From: Junyan He <junyan...@intel.com>
When we save snapshot, we need qemu_file to support save dependency
operations. It should call brv_driver's save dependency functions
to implement these operations.
Signed-off-by: Junyan He <junyan...@intel.com>
---
migration/qemu-file.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++
migration/qemu-file.h | 14 ++++++++++++
migration/savevm.c | 33 +++++++++++++++++++++++++---
3 files changed, 105 insertions(+), 3 deletions(-)
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 2ab2bf3..9d2a39a 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -46,10 +46,13 @@ struct QEMUFile {
int buf_index;
int buf_size; /* 0 when writing */
uint8_t buf[IO_BUF_SIZE];
+ char ref_name_str[128]; /* maybe snapshot id */
DECLARE_BITMAP(may_free, MAX_IOV_SIZE);
struct iovec iov[MAX_IOV_SIZE];
unsigned int iovcnt;
+ bool support_dependency;
+ int32_t dependency_aligment;
int last_error;
};
@@ -745,3 +748,61 @@ void qemu_file_set_blocking(QEMUFile *f, bool block)
f->ops->set_blocking(f->opaque, block);
}
}
+
+void qemu_file_set_support_dependency(QEMUFile *f, int32_t alignment)
+{
+ f->dependency_aligment = alignment;
+ f->support_dependency = true;
+}
+
+bool qemu_file_is_support_dependency(QEMUFile *f, int32_t *alignment)
+{
+ if (f->support_dependency && alignment) {
+ *alignment = f->dependency_aligment;
+ }
+
+ return f->support_dependency;
+}
+
+/* This function set the reference name for snapshot usage. Sometimes it needs
+ * to depend on other snapshot's data to avoid redundance.
+ */
+bool qemu_file_set_ref_name(QEMUFile *f, const char *name)
+{
+ if (strlen(name) + 1 > sizeof(f->ref_name_str)) {
+ return false;
+ }
+
+ memcpy(f->ref_name_str, name, strlen(name) + 1);
+ return true;
+}
+
+ssize_t qemu_file_save_dependency(QEMUFile *f, int64_t depend_offset,
+ int64_t size)
+{
+ ssize_t ret;
+
+ if (f->support_dependency == false) {
+ return -1;
+ }
+
+ assert(f->ops->save_dependency);
+
+ if (!QEMU_IS_ALIGNED(depend_offset, f->dependency_aligment)) {
+ return -1;
+ }
+
+ qemu_fflush(f);
+
+ if (!QEMU_IS_ALIGNED(f->pos, f->dependency_aligment)) {
+ return -1;
+ }
+
+ ret = f->ops->save_dependency(f->opaque, f->ref_name_str,
+ depend_offset, size, f->pos);
+ if (ret > 0) {
+ f->pos += size;
+ }
+
+ return ret;
+}
diff --git a/migration/qemu-file.h b/migration/qemu-file.h
index aae4e5e..137b917 100644
--- a/migration/qemu-file.h
+++ b/migration/qemu-file.h
@@ -57,6 +57,14 @@ typedef ssize_t (QEMUFileWritevBufferFunc)(void *opaque,
struct iovec *iov,
int iovcnt, int64_t pos);
/*
+ * This function add reference to the dependency data in snapshot specified by
+ * ref_name_str to this file's offset
+ */
+typedef ssize_t (QEMUFileSaveDependencyFunc)(void *opaque, const char *name,
+ int64_t depend_offset,
+ int64_t offset, int64_t size);
+
+/*
* This function provides hooks around different
* stages of RAM migration.
* 'opaque' is the backend specific data in QEMUFile
@@ -104,6 +112,7 @@ typedef struct QEMUFileOps {
QEMUFileWritevBufferFunc *writev_buffer;
QEMURetPathFunc *get_return_path;
QEMUFileShutdownFunc *shut_down;
+ QEMUFileSaveDependencyFunc *save_dependency;
} QEMUFileOps;
typedef struct QEMUFileHooks {
@@ -153,6 +162,11 @@ int qemu_file_shutdown(QEMUFile *f);
QEMUFile *qemu_file_get_return_path(QEMUFile *f);
void qemu_fflush(QEMUFile *f);
void qemu_file_set_blocking(QEMUFile *f, bool block);
+bool qemu_file_set_ref_name(QEMUFile *f, const char *name);
+void qemu_file_set_support_dependency(QEMUFile *f, int32_t alignment);
+bool qemu_file_is_support_dependency(QEMUFile *f, int32_t *alignment);
+ssize_t qemu_file_save_dependency(QEMUFile *f, int64_t depend_offset,
+ int64_t size);
size_t qemu_get_counted_string(QEMUFile *f, char buf[256]);
diff --git a/migration/savevm.c b/migration/savevm.c
index 358c5b5..1bbd6aa 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -196,6 +196,20 @@ static ssize_t block_writev_buffer(void *opaque, struct
iovec *iov, int iovcnt,
return qiov.size;
}
+static ssize_t block_save_dependency(void *opaque, const char *id_name,
+ int64_t depend_offset,
+ int64_t offset, int64_t size)
+{
+ int ret = bdrv_snapshot_save_dependency(opaque, id_name,
+ depend_offset, offset,
+ size, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return size;
+}
+
static ssize_t block_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
size_t size)
{
@@ -213,15 +227,28 @@ static const QEMUFileOps bdrv_read_ops = {
};
static const QEMUFileOps bdrv_write_ops = {
- .writev_buffer = block_writev_buffer,
- .close = bdrv_fclose
+ .writev_buffer = block_writev_buffer,
+ .close = bdrv_fclose,
+ .save_dependency = block_save_dependency
};
static QEMUFile *qemu_fopen_bdrv(BlockDriverState *bs, int is_writable)
{
+ int ret = 0;
+ int32_t alignment = 0;
+ QEMUFile *f = NULL;
+
if (is_writable) {
- return qemu_fopen_ops(bs, &bdrv_write_ops);
+ f = qemu_fopen_ops(bs, &bdrv_write_ops);
+
+ ret = bdrv_snapshot_support_dependency(bs, &alignment);
+ if (ret > 0) {
+ qemu_file_set_support_dependency(f, alignment);
+ }
+
+ return f;
}
+
return qemu_fopen_ops(bs, &bdrv_read_ops);
}
--
2.7.4
