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[Qemu-devel] [PATCH COLO-Frame v13 18/39] COLO: Flush PVM's cached RAM i
From: |
zhanghailiang |
Subject: |
[Qemu-devel] [PATCH COLO-Frame v13 18/39] COLO: Flush PVM's cached RAM into SVM's memory |
Date: |
Tue, 29 Dec 2015 15:09:14 +0800 |
During the time of VM's running, PVM may dirty some pages, we will transfer
PVM's dirty pages to SVM and store them into SVM's RAM cache at next checkpoint
time. So, the content of SVM's RAM cache will always be same with PVM's memory
after checkpoint.
Instead of flushing all content of PVM's RAM cache into SVM's MEMORY,
we do this in a more efficient way:
Only flush any page that dirtied by PVM since last checkpoint.
In this way, we can ensure SVM's memory same with PVM's.
Besides, we must ensure flush RAM cache before load device state.
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Signed-off-by: Gonglei <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
---
v12:
- Add a trace point in the end of colo_flush_ram_cache() (Dave's suggestion)
- Add Reviewed-by tag
v11:
- Move the place of 'need_flush' (Dave's suggestion)
- Remove unused 'DPRINTF("Flush ram_cache\n")'
v10:
- trace the number of dirty pages that be received.
---
include/migration/migration.h | 1 +
migration/colo.c | 2 --
migration/ram.c | 38 ++++++++++++++++++++++++++++++++++++++
trace-events | 2 ++
4 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 6907986..14b9f3d 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -336,4 +336,5 @@ PostcopyState postcopy_state_set(PostcopyState new_state);
/* ram cache */
int colo_init_ram_cache(void);
void colo_release_ram_cache(void);
+void colo_flush_ram_cache(void);
#endif
diff --git a/migration/colo.c b/migration/colo.c
index 8414feb..11d2b51 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -417,8 +417,6 @@ void *colo_process_incoming_thread(void *opaque)
}
qemu_mutex_unlock_iothread();
- /* TODO: flush vm state */
-
colo_put_cmd(mis->to_src_file, COLO_COMMAND_VMSTATE_LOADED,
&local_err);
if (local_err) {
diff --git a/migration/ram.c b/migration/ram.c
index 3d5947b..8ff7f7c 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2458,6 +2458,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
* be atomic
*/
bool postcopy_running = postcopy_state_get() >=
POSTCOPY_INCOMING_LISTENING;
+ bool need_flush = false;
seq_iter++;
@@ -2492,6 +2493,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
/* After going into COLO, we should load the Page into colo_cache
*/
if (ram_cache_enable) {
host = colo_cache_from_block_offset(block, addr);
+ need_flush = true;
} else {
host = host_from_ram_block_offset(block, addr);
}
@@ -2585,6 +2587,10 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
}
rcu_read_unlock();
+
+ if (!ret && ram_cache_enable && need_flush) {
+ colo_flush_ram_cache();
+ }
DPRINTF("Completed load of VM with exit code %d seq iteration "
"%" PRIu64 "\n", ret, seq_iter);
return ret;
@@ -2657,6 +2663,38 @@ void colo_release_ram_cache(void)
rcu_read_unlock();
}
+/*
+ * Flush content of RAM cache into SVM's memory.
+ * Only flush the pages that be dirtied by PVM or SVM or both.
+ */
+void colo_flush_ram_cache(void)
+{
+ RAMBlock *block = NULL;
+ void *dst_host;
+ void *src_host;
+ ram_addr_t offset = 0;
+
+ trace_colo_flush_ram_cache_begin(migration_dirty_pages);
+ rcu_read_lock();
+ block = QLIST_FIRST_RCU(&ram_list.blocks);
+ while (block) {
+ ram_addr_t ram_addr_abs;
+ offset = migration_bitmap_find_dirty(block, offset, &ram_addr_abs);
+ migration_bitmap_clear_dirty(ram_addr_abs);
+ if (offset >= block->used_length) {
+ offset = 0;
+ block = QLIST_NEXT_RCU(block, next);
+ } else {
+ dst_host = block->host + offset;
+ src_host = block->colo_cache + offset;
+ memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+ }
+ }
+ rcu_read_unlock();
+ trace_colo_flush_ram_cache_end();
+ assert(migration_dirty_pages == 0);
+}
+
static SaveVMHandlers savevm_ram_handlers = {
.save_live_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
diff --git a/trace-events b/trace-events
index 51b2305..578b775 100644
--- a/trace-events
+++ b/trace-events
@@ -1266,6 +1266,8 @@ migration_throttle(void) ""
ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
ram_postcopy_send_discard_bitmap(void) ""
ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start:
%zx len: %zx"
+colo_flush_ram_cache_begin(uint64_t dirty_pages) "dirty_pages %" PRIu64
+colo_flush_ram_cache_end(void) ""
# hw/display/qxl.c
disable qxl_interface_set_mm_time(int qid, uint32_t mm_time) "%d %d"
--
1.8.3.1
- [Qemu-devel] [PATCH COLO-Frame v13 12/39] QEMUSizedBuffer: Introduce two help functions for qsb, (continued)
- [Qemu-devel] [PATCH COLO-Frame v13 12/39] QEMUSizedBuffer: Introduce two help functions for qsb, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 13/39] COLO: Save PVM state to secondary side when do checkpoint, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 10/39] COLO: Implement colo checkpoint protocol, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 07/39] migration: Integrate COLO checkpoint process into loadvm, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 16/39] ram/COLO: Record the dirty pages that SVM received, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 08/39] migration: Rename the'file' member of MigrationState, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 19/39] COLO: Add checkpoint-delay parameter for migrate-set-parameters, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 22/39] COLO failover: Introduce state to record failover process, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 15/39] COLO: Load PVM's dirty pages into SVM's RAM cache temporarily, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 24/39] COLO: Implement failover work for Secondary VM, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 18/39] COLO: Flush PVM's cached RAM into SVM's memory,
zhanghailiang <=
- [Qemu-devel] [PATCH COLO-Frame v13 02/39] migration: Introduce capability 'x-colo' to migration, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 20/39] COLO: synchronize PVM's state to SVM periodically, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 27/39] COLO failover: Don't do failover during loading VM's state, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 32/39] COLO: Separate the process of saving/loading ram and device state, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 23/39] COLO: Implement failover work for Primary VM, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 11/39] COLO: Add a new RunState RUN_STATE_COLO, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 09/39] COLO/migration: Create a new communication path from destination to source, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 33/39] COLO: Split qemu_savevm_state_begin out of checkpoint process, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 14/39] ram: Split host_from_stream_offset() into two helper functions, zhanghailiang, 2015/12/29
- [Qemu-devel] [PATCH COLO-Frame v13 17/39] COLO: Load VMState into qsb before restore it, zhanghailiang, 2015/12/29