From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33595) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YH9OQ-00077U-A6 for qemu-devel@nongnu.org; Fri, 30 Jan 2015 06:05:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YH9OM-0007YS-0O for qemu-devel@nongnu.org; Fri, 30 Jan 2015 06:05:42 -0500 Received: from mail-wg0-x22b.google.com ([2a00:1450:400c:c00::22b]:35411) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YH9OL-0007Y8-CM for qemu-devel@nongnu.org; Fri, 30 Jan 2015 06:05:37 -0500 Received: by mail-wg0-f43.google.com with SMTP id y19so26244089wgg.2 for ; Fri, 30 Jan 2015 03:05:36 -0800 (PST) Sender: Paolo Bonzini Message-ID: <54CB657C.20608@redhat.com> Date: Fri, 30 Jan 2015 12:05:32 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20150122085127.5276.53895.stgit@PASHA-ISP.def.inno> <20150122085249.5276.26806.stgit@PASHA-ISP.def.inno> In-Reply-To: <20150122085249.5276.26806.stgit@PASHA-ISP.def.inno> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH v8 14/21] replay: checkpoints List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pavel Dovgalyuk , qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, peter.crosthwaite@xilinx.com, mark.burton@greensocs.com, real@ispras.ru, batuzovk@ispras.ru, maria.klimushenkova@ispras.ru, alex.bennee@linaro.org, afaerber@suse.de, fred.konrad@greensocs.com On 22/01/2015 09:52, Pavel Dovgalyuk wrote: > This patch introduces checkpoints that synchronize cpu thread and iothread. > When checkpoint is met in the code all asynchronous events from the queue > are executed. > > Signed-off-by: Pavel Dovgalyuk I cannot understand this patch. Please document the design in docs/ and explain why you have done the checkpoints this way. In particular I cannot understand why you have these six checkpoints: + CHECKPOINT_CLOCK_VIRTUAL, + CHECKPOINT_CLOCK_VIRTUAL_ALL, + CHECKPOINT_CLOCK_HOST, + CHECKPOINT_CLOCK_HOST_ALL, + CHECKPOINT_CLOCK_VIRTUAL_RT, + CHECKPOINT_CLOCK_VIRTUAL_RT_ALL, 1) why do you need separate checkpoints for each clock? 2) why do you need separate checkpoints for _ALL and single-aio-context? Paolo > --- > block.c | 11 ++++++++++ > cpus.c | 7 ++++++- > include/qemu/timer.h | 6 ++++-- > main-loop.c | 5 +++++ > qemu-timer.c | 49 ++++++++++++++++++++++++++++++++++++++-------- > replay/replay-internal.h | 5 ++++- > replay/replay.c | 36 ++++++++++++++++++++++++++++++++++ > replay/replay.h | 21 ++++++++++++++++++++ > stubs/replay.c | 11 ++++++++++ > vl.c | 4 +++- > 10 files changed, 142 insertions(+), 13 deletions(-) > > diff --git a/block.c b/block.c > index cbe4a32..a4f45c3 100644 > --- a/block.c > +++ b/block.c > @@ -1994,6 +1994,11 @@ void bdrv_drain_all(void) > BlockDriverState *bs; > > while (busy) { > + if (!replay_checkpoint(CHECKPOINT_BDRV_DRAIN)) { > + /* Do not wait anymore, we stopped at some place in > + the middle of execution during replay */ > + return; > + } > busy = false; > > QTAILQ_FOREACH(bs, &bdrv_states, device_list) { > @@ -2004,6 +2009,12 @@ void bdrv_drain_all(void) > aio_context_release(aio_context); > } > } > + if (replay_mode == REPLAY_MODE_PLAY) { > + /* Skip checkpoints from the log */ > + while (replay_checkpoint(CHECKPOINT_BDRV_DRAIN)) { > + /* Nothing */ > + } > + } > } > > /* make a BlockDriverState anonymous by removing from bdrv_state and > diff --git a/cpus.c b/cpus.c > index 01d89aa..9c32491 100644 > --- a/cpus.c > +++ b/cpus.c > @@ -388,7 +388,7 @@ void qtest_clock_warp(int64_t dest) > timers_state.qemu_icount_bias += warp; > seqlock_write_unlock(&timers_state.vm_clock_seqlock); > > - qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL); > + qemu_clock_run_timers(QEMU_CLOCK_VIRTUAL, false); > clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > } > qemu_clock_notify(QEMU_CLOCK_VIRTUAL); > @@ -408,6 +408,11 @@ void qemu_clock_warp(QEMUClockType type) > return; > } > > + /* warp clock deterministically in record/replay mode */ > + if (!replay_checkpoint(CHECKPOINT_CLOCK_WARP)) { > + return; > + } > + > /* > * If the CPUs have been sleeping, advance QEMU_CLOCK_VIRTUAL timer now. > * This ensures that the deadline for the timer is computed correctly below. > diff --git a/include/qemu/timer.h b/include/qemu/timer.h > index 0c2472c..26927b0 100644 > --- a/include/qemu/timer.h > +++ b/include/qemu/timer.h > @@ -240,13 +240,14 @@ void qemu_clock_unregister_reset_notifier(QEMUClockType type, > /** > * qemu_clock_run_timers: > * @type: clock on which to operate > + * @run_all: true, when called from qemu_clock_run_all_timers > * > * Run all the timers associated with the default timer list > * of a clock. > * > * Returns: true if any timer ran. > */ > -bool qemu_clock_run_timers(QEMUClockType type); > +bool qemu_clock_run_timers(QEMUClockType type, bool run_all); > > /** > * qemu_clock_run_all_timers: > @@ -337,12 +338,13 @@ QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list); > /** > * timerlist_run_timers: > * @timer_list: the timer list to use > + * @run_all: true, when called from qemu_clock_run_all_timers > * > * Call all expired timers associated with the timer list. > * > * Returns: true if any timer expired > */ > -bool timerlist_run_timers(QEMUTimerList *timer_list); > +bool timerlist_run_timers(QEMUTimerList *timer_list, bool run_all); > > /** > * timerlist_notify: > diff --git a/main-loop.c b/main-loop.c > index 981bcb5..d6e93c3 100644 > --- a/main-loop.c > +++ b/main-loop.c > @@ -497,6 +497,11 @@ int main_loop_wait(int nonblocking) > slirp_pollfds_poll(gpollfds, (ret < 0)); > #endif > > + /* CPU thread can infinitely wait for event after > + missing the warp */ > + if (replay_mode == REPLAY_MODE_PLAY) { > + qemu_clock_warp(QEMU_CLOCK_VIRTUAL); > + } > qemu_clock_run_all_timers(); > > return ret; > diff --git a/qemu-timer.c b/qemu-timer.c > index bc981a2..b6eb7b3 100644 > --- a/qemu-timer.c > +++ b/qemu-timer.c > @@ -465,7 +465,7 @@ bool timer_expired(QEMUTimer *timer_head, int64_t current_time) > return timer_expired_ns(timer_head, current_time * timer_head->scale); > } > > -bool timerlist_run_timers(QEMUTimerList *timer_list) > +bool timerlist_run_timers(QEMUTimerList *timer_list, bool run_all) > { > QEMUTimer *ts; > int64_t current_time; > @@ -473,6 +473,32 @@ bool timerlist_run_timers(QEMUTimerList *timer_list) > QEMUTimerCB *cb; > void *opaque; > > + switch (timer_list->clock->type) { > + case