| Message ID | 20190117073758.5399.16268.stgit@pasha-VirtualBox |
|---|---|
| State | New |
| Headers | show |
| Series | Fixing record/replay and adding reverse debugging | expand |
Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> writes: > This patch introduces replay_break, replay_delete_break > qmp and hmp commands. > These commands allow stopping at the specified instruction. > It may be useful for debugging when there are some known > events that should be investigated. > replay_break command has one argument - number of instructions > executed since the start of the replay. > replay_delete_break removes previously set breakpoint. > > Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> > > -- > > v2: > - renamed replay_break qmp command into replay-break > (suggested by Eric Blake) > v7: > - introduces replay_delete_break command > v9: > - changed 'step' parameter name to 'icount' > - moved json stuff to replay.json and updated the description > (suggested by Markus Armbruster) > v10: > - updated descriptions (suggested by Markus Armbruster) > --- > hmp-commands.hx | 34 ++++++++++++++++++ > hmp.h | 2 + > qapi/replay.json | 36 +++++++++++++++++++ > replay/replay-debugging.c | 86 +++++++++++++++++++++++++++++++++++++++++++++ > replay/replay-internal.h | 4 ++ > replay/replay.c | 17 +++++++++ > 6 files changed, 179 insertions(+) > > diff --git a/hmp-commands.hx b/hmp-commands.hx > index ba71558..d529f24 100644 > --- a/hmp-commands.hx > +++ b/hmp-commands.hx > @@ -1890,6 +1890,40 @@ Set QOM property @var{property} of object at location @var{path} to value @var{v > ETEXI > > { > + .name = "replay_break", > + .args_type = "icount:i", > + .params = "icount", > + .help = "set breakpoint at the specified instruction count", > + .cmd = hmp_replay_break, > + }, > + > +STEXI > +@item replay_break @var{icount} > +@findex replay_break > +Set replay breakpoint at instruction count @var{icount}. > +Execution stops when the specified instruction is reached. > +There can be at most one breakpoint. When breakpoint is set, any prior > +one is removed. The breakpoint may be set only in replay mode and only > +"in the future", i.e. at instruction counts greater than the current one. > +The current instruction count can be observed with 'info replay'. > +ETEXI > + > + { > + .name = "replay_delete_break", > + .args_type = "", > + .params = "", > + .help = "removes replay breakpoint", > + .cmd = hmp_replay_delete_break, > + }, > + > +STEXI > +@item replay_delete_break > +@findex replay_delete_break > +Removes replay breakpoint which was previously set with replay_break. > +The command is ignored when there are no replay breakpoints. > +ETEXI > + > + { > .name = "info", > .args_type = "item:s?", > .params = "[subcommand]", > diff --git a/hmp.h b/hmp.h > index d792149..c9b9b4f 100644 > --- a/hmp.h > +++ b/hmp.h > @@ -149,5 +149,7 @@ void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict); > void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict); > void hmp_info_sev(Monitor *mon, const QDict *qdict); > void hmp_info_replay(Monitor *mon, const QDict *qdict); > +void hmp_replay_break(Monitor *mon, const QDict *qdict); > +void hmp_replay_delete_break(Monitor *mon, const QDict *qdict); > > #endif > diff --git a/qapi/replay.json b/qapi/replay.json > index ef2fb4b..cb94991 100644 > --- a/qapi/replay.json > +++ b/qapi/replay.json > @@ -63,3 +63,39 @@ > ## > { 'command': 'query-replay', > 'returns': 'ReplayInfo' } > + > +## > +# @replay-break: > +# > +# Set replay breakpoint at instruction count @icount. > +# Execution stops when the specified instruction is reached. > +# There can be at most one breakpoint. When breakpoint is set, any prior > +# one is removed. The breakpoint may be set only in replay mode and only > +# "in the future", i.e. at instruction counts greater than the current one. > +# The current instruction count can be observed with @query-replay. > +# > +# @icount: instruction count to stop at > +# > +# Since: 4.0 > +# > +# Example: > +# > +# -> { "execute": "replay-break", "data": { "icount": 220414 } } > +# > +## > +{ 'command': 'replay-break', 'data': { 'icount': 'int' } } > + > +## > +# @replay-delete-break: > +# > +# Removes replay breakpoint which was set with @replay-break. > +# The command is ignored when there are no replay breakpoints. > +# > +# Since: 4.0 > +# > +# Example: > +# > +# -> { "execute": "replay-delete-break" } > +# > +## > +{ 'command': 'replay-delete-break' } > diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c > index 51f1c4d..a94685e 100644 > --- a/replay/replay-debugging.c > +++ b/replay/replay-debugging.c > @@ -16,6 +16,8 @@ > #include "hmp.h" > #include "monitor/monitor.h" > #include "qapi/qapi-commands-replay.h" > +#include "qapi/qmp/qdict.h" > +#include "qemu/timer.h" > > void hmp_info_replay(Monitor *mon, const QDict *qdict) > { > @@ -41,3 +43,87 @@ ReplayInfo *qmp_query_replay(Error **errp) > retval->icount = replay_get_current_step(); > return retval; > } > + > +static void replay_break(uint64_t icount, QEMUTimerCB callback, void *opaque) > +{ > + assert(replay_mode == REPLAY_MODE_PLAY); > + assert(replay_mutex_locked()); > + assert(replay_break_icount >= replay_get_current_step()); The identifier replay_get_current_step() is one of the few remaining instances of "step" terminology. Whether to normalize them to "icount" is entirely up to you. > + assert(callback); > + > + replay_break_icount = icount; > + > + if (replay_break_timer) { > + timer_del(replay_break_timer); > + } else { > + replay_break_timer = timer_new_ns(QEMU_CLOCK_REALTIME, > + callback, opaque); > + } > +} [...] QAPI schema part Acked-by: Markus Armbruster <armbru@redhat.com>
> From: Markus Armbruster [mailto:armbru@redhat.com] > Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> writes: > > > This patch introduces replay_break, replay_delete_break > > qmp and hmp commands. > > These commands allow stopping at the specified instruction. > > It may be useful for debugging when there are some known > > events that should be investigated. > > replay_break command has one argument - number of instructions > > executed since the start of the replay. > > replay_delete_break removes previously set breakpoint. > > > > Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> > > > > -- > > + > > +static void replay_break(uint64_t icount, QEMUTimerCB callback, void *opaque) > > +{ > > + assert(replay_mode == REPLAY_MODE_PLAY); > > + assert(replay_mutex_locked()); > > + assert(replay_break_icount >= replay_get_current_step()); > > The identifier replay_get_current_step() is one of the few remaining > instances of "step" terminology. Whether to normalize them to "icount" > is entirely up to you. This is already done with the last patch in the series. Pavel Dovgalyuk
diff --git a/hmp-commands.hx b/hmp-commands.hx index ba71558..d529f24 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -1890,6 +1890,40 @@ Set QOM property @var{property} of object at location @var{path} to value @var{v ETEXI { + .name = "replay_break", + .args_type = "icount:i", + .params = "icount", + .help = "set breakpoint at the specified instruction count", + .cmd = hmp_replay_break, + }, + +STEXI +@item replay_break @var{icount} +@findex replay_break +Set replay breakpoint at instruction count @var{icount}. +Execution stops when the specified instruction is reached. +There can be at most one breakpoint. When breakpoint is set, any prior +one is removed. The breakpoint may be set only in replay mode and only +"in the future", i.e. at instruction counts greater than the current one. +The current instruction count can be observed with 'info replay'. +ETEXI + + { + .name = "replay_delete_break", + .args_type = "", + .params = "", + .help = "removes replay breakpoint", + .cmd = hmp_replay_delete_break, + }, + +STEXI +@item replay_delete_break +@findex replay_delete_break +Removes replay breakpoint which was previously set with replay_break. +The command is ignored when there are no replay breakpoints. +ETEXI + + { .name = "info", .args_type = "item:s?", .params = "[subcommand]", diff --git a/hmp.h b/hmp.h index d792149..c9b9b4f 100644 --- a/hmp.h +++ b/hmp.h @@ -149,5 +149,7 @@ void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict); void hmp_info_memory_size_summary(Monitor *mon, const QDict *qdict); void hmp_info_sev(Monitor *mon, const QDict *qdict); void hmp_info_replay(Monitor *mon, const QDict *qdict); +void hmp_replay_break(Monitor *mon, const QDict *qdict); +void hmp_replay_delete_break(Monitor *mon, const QDict *qdict); #endif diff --git a/qapi/replay.json b/qapi/replay.json index ef2fb4b..cb94991 100644 --- a/qapi/replay.json +++ b/qapi/replay.json @@ -63,3 +63,39 @@ ## { 'command': 'query-replay', 'returns': 'ReplayInfo' } + +## +# @replay-break: +# +# Set replay breakpoint at instruction count @icount. +# Execution stops when the specified instruction is reached. +# There can be at most one breakpoint. When breakpoint is set, any prior +# one is removed. The breakpoint may be set only in replay mode and only +# "in the future", i.e. at instruction counts greater than the current one. +# The current instruction count can be observed with @query-replay. +# +# @icount: instruction count to stop at +# +# Since: 4.0 +# +# Example: +# +# -> { "execute": "replay-break", "data": { "icount": 220414 } } +# +## +{ 'command': 'replay-break', 'data': { 'icount': 'int' } } + +## +# @replay-delete-break: +# +# Removes replay breakpoint which was set with @replay-break. +# The command is ignored when there are no replay breakpoints. +# +# Since: 4.0 +# +# Example: +# +# -> { "execute": "replay-delete-break" } +# +## +{ 'command': 'replay-delete-break' } diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c index 51f1c4d..a94685e 100644 --- a/replay/replay-debugging.c +++ b/replay/replay-debugging.c @@ -16,6 +16,8 @@ #include "hmp.h" #include "monitor/monitor.h" #include "qapi/qapi-commands-replay.h" +#include "qapi/qmp/qdict.h" +#include "qemu/timer.h" void hmp_info_replay(Monitor *mon, const QDict *qdict) { @@ -41,3 +43,87 @@ ReplayInfo *qmp_query_replay(Error **errp) retval->icount = replay_get_current_step(); return retval; } + +static void replay_break(uint64_t icount, QEMUTimerCB callback, void *opaque) +{ + assert(replay_mode == REPLAY_MODE_PLAY); + assert(replay_mutex_locked()); + assert(replay_break_icount >= replay_get_current_step()); + assert(callback); + + replay_break_icount = icount; + + if (replay_break_timer) { + timer_del(replay_break_timer); + } else { + replay_break_timer = timer_new_ns(QEMU_CLOCK_REALTIME, + callback, opaque); + } +} + +static void replay_delete_break(void) +{ + assert(replay_mode == REPLAY_MODE_PLAY); + assert(replay_mutex_locked()); + + if (replay_break_timer) { + timer_del(replay_break_timer); + timer_free(replay_break_timer); + replay_break_timer = NULL; + } + replay_break_icount = -1ULL; +} + +static void replay_stop_vm(void *opaque) +{ + vm_stop(RUN_STATE_PAUSED); + replay_delete_break(); +} + +void qmp_replay_break(int64_t icount, Error **errp) +{ + if (replay_mode == REPLAY_MODE_PLAY) { + if (icount >= replay_get_current_step()) { + replay_break(icount, replay_stop_vm, NULL); + } else { + error_setg(errp, + "cannot set breakpoint at the instruction in the past"); + } + } else { + error_setg(errp, "setting the breakpoint is allowed only in play mode"); + } +} + +void hmp_replay_break(Monitor *mon, const QDict *qdict) +{ + int64_t icount = qdict_get_try_int(qdict, "icount", -1LL); + Error *err = NULL; + + qmp_replay_break(icount, &err); + if (err) { + error_report_err(err); + error_free(err); + return; + } +} + +void qmp_replay_delete_break(Error **errp) +{ + if (replay_mode == REPLAY_MODE_PLAY) { + replay_delete_break(); + } else { + error_setg(errp, "replay breakpoints are allowed only in play mode"); + } +} + +void hmp_replay_delete_break(Monitor *mon, const QDict *qdict) +{ + Error *err = NULL; + + qmp_replay_delete_break(&err); + if (err) { + error_report_err(err); + error_free(err); + return; + } +} diff --git a/replay/replay-internal.h b/replay/replay-internal.h index af6f4d5..8c15a41 100644 --- a/replay/replay-internal.h +++ b/replay/replay-internal.h @@ -91,6 +91,10 @@ extern ReplayState replay_state; /* File for replay writing */ extern FILE *replay_file; +/* Instruction count of the replay breakpoint */ +extern uint64_t replay_break_icount; +/* Timer for the replay breakpoint callback */ +extern QEMUTimer *replay_break_timer; void replay_put_byte(uint8_t byte); void replay_put_event(uint8_t event); diff --git a/replay/replay.c b/replay/replay.c index aa53411..1be34aa 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -34,6 +34,10 @@ static char *replay_filename; ReplayState replay_state; static GSList *replay_blockers; +/* Replay breakpoints */ +uint64_t replay_break_icount = -1ULL; +QEMUTimer *replay_break_timer; + bool replay_next_event_is(int event) { bool res = false; @@ -73,6 +77,13 @@ int replay_get_instructions(void) replay_mutex_lock(); if (replay_next_event_is(EVENT_INSTRUCTION)) { res = replay_state.instructions_count; + if (replay_break_icount != -1LL) { + uint64_t current = replay_get_current_step(); + assert(replay_break_icount >= current); + if (current + res > replay_break_icount) { + res = replay_break_icount - current; + } + } } replay_mutex_unlock(); return res; @@ -99,6 +110,12 @@ void replay_account_executed_instructions(void) will be read from the log. */ qemu_notify_event(); } + /* Execution reached the break step */ + if (replay_break_icount == replay_state.current_step) { + /* Cannot make callback directly from the vCPU thread */ + timer_mod_ns(replay_break_timer, + qemu_clock_get_ns(QEMU_CLOCK_REALTIME)); + } } } }
This patch introduces replay_break, replay_delete_break qmp and hmp commands. These commands allow stopping at the specified instruction. It may be useful for debugging when there are some known events that should be investigated. replay_break command has one argument - number of instructions executed since the start of the replay. replay_delete_break removes previously set breakpoint. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> -- v2: - renamed replay_break qmp command into replay-break (suggested by Eric Blake) v7: - introduces replay_delete_break command v9: - changed 'step' parameter name to 'icount' - moved json stuff to replay.json and updated the description (suggested by Markus Armbruster) v10: - updated descriptions (suggested by Markus Armbruster) --- hmp-commands.hx | 34 ++++++++++++++++++ hmp.h | 2 + qapi/replay.json | 36 +++++++++++++++++++ replay/replay-debugging.c | 86 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-internal.h | 4 ++ replay/replay.c | 17 +++++++++ 6 files changed, 179 insertions(+)