1 files changed, 21 insertions, 0 deletions
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index c03bb20bc9..d94498a97b 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -1302,6 +1302,27 @@ bool css_schid_final(int m, uint8_t cssid, uint8_t ssid, uint16_t schid)
                                  (MAX_SCHID + 1) / sizeof(unsigned long));
 }
 
+unsigned int css_find_free_chpid(uint8_t cssid)
+{
+    CssImage *css = channel_subsys.css[cssid];
+    unsigned int chpid;
+
+    if (!css) {
+        return MAX_CHPID + 1;
+    }
+
+    for (chpid = 0; chpid <= MAX_CHPID; chpid++) {
+        /* skip reserved chpid */
+        if (chpid == VIRTIO_CCW_CHPID) {
+            continue;
+        }
+        if (!css->chpids[chpid].in_use) {
+            return chpid;
+        }
+    }
+    return MAX_CHPID + 1;
+}
+
 static int css_add_virtual_chpid(uint8_t cssid, uint8_t chpid, uint8_t type)
 {
     CssImage *css;