1 files changed, 53 insertions, 16 deletions

diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c b/drivers/xen/xenbus/xenbus_probe_frontend.c
index f20c5f178b40..a31b54d48839 100644
--- a/drivers/xen/xenbus