization
information for audio out and inputs from the microphone.
v2: removed unneeded whitespace change
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-id: 20170202055054.4848.94901.stgit@PASHA-ISP.lan02.inno
[ kraxel: add qemu/error-report.h include to fix osx build failure ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds support of recording and replaying network packets in
irount rr mode.
Record and replay for network interactions is performed with the network filter.
Each backend must have its own instance of the replay filter as follows:
-netdev user,id=net1 -device rtl8139,netdev=net1
-object filter-replay,id=replay,netdev=net1
Replay network filter is used to record and replay network packets. While
recording the virtual machine this filter puts all packets coming from
the outer world into the log. In replay mode packets from the log are
injected into the network device. All interactions with network backend
in replay mode are disabled.
v5 changes:
- using iov_to_buf function instead of loop
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
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>
This patch introduces vmstate for replay data structures.
It allows saving and loading vmstate while replaying.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20160926080810.6992.68420.stgit@PASHA-ISP>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch moves replay static variables into the structure
to allow saving and loading them with savevm/loadvm.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20160926080804.6992.87687.stgit@PASHA-ISP>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
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>
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>
Reviewed-by: Eric Blake <eblake@redhat.com>
This records user input (keyboard and mouse events) in record mode and replays
these input events in replay mode.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162524.8676.11696.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
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>
This patch adds deterministic replay for hardware periodic countdown timers.
ptimer uses bottom halves layer to execute such an asynchronous callback.
We put this callback into the replay queue instead of bottom halves one.
When checkpoint is met by main loop thread, the replay queue is processed
and callback is executed. Binding callback moment to one of the checkpoints
makes it deterministic.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162456.8676.83366.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
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>
This patch records and replays simulator shutdown event.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162433.8676.32262.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
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>
This patch adds module for saving and replaying asynchronous events.
These events include network packets, keyboard and mouse input,
USB packets, thread pool and bottom halves callbacks.
All events are stored in the queue to be processed at synchronization points
such as beginning of TB execution, or checkpoint in the iothread.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162422.8676.88696.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
This patch includes modifications of common cpu files. All interrupts and
exceptions occured during recording are written into the replay log.
These events allow correct replaying the execution by kicking cpu thread
when one of these events is found in the log.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162416.8676.57647.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds icount event to the replay subsystem. This event corresponds
to execution of several instructions and used to synchronize input events
in the replay phase.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162354.8676.31351.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This mutex will protect read/write operations for replay log.
Using mutex is necessary because most of the events consist of
several fields stored in the log. The mutex will help to avoid races.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162348.8676.8628.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch adds functions to perform read and write operations
with replay log.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162342.8676.29445.stgit@PASHA-ISP.def.inno>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
