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>
This commit is contained in:
Dr. David Alan Gilbert 2015-11-05 18:10:50 +00:00 committed by Juan Quintela
parent 70b2047774
commit 7b89bf279f
4 changed files with 129 additions and 110 deletions

View File

@ -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 */

View File

@ -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;

View File

@ -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)
@ -1162,14 +1169,113 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
}
}
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 @@ int qemu_loadvm_state(QEMUFile *f)
}
}
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 @@ 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",
@ -1341,14 +1356,6 @@ 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;
}

View File

@ -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"