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[Qemu-devel] [PATCH V9 07/20] COLO: Load dirty pages into SVM's RAM cach
From: |
Zhang Chen |
Subject: |
[Qemu-devel] [PATCH V9 07/20] COLO: Load dirty pages into SVM's RAM cache firstly |
Date: |
Thu, 28 Jun 2018 04:41:23 +0800 |
We should not load PVM's state directly into SVM, because there maybe some
errors happen when SVM is receving data, which will break SVM.
We need to ensure receving all data before load the state into SVM. We use
an extra memory to cache these data (PVM's ram). The ram cache in secondary side
is initially the same as SVM/PVM's memory. And in the process of checkpoint,
we cache the dirty pages of PVM into this ram cache firstly, so this ram cache
always the same as PVM's memory at every checkpoint, then we flush this cached
ram
to SVM after we receive all PVM's state.
Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Signed-off-by: Zhang Chen <address@hidden>
---
include/exec/ram_addr.h | 1 +
migration/migration.c | 6 +++
migration/ram.c | 83 ++++++++++++++++++++++++++++++++++++++++-
migration/ram.h | 4 ++
migration/savevm.c | 2 +-
5 files changed, 93 insertions(+), 3 deletions(-)
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index cf2446a176..51ec153a57 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -27,6 +27,7 @@ struct RAMBlock {
struct rcu_head rcu;
struct MemoryRegion *mr;
uint8_t *host;
+ uint8_t *colo_cache; /* For colo, VM's ram cache */
ram_addr_t offset;
ram_addr_t used_length;
ram_addr_t max_length;
diff --git a/migration/migration.c b/migration/migration.c
index d57a23dcfd..a17f81a245 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -441,6 +441,10 @@ static void process_incoming_migration_co(void *opaque)
error_report_err(local_err);
exit(EXIT_FAILURE);
}
+ if (colo_init_ram_cache() < 0) {
+ error_report("Init ram cache failed");
+ exit(EXIT_FAILURE);
+ }
mis->migration_incoming_co = qemu_coroutine_self();
qemu_thread_create(&mis->colo_incoming_thread, "COLO incoming",
colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
@@ -449,6 +453,8 @@ static void process_incoming_migration_co(void *opaque)
/* Wait checkpoint incoming thread exit before free resource */
qemu_thread_join(&mis->colo_incoming_thread);
+ /* We hold the global iothread lock, so it is safe here */
+ colo_release_ram_cache();
}
if (ret < 0) {
diff --git a/migration/ram.c b/migration/ram.c
index cd5f55117d..30cc83996f 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2858,6 +2858,20 @@ static inline void *host_from_ram_block_offset(RAMBlock
*block,
return block->host + offset;
}
+static inline void *colo_cache_from_block_offset(RAMBlock *block,
+ ram_addr_t offset)
+{
+ if (!offset_in_ramblock(block, offset)) {
+ return NULL;
+ }
+ if (!block->colo_cache) {
+ error_report("%s: colo_cache is NULL in block :%s",
+ __func__, block->idstr);
+ return NULL;
+ }
+ return block->colo_cache + offset;
+}
+
/**
* ram_handle_compressed: handle the zero page case
*
@@ -3062,6 +3076,58 @@ static void decompress_data_with_multi_threads(QEMUFile
*f,
qemu_mutex_unlock(&decomp_done_lock);
}
+/*
+ * colo cache: this is for secondary VM, we cache the whole
+ * memory of the secondary VM, it is need to hold the global lock
+ * to call this helper.
