fix #4476: savevm-async: avoid looping without progress

when pend_postcopy is large. By definition, pend_postcopy won't
decrease when iterating, so a value larger than the cutoff of 400000
would lead to essentially empty iterations, filling up the state file
until only 30 MiB + pending_size remain and the second half of the
check would trigger.

Avoid this, by not considering pend_postcopy for the cutoff to enter
the final phase.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
master
Fiona Ebner 2023-01-26 14:46:13 +01:00 committed by Thomas Lamprecht
parent ade9f50160
commit 8051a24b5f
3 changed files with 13 additions and 11 deletions

View File

@ -24,7 +24,8 @@ Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
[improve aborting]
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
[FE: further improve aborting
adapt to removal of QEMUFileOps]
adapt to removal of QEMUFileOps
improve condition for entering final stage]
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
hmp-commands-info.hx | 13 +
@ -32,13 +33,13 @@ Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
include/migration/snapshot.h | 2 +
include/monitor/hmp.h | 5 +
migration/meson.build | 1 +
migration/savevm-async.c | 531 +++++++++++++++++++++++++++++++++++
migration/savevm-async.c | 532 +++++++++++++++++++++++++++++++++++
monitor/hmp-cmds.c | 57 ++++
qapi/migration.json | 34 +++
qapi/misc.json | 32 +++
qemu-options.hx | 12 +
softmmu/vl.c | 10 +
11 files changed, 730 insertions(+)
11 files changed, 731 insertions(+)
create mode 100644 migration/savevm-async.c
diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
@ -154,10 +155,10 @@ index 8cac83c06c..0842d00cd2 100644
), gnutls)
diff --git a/migration/savevm-async.c b/migration/savevm-async.c
new file mode 100644
index 0000000000..05d394c0e2
index 0000000000..4a4e91a26d
--- /dev/null
+++ b/migration/savevm-async.c
@@ -0,0 +1,531 @@
@@ -0,0 +1,532 @@
+#include "qemu/osdep.h"
+#include "migration/channel-savevm-async.h"
+#include "migration/migration.h"
@ -415,7 +416,8 @@ index 0000000000..05d394c0e2
+
+ maxlen = blk_getlength(snap_state.target) - 30*1024*1024;
+
+ if (pending_size > 400000 && snap_state.bs_pos + pending_size < maxlen) {
+ /* Note that there is no progress for pend_postcopy when iterating */
+ if (pending_size - pend_postcopy > 400000 && snap_state.bs_pos + pending_size < maxlen) {
+ ret = qemu_savevm_state_iterate(snap_state.file, false);
+ if (ret < 0) {
+ save_snapshot_error("qemu_savevm_state_iterate error %d", ret);

View File

@ -192,10 +192,10 @@ index fa13d04d78..914f1a63a8 100644
int qemu_fclose(QEMUFile *f);
diff --git a/migration/savevm-async.c b/migration/savevm-async.c
index 05d394c0e2..bafe6ae5eb 100644
index 4a4e91a26d..20aae335ca 100644
--- a/migration/savevm-async.c
+++ b/migration/savevm-async.c
@@ -367,7 +367,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
@@ -368,7 +368,7 @@ void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
QIOChannel *ioc = QIO_CHANNEL(qio_channel_savevm_async_new(snap_state.target,
&snap_state.bs_pos));
@ -204,7 +204,7 @@ index 05d394c0e2..bafe6ae5eb 100644
if (!snap_state.file) {
error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
@@ -500,7 +500,8 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
@@ -501,7 +501,8 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
blk_op_block_all(be, blocker);
/* restore the VM state */

View File

@ -11,7 +11,7 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
1 file changed, 5 insertions(+)
diff --git a/migration/savevm-async.c b/migration/savevm-async.c
index bafe6ae5eb..da3634048f 100644
index 20aae335ca..94c5ae1c81 100644
--- a/migration/savevm-async.c
+++ b/migration/savevm-async.c
@@ -20,6 +20,7 @@
@ -22,7 +22,7 @@ index bafe6ae5eb..da3634048f 100644
/* #define DEBUG_SAVEVM_STATE */
@@ -514,6 +515,10 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
@@ -515,6 +516,10 @@ int load_snapshot_from_blockdev(const char *filename, Error **errp)
dirty_bitmap_mig_before_vm_start();
qemu_fclose(f);