| Message ID | 20160921113315.1420.49751.stgit@PASHA-ISP.def.inno (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 21/09/2016 13:33, Pavel Dovgalyuk wrote: > +New VM snapshots may be created in replay mode. They can be used later > +to recover the desired VM state. All VM states created in replay mode > +are associated with the moment of time in the replay scenario. > +After recovering the VM state replay will start from that position. > + > +Default starting snapshot name may be specified with icount field > +rrsnapshot as follows: > + -icount shift=7,rr=record,rrfile=replay.bin,rrsnapshot=snapshot_name > + > +This snapshot is created at start of recording and restored at start > +of replaying. It also can be loaded while replaying to roll back > +the execution. Should you mention somewhere that you need -snapshot for raw images? Paolo
> From: Paolo Bonzini [mailto:pbonzini@redhat.com] > On 21/09/2016 13:33, Pavel Dovgalyuk wrote: > > +New VM snapshots may be created in replay mode. They can be used later > > +to recover the desired VM state. All VM states created in replay mode > > +are associated with the moment of time in the replay scenario. > > +After recovering the VM state replay will start from that position. > > + > > +Default starting snapshot name may be specified with icount field > > +rrsnapshot as follows: > > + -icount shift=7,rr=record,rrfile=replay.bin,rrsnapshot=snapshot_name > > + > > +This snapshot is created at start of recording and restored at start > > +of replaying. It also can be loaded while replaying to roll back > > +the execution. > > Should you mention somewhere that you need -snapshot for raw images? Do you mean when rrsnapshot is used with raw images? I'll update the docs. Pavel Dovgalyuk
On 21/09/2016 17:49, Pavel Dovgalyuk wrote: >> From: Paolo Bonzini [mailto:pbonzini@redhat.com] >> On 21/09/2016 13:33, Pavel Dovgalyuk wrote: >>> +New VM snapshots may be created in replay mode. They can be used later >>> +to recover the desired VM state. All VM states created in replay mode >>> +are associated with the moment of time in the replay scenario. >>> +After recovering the VM state replay will start from that position. >>> + >>> +Default starting snapshot name may be specified with icount field >>> +rrsnapshot as follows: >>> + -icount shift=7,rr=record,rrfile=replay.bin,rrsnapshot=snapshot_name >>> + >>> +This snapshot is created at start of recording and restored at start >>> +of replaying. It also can be loaded while replaying to roll back >>> +the execution. >> >> Should you mention somewhere that you need -snapshot for raw images? > > Do you mean when rrsnapshot is used with raw images? I mean that (if I understand correctly) raw images are corrupted if you don't use -snapshot (the record overwrites them, and the replay reads overwritten data). Paolo > I'll update the docs. > > Pavel Dovgalyuk >
> From: Paolo Bonzini [mailto:pbonzini@redhat.com] > On 21/09/2016 17:49, Pavel Dovgalyuk wrote: > >> From: Paolo Bonzini [mailto:pbonzini@redhat.com] > >> On 21/09/2016 13:33, Pavel Dovgalyuk wrote: > >>> +New VM snapshots may be created in replay mode. They can be used later > >>> +to recover the desired VM state. All VM states created in replay mode > >>> +are associated with the moment of time in the replay scenario. > >>> +After recovering the VM state replay will start from that position. > >>> + > >>> +Default starting snapshot name may be specified with icount field > >>> +rrsnapshot as follows: > >>> + -icount shift=7,rr=record,rrfile=replay.bin,rrsnapshot=snapshot_name > >>> + > >>> +This snapshot is created at start of recording and restored at start > >>> +of replaying. It also can be loaded while replaying to roll back > >>> +the execution. > >> > >> Should you mention somewhere that you need -snapshot for raw images? > > > > Do you mean when rrsnapshot is used with raw images? > > I mean that (if I understand correctly) raw images are corrupted if you > don't use -snapshot (the record overwrites them, and the replay reads > overwritten data). I tried running record/replay with raw image. Record finished without an error, but replay couldn't start, because there was no snapshot to load. I think the solution is checking savevm return code and exiting if snapshot cannot be created. Pavel Dovgalyuk
On 22/09/2016 07:37, Pavel Dovgalyuk wrote: >> > I mean that (if I understand correctly) raw images are corrupted if you >> > don't use -snapshot (the record overwrites them, and the replay reads >> > overwritten data). > I tried running record/replay with raw image. Record finished without an error, > but replay couldn't start, because there was no snapshot to load. > I think the solution is checking savevm return code and exiting if snapshot cannot be created. Yep, good idea. Paolo
