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[Qemu-devel] [PATCH COLO-Frame v7 14/34] COLO RAM: Flush cached RAM into
From: |
zhanghailiang |
Subject: |
[Qemu-devel] [PATCH COLO-Frame v7 14/34] COLO RAM: Flush cached RAM into SVM's memory |
Date: |
Thu, 9 Jul 2015 11:16:22 +0800 |
During the time of VM's running, PVM/SVM 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 some with PVM's memory
after checkpoint.
Instead of flushing all content of SVM's RAM cache into SVM's MEMORY,
we do this in a more efficient way:
Only flush any page that dirtied by PVM or SVM since last checkpoint.
In this way, we 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: Lai Jiangshan <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Signed-off-by: Yang Hongyang <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
include/migration/colo.h | 1 +
migration/colo.c | 2 --
migration/ram.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 93 insertions(+), 2 deletions(-)
diff --git a/include/migration/colo.h b/include/migration/colo.h
index 2fa9c73..c01364e 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -37,5 +37,6 @@ void *colo_process_incoming_checkpoints(void *opaque);
bool loadvm_in_colo_state(void);
/* ram cache */
int create_and_init_ram_cache(void);
+void colo_flush_ram_cache(void);
void release_ram_cache(void);
#endif
diff --git a/migration/colo.c b/migration/colo.c
index ba83966..ece8cb4 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -414,8 +414,6 @@ void *colo_process_incoming_checkpoints(void *opaque)
}
qemu_mutex_unlock_iothread();
- /* TODO: flush vm state */
-
ret = colo_ctl_put(ctl, COLO_CHECKPOINT_LOADED);
if (ret < 0) {
goto out;
diff --git a/migration/ram.c b/migration/ram.c
index 7a1a1b6..d6593f3 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1522,6 +1522,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
int flags = 0, ret = 0;
static uint64_t seq_iter;
int len = 0;
+ bool need_flush = false;
seq_iter++;
@@ -1590,6 +1591,8 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
ret = -EINVAL;
break;
}
+
+ need_flush = true;
ch = qemu_get_byte(f);
ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
break;
@@ -1600,6 +1603,8 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
ret = -EINVAL;
break;
}
+
+ need_flush = true;
qemu_get_buffer(f, host, TARGET_PAGE_SIZE);
break;
case RAM_SAVE_FLAG_COMPRESS_PAGE:
@@ -1632,6 +1637,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
ret = -EINVAL;
break;
}
+ need_flush = true;
break;
case RAM_SAVE_FLAG_EOS:
/* normal exit */
@@ -1651,6 +1657,11 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
}
rcu_read_unlock();
+
+ if (!ret && ram_cache_enable && need_flush) {
+ DPRINTF("Flush ram_cache\n");
+ colo_flush_ram_cache();
+ }
DPRINTF("Completed load of VM with exit code %d seq iteration "
"%" PRIu64 "\n", ret, seq_iter);
return ret;
@@ -1736,6 +1747,87 @@ static void
*memory_region_get_ram_cache_ptr(MemoryRegion *mr, RAMBlock *block)
return block->host_cache + (addr - block->offset);
}
+/* fix me: should this helper function be merged with
+ * migration_bitmap_find_and_reset_dirty ?
+ */
+static inline
+ram_addr_t host_bitmap_find_and_reset_dirty(MemoryRegion *mr,
+ ram_addr_t start)
+{
+ unsigned long base = mr->ram_addr >> TARGET_PAGE_BITS;
+ unsigned long nr = base + (start >> TARGET_PAGE_BITS);
+ uint64_t mr_size = TARGET_PAGE_ALIGN(memory_region_size(mr));
+ unsigned long size = base + (mr_size >> TARGET_PAGE_BITS);
+
+ unsigned long next;
+
+ next = find_next_bit(ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION],
+ size, nr);
+ if (next < size) {
+ clear_bit(next, ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION]);
+ }
+ return (next - base) << TARGET_PAGE_BITS;
+}
+
+/*
+* 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 ca = 0, ha = 0;
+ bool got_ca = 0, got_ha = 0;
+ int64_t host_dirty = 0, both_dirty = 0;
+
+ address_space_sync_dirty_bitmap(&address_space_memory);
+ rcu_read_lock();
+ block = QLIST_FIRST_RCU(&ram_list.blocks);
+ while (true) {
+ if (ca < block->used_length && ca <= ha) {
+ ca = migration_bitmap_find_and_reset_dirty(block->mr, ca);
+ if (ca < block->used_length) {
+ got_ca = 1;
+ }
+ }
+ if (ha < block->used_length && ha <= ca) {
+ ha = host_bitmap_find_and_reset_dirty(block->mr, ha);
+ if (ha < block->used_length && ha != ca) {
+ got_ha = 1;
+ }
+ host_dirty += (ha < block->used_length ? 1 : 0);
+ both_dirty += (ha < block->used_length && ha == ca ? 1 : 0);
+ }
+ if (ca >= block->used_length && ha >= block->used_length) {
+ ca = 0;
+ ha = 0;
+ block = QLIST_NEXT_RCU(block, next);
+ if (!block) {
+ break;
+ }
+ } else {
+ if (got_ha) {
+ got_ha = 0;
+ dst_host = memory_region_get_ram_ptr(block->mr) + ha;
+ src_host = memory_region_get_ram_cache_ptr(block->mr, block)
+ + ha;
+ memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+ }
+ if (got_ca) {
+ got_ca = 0;
+ dst_host = memory_region_get_ram_ptr(block->mr) + ca;
+ src_host = memory_region_get_ram_cache_ptr(block->mr, block)
+ + ca;
+ memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+ }
+ }
+ }
+ rcu_read_unlock();
+ assert(migration_dirty_pages == 0);
+}
+
static SaveVMHandlers savevm_ram_handlers = {
.save_live_setup = ram_save_setup,
.save_live_iterate = ram_save_iterate,
--
1.7.12.4
- [Qemu-devel] [PATCH COLO-Frame v7 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT), zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 08/34] COLO: Add a new RunState RUN_STATE_COLO, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 10/34] COLO: Save VM state to slave when do checkpoint, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 06/34] migration: Integrate COLO checkpoint process into loadvm, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 15/34] COLO failover: Introduce a new command to trigger a failover, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 14/34] COLO RAM: Flush cached RAM into SVM's memory,
zhanghailiang <=
- [Qemu-devel] [PATCH COLO-Frame v7 22/34] tap: Make launch_script() public, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 25/34] COLO NIC: Implement colo nic init/destroy function, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 07/34] COLO: Implement colo checkpoint protocol, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 05/34] migration: Integrate COLO checkpoint process into migration, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 09/34] QEMUSizedBuffer: Introduce two help functions for qsb, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 02/34] migration: Introduce capability 'colo' to migration, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 29/34] COLO: Improve checkpoint efficiency by do additional periodic checkpoint, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 12/34] COLO VMstate: Load VM state into qsb before restore it, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 32/34] COLO: Disable qdev hotplug when VM is in COLO mode, zhanghailiang, 2015/07/08
- [Qemu-devel] [PATCH COLO-Frame v7 30/34] COLO: Add colo-set-checkpoint-period command, zhanghailiang, 2015/07/08