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[Qemu-devel] [PATCH COLO-Frame v17 13/34] COLO: Flush PVM's cached RAM i
From: |
zhanghailiang |
Subject: |
[Qemu-devel] [PATCH COLO-Frame v17 13/34] COLO: Flush PVM's cached RAM into SVM's memory |
Date: |
Fri, 3 Jun 2016 15:52:25 +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 5cd1ff1..566b2a5 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -364,4 +364,5 @@ 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 28aef3f..396cdcf 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -408,8 +408,6 @@ void *colo_process_incoming_thread(void *opaque)
}
qemu_mutex_unlock_iothread();
- /* TODO: flush vm state */
-
colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
&local_err);
if (local_err) {
diff --git a/migration/ram.c b/migration/ram.c
index 13e28c7..91d1287 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2466,6 +2466,7 @@ 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++;
@@ -2500,6 +2501,7 @@ 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);
}
@@ -2592,6 +2594,10 @@ 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;
@@ -2664,6 +2670,38 @@ 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 1dd4344..b58adc3 100644
--- a/trace-events
+++ b/trace-events
@@ -1286,6 +1286,8 @@ 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 v17 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT), zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 01/34] configure: Add parameter for configure to enable/disable COLO support, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 06/34] COLO/migration: Create a new communication path from destination to source, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 04/34] migration: Integrate COLO checkpoint process into migration, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 02/34] migration: Introduce capability 'x-colo' to migration, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 07/34] COLO: Implement COLO checkpoint protocol, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 09/34] COLO: Save PVM state to secondary side when do checkpoint, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 13/34] COLO: Flush PVM's cached RAM into SVM's memory,
zhanghailiang <=
- [Qemu-devel] [PATCH COLO-Frame v17 12/34] COLO: Load VMState into buffer before restore it, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 15/34] COLO: Synchronize PVM's state to SVM periodically, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 14/34] COLO: Add checkpoint-delay parameter for migrate-set-parameters, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 08/34] COLO: Add a new RunState RUN_STATE_COLO, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 27/34] migration/savevm: Export two helper functions for savevm process, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 10/34] COLO: Load PVM's dirty pages into SVM's RAM cache temporarily, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 21/34] COLO failover: Shutdown related socket fd when do failover, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 03/34] COLO: migrate colo related info to secondary node, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 11/34] ram/COLO: Record the dirty pages that SVM received, zhanghailiang, 2016/06/03
- [Qemu-devel] [PATCH COLO-Frame v17 18/34] COLO: Implement failover work for Primary VM, zhanghailiang, 2016/06/03