From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
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 <dgilb...@redhat.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
Reviewed-by: Amit Shah <amit.s...@redhat.com>
Signed-off-by: Juan Quintela <quint...@redhat.com>
---
include/migration/migration.h | 6 ++
migration/migration.c | 2 +
migration/savevm.c | 141 ++++++++++++++++++++++--------------------
trace-events | 4 ++
4 files changed, 86 insertions(+), 67 deletions(-)
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 @@ typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
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 b0782c6..dd422a2 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -98,12 +98,14 @@ MigrationIncomingState
*migration_incoming_state_new(QEMUFile* f)
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 1a29a31..38ec58f 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1051,11 +1051,18 @@ static SaveStateEntry *find_se(const char *idstr, int
instance_id)
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)
@@ -1161,47 +1168,10 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
}
}
-int qemu_loadvm_state(QEMUFile *f)
+static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
{
- 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);
- return -EINVAL;
- }
-
- v = qemu_get_be32(f);
- if (v != QEMU_VM_FILE_MAGIC) {
- error_report("Not a migration stream");
- return -EINVAL;
- }
-
- v = qemu_get_be32(f);
- if (v == QEMU_VM_FILE_VERSION_COMPAT) {
- error_report("SaveVM v2 format is obsolete and don't work anymore");
- return -ENOTSUP;
- }
- if (v != QEMU_VM_FILE_VERSION) {
- error_report("Unsupported migration stream version");
- return -ENOTSUP;
- }
-
- if (!savevm_state.skip_configuration) {
- if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
- error_report("Configuration section missing");
- return -EINVAL;
- }
- ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
-
- if (ret) {
- return ret;
- }
- }
while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) {
uint32_t instance_id, version_id, section_id;
@@ -1230,16 +1200,14 @@ int qemu_loadvm_state(QEMUFile *f)
if (se == NULL) {
error_report("Unknown savevm section or instance '%s' %d",
idstr, instance_id);
- ret = -EINVAL;
- goto out;
+ 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);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
/* Add entry */
@@ -1254,11 +1222,10 @@ int qemu_loadvm_state(QEMUFile *f)
if (ret < 0) {
error_report("error while loading state for instance 0x%x of"
" device '%s'", instance_id, idstr);
- goto out;
+ return ret;
}
if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
break;
case QEMU_VM_SECTION_PART:
@@ -1273,35 +1240,83 @@ int qemu_loadvm_state(QEMUFile *f)
}
if (le == NULL) {
error_report("Unknown savevm section %d", section_id);
- ret = -EINVAL;
- goto out;
+ 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);
- goto out;
+ return ret;
}
if (!check_section_footer(f, le)) {
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
break;
case QEMU_VM_COMMAND:
ret = loadvm_process_command(f);
- if (ret < 0) {
- goto out;
+ 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);
- ret = -EINVAL;
- goto out;
+ return -EINVAL;
}
}
- file_error_after_eof = qemu_file_get_error(f);
+ return 0;
+}
+
+int qemu_loadvm_state(QEMUFile *f)
+{
+ MigrationIncomingState *mis = migration_incoming_get_current();
+ Error *local_err = NULL;
+ unsigned int v;
+ int ret;
+
+ if (qemu_savevm_state_blocked(&local_err)) {
+ error_report_err(local_err);
+ return -EINVAL;
+ }
+
+ v = qemu_get_be32(f);
+ if (v != QEMU_VM_FILE_MAGIC) {
+ error_report("Not a migration stream");
+ return -EINVAL;
+ }
+
+ v = qemu_get_be32(f);
+ if (v == QEMU_VM_FILE_VERSION_COMPAT) {
+ error_report("SaveVM v2 format is obsolete and don't work anymore");
+ return -ENOTSUP;
+ }
+ if (v != QEMU_VM_FILE_VERSION) {
+ error_report("Unsupported migration stream version");
+ return -ENOTSUP;
+ }
+
+ if (!savevm_state.skip_configuration) {
+ if (qemu_get_byte(f) != QEMU_VM_CONFIGURATION) {
+ error_report("Configuration section missing");
+ return -EINVAL;
+ }
+ ret = vmstate_load_state(f, &vmstate_configuration, &savevm_state, 0);
+
+ if (ret) {
+ return ret;
+ }
+ }
+
+ ret = qemu_loadvm_state_main(f, mis);
+ qemu_event_set(&mis->main_thread_load_event);
+
+ trace_qemu_loadvm_state_post_main(ret);
+
+ if (ret == 0) {
+ ret = qemu_file_get_error(f);
+ }
/*
* Try to read in the VMDESC section as well, so that dumping tools that
@@ -1313,10 +1328,10 @@ int qemu_loadvm_state(QEMUFile *f)
* 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",
@@ -1340,14 +1355,6 @@ int qemu_loadvm_state(QEMUFile *f)
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 @@ virtio_gpu_fence_resp(uint64_t fence) "fence 0x%" PRIx64
# 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"
--
2.5.0