+ */
+int colo_init_ram_cache(void)
+{
+ RAMBlock *block;
+
+ rcu_read_lock();
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ block->colo_cache = qemu_anon_ram_alloc(block->used_length,
+ NULL,
+ false);
+ if (!block->colo_cache) {
+ error_report("%s: Can't alloc memory for COLO cache of block %s,"
+ "size 0x" RAM_ADDR_FMT, __func__, block->idstr,
+ block->used_length);
+ goto out_locked;
+ }
+ memcpy(block->colo_cache, block->host, block->used_length);
+ }
+ rcu_read_unlock();
+ return 0;
+
+out_locked:
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ if (block->colo_cache) {
+ qemu_anon_ram_free(block->colo_cache, block->used_length);
+ block->colo_cache = NULL;
+ }
+ }
+
+ rcu_read_unlock();
+ return -errno;
+}
+
+/* It is need to hold the global lock to call this helper */
+void colo_release_ram_cache(void)
+{
+ RAMBlock *block;
+
+ rcu_read_lock();
+ QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+ if (block->colo_cache) {
+ qemu_anon_ram_free(block->colo_cache, block->used_length);
+ block->colo_cache = NULL;
+ }
+ }
+ rcu_read_unlock();
+}
+
/**
* ram_load_setup: Setup RAM for migration incoming side
*
@@ -3078,6 +3144,7 @@ static int ram_load_setup(QEMUFile *f, void *opaque)
xbzrle_load_setup();
ramblock_recv_map_init();
+
return 0;
}
@@ -3091,6 +3158,7 @@ static int ram_load_cleanup(void *opaque)
g_free(rb->receivedmap);
rb->receivedmap = NULL;
}
+
return 0;
}
@@ -3324,13 +3392,24 @@ static int ram_load(QEMUFile *f, void *opaque, int
version_id)
RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
RAMBlock *block = ram_block_from_stream(f, flags);
- host = host_from_ram_block_offset(block, addr);
+ /*
+ * After going into COLO, we should load the Page into colo_cache.
+ */
+ if (migration_incoming_in_colo_state()) {
+ host = colo_cache_from_block_offset(block, addr);
+ } else {
+ host = host_from_ram_block_offset(block, addr);
+ }
if (!host) {
error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
ret = -EINVAL;
break;
}
- ramblock_recv_bitmap_set(block, host);
+
+ if (!migration_incoming_in_colo_state()) {
+ ramblock_recv_bitmap_set(block, host);
+ }
+
trace_ram_load_loop(block->idstr, (uint64_t)addr, flags, host);
}
diff --git a/migration/ram.h b/migration/ram.h
index d386f4d641..d5e81d4d48 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -70,4 +70,8 @@ int64_t ramblock_recv_bitmap_send(QEMUFile *file,
const char *block_name);
int ram_dirty_bitmap_reload(MigrationState *s, RAMBlock *rb);
+/* ram cache */
+int colo_init_ram_cache(void);
+void colo_release_ram_cache(void);
+
#endif
diff --git a/migration/savevm.c b/migration/savevm.c
index 3e5b85636f..fe9ca86a78 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1929,7 +1929,7 @@ static int
loadvm_handle_recv_bitmap(MigrationIncomingState *mis,
static int loadvm_process_enable_colo(MigrationIncomingState *mis)
{
migration_incoming_enable_colo();
- return 0;
+ return colo_init_ram_cache();
}
/*
--
2.17.GIT
- [Qemu-devel] [PATCH V9 00/20] COLO: integrate colo frame with block replication and COLO proxy, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 01/20] filter-rewriter: Add TCP state machine and fix memory leak in connection_track_table, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 02/20] colo-compare: implement the process of checkpoint, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 03/20] colo-compare: use notifier to notify packets comparing result, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 04/20] COLO: integrate colo compare with colo frame, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 05/20] COLO: Add block replication into colo process, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 06/20] COLO: Remove colo_state migration struct, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 07/20] COLO: Load dirty pages into SVM's RAM cache firstly,
Zhang Chen <=
- [Qemu-devel] [PATCH V9 08/20] ram/COLO: Record the dirty pages that SVM received, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 09/20] COLO: Flush memory data from ram cache, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 10/20] qmp event: Add COLO_EXIT event to notify users while exited COLO, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 11/20] qapi/migration.json: Rename COLO unknown mode to none mode., Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 12/20] qapi: Add new command to query colo status, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 14/20] COLO: flush host dirty ram from cache, Zhang Chen, 2018/06/27
- [Qemu-devel] [PATCH V9 13/20] savevm: split the process of different stages for loadvm/savevm, Zhang Chen, 2018/06/27