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 calls to replay functions into the icount setup block.
In record mode number of executed instructions is written to the log.
In replay mode number of istructions to execute is taken from the replay log.
When replayed instructions counter is expired qemu_notify_event()
function is called to wake up the iothread.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20150917162405.8676.31890.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>
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>
