We record the address of the dirty pages that received,
it will help flushing pages that cached into SVM.
We record them by re-using migration dirty bitmap.
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
v16:
- Use the new wrapper memory_region_get_ram_addr() modified in commit 7ebb2745
v12:
- Add Reviewed-by tag
v11:
- Split a new helper function from original
host_from_stream_offset() (Dave's suggestion)
- Only do recording work in this patch
v10:
- New patch split from v9's patch 13
- Rebase to master to use 'migration_bitmap_rcu'
---
migration/ram.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index ac55980..99449c3 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2190,6 +2190,9 @@ static inline void *host_from_ram_block_offset(RAMBlock
*block,
static inline void *colo_cache_from_block_offset(RAMBlock *block,
ram_addr_t offset)
{
+ unsigned long *bitmap;
+ long k;
+
if (!offset_in_ramblock(block, offset)) {
return NULL;
}
@@ -2198,6 +2201,17 @@ static inline void
*colo_cache_from_block_offset(RAMBlock *block,
__func__, block->idstr);
return NULL;
}
+
+ k = (memory_region_get_ram_addr(block->mr) + offset) >> TARGET_PAGE_BITS;
+ bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+ /*
+ * During colo checkpoint, we need bitmap of these migrated pages.
+ * It help us to decide which pages in ram cache should be flushed
+ * into VM's RAM later.
+ */
+ if (!test_and_set_bit(k, bitmap)) {
+ migration_dirty_pages++;
+ }
return block->colo_cache + offset;
}
@@ -2624,6 +2638,7 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
int colo_init_ram_cache(void)
{
RAMBlock *block;
+ int64_t ram_cache_pages = last_ram_offset() >> TARGET_PAGE_BITS;
rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
@@ -2638,6 +2653,15 @@ int colo_init_ram_cache(void)
}
rcu_read_unlock();
ram_cache_enable = true;
+ /*
+ * Record the dirty pages that sent by PVM, we use this dirty bitmap
together
+ * with to decide which page in cache should be flushed into SVM's RAM. Here
+ * we use the same name 'migration_bitmap_rcu' as for migration.
+ */
+ migration_bitmap_rcu = g_new0(struct BitmapRcu, 1);
+ migration_bitmap_rcu->bmap = bitmap_new(ram_cache_pages);
+ migration_dirty_pages = 0;
+
return 0;
out_locked:
@@ -2655,9 +2679,15 @@ out_locked:
void colo_release_ram_cache(void)
{
RAMBlock *block;
+ struct BitmapRcu *bitmap = migration_bitmap_rcu;
ram_cache_enable = false;
+ atomic_rcu_set(&migration_bitmap_rcu, NULL);
+ if (bitmap) {
+ call_rcu(bitmap, migration_bitmap_free, rcu);
+ }
+
rcu_read_lock();
QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
if (block->colo_cache) {
--
1.8.3.1
