1 files changed, 25 insertions, 0 deletions
diff --git a/cutils.c b/cutils.c
index bd9a01950a..ffe5c717e4 100644
--- a/cutils.c
+++ b/cutils.c
@@ -151,6 +151,31 @@ void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len)
     ++qiov->niov;
 }
 
+/*
+ * Copies iovecs from src to the end dst until src is completely copied or the
+ * total size of the copied iovec reaches size. The size of the last copied
+ * iovec is changed in order to fit the specified total size if it isn't a
+ * perfect fit already.
+ */
+void qemu_iovec_concat(QEMUIOVector *dst, QEMUIOVector *src, size_t size)
+{
+    int i;
+    size_t done;
+
+    assert(dst->nalloc != -1);
+
+    done = 0;
+    for (i = 0; (i < src->niov) && (done != size); i++) {
+        if (done + src->iov[i].iov_len > size) {
+            qemu_iovec_add(dst, src->iov[i].iov_base, size - done);
+            break;
+        } else {
+            qemu_iovec_add(dst, src->iov[i].iov_base, src->iov[i].iov_len);
+        }
+        done += src->iov[i].iov_len;
+    }
+}
+
 void qemu_iovec_destroy(QEMUIOVector *qiov)
 {
     assert(qiov->nalloc != -1);