[PATCH 5/6] savevm: Allow set_params and save_live_state to error

Alex Williamson
2010-10-06T20:59:31Z

This lets a save state handler NAK a migration or cancel if
it runs into problems.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---

block-migration.c | 4 +++-
hw/hw.h | 2 +-
savevm.c | 18 +++++++++++++++---
3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/block-migration.c b/block-migration.c
index 0bfdb73..5fb3b72 100644
--- a/block-migration.c
+++ b/block-migration.c
@@ -628,13 +628,15 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
return 0;
}

-static void block_set_params(int blk_enable, int shared_base, void *opaque)
+static int block_set_params(int blk_enable, int shared_base, void *opaque)
{
block_mig_state.blk_enable = blk_enable;
block_mig_state.shared_base = shared_base;

/* shared base means that blk_enable = 1 */
block_mig_state.blk_enable |= shared_base;
+
+ return 0;
}

void blk_mig_init(void)
diff --git a/hw/hw.h b/hw/hw.h
index 91a60ca..95f2d52 100644
--- a/hw/hw.h
+++ b/hw/hw.h
@@ -239,7 +239,7 @@ static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv)
int64_t qemu_ftell(QEMUFile *f);
int64_t qemu_fseek(QEMUFile *f, int64_t pos, int whence);

-typedef void SaveSetParamsHandler(int blk_enable, int shared, void * opaque);
+typedef int SaveSetParamsHandler(int blk_enable, int shared, void * opaque);
typedef int SaveStateHandler(QEMUFile *f, void *opaque);
typedef int SaveLiveStateHandler(Monitor *mon, QEMUFile *f, int stage,
void *opaque);
diff --git a/savevm.c b/savevm.c
index 89c5fac..ad3ab86 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1414,12 +1414,16 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
int shared)
{
SaveStateEntry *se;
+ int ret;

QTAILQ_FOREACH(se, &savevm_handlers, entry) {
if(se->set_params == NULL) {
continue;
}
- se->set_params(blk_enable, shared, se->opaque);
+ ret = se->set_params(blk_enable, shared, se->opaque);
+ if (ret < 0) {
+ return ret;
+ }
}

qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
@@ -1443,7 +1447,10 @@ int qemu_savevm_state_begin(Monitor *mon, QEMUFile *f, int blk_enable,
qemu_put_be32(f, se->instance_id);
qemu_put_be32(f, se->version_id);

- se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
+ ret = se->save_live_state(mon, f, QEMU_VM_SECTION_START, se->opaque);
+ if (ret < 0) {
+ return ret;
+ }
}

if (qemu_file_has_error(f)) {
@@ -1474,6 +1481,8 @@ int qemu_savevm_state_iterate(Monitor *mon, QEMUFile *f)
and reduces the probability that a faster changing state is
synchronized over and over again. */
break;
+ } else if (ret < 0) {
+ return ret;
}
}

@@ -1503,7 +1512,10 @@ int qemu_savevm_state_complete(Monitor *mon, QEMUFile *f)
qemu_put_byte(f, QEMU_VM_SECTION_END);
qemu_put_be32(f, se->section_id);

- se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
+ r = se->save_live_state(mon, f, QEMU_VM_SECTION_END, se->opaque);
+ if (r < 0) {
+ return r;
+ }
}

QTAILQ_FOREACH(se, &savevm_handlers, entry) {