1 files changed, 19 insertions, 0 deletions
diff --git a/cutils.c b/cutils.c
index 658746b8f0..a1652ab0bc 100644
--- a/cutils.c
+++ b/cutils.c
@@ -23,6 +23,7 @@
  */
 #include "qemu-common.h"
 #include "host-utils.h"
+#include <assert.h>
 
 void pstrcpy(char *buf, int buf_size, const char *str)
 {
@@ -112,8 +113,22 @@ void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint)
     qiov->size = 0;
 }
 
+void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov)
+{
+    int i;
+
+    qiov->iov = iov;
+    qiov->niov = niov;
+    qiov->nalloc = -1;
+    qiov->size = 0;
+    for (i = 0; i < niov; i++)
+        qiov->size += iov[i].iov_len;
+}
+
 void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 {
+    assert(qiov->nalloc != -1);
+
     if (qiov->niov == qiov->nalloc) {
         qiov->nalloc = 2 * qiov->nalloc + 1;
         qiov->iov = qemu_realloc(qiov->iov, qiov->nalloc * sizeof(struct iovec));
@@ -126,11 +141,15 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
 
 void qemu_iovec_destroy(QEMUIOVector *qiov)
 {
+    assert(qiov->nalloc != -1);
+
     qemu_free(qiov->iov);
 }
 
 void qemu_iovec_reset(QEMUIOVector *qiov)
 {
+    assert(qiov->nalloc != -1);
+
     qiov->niov = 0;
     qiov->size = 0;
 }