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[Qemu-devel] [PATCH COLO-Frame v16 14/35] COLO: Flush PVM's cached RAM i
From: |
zhanghailiang |
Subject: |
[Qemu-devel] [PATCH COLO-Frame v16 14/35] COLO: Flush PVM's cached RAM into SVM's memory |
Date: |
Fri, 8 Apr 2016 14:26:16 +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 d7e6e81..820e008 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -341,4 +341,5 @@ 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 52a2c3e..4dae069 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -418,8 +418,6 @@ 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 0af43d4..1f399a8 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 2a630dd..ebd93ee 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 v16 03/35] COLO: migrate colo related info to secondary node, (continued)
- [Qemu-devel] [PATCH COLO-Frame v16 03/35] COLO: migrate colo related info to secondary node, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 05/35] migration: Integrate COLO checkpoint process into loadvm, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 02/35] migration: Introduce capability 'x-colo' to migration, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 01/35] configure: Add parameter for configure to enable/disable COLO support, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 06/35] COLO/migration: Create a new communication path from destination to source, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 07/35] COLO: Implement colo checkpoint protocol, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 04/35] migration: Integrate COLO checkpoint process into migration, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 09/35] QEMUSizedBuffer: Introduce two help functions for qsb, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 13/35] COLO: Load VMState into qsb before restore it, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 10/35] COLO: Save PVM state to secondary side when do checkpoint, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 14/35] COLO: Flush PVM's cached RAM into SVM's memory,
zhanghailiang <=
- [Qemu-devel] [PATCH COLO-Frame v16 12/35] ram/COLO: Record the dirty pages that SVM received, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 23/35] COLO failover: Don't do failover during loading VM's state, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 20/35] COLO: Implement failover work for Secondary VM, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 16/35] COLO: synchronize PVM's state to SVM periodically, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 26/35] savevm: Introduce two helper functions for save/find loadvm_handlers entry, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 27/35] migration/savevm: Add new helpers to process the different stages of loadvm, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 28/35] migration/savevm: Export two helper functions for savevm process, zhanghailiang, 2016/04/08
- [Qemu-devel] [PATCH COLO-Frame v16 24/35] COLO: Process shutdown command for VM in COLO state, zhanghailiang, 2016/04/08