[Qemu-devel] [PATCH v5 3/9] dump: Add API to write vmcore

[Qiao Nuohan <qiaonuohan@cn.fujitsu.com>]

Function is used to write vmcore. If flag_flatten is specified, flatten format
will be used. In flatten format, data is written block by block in vmcore.
struct MakedumpfileDataHeader is used to indicate the offset and size of a data
block.

struct MakedumpfileDataHeader {
    int64_t offset;
    int64_t buf_size;
};

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Zhang Xiaohe <zhangxh@cn.fujitsu.com>
---
 dump.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index f04d4fc..6f14b8d 100644
--- a/dump.c
+++ b/dump.c
@@ -714,6 +714,34 @@ static int write_end_flat_header(int fd)
     return 0;
 }
 
+static int write_buffer(int fd, bool flag_flatten, off_t offset, void *buf,
+                        size_t size)
+{
+    size_t written_size;
+    MakedumpfileDataHeader mdh;
+
+    if (flag_flatten) {
+        mdh.offset = cpu_to_be64(offset);
+        mdh.buf_size = cpu_to_be64(size);
+
+        written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
+        if (written_size != sizeof(mdh)) {
+            return -1;
+        }
+    } else {
+        if (lseek(fd, offset, SEEK_SET) < 0) {
+            return -1;
+        }
+    }
+
+    written_size = qemu_write_full(fd, buf, size);
+    if (written_size != size) {
+        return -1;
+    }
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     RAMBlock *block;
-- 
1.7.1