@@ -75,6 +75,11 @@ int qemu_fclose(QEMUFile *f);
int64_t qemu_ftell(QEMUFile *f);
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size);
void qemu_put_byte(QEMUFile *f, int v);
+/*
+ * put_buffer without copying the buffer.
+ * The buffer should be available till it is sent asynchronously.
+ */
+void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size);
static inline void qemu_put_ubyte(QEMUFile *f, unsigned int v)
{
@@ -633,6 +633,28 @@ static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size)
}
}
+void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, int size)
+{
+ if (f->last_error) {
+ return;
+ }
+
+ if (f->is_write == 0 && f->buf_index > 0) {
+ fprintf(stderr,
+ "Attempted to write to buffer while read buffer is not empty\n");
+ abort();
+ }
+
+ add_to_iovec(f, buf, size);
+
+ f->is_write = 1;
+ f->bytes_xfer += size;
+
+ if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
+ qemu_fflush(f);
+ }
+}
+
void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
{
int l;
@@ -652,18 +674,14 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)
if (l > size)
l = size;
memcpy(f->buf + f->buf_index, buf, l);
- add_to_iovec(f, f->buf + f->buf_index, l);
f->is_write = 1;
f->buf_index += l;
- f->bytes_xfer += l;
+ qemu_put_buffer_async(f, f->buf + (f->buf_index - l), l);
+ if (qemu_file_get_error(f)) {
+ break;
+ }
buf += l;
size -= l;
- if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) {
- qemu_fflush(f);
- if (qemu_file_get_error(f)) {
- break;
- }
- }
}
}
This allows us to add a buffer to the iovec to send without copying it into the static buffer, the buffer will be sent later when qemu_fflush is called. Signed-off-by: Orit Wasserman <owasserm@redhat.com> --- include/migration/qemu-file.h | 5 +++++ savevm.c | 34 ++++++++++++++++++++++++++-------- 2 files changed, 31 insertions(+), 8 deletions(-)