Commit Graph

13 Commits

Author SHA1 Message Date
Peter Maydell 0b57007755 replay: Exit on errors reading from replay log
Currently replay_get_byte() does not check for an error
from getc(). Coverity points out (CID 1390622) that this
could result in unexpected behaviour (such as looping
forever, if we use the replay_get_dword() return value
for a loop count). We don't expect reads from the replay
log to fail, and if they do there is no way we can
continue. So make them fatal errors.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-id: 20181106153330.5139-1-peter.maydell@linaro.org
2018-11-08 13:24:35 +00:00
Paolo Bonzini 74c0b816ad replay: pass raw icount value to replay_save_clock
This avoids lock recursion when REPLAY_CLOCK is called inside the
timers spinlock.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:15 +02:00
Pavel Dovgalyuk 6dc0f52963 replay: check return values of fwrite
This patch adds error reporting when fwrite cannot completely
save the buffer to the file.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20180227095259.1060.86410.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2018-03-12 17:10:37 +01:00
Alex Bennée d759c951f3 replay: push replay_mutex_lock up the call tree
Now instead of using the replay_lock to guard the output of the log we
now use it to protect the whole execution section. This replaces what
the BQL used to do when it was held during TCG execution.

We also introduce some rules for locking order - mainly that you
cannot take the replay_mutex while holding the BQL. This leads to some
slight sophistry during start-up and extending the
replay_mutex_destroy function to unlock the mutex without checking
for the BQL condition so it can be cleanly dropped in the non-replay
case.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Tested-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20180227095248.1060.40374.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2018-03-12 17:10:36 +01:00
Pavel Dovgalyuk 1a423896fa replay: don't destroy mutex at exit
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>
2018-03-12 17:09:50 +01:00
Alex Bennée a36544d34c replay: make locking visible outside replay code
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>
2018-03-12 16:12:50 +01:00
Alex Bennée 180d30bebe replay/replay-internal.c: track holding of replay_lock
This is modelled after the iothread mutex lock. We keep a TLS flag to
indicate when that thread has acquired the lock and assert we don't
double-lock or release when we shouldn't have.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20180227095237.1060.44661.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-12 16:12:50 +01:00
Alex Bennée 982263ce71 replay: assert time only goes forward
If we find ourselves trying to add an event to the log where time has
gone backwards it is because a vCPU event has occurred and the
main-loop is not yet aware of time moving forward. This should not
happen and if it does its better to fail early than generate a log
that will have weird behaviour.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
2017-04-10 10:23:38 +01:00
Pavel Dovgalyuk f186d64d8f replay: move internal data to the structure
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>
2016-09-27 11:57:30 +02:00
Peter Maydell d38ea87ac5 all: Clean up includes
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>
Message-id: 1454089805-5470-16-git-send-email-peter.maydell@linaro.org
2016-02-04 17:41:30 +00:00
Pavel Dovgalyuk 26bc60ac82 replay: introduce icount event
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>
2015-11-05 12:19:09 +01:00
Pavel Dovgalyuk c16861ef1b replay: introduce mutex to protect the replay log
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>
2015-11-05 12:19:09 +01:00
Pavel Dovgalyuk c92079f45f replay: internal functions for replay log
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>
2015-11-05 12:19:09 +01:00