QEMU_CLOCK_REALTIME: > + break; > + default: > + case QEMU_CLOCK_VIRTUAL: > + if ((replay_mode != REPLAY_MODE_NONE && !runstate_is_running()) > + || !replay_checkpoint(run_all ? CHECKPOINT_CLOCK_VIRTUAL_ALL > + : CHECKPOINT_CLOCK_VIRTUAL)) { > + return false; > + } > + break; > + case QEMU_CLOCK_HOST: > + if ((replay_mode != REPLAY_MODE_NONE && !runstate_is_running()) > + || !replay_checkpoint(run_all ? CHECKPOINT_CLOCK_HOST_ALL > + : CHECKPOINT_CLOCK_HOST)) { > + return false; > + } > + case QEMU_CLOCK_VIRTUAL_RT: > + if ((replay_mode != REPLAY_MODE_NONE && !runstate_is_running()) > + || !replay_checkpoint(run_all ? CHECKPOINT_CLOCK_VIRTUAL_RT_ALL > + : CHECKPOINT_CLOCK_VIRTUAL_RT)) { > + return false; > + } > + break; > + } > + > qemu_event_reset(&timer_list->timers_done_ev); > if (!timer_list->clock->enabled) { > goto out; > @@ -505,9 +531,9 @@ out: > return progress; > } > > -bool qemu_clock_run_timers(QEMUClockType type) > +bool qemu_clock_run_timers(QEMUClockType type, bool run_all) > { > - return timerlist_run_timers(main_loop_tlg.tl[type]); > + return timerlist_run_timers(main_loop_tlg.tl[type], run_all); > } > > void timerlistgroup_init(QEMUTimerListGroup *tlg, > @@ -532,7 +558,7 @@ bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg) > QEMUClockType type; > bool progress = false; > for (type = 0; type < QEMU_CLOCK_MAX; type++) { > - progress |= timerlist_run_timers(tlg->tl[type]); > + progress |= timerlist_run_timers(tlg->tl[type], false); > } > return progress; > } > @@ -541,11 +567,18 @@ int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg) > { > int64_t deadline = -1; > QEMUClockType type; > + bool play = replay_mode == REPLAY_MODE_PLAY; > for (type = 0; type < QEMU_CLOCK_MAX; type++) { > if (qemu_clock_use_for_deadline(tlg->tl[type]->clock->type)) { > - deadline = qemu_soonest_timeout(deadline, > - timerlist_deadline_ns( > - tlg->tl[type])); > + if (!play || tlg->tl[type]->clock->type == QEMU_CLOCK_REALTIME) { > + deadline = qemu_soonest_timeout(deadline, > + timerlist_deadline_ns( > + tlg->tl[type])); > + } else { > + /* Read clock from the replay file and > + do not calculate the deadline, based on virtual clock. */ > + qemu_clock_get_ns(tlg->tl[type]->clock->type); > + } > } > } > return deadline; > @@ -615,7 +648,7 @@ bool qemu_clock_run_all_timers(void) > QEMUClockType type; > > for (type = 0; type < QEMU_CLOCK_MAX; type++) { > - progress |= qemu_clock_run_timers(type); > + progress |= qemu_clock_run_timers(type, true); > } > > return progress; > diff --git a/replay/replay-internal.h b/replay/replay-internal.h > index 68b2d45..c0a5800 100755 > --- a/replay/replay-internal.h > +++ b/replay/replay-internal.h > @@ -31,7 +31,10 @@ enum ReplayEvents { > EVENT_SHUTDOWN, > /* for clock read/writes */ > /* some of grteater codes are reserved for clocks */ > - EVENT_CLOCK > + EVENT_CLOCK, > + /* for checkpoint event */ > + /* some of grteater codes are reserved for checkpoints */ > + EVENT_CHECKPOINT = EVENT_CLOCK + REPLAY_CLOCK_COUNT > }; > > /* Asynchronous events IDs */ > diff --git a/replay/replay.c b/replay/replay.c > index cfa69fa..7c4a801 100755 > --- a/replay/replay.c > +++ b/replay/replay.c > @@ -163,3 +163,39 @@ void replay_shutdown_request(void) > replay_put_event(EVENT_SHUTDOWN); > } > } > + > +bool replay_checkpoint(ReplayCheckpoint checkpoint) > +{ > + bool res = false; > + replay_save_instructions(); > + > + if (replay_file) { > + if (replay_mode == REPLAY_MODE_PLAY) { > + replay_mutex_lock(); > + if (!skip_async_events(EVENT_CHECKPOINT + checkpoint)) { > + if (replay_data_kind == EVENT_ASYNC) { > + replay_read_events(checkpoint); > + replay_fetch_data_kind(); > + res = replay_data_kind != EVENT_ASYNC; > + replay_mutex_unlock(); > + return res; > + } > + replay_mutex_unlock(); > + return res; > + } > + replay_has_unread_data = 0; > + replay_read_events(checkpoint); > + replay_fetch_data_kind(); > + res = replay_data_kind != EVENT_ASYNC; > + replay_mutex_unlock(); > + return res; > + } else if (replay_mode == REPLAY_MODE_RECORD) { > + replay_mutex_lock(); > + replay_put_event(EVENT_CHECKPOINT + checkpoint); > + replay_save_events(checkpoint); > + replay_mutex_unlock(); > + } > + } > + > + return true; > +} > diff --git a/replay/replay.h b/replay/replay.h > index e1c5fcf..39822b4 100755 > --- a/replay/replay.h > +++ b/replay/replay.h > @@ -29,6 +29,21 @@ enum ReplayClockKind { > }; > typedef enum ReplayClockKind ReplayClockKind; > > +/* IDs of the checkpoints */ > +enum ReplayCheckpoint { > + CHECKPOINT_BDRV_DRAIN, > + CHECKPOINT_CLOCK_WARP, > + CHECKPOINT_RESET_REQUESTED, > + CHECKPOINT_CLOCK_VIRTUAL, > + CHECKPOINT_CLOCK_VIRTUAL_ALL, > + CHECKPOINT_CLOCK_HOST, > + CHECKPOINT_CLOCK_HOST_ALL, > + CHECKPOINT_CLOCK_VIRTUAL_RT, > + CHECKPOINT_CLOCK_VIRTUAL_RT_ALL, > + CHECKPOINT_COUNT > +}; > +typedef enum ReplayCheckpoint ReplayCheckpoint; > + > extern ReplayMode replay_mode; > > /* Processing the instructions */ > @@ -80,6 +95,12 @@ void replay_get_timedate(struct tm *tm); > > /*! Called when qemu shutdown is requested. */ > void replay_shutdown_request(void); > +/*! Should be called at check points in the execution. > + These check points are skipped, if they were not met. > + Saves checkpoint in the SAVE mode and validates in the PLAY mode. > + Returns 0 in PLAY mode if checkpoint was not found. > + Returns 1 in all other cases. */ > +bool replay_checkpoint(ReplayCheckpoint checkpoint); > > /* Asynchronous events queue */ > > diff --git a/stubs/replay.c b/stubs/replay.c > index 121bca6..1be3575 100755 > --- a/stubs/replay.c > +++ b/stubs/replay.c > @@ -1,4 +1,5 @@ > #include "replay/replay.h" > +#include "sysemu/sysemu.h" > > ReplayMode replay_mode; > > @@ -10,3 +11,13 @@ int64_t replay_read_clock(unsigned int kind) > { > return 0; > } > + > +bool replay_checkpoint(ReplayCheckpoint checkpoint) > +{ > + return 0; > +} > + > +int runstate_is_running(void) > +{ > + return 0; > +} > diff --git a/vl.c b/vl.c > index 905ea8a..86ba385 100644 > --- a/vl.c > +++ b/vl.c > @@ -1767,7 +1767,9 @@ static bool main_loop_should_exit(void) > return true; > } > } > - if (qemu_reset_requested()) { > + if (qemu_reset_requested_get() > + && replay_checkpoint(CHECKPOINT_RESET_REQUESTED)) { > + qemu_reset_requested(); > pause_all_vcpus(); > cpu_synchronize_all_states(); > qemu_system_reset(VMRESET_REPORT); > > >