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2020-09-01util/qemu-timer: Fix typo in descriptionPhilippe Mathieu-Daudé1-1/+1
Remove the second 'and' introduced in commit e81f86790f ("qemu-timer: avoid checkpoints for virtual clock timers in external subsystems"). Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Li Qiang <liq3ea@gmail.com> Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20200811151643.21293-3-philmd@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-06-26replay: synchronize on every virtual timer callbackPavel Dovgalyuk1-23/+9
Sometimes virtual timer callbacks depend on order of virtual timer processing and warping of virtual clock. Therefore every callback should be logged to make replay deterministic. This patch creates a checkpoint before every virtual timer callback. With these checkpoints virtual timers processing and clock warping events order is completely deterministic. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Acked-by: Alex Bennée <alex.bennee@linaro.org> -- v2: - remove mutex lock/unlock for virtual clock checkpoint since it is not process any asynchronous events (commit ca9759c2a92f528f256fef0e3922416f7bb47bf9) - bump record/replay log file version Message-Id: <159012932716.27256.8854065545365559921.stgit@pasha-ThinkPad-X280> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-04lockable: replaced locks with lock guard macros where appropriateDaniel Brodsky1-9/+8
- ran regexp "qemu_mutex_lock\(.*\).*\n.*if" to find targets - replaced result with QEMU_LOCK_GUARD if all unlocks at function end - replaced result with WITH_QEMU_LOCK_GUARD if unlock not at end Signed-off-by: Daniel Brodsky <dnbrdsky@gmail.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-id: 20200404042108.389635-3-dnbrdsky@gmail.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-03-17lockable: add lock guardsStefan Hajnoczi1-12/+11
This patch introduces two lock guard macros that automatically unlock a lock object (QemuMutex and others): void f(void) { QEMU_LOCK_GUARD(&mutex); if (!may_fail()) { return; /* automatically unlocks mutex */ } ... } and: WITH_QEMU_LOCK_GUARD(&mutex) { if (!may_fail()) { return; /* automatically unlocks mutex */ } } /* automatically unlocks mutex here */ ... Convert qemu-timer.c functions that benefit from these macros as an example. Manual qemu_mutex_lock/unlock() callers are left unmodified in cases where clarity would not improve by switching to the macros. Many other QemuMutex users remain in the codebase that might benefit from lock guards. Over time they can be converted, if that is desirable. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> [Use QEMU_MAKE_LOCKABLE_NONNULL. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-24qemu-timer: reuse MIN macro in qemu_timeout_ns_to_msFrediano Ziglio1-5/+1
Signed-off-by: Frediano Ziglio <fziglio@redhat.com> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20191023122652.2999-3-fziglio@redhat.com> [lv: removed the two useless casts] Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2019-08-20util/qemu-timer: refactor deadline calculation for external timersPavel Dovgalyuk1-3/+27
icount-based record/replay uses qemu_clock_deadline_ns_all to measure the period until vCPU may be interrupted. This function takes in account the virtual timers, because they belong to the virtual devices that may generate interrupt request or affect the virtual machine state. However, there are a subset of virtual timers, that are marked with 'external' flag. These do not change the virtual machine state and only based on virtual clock. Calculating the deadling using the external timers breaks the determinism, because they do not belong to the replayed part of the virtual machine. This patch fixes the deadline calculation for this case by adding new parameter for skipping the external timers when it is needed. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> -- v2 changes: - added new parameter for timer attribute mask Message-Id: <156404426682.18669.17014100602930969222.stgit@pasha-Precision-3630-Tower> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-20timer: last, remove last bits of lastDr. David Alan Gilbert1-21/+1
The reset notifiers kept a 'last' counter to notice jumps; now that we've remove the notifier we don't need to keep 'last'. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20190724115823.4199-5-dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-20timer: Remove reset notifiersDr. David Alan Gilbert1-20/+1
