migration/multifd: Add new migration option zero-page-detection.

This new parameter controls where the zero page checking is running.
1. If this parameter is set to 'legacy', zero page checking is
done in the migration main thread.
2. If this parameter is set to 'none', zero page checking is disabled.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Link: https://lore.kernel.org/r/20240311180015.3359271-4-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
Hao Xiang 2024-03-11 18:00:11 +00:00 committed by Peter Xu
parent c3cdf3fb18
commit 5fdbb1dfcc
7 changed files with 79 additions and 3 deletions

View file

@ -344,6 +344,11 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
monitor_printf(mon, "%s: %s\n",
MigrationParameter_str(MIGRATION_PARAMETER_MULTIFD_COMPRESSION),
MultiFDCompression_str(params->multifd_compression));
assert(params->has_zero_page_detection);
monitor_printf(mon, "%s: %s\n",
MigrationParameter_str(MIGRATION_PARAMETER_ZERO_PAGE_DETECTION),
qapi_enum_lookup(&ZeroPageDetection_lookup,
params->zero_page_detection));
monitor_printf(mon, "%s: %" PRIu64 " bytes\n",
MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
params->xbzrle_cache_size);
@ -634,6 +639,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
p->has_multifd_zstd_level = true;
visit_type_uint8(v, param, &p->multifd_zstd_level, &err);
break;
case MIGRATION_PARAMETER_ZERO_PAGE_DETECTION:
p->has_zero_page_detection = true;
visit_type_ZeroPageDetection(v, param, &p->zero_page_detection, &err);
break;
case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
p->has_xbzrle_cache_size = true;
if (!visit_type_size(v, param, &cache_size, &err)) {

View file

@ -179,6 +179,9 @@ Property migration_properties[] = {
DEFINE_PROP_MIG_MODE("mode", MigrationState,
parameters.mode,
MIG_MODE_NORMAL),
DEFINE_PROP_ZERO_PAGE_DETECTION("zero-page-detection", MigrationState,
parameters.zero_page_detection,
ZERO_PAGE_DETECTION_LEGACY),
/* Migration capabilities */
DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@ -938,6 +941,13 @@ uint64_t migrate_xbzrle_cache_size(void)
return s->parameters.xbzrle_cache_size;
}
ZeroPageDetection migrate_zero_page_detection(void)
{
MigrationState *s = migrate_get_current();
return s->parameters.zero_page_detection;
}
/* parameter setters */
void migrate_set_block_incremental(bool value)
@ -1048,6 +1058,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
params->vcpu_dirty_limit = s->parameters.vcpu_dirty_limit;
params->has_mode = true;
params->mode = s->parameters.mode;
params->has_zero_page_detection = true;
params->zero_page_detection = s->parameters.zero_page_detection;
return params;
}
@ -1084,6 +1096,7 @@ void migrate_params_init(MigrationParameters *params)
params->has_x_vcpu_dirty_limit_period = true;
params->has_vcpu_dirty_limit = true;
params->has_mode = true;
params->has_zero_page_detection = true;
}
/*
@ -1398,6 +1411,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params,
if (params->has_mode) {
dest->mode = params->mode;
}
if (params->has_zero_page_detection) {
dest->zero_page_detection = params->zero_page_detection;
}
}
static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@ -1548,6 +1565,10 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
if (params->has_mode) {
s->parameters.mode = params->mode;
}
if (params->has_zero_page_detection) {
s->parameters.zero_page_detection = params->zero_page_detection;
}
}
void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)

View file

@ -90,6 +90,7 @@ const char *migrate_tls_authz(void);
const char *migrate_tls_creds(void);
const char *migrate_tls_hostname(void);
uint64_t migrate_xbzrle_cache_size(void);
ZeroPageDetection migrate_zero_page_detection(void);
/* parameters setters */

View file

@ -1140,6 +1140,10 @@ static int save_zero_page(RAMState *rs, PageSearchStatus *pss,
QEMUFile *file = pss->pss_channel;
int len = 0;
if (migrate_zero_page_detection() == ZERO_PAGE_DETECTION_NONE) {
return 0;
}
if (!buffer_is_zero(p, TARGET_PAGE_SIZE)) {
return 0;
}