Rework loadvm path for subloops
Postcopy needs to have two migration streams loading concurrently;
one from memory (with the device state) and the other from the fd
with the memory transactions.
Split the core of qemu_loadvm_state out so we can use it for both.
Allow the inner loadvm loop to quit and cause the parent loops to
exit as well.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 571466b..3dc95f4 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -57,6 +57,12 @@
struct MigrationIncomingState {
QEMUFile *from_src_file;
+ /*
+ * Free at the start of the main state load, set as the main thread finishes
+ * loading state.
+ */
+ QemuEvent main_thread_load_event;
+
QEMUFile *to_src_file;
QemuMutex rp_mutex; /* We send replies from multiple threads */
diff --git a/migration/migration.c b/migration/migration.c
index 295deb8..e4f91a9 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -98,12 +98,14 @@
mis_current->from_src_file = f;
QLIST_INIT(&mis_current->loadvm_handlers);
qemu_mutex_init(&mis_current->rp_mutex);
+ qemu_event_init(&mis_current->main_thread_load_event, false);
return mis_current;
}
void migration_incoming_state_destroy(void)
{
+ qemu_event_destroy(&mis_current->main_thread_load_event);
loadvm_free_handlers(mis_current);
g_free(mis_current);
mis_current = NULL;
diff --git a/migration/savevm.c b/migration/savevm.c
index 1ffe7b0..6b04f46 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1051,11 +1051,18 @@
return NULL;
}
+enum LoadVMExitCodes {
+ /* Allow a command to quit all layers of nested loadvm loops */
+ LOADVM_QUIT = 1,
+};
+
+static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
/**
* loadvm_process_command: Process an incoming 'QEMU_VM_COMMAND'
*
- * Returns: 0 on success, negative on error (in which case it will issue an
- * error message).
+ * Returns: 0 on just a normal return
+ * LOADVM_QUIT All good, but exit the loop
+ * <0 error (in which case it will issue an error message).
* @f: The stream to read the command data from.
*/
static int loadvm_process_command(QEMUFile *f)
@@ -1162,14 +1169,113 @@
}
}
+static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+{
+ uint8_t section_type;
+ int ret;
+
+ while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
+ uint32_t instance_id, version_id, section_id;
+ SaveStateEntry *se;
+ LoadStateEntry *le;
+ char idstr[256];
+
+ trace_qemu_loadvm_state_section(section_type);
+ switch (section_type) {
+ case QEMU_VM_SECTION_START:
+ case QEMU_VM_SECTION_FULL:
+ /* Read section start */
+ section_id = qemu_get_be32(f);
+ if (!qemu_get_counted_string(f, idstr)) {
+ error_report("Unable to read ID string for section %u",
+ section_id);
+ return -EINVAL;
+ }
+ instance_id = qemu_get_be32(f);
+ version_id = qemu_get_be32(f);
+
+ trace_qemu_loadvm_state_section_startfull(section_id, idstr,
+ instance_id, version_id);
+ /* Find savevm section */
+ se = find_se(idstr, instance_id);
+ if (se == NULL) {
+ error_report("Unknown savevm section or instance '%s' %d",
+ idstr, instance_id);
+ return -EINVAL;
+ }
+
+ /* Validate version */
+ if (version_id > se->version_id) {
+ error_report("savevm: unsupported version %d for '%s' v%d",
+ version_id, idstr, se->version_id);
+ return -EINVAL;
+ }
+
+ /* Add entry */
+ le = g_malloc0(sizeof(*le));
+
+ le->se = se;
+ le->section_id = section_id;
+ le->version_id = version_id;
+ QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
+
+ ret = vmstate_load(f, le->se, le->version_id);
+ if (ret < 0) {
+ error_report("error while loading state for instance 0x%x of"
+ " device '%s'", instance_id, idstr);
+ return ret;
+ }
+ if (!check_section_footer(f, le)) {
+ return -EINVAL;
+ }
+ break;
+ case QEMU_VM_SECTION_PART:
+ case QEMU_VM_SECTION_END:
+ section_id = qemu_get_be32(f);
+
+ trace_qemu_loadvm_state_section_partend(section_id);
+ QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
+ if (le->section_id == section_id) {
+ break;
+ }
+ }
+ if (le == NULL) {
+ error_report("Unknown savevm section %d", section_id);
+ return -EINVAL;
+ }
+
+ ret = vmstate_load(f, le->se, le->version_id);
+ if (ret < 0) {
+ error_report("error while loading state section id %d(%s)",
+ section_id, le->se->idstr);
+ return ret;
+ }
+ if (!check_section_footer(f, le)) {
+ return -EINVAL;
+ }
+ break;
+ case QEMU_VM_COMMAND:
+ ret = loadvm_process_command(f);
+ trace_qemu_loadvm_state_section_command(ret);