diff --git a/docs/replay.txt b/docs/replay.txt index 347b2ff..03e1931 100644 --- a/docs/replay.txt +++ b/docs/replay.txt @@ -196,6 +196,22 @@ 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. +Snapshotting +------------ + +New VM snapshots may be created in replay mode. They can be used later +to recover the desired VM state. All VM states created in replay mode +are associated with the moment of time in the replay scenario. +After recovering the VM state replay will start from that position. + +Default starting snapshot name may be specified with icount field +rrsnapshot as follows: + -icount shift=7,rr=record,rrfile=replay.bin,rrsnapshot=snapshot_name + +This snapshot is created at start of recording and restored at start +of replaying. It also can be loaded while replaying to roll back +the execution. + Network devices --------------- diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index a408633..95a35ee 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -43,6 +43,9 @@ typedef struct ReplayNetState ReplayNetState; extern ReplayMode replay_mode; +/* Name of the initial VM snapshot */ +extern char *replay_snapshot; + /* Replay process control functions */ /*! Enables recording or saving event log with specified parameters */ @@ -145,4 +148,10 @@ void replay_unregister_net(ReplayNetState *rns); void replay_net_packet_event(ReplayNetState *rns, unsigned flags, const struct iovec *iov, int iovcnt); +/* VM state operations */ + +/*! Called at the start of execution. + Loads or saves initial vmstate depending on execution mode. */ +void replay_vmstate_init(void); + #endif diff --git a/qemu-options.hx b/qemu-options.hx index 0b621bb..1aa046e 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3367,12 +3367,12 @@ re-inject them. ETEXI DEF("icount", HAS_ARG, QEMU_OPTION_icount, \ - "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>]\n" \ + "-icount [shift=N|auto][,align=on|off][,sleep=on|off,rr=record|replay,rrfile=<filename>,rrsnapshot=<snapshot>]\n" \ " enable virtual instruction counter with 2^N clock ticks per\n" \ " instruction, enable aligning the host and virtual clocks\n" \ " or disable real time cpu sleeping\n", QEMU_ARCH_ALL) STEXI -@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename}] +@item -icount [shift=@var{N}|auto][,rr=record|replay,rrfile=@var{filename},rrsnapshot=@var{snapshot}] @findex -icount Enable virtual instruction counter. The virtual cpu will execute one instruction every 2^@var{N} ns of virtual time. If @code{auto} is specified @@ -3405,6 +3405,10 @@ when the shift value is high (how high depends on the host machine). When @option{rr} option is specified deterministic record/replay is enabled. Replay log is written into @var{filename} file in record mode and read from this file in replay mode. + +Option rrsnapshot is used to create new vm snapshot named @var{snapshot} +at the start of execution recording. In replay mode this option is used +to load the initial VM state. ETEXI DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \ diff --git a/replay/Makefile.objs b/replay/Makefile.objs index f55a6b5..4600d74 100644 --- a/replay/Makefile.objs +++ b/replay/Makefile.objs @@ -5,3 +5,4 @@ common-obj-y += replay-time.o common-obj-y += replay-input.o common-obj-y += replay-char.o common-obj-y += replay-net.o +common-obj-y += replay-snapshot.o diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c new file mode 100644 index 0000000..970b893 --- /dev/null +++ b/replay/replay-snapshot.c @@ -0,0 +1,37 @@ +/* + * replay-snapshot.c + * + * Copyright (c) 2010-2016 Institute for System Programming + * of the Russian Academy of Sciences. + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qemu-common.h" +#include "sysemu/replay.h" +#include "replay-internal.h" +#include "sysemu/sysemu.h" +#include "monitor/monitor.h" +#include "qapi/qmp/qstring.h" +#include "qemu/error-report.h" + +void replay_vmstate_init(void) +{ + if (replay_snapshot) { + if (replay_mode == REPLAY_MODE_RECORD) { + QDict *opts = qdict_new(); + qdict_put(opts, "name", qstring_from_str(replay_snapshot)); + hmp_savevm(cur_mon, opts); + QDECREF(opts); + } else if (replay_mode == REPLAY_MODE_PLAY) { + if (load_vmstate(replay_snapshot) != 0) { + error_report("Could not load snapshot for replay"); + exit(1); + } + } + } +} diff --git a/replay/replay.c b/replay/replay.c index e040f6f..87b93d7 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -26,6 +26,7 @@ #define HEADER_SIZE (sizeof(uint32_t) + sizeof(uint64_t)) ReplayMode replay_mode = REPLAY_MODE_NONE; +char *replay_snapshot; /* Name of replay file */ static char *replay_filename; @@ -291,6 +292,8 @@ void replay_configure(QemuOpts *opts) exit(1); } + replay_snapshot = g_strdup(qemu_opt_get(opts, "rrsnapshot")); + replay_enable(fname, mode); out: @@ -344,6 +347,9 @@ void replay_finish(void) replay_filename = NULL; } + g_free(replay_snapshot); + replay_snapshot = NULL; + replay_finish_events(); replay_mutex_destroy(); } diff --git a/vl.c b/vl.c index fd7f17e..c5ceb99 100644 --- a/vl.c +++ b/vl.c @@ -460,6 +460,9 @@ static QemuOptsList qemu_icount_opts = { }, { .name = "rrfile", .type = QEMU_OPT_STRING, + }, { + .name = "rrsnapshot", + .type = QEMU_OPT_STRING, }, { /* end of list */ } }, @@ -4410,7 +4413,8 @@ int main(int argc, char **argv, char **envp) } /* open the virtual block devices */ - if (snapshot || replay_mode != REPLAY_MODE_NONE) { + if (snapshot + || (replay_mode != REPLAY_MODE_NONE && !replay_snapshot)) { qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot, NULL, NULL); } @@ -4590,7 +4594,9 @@ int main(int argc, char **argv, char **envp) replay_checkpoint(CHECKPOINT_RESET); qemu_system_reset(VMRESET_SILENT); register_global_state(); - if (loadvm) { + if (replay_mode != REPLAY_MODE_NONE) { + replay_vmstate_init(); + } else if (loadvm) { if (load_vmstate(loadvm) < 0) { autostart = 0; }
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> --- docs/replay.txt | 16 ++++++++++++++++ include/sysemu/replay.h | 9 +++++++++ qemu-options.hx | 8 ++++++-- replay/Makefile.objs | 1 + replay/replay-snapshot.c | 37 +++++++++++++++++++++++++++++++++++++ replay/replay.c | 6 ++++++ vl.c | 10 ++++++++-- 7 files changed, 83 insertions(+), 4 deletions(-) create mode 100644 replay/replay-snapshot.c