Introduce two new QEMUSizedBuffer APIs which will be used by COLO to buffer
VM state:
One is qsb_put_buffer(), which put the content of a given QEMUSizedBuffer
into QEMUFile, this is used to send buffered VM state to secondary.
Another is qsb_fill_buffer(), read 'size' bytes of data from the file into
qsb, this is used to get VM state from socket into a buffer.
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
v11:
- size_t'ify these two help functions (Dave's suggestion)
Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
---
include/migration/qemu-file.h | 3 ++-
migration/qemu-file-buf.c | 61 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h
index b5d08d2..ca6a582 100644
--- a/include/migration/qemu-file.h
+++ b/include/migration/qemu-file.h
@@ -150,7 +150,8 @@ ssize_t qsb_get_buffer(const QEMUSizedBuffer *, off_t
start, size_t count,
uint8_t *buf);
ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t *buf,
off_t pos, size_t count);
-
+void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, size_t size);
+size_t qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, size_t size);
/*
* For use on files opened with qemu_bufopen
diff --git a/migration/qemu-file-buf.c b/migration/qemu-file-buf.c
index 49516b8..c50a495 100644
--- a/migration/qemu-file-buf.c
+++ b/migration/qemu-file-buf.c
@@ -366,6 +366,67 @@ ssize_t qsb_write_at(QEMUSizedBuffer *qsb, const uint8_t
*source,
return count;
}
+/**
+ * Put the content of a given QEMUSizedBuffer into QEMUFile.
+ *
+ * @f: A QEMUFile
+ * @qsb: A QEMUSizedBuffer
+ * @size: size of content to write
+ */
+void qsb_put_buffer(QEMUFile *f, QEMUSizedBuffer *qsb, size_t size)
+{
+ size_t l;
+ int i;
+
+ for (i = 0; i < qsb->n_iov && size > 0; i++) {
+ l = MIN(qsb->iov[i].iov_len, size);
+ qemu_put_buffer(f, qsb->iov[i].iov_base, l);
+ size -= l;
+ }
+}
+
+/*
+ * Read 'size' bytes of data from the file into qsb.
+ * always fill from pos 0 and used after qsb_create().
+ *
+ * It will return size bytes unless there was an error, in which case it will
+ * return as many as it managed to read (assuming blocking fd's which
+ * all current QEMUFile are)
+ */
+size_t qsb_fill_buffer(QEMUSizedBuffer *qsb, QEMUFile *f, size_t size)
+{
+ ssize_t rc = qsb_grow(qsb, size);
+ ssize_t pending = size;
+ int i;
+ uint8_t *buf = NULL;
+
+ qsb->used = 0;
+
+ if (rc < 0) {
+ return rc;
+ }
+
+ for (i = 0; i < qsb->n_iov && pending > 0; i++) {
+ size_t doneone = 0;
+ /* read until iov full */
+ while (doneone < qsb->iov[i].iov_len && pending > 0) {
+ size_t readone = 0;
+
+ buf = qsb->iov[i].iov_base;
+ readone = qemu_get_buffer(f, buf,
+ MIN(qsb->iov[i].iov_len - doneone, pending));
+ if (readone == 0) {
+ return qsb->used;
+ }
+ buf += readone;
+ doneone += readone;
+ pending -= readone;
+ qsb->used += readone;
+ }
+ }
+ return qsb->used;
+}
+
typedef struct QEMUBuffer {
QEMUSizedBuffer *qsb;
QEMUFile *file;
--
1.8.3.1