Remove the reset notifer from the core qemu-timer code. The only user was mc146818 and we've just remove it's use. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20190724115823.4199-3-dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-08-16Clean up inclusion of sysemu/sysemu.hMarkus Armbruster1-1/+0
In my "build everything" tree, changing sysemu/sysemu.h triggers a recompile of some 5400 out of 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h). Almost a third of its inclusions are actually superfluous. Delete them. Downgrade two more to qapi/qapi-types-run-state.h, and move one from char/serial.h to char/serial.c. hw/semihosting/config.c, monitor/monitor.c, qdev-monitor.c, and stubs/semihost.c define variables declared in sysemu/sysemu.h without including it. The compiler is cool with that, but include it anyway. This doesn't reduce actual use much, as it's still included into widely included headers. The next commit will tackle that. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-Id: <20190812052359.30071-27-armbru@redhat.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
2018-10-19qemu-timer: avoid checkpoints for virtual clock timers in external subsystemsArtem Pisarenko1-7/+43
Adds EXTERNAL attribute definition to qemu timers subsystem and assigns it to virtual clock timers, used in slirp (ICMP IPv6) and ui (key queue). Virtual clock processing in rr mode can use this attribute instead of a separate clock type. Fixes: 87f4fe7653baf55b5c2f2753fe6003f473c07342 Fixes: 775a412bf83f6bc0c5c02091ee06cf649b34c593 Fixes: 9888091404a702d7ec79d51b088d994b9fc121bd Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com> Message-Id: <e771f96ab94e86b54b9a783c974f2af3009fe5d1.1539764043.git.artem.k.pisarenko@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19qemu-timer: introduce timer attributesArtem Pisarenko1-4/+9
Attributes are simple flags, associated with individual timers for their whole lifetime. They intended to be used to mark individual timers for special handling when they fire. New/init functions family in timer interface updated and refactored (new 'attribute' argument added, timer_list replaced with timer_list_group+type combinations, comments improved to avoid info duplication). Also existing aio interface extended with attribute-enabled variants of functions, which create/initialize timers. Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com> Message-Id: <f47b81dbce734e9806f9516eba8ca588e6321c2f.1539764043.git.artem.k.pisarenko@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19Revert some patches from recent [PATCH v6] "Fixing record/replay and adding ↵Artem Pisarenko1-2/+0
reverse debugging" That patch series introduced new virtual clock type for use in external subsystems. It breaks desired behavior in non-record/replay usage scenarios due to a small change to existing behavior. Processing of virtual timers belonging to new clock type is kicked off to the main loop, which makes these timers asynchronous with vCPU thread and, in icount mode, with whole guest execution. This breaks expected determinism in non-record/replay icount mode of emulation where these "external subsystems" are isolated from the host (i.e. they are external only to guest core, not to the entire emulation environment). Example for slirp ("user" backend for network device): User runs qemu in icount mode with rtc clock=vm without any external communication interfaces but with "-netdev user,restrict=on". It expects deterministic execution, because network services are emulated inside qemu and isolated from host. There are no reasons to get reply from DHCP server with different delay or something like that. The next patches revert reimplements the same changes in a better way. This reverts commit 87f4fe7653baf55b5c2f2753fe6003f473c07342. This reverts commit 775a412bf83f6bc0c5c02091ee06cf649b34c593. This reverts commit 9888091404a702d7ec79d51b088d994b9fc121bd. Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com> Message-Id: <18b1e7c8f155fe26976f91be06bde98eef6f8751.1539764043.git.artem.k.pisarenko@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02timer: introduce new virtual clockPavel Dovgalyuk1-0/+2
Slirp and VNC modules use virtual clock for processing some events that are related to the guest execution speed. But virtual clock-related events are consideres to be deterministic and are recorded/replayed by icount mechanism. But slirp and VNC lie outside the recorded guest core (which includes CPU and peripherals). Therefore slirp and VNC are external for the guest, but should work at guest speed. This patch introduces new virtual clock which can be used for external subsystems for running timers that are synchronized with the guest. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Message-Id: <20180912082002.3228.82417.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-30timer: remove replay clock probe in deadline calculationPavel Dovgalyuk1-9/+2
