From: Juan Quintela <quint...@redhat.com>
Signed-off-by: Juan Quintela <quint...@redhat.com>
Reviewed-by: Leonardo Bras <leob...@redhat.com>
---
migration/multifd.c | 7 ++++---
migration/options.c | 13 +++++++------
migration/ram.c | 45 ++++++++++++++++++++++++++++++++++++++-------
qapi/migration.json | 1 -
4 files changed, 49 insertions(+), 17 deletions(-)
diff --git a/migration/multifd.c b/migration/multifd.c
index 1b994790d5..1198ffde9c 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -13,6 +13,7 @@
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "qemu/rcu.h"
+#include "qemu/cutils.h"
#include "exec/target_page.h"
#include "sysemu/sysemu.h"
#include "exec/ramblock.h"
@@ -459,7 +460,6 @@ static int multifd_send_pages(QEMUFile *f)
p->packet_num = multifd_send_state->packet_num++;
multifd_send_state->pages = p->pages;
p->pages = pages;
-
qemu_mutex_unlock(&p->mutex);
qemu_sem_post(&p->sem);
@@ -684,7 +684,7 @@ static void *multifd_send_thread(void *opaque)
MigrationThread *thread = NULL;
Error *local_err = NULL;
/* qemu older than 8.2 don't understand zero page on multifd channel */
- bool use_zero_page = !migrate_use_main_zero_page();
+ bool use_multifd_zero_page = !migrate_use_main_zero_page();
int ret = 0;
bool use_zero_copy_send = migrate_zero_copy_send();
@@ -713,6 +713,7 @@ static void *multifd_send_thread(void *opaque)
RAMBlock *rb = p->pages->block;
uint64_t packet_num = p->packet_num;
uint32_t flags;
+
p->normal_num = 0;
p->zero_num = 0;
@@ -724,7 +725,7 @@ static void *multifd_send_thread(void *opaque)
for (int i = 0; i < p->pages->num; i++) {
uint64_t offset = p->pages->offset[i];
- if (use_zero_page &&
+ if (use_multifd_zero_page &&
buffer_is_zero(rb->host + offset, p->page_size)) {
p->zero[p->zero_num] = offset;
p->zero_num++;
diff --git a/migration/options.c b/migration/options.c
index 00c0c4a0d6..97d121d4d7 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -195,6 +195,7 @@ Property migration_properties[] = {
DEFINE_PROP_MIG_CAP("x-block", MIGRATION_CAPABILITY_BLOCK),
DEFINE_PROP_MIG_CAP("x-return-path", MIGRATION_CAPABILITY_RETURN_PATH),
DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD),
+ DEFINE_PROP_MIG_CAP("x-main-zero-page",
MIGRATION_CAPABILITY_MAIN_ZERO_PAGE),
DEFINE_PROP_MIG_CAP("x-background-snapshot",
MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT),
#ifdef CONFIG_LINUX
@@ -288,13 +289,9 @@ bool migrate_multifd(void)
bool migrate_use_main_zero_page(void)
{
- //MigrationState *s;
-
- //s = migrate_get_current();
+ MigrationState *s = migrate_get_current();
- // We will enable this when we add the right code.
- // return s->enabled_capabilities[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE];
- return true;
+ return s->capabilities[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE];
}
bool migrate_pause_before_switchover(void)
@@ -457,6 +454,7 @@ INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE,
MIGRATION_CAPABILITY_RETURN_PATH,
MIGRATION_CAPABILITY_MULTIFD,
+ MIGRATION_CAPABILITY_MAIN_ZERO_PAGE,
MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER,
MIGRATION_CAPABILITY_AUTO_CONVERGE,
MIGRATION_CAPABILITY_RELEASE_RAM,
@@ -534,6 +532,9 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps,
Error **errp)
error_setg(errp, "Postcopy is not yet compatible with multifd");
return false;
}
+ if (new_caps[MIGRATION_CAPABILITY_MAIN_ZERO_PAGE]) {
+ error_setg(errp, "Postcopy is not yet compatible with main zero
copy");
+ }
}
if (new_caps[MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT]) {
diff --git a/migration/ram.c b/migration/ram.c
index 8c7886ab79..f7a42feff2 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2059,17 +2059,42 @@ static int ram_save_target_page_legacy(RAMState *rs,
PageSearchStatus *pss)
if (save_zero_page(rs, pss, offset)) {
return 1;
}
-
/*
- * Do not use multifd in postcopy as one whole host page should be
- * placed. Meanwhile postcopy requires atomic update of pages, so even
- * if host page size == guest page size the dest guest during run may
- * still see partially copied pages which is data corruption.
+ * Do not use multifd for:
+ * 1. Compression as the first page in the new block should be posted out
+ * before sending the compressed page
+ * 2. In postcopy as one whole host page should be placed
*/
- if (migrate_multifd() && !migration_in_postcopy()) {
+ if (!migrate_compress() && migrate_multifd() && !migration_in_postcopy()) {
+ return ram_save_multifd_page(pss->pss_channel, block, offset);
+ }
+
+ return ram_save_page(rs, pss);
+}
+
+/**
+ * ram_save_target_page_multifd: save one target page
+ *
+ * Returns the number of pages written
+ *
+ * @rs: current RAM state
+ * @pss: data about the page we want to send
+ */
+static int ram_save_target_page_multifd(RAMState *rs, PageSearchStatus *pss)
+{
+ RAMBlock *block = pss->block;
+ ram_addr_t offset = ((ram_addr_t)pss->page) << TARGET_PAGE_BITS;
+ int res;
+
+ if (!migration_in_postcopy()) {
return ram_save_multifd_page(pss->pss_channel, block, offset);
}
+ res = save_zero_page(rs, pss, offset);
+ if (res > 0) {
+ return res;
+ }
+
return ram_save_page(rs, pss);
}
@@ -2982,9 +3007,15 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
}
migration_ops = g_malloc0(sizeof(MigrationOps));
- migration_ops->ram_save_target_page = ram_save_target_page_legacy;
+
+ if (migrate_multifd() && !migrate_use_main_zero_page()) {
+ migration_ops->ram_save_target_page = ram_save_target_page_multifd;
+ } else {
+ migration_ops->ram_save_target_page = ram_save_target_page_legacy;
+ }
qemu_mutex_unlock_iothread();
+
ret = multifd_send_sync_main(f);
qemu_mutex_lock_iothread();
if (ret < 0) {
diff --git a/qapi/migration.json b/qapi/migration.json
index 09e4393591..9783289bfc 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -531,7 +531,6 @@
# and can result in more stable read performance. Requires KVM
# with accelerator property "dirty-ring-size" set. (Since 8.1)
#
-#
# @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.
--
2.30.2