+ if ((ret < 0) || (ret & LOADVM_QUIT)) {
+ return ret;
+ }
+ break;
+ default:
+ error_report("Unknown savevm section type %d", section_type);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
int qemu_loadvm_state(QEMUFile *f)
{
MigrationIncomingState *mis = migration_incoming_get_current();
Error *local_err = NULL;
- uint8_t section_type;
unsigned int v;
int ret;
- int file_error_after_eof = -1;
if (qemu_savevm_state_blocked(&local_err)) {
error_report_err(local_err);
@@ -1204,106 +1310,15 @@
}
}
- while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
- uint32_t instance_id, version_id, section_id;
- SaveStateEntry *se;
- LoadStateEntry *le;
- char idstr[256];
+ ret = qemu_loadvm_state_main(f, mis);
+ qemu_event_set(&mis->main_thread_load_event);
- trace_qemu_loadvm_state_section(section_type);
- switch (section_type) {
- case QEMU_VM_SECTION_START:
- case QEMU_VM_SECTION_FULL:
- /* Read section start */
- section_id = qemu_get_be32(f);
- if (!qemu_get_counted_string(f, idstr)) {
- error_report("Unable to read ID string for section %u",
- section_id);
- return -EINVAL;
- }
- instance_id = qemu_get_be32(f);
- version_id = qemu_get_be32(f);
+ trace_qemu_loadvm_state_post_main(ret);
- trace_qemu_loadvm_state_section_startfull(section_id, idstr,
- instance_id, version_id);
- /* Find savevm section */
- se = find_se(idstr, instance_id);
- if (se == NULL) {
- error_report("Unknown savevm section or instance '%s' %d",
- idstr, instance_id);
- ret = -EINVAL;
- goto out;
- }
-
- /* Validate version */
- if (version_id > se->version_id) {
- error_report("savevm: unsupported version %d for '%s' v%d",
- version_id, idstr, se->version_id);
- ret = -EINVAL;
- goto out;
- }
-
- /* Add entry */
- le = g_malloc0(sizeof(*le));
-
- le->se = se;
- le->section_id = section_id;
- le->version_id = version_id;
- QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
-
- ret = vmstate_load(f, le->se, le->version_id);
- if (ret < 0) {
- error_report("error while loading state for instance 0x%x of"
- " device '%s'", instance_id, idstr);
- goto out;
- }
- if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
- }
- break;
- case QEMU_VM_SECTION_PART:
- case QEMU_VM_SECTION_END:
- section_id = qemu_get_be32(f);
-
- trace_qemu_loadvm_state_section_partend(section_id);
- QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
- if (le->section_id == section_id) {
- break;
- }
- }
- if (le == NULL) {
- error_report("Unknown savevm section %d", section_id);
- ret = -EINVAL;
- goto out;
- }
-
- ret = vmstate_load(f, le->se, le->version_id);
- if (ret < 0) {
- error_report("error while loading state section id %d(%s)",
- section_id, le->se->idstr);
- goto out;
- }
- if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
- }
- break;
- case QEMU_VM_COMMAND:
- ret = loadvm_process_command(f);
- if (ret < 0) {
- goto out;
- }
- break;
- default:
- error_report("Unknown savevm section type %d", section_type);
- ret = -EINVAL;
- goto out;
- }
+ if (ret == 0) {
+ ret = qemu_file_get_error(f);
}
- file_error_after_eof = qemu_file_get_error(f);
-
/*
* Try to read in the VMDESC section as well, so that dumping tools that
* intercept our migration stream have the chance to see it.
@@ -1314,10 +1329,10 @@
* We also mustn't read data that isn't there; some transports (RDMA)
* will stall waiting for that data when the source has already closed.
*/
- if (should_send_vmdesc()) {
+ if (ret == 0 && should_send_vmdesc()) {
uint8_t *buf;
uint32_t size;
- section_type = qemu_get_byte(f);
+ uint8_t section_type = qemu_get_byte(f);
if (section_type != QEMU_VM_VMDESCRIPTION) {
error_report("Expected vmdescription section, but got %d",
@@ -1341,14 +1356,6 @@
cpu_synchronize_all_post_init();
- ret = 0;
-
-out:
- if (ret == 0) {
- /* We may not have a VMDESC section, so ignore relative errors */
- ret = file_error_after_eof;
- }
-
return ret;
}
diff --git a/trace-events b/trace-events
index d61fcf9..fbb099d 100644
--- a/trace-events
+++ b/trace-events
@@ -1202,7 +1202,11 @@
# migration/savevm.c
qemu_loadvm_state_section(unsigned int section_type) "%d"
+qemu_loadvm_state_section_command(int ret) "%d"
qemu_loadvm_state_section_partend(uint32_t section_id) "%u"
+qemu_loadvm_state_main(void) ""
+qemu_loadvm_state_main_quit_parent(void) ""
+qemu_loadvm_state_post_main(int ret) "%d"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
loadvm_process_command_ping(uint32_t val) "%x"