Ciro Santilli reported that commit a5ed352596a8b7eb2f9acce34371b944ac3056c4 breaks the execution replay. It happens due to the probing the clock for the new instances of iothread. However, this probing was made in replay mode for the timer lists that are empty. This patch removes clock probing in replay mode. It is an artifact of the old version with another thread model. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Message-Id: <20180725121526.12867.17866.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-12replay: save prior value of the host clockPavel Dovgalyuk1-0/+12
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>
2017-03-14icount: process QEMU_CLOCK_VIRTUAL timers in vCPU threadPaolo Bonzini1-1/+3
icount has become much slower after tcg_cpu_exec has stopped using the BQL. There is also a latent bug that is masked by the slowness. The slowness happens because every occurrence of a QEMU_CLOCK_VIRTUAL timer now has to wake up the I/O thread and wait for it. The rendez-vous is mediated by the BQL QemuMutex: - handle_icount_deadline wakes up the I/O thread with BQL taken - the I/O thread wakes up and waits on the BQL - the VCPU thread releases the BQL a little later - the I/O thread raises an interrupt, which calls qemu_cpu_kick - the VCPU thread notices the interrupt, takes the BQL to process it and waits on it All this back and forth is extremely expensive, causing a 6 to 8-fold slowdown when icount is turned on. One may think that the issue is that the VCPU thread is too dependent on the BQL, but then the latent bug comes in. I first tried removing the BQL completely from the x86 cpu_exec, only to see everything break. The only way to fix it (and make everything slow again) was to add a dummy BQL lock/unlock pair. This is because in -icount mode you really have to process the events before the CPU restarts executing the next instruction. Therefore, this series moves the processing of QEMU_CLOCK_VIRTUAL timers straight in the vCPU thread when running in icount mode. The required changes include: - make the timer notification callback wake up TCG's single vCPU thread when run from another thread. By using async_run_on_cpu, the callback can override all_cpu_threads_idle() when the CPU is halted. - move handle_icount_deadline after qemu_tcg_wait_io_event, so that the timer notification callback is invoked after the dummy work item wakes up the vCPU thread - make handle_icount_deadline run the timers instead of just waking the I/O thread. - stop processing the timers in the main loop Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14cpus: define QEMUTimerListNotifyCB for QEMU system emulationPaolo Bonzini1-5/+5
There is no change for now, because the callback just invokes qemu_notify_event. Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14qemu-timer: do not include sysemu/cpus.h from util/qemu-timer.hPaolo Bonzini1-0/+1
This dependency is the wrong way, and we will need util/qemu-timer.h from sysemu/cpus.h in the next patch. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14qemu-timer: fix off-by-onePaolo Bonzini1-1/+1
If the first timer is exactly at the current value of the clock, the deadline is met and the timer should fire. This fixes itself on the next iteration of the loop without icount; with icount, however, execution of instructions will stop exactly at the deadline and won't proceed. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-01timer: use an inline function for freeMarc-André Lureau1-5/+0
Similarly to allocation, do it from an inline function. This allows tests to only use the headers for allocation/free of timer. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Greg Kurz <groug@kaod.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-02-21block: move AioContext, QEMUTimer, main-loop to libqemuutilPaolo Bonzini1-0/+669
AioContext is fairly self contained, the only dependency is QEMUTimer but that in turn doesn't need anything else. So move them out of block-obj-y to avoid introducing a dependency from io/ to block-obj-y. main-loop and its dependency iohandler also need to be moved, because later in this series io/ will call iohandler_get_aio_context. [Changed copyright "the QEMU team" to "other QEMU contributors" as suggested by Daniel Berrange and agreed by Paolo. --Stefan] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 20170213135235.12274-2-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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