From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 31 Jul 2008 12:30:24 +0000 (+0100)
Subject: mini-os: make init_pcifront fail early if there is no backend
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14165^2~64
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=adacb92a2b5e3ef66b924dc59ab1c2b2c98195c6;p=xen.git

mini-os: make init_pcifront fail early if there is no backend

Else, we would leave entries in xenstore, which disturbs xend.

Signed-off-by: Samuel Thibault <samuel.thibault@eu.citrix.com>
---

diff --git a/extras/mini-os/pcifront.c b/extras/mini-os/pcifront.c
index a924a6e8d9..5b68d86b56 100644
--- a/extras/mini-os/pcifront.c
+++ b/extras/mini-os/pcifront.c
@@ -57,6 +57,7 @@ struct pcifront_dev *init_pcifront(char *_nodename)
     int retry=0;
     char* msg;
     char* nodename = _nodename ? _nodename : "device/pci/0";
+    int dom;
 
     struct pcifront_dev *dev;
 
@@ -64,12 +65,18 @@ struct pcifront_dev *init_pcifront(char *_nodename)
 
     printk("******************* PCIFRONT for %s **********\n\n\n", nodename);
 
+    snprintf(path, sizeof(path), "%s/backend-id", nodename);
+    dom = xenbus_read_integer(path); 
+    if (dom == -1) {
+        printk("no backend\n");
+        return NULL;
+    }
+
     dev = malloc(sizeof(*dev));
     memset(dev, 0, sizeof(*dev));
     dev->nodename = strdup(nodename);
+    dev->dom = dom;
 
-    snprintf(path, sizeof(path), "%s/backend-id", nodename);
-    dev->dom = xenbus_read_integer(path); 
     evtchn_alloc_unbound(dev->dom, pcifront_handler, dev, &dev->evtchn);
 
     dev->info = (struct xen_pci_sharedinfo*) alloc_page();