Merge remote-tracking branch 'cohuck/virtio-ccw-upstr' into staging

# By Cornelia Huck
# Via Cornelia Huck
* cohuck/virtio-ccw-upstr:
  virtio-ccw: Queue sanity check for notify hypercall.
diff --git a/include/char/char.h b/include/char/char.h
index 0326b2a..5c3a7a5 100644
--- a/include/char/char.h
+++ b/include/char/char.h
@@ -170,6 +170,21 @@
 int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len);
 
 /**
+ * @qemu_chr_fe_write_all:
+ *
+ * Write data to a character backend from the front end.  This function will
+ * send data from the front end to the back end.  Unlike @qemu_chr_fe_write,
+ * this function will block if the back end cannot consume all of the data
+ * attempted to be written.
+ *
+ * @buf the data
+ * @len the number of bytes to send
+ *
+ * Returns: the number of bytes consumed
+ */
+int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len);
+
+/**
  * @qemu_chr_fe_ioctl:
  *
  * Issue a device specific ioctl to a backend.
diff --git a/qemu-char.c b/qemu-char.c
index 4e011df..936150f 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -140,6 +140,33 @@
     return s->chr_write(s, buf, len);
 }
 
+int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len)
+{
+    int offset = 0;
+    int res;
+
+    while (offset < len) {
+        do {
+            res = s->chr_write(s, buf + offset, len - offset);
+            if (res == -1 && errno == EAGAIN) {
+                g_usleep(100);
+            }
+        } while (res == -1 && errno == EAGAIN);
+
+        if (res == 0) {
+            break;
+        }
+
+        if (res < 0) {
+            return res;
+        }
+
+        offset += res;
+    }
+
+    return offset;
+}
+
 int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void *arg)
 {
     if (!s->chr_ioctl)
diff --git a/qtest.c b/qtest.c
index 5e0e9ec..b03b68a 100644
--- a/qtest.c
+++ b/qtest.c
@@ -191,7 +191,7 @@
     len = vsnprintf(buffer, sizeof(buffer), fmt, ap);
     va_end(ap);
 
-    qemu_chr_fe_write(chr, (uint8_t *)buffer, len);
+    qemu_chr_fe_write_all(chr, (uint8_t *)buffer, len);
     if (qtest_log_fp && qtest_opened) {
         fprintf(qtest_log_fp, "%s", buffer);
     }