migration: introduce icount field for snapshots

Saving icount as a parameters of the snapshot allows navigation between
them in the execution replay scenario.
This information can be used for finding a specific snapshot for proceeding
the recorded execution to the specific moment of the time.
E.g., 'reverse step' action (introduced in one of the following patches)
needs to load the nearest snapshot which is prior to the current moment
of time.
This patch also updates snapshot test which verifies qemu monitor output.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
--

v4 changes:
 - squashed format update with test output update
v7 changes:
 - introduced the spaces between the fields in snapshot info output
 - updated the test to match new field widths
Message-Id: <160174518865.12451.14327573383978752463.stgit@pasha-ThinkPad-X280>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/block/qapi.c b/block/qapi.c
index f423ece98ca2525adeab93d0b235e88e077a9356..036da085eea66bd1ad866f5be06f22330297437c 100644 (file)
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -230,6 +230,8 @@ int bdrv_query_snapshot_info_list(BlockDriverState *bs,
         info->date_nsec     = sn_tab[i].date_nsec;
         info->vm_clock_sec  = sn_tab[i].vm_clock_nsec / 1000000000;
         info->vm_clock_nsec = sn_tab[i].vm_clock_nsec % 1000000000;
+        info->icount        = sn_tab[i].icount;
+        info->has_icount    = sn_tab[i].icount != -1ULL;
 
         info_list = g_new0(SnapshotInfoList, 1);
         info_list->value = info;
@@ -694,14 +696,15 @@ BlockStatsList *qmp_query_blockstats(bool has_query_nodes,
 void bdrv_snapshot_dump(QEMUSnapshotInfo *sn)
 {
     char date_buf[128], clock_buf[128];
+    char icount_buf[128] = {0};
     struct tm tm;
     time_t ti;
     int64_t secs;
     char *sizing = NULL;
 
     if (!sn) {
-        qemu_printf("%-10s%-20s%11s%20s%15s",
-                    "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
+        qemu_printf("%-10s%-18s%7s%20s%13s%11s",
+                    "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK", "ICOUNT");
     } else {
         ti = sn->date_sec;
         localtime_r(&ti, &tm);
@@ -715,11 +718,16 @@ void bdrv_snapshot_dump(QEMUSnapshotInfo *sn)
                  (int)(secs % 60),
                  (int)((sn->vm_clock_nsec / 1000000) % 1000));
         sizing = size_to_str(sn->vm_state_size);
-        qemu_printf("%-10s%-20s%11s%20s%15s",
+        if (sn->icount != -1ULL) {
+            snprintf(icount_buf, sizeof(icount_buf),
+                "%"PRId64, sn->icount);
+        }
+        qemu_printf("%-9s %-17s %7s%20s%13s%11s",
                     sn->id_str, sn->name,
                     sizing,
                     date_buf,
-                    clock_buf);
+                    clock_buf,
+                    icount_buf);
     }
     g_free(sizing);
 }
@@ -881,6 +889,8 @@ void bdrv_image_info_dump(ImageInfo *info)
                 .date_nsec = elem->value->date_nsec,
                 .vm_clock_nsec = elem->value->vm_clock_sec * 1000000000ULL +
                                  elem->value->vm_clock_nsec,
+                .icount = elem->value->has_icount ?
+                          elem->value->icount : -1ULL,
             };
 
             pstrcpy(sn.id_str, sizeof(sn.id_str), elem->value->id);

diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index d68b25e0c55917debe6bf9847453320df1472486..2e98c7f4b620ffadc10f6f181c75c45e1f3f86b2 100644 (file)
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -663,6 +663,7 @@ int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info)
     sn->date_sec = sn_info->date_sec;
     sn->date_nsec = sn_info->date_nsec;
     sn->vm_clock_nsec = sn_info->vm_clock_nsec;
+    sn->icount = sn_info->icount;
     sn->extra_data_size = sizeof(QCowSnapshotExtraData);
 
