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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>