@@ -472,12 +472,18 @@
# Requires that QEMU be permitted to use locked memory
# for guest RAM pages.
# (since 7.1)
+#
# @postcopy-preempt: If enabled, the migration process will allow postcopy
# requests to preempt precopy stream, so postcopy requests
# will be handled faster. This is a performance feature and
# should not affect the correctness of postcopy migration.
# (since 7.1)
#
+# @main-zero-page: If enabled, the detection of zero pages will be
+# done on the main thread. Otherwise it is done on
+# the multifd threads.
+# (since 8.0)
+#
# Features:
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
#
@@ -492,7 +498,7 @@
'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',
{ 'name': 'x-ignore-shared', 'features': [ 'unstable' ] },
'validate-uuid', 'background-snapshot',
- 'zero-copy-send', 'postcopy-preempt'] }
+ 'zero-copy-send', 'postcopy-preempt', 'main-zero-page'] }
##
# @MigrationCapabilityStatus:
@@ -408,6 +408,7 @@ int migrate_multifd_channels(void);
MultiFDCompression migrate_multifd_compression(void);
int migrate_multifd_zlib_level(void);
int migrate_multifd_zstd_level(void);
+bool migrate_use_main_zero_page(void);
#ifdef CONFIG_LINUX
bool migrate_use_zero_copy_send(void);
@@ -48,6 +48,7 @@ const size_t hw_compat_7_1_len = G_N_ELEMENTS(hw_compat_7_1);
GlobalProperty hw_compat_7_0[] = {
{ "arm-gicv3-common", "force-8-bit-prio", "on" },
{ "nvme-ns", "eui64-default", "on"},
+ { "migration", "main-zero-page", "true" },
};
const size_t hw_compat_7_0_len = G_N_ELEMENTS(hw_compat_7_0);
@@ -164,7 +164,8 @@ INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
MIGRATION_CAPABILITY_XBZRLE,
MIGRATION_CAPABILITY_X_COLO,
MIGRATION_CAPABILITY_VALIDATE_UUID,
- MIGRATION_CAPABILITY_ZERO_COPY_SEND);
+ MIGRATION_CAPABILITY_ZERO_COPY_SEND,
+ MIGRATION_CAPABILITY_MAIN_ZERO_PAGE);
/* When we add fault tolerance, we could have several
migrations at once. For now we don't need to add
@@ -2611,6 +2612,14 @@ bool migrate_use_multifd(void)
return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
}
+bool migrate_use_main_zero_page(void)
+{
+ MigrationState *s = migrate_get_current();
+
+ /* We will enable this when we add the right code. */
+ return true || s->enabled_capabilities[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE];
+}
+
bool migrate_pause_before_switchover(void)
{
MigrationState *s;
@@ -4427,6 +4436,8 @@ static Property migration_properties[] = {
DEFINE_PROP_MIG_CAP("x-zero-copy-send",
MIGRATION_CAPABILITY_ZERO_COPY_SEND),
#endif
+ DEFINE_PROP_MIG_CAP("main-zero-page",
+ MIGRATION_CAPABILITY_MAIN_ZERO_PAGE),
DEFINE_PROP_END_OF_LIST(),
};
We have to enable it by default until we introduce the new code. Signed-off-by: Juan Quintela <quintela@redhat.com> --- Change it to a capability. As capabilities are off by default, have to change MULTIFD_ZERO_PAGE to MAIN_ZERO_PAGE, so it is false for default, and true for older versions. --- qapi/migration.json | 8 +++++++- migration/migration.h | 1 + hw/core/machine.c | 1 + migration/migration.c | 13 ++++++++++++- 4 files changed, 21 insertions(+), 2 deletions(-)