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2022-06-06docs: move replay docs to docs/system/replay.rstPavel Dovgalyuk
This patch adds replay description page, converting prior text from docs/replay.txt. The text was also updated and some sections were moved to devel part of the docs. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Acked-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <165364839601.688121.5131456980322853233.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-06-06replay: rewrite async event handlingPavel Dovgalyuk
This patch decouples checkpoints and async events. It was a tricky part of replay implementation. Now it becomes much simpler and easier to maintain. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Acked-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <165364837856.688121.8785039478408995979.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-11-18docs: Fix some typos (found by codespell)Stefan Weil
Fix also a similar typo in a code comment. Signed-off-by: Stefan Weil <sw@weilnetz.de> Message-Id: <20201117193448.393472-1-sw@weilnetz.de> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-06replay: describe reverse debugging in docs/replay.txtPavel Dovgalyuk
This patch updates the documentation and describes usage of the reverse debugging in QEMU+GDB. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> -- v4 changes: - added an example of the command line for reverse debugging of the diskless machine Message-Id: <160174523509.12451.1409905901920738979.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-05icount: rename functions to be consistent with the module nameClaudio Fontana
Signed-off-by: Claudio Fontana <cfontana@suse.de> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-12docs: Be consistent about capitalization of 'Arm'Peter Maydell
The company 'Arm' went through a rebranding some years back involving a recapitalization from 'ARM' to 'Arm'. As a result our documentation is a bit inconsistent between the two forms. It's not worth trying to update everywhere in QEMU, but it's easy enough to make docs/ consistent. Note that "ARMv8" and similar architecture names, and older CPU names like "ARM926" still retain all-caps. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com> Message-id: 20200309215818.2021-6-peter.maydell@linaro.org
2020-01-07replay: record and replay random number sourcesPavel Dovgalyuk
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>
2019-10-14replay: update docs for record/replay with block devicesPavel Dovgalyuk
This patch updates the description of the command lines for using record/replay with attached block devices. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-06doc: fix typos for documents in treeLike Xu
Signed-off-by: Like Xu <like.xu@linux.intel.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1550640446-18788-1-git-send-email-like.xu@linux.intel.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2018-09-25docs: Fix some typos (most found by codespell)Stefan Weil
Signed-off-by: Stefan Weil <sw@weilnetz.de> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>
2018-03-12replay: update documentationPavel Dovgalyuk
This patch clarifies the description of the record/replay feature in docs/replay.txt Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20180227095333.1060.1331.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
2018-03-12replay: push replay_mutex_lock up the call treeAlex Bennée
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>
2018-03-12replay: added replay log format descriptionPavel Dovgalyuk
This patch adds description of the replay log file format into the docs/replay.txt. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20180227095220.1060.58759.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-01replay: add record/replay for audio passthroughPavel Dovgalyuk
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>
2017-01-27replay: save/load initial statePavel Dovgalyuk
This patch implements initial vmstate creation or loading at the start of record/replay. It is needed for rewinding the execution in the replay mode. v4 changes: - snapshots are not created by default anymore v3 changes: - added rrsnapshot option Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20170124071746.4572.61449.stgit@PASHA-ISP> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-06record/replay: add network supportPavel Dovgalyuk
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>
2016-03-30replay: introduce block devices record/replayPavel Dovgalyuk
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>
2016-03-15icount: decouple warp callsPavel Dovgalyuk
qemu_clock_warp function is called to update virtual clock when CPU is sleeping. This function includes replay checkpoint to make execution deterministic in icount mode. Record/replay module flushes async event queue at checkpoints. Some of the events (e.g., block devices operations) include interaction with hardware. E.g., APIC polled by block devices sets one of IRQ flags. Flag to be set depends on currently executed thread (CPU or iothread). Therefore in replay mode we have to process the checkpoints in the same thread as they were recorded. qemu_clock_warp function (and its checkpoint) may be called from different thread. This patch decouples two different execution cases of this function: call when CPU is sleeping from iothread and call from cpu thread to update virtual clock. First task is performed by qemu_start_warp_timer function. It sets warp timer event to the moment of nearest pending virtual timer. Second function (qemu_account_warp_timer) is called from cpu thread before execution of the code. It advances virtual clock by adding the length of period while CPU was sleeping. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> Message-Id: <20160310115609.4812.44986.stgit@PASHA-ISP> [Update docs. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-05replay: global variables and function stubsPavel Dovgalyuk
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>