     /* Allocate the L1 table of the snapshot and copy the current one there. */
@@ -1007,6 +1008,7 @@ int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab)
         sn_info->date_sec = sn->date_sec;
         sn_info->date_nsec = sn->date_nsec;
         sn_info->vm_clock_nsec = sn->vm_clock_nsec;
+        sn_info->icount = sn->icount;
     }
     *psn_tab = sn_tab;
     return s->nb_snapshots;

diff --git a/blockdev.c b/blockdev.c
index bebd3ba1c38c5d9a5e02e80e77eef03107a05015..a6ae475dac0eb2d7d0003befff684d677e93a36e 100644 (file)
--- a/blockdev.c
+++ b/blockdev.c
@@ -59,6 +59,7 @@
 #include "sysemu/arch_init.h"
 #include "sysemu/qtest.h"
 #include "sysemu/runstate.h"
+#include "sysemu/replay.h"
 #include "qemu/cutils.h"
 #include "qemu/help_option.h"
 #include "qemu/main-loop.h"
@@ -1190,6 +1191,10 @@ SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
     info->vm_state_size = sn.vm_state_size;
     info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
     info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
+    if (sn.icount != -1ULL) {
+        info->icount = sn.icount;
+        info->has_icount = true;
+    }
 
     return info;
 
@@ -1350,6 +1355,11 @@ static void internal_snapshot_prepare(BlkActionState *common,
     sn->date_sec = tv.tv_sec;
     sn->date_nsec = tv.tv_usec * 1000;
     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    if (replay_mode != REPLAY_MODE_NONE) {
+        sn->icount = replay_get_current_icount();
+    } else {
+        sn->icount = -1ULL;
+    }
 
     ret1 = bdrv_snapshot_create(bs, sn);
     if (ret1 < 0) {

diff --git a/include/block/snapshot.h b/include/block/snapshot.h
index 2bfcd57578982cbe312b71fc6be8c3e774a62ef7..b0fe42993dccf8d587159cbd6c9824faea6c071e 100644 (file)
--- a/include/block/snapshot.h
+++ b/include/block/snapshot.h
@@ -42,6 +42,7 @@ typedef struct QEMUSnapshotInfo {
     uint32_t date_sec; /* UTC date of the snapshot */
     uint32_t date_nsec;
     uint64_t vm_clock_nsec; /* VM clock relative to boot */
+    uint64_t icount; /* record/replay step */
 } QEMUSnapshotInfo;
 
 int bdrv_snapshot_find(BlockDriverState *bs, QEMUSnapshotInfo *sn_info,

diff --git a/migration/savevm.c b/migration/savevm.c
index 34e4b710521bc7206d700fa944f43c0bab5f8a63..0e8dc78684f8b54b115ab8a2246dbe5920bd1b2d 100644 (file)
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2723,6 +2723,11 @@ int save_snapshot(const char *name, Error **errp)
     sn->date_sec = tv.tv_sec;
     sn->date_nsec = tv.tv_usec * 1000;
     sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+    if (replay_mode != REPLAY_MODE_NONE) {
+        sn->icount = replay_get_current_icount();
+    } else {
+        sn->icount = -1ULL;
+    }
 
     if (name) {
         ret = bdrv_snapshot_find(bs, old_sn, name);

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 12a24772b559617eb47f634ce3bd8df6421ad5da..fdc2e5cb28c7e1da27047fa92ccb99261816d724 100644 (file)
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -27,13 +27,18 @@
 #
 # @vm-clock-nsec: fractional part in nano seconds to be used with vm-clock-sec
 #
+# @icount: Current instruction count. Appears when execution record/replay
+#          is enabled. Used for "time-traveling" to match the moment
+#          in the recorded execution with the snapshots. (since 5.2)
+#
 # Since: 1.3
 #
 ##
 { 'struct': 'SnapshotInfo',
   'data': { 'id': 'str', 'name': 'str', 'vm-state-size': 'int',
             'date-sec': 'int', 'date-nsec': 'int',
-            'vm-clock-sec': 'int', 'vm-clock-nsec': 'int' } }
+            'vm-clock-sec': 'int', 'vm-clock-nsec': 'int',
+            '*icount': 'int' } }
 
 ##
 # @ImageInfoSpecificQCow2EncryptionBase:
@@ -5363,7 +5368,8 @@
 #                    "date-sec": 1000012,
 #                    "date-nsec": 10,
 #                    "vm-clock-sec": 100,
-#                    "vm-clock-nsec": 20
+#                    "vm-clock-nsec": 20,
+#                    "icount": 220414
 #      }
 #    }
 #

diff --git a/stubs/replay.c b/stubs/replay.c
index 5974ec1f50e60f40fc90b12de6537460045b9cbd..eacb366aa84eef0addbda18ac0944f520286f8b7 100644 (file)
--- a/stubs/replay.c
+++ b/stubs/replay.c
@@ -88,3 +88,8 @@ int replay_read_random(void *buf, size_t len)
 {
     return 0;
 }
+
+uint64_t replay_get_current_icount(void)
+{
+    return 0;
+}

diff --git a/tests/qemu-iotests/261 b/tests/qemu-iotests/261
index 848ffa760d74ca0782eb9fc8dcab97f96d691794..847b4c6a3752b8b808a36d3304bf06cc73be26ce 100755 (executable)
--- a/tests/qemu-iotests/261
+++ b/tests/qemu-iotests/261
@@ -392,7 +392,7 @@ _check_test_img -r all
 
 echo
 echo "$((sn_count - 1)) snapshots should remain:"
-echo "  qemu-img info reports $(_img_info | grep -c '^ \{34\}') snapshots"
+echo "  qemu-img info reports $(_img_info | grep -c '^ \{32\}') snapshots"
 echo "  Image header reports $(peek_file_be "$TEST_IMG" 60 4) snapshots"
 
 echo
@@ -519,7 +519,7 @@ _check_test_img -r all
 
 echo
 echo '65536 snapshots should remain:'
-echo "  qemu-img info reports $(_img_info | grep -c '^ \{34\}') snapshots"
+echo "  qemu-img info reports $(_img_info | grep -c '^ \{32\}') snapshots"
 echo "  Image header reports $(peek_file_be "$TEST_IMG" 60 4) snapshots"
 
 # success, all done

diff --git a/tests/qemu-iotests/267.out b/tests/qemu-iotests/267.out
index 215902b3ad27d6ed6ee949ba14ec49951b13165e..27471ffae833ed5c4b98ff8df520a43971f4de76 100644 (file)
--- a/tests/qemu-iotests/267.out
+++ b/tests/qemu-iotests/267.out
@@ -33,8 +33,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -44,8 +44,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -69,8 +69,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -94,8 +94,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -105,8 +105,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -119,8 +119,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -134,8 +134,8 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
@@ -145,15 +145,15 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
 Internal snapshots on overlay:
 Snapshot list:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
-1         snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+1         snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 Internal snapshots on backing file:
 
 === -blockdev with NBD server on the backing file ===
@@ -166,17 +166,17 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
 (qemu) info snapshots
 List of snapshots present on all disks:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
---        snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+--        snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 (qemu) loadvm snap0
 (qemu) quit
 
 Internal snapshots on overlay:
 Snapshot list:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
-1         snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+1         snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 Internal snapshots on backing file:
 Snapshot list:
-ID        TAG                 VM SIZE                DATE       VM CLOCK
-1         snap0                  SIZE yyyy-mm-dd hh:mm:ss   00:00:00.000
+ID        TAG               VM SIZE                DATE     VM CLOCK     ICOUNT
+1         snap0                SIZE yyyy-mm-dd hh:mm:ss 00:00:00.000           
 *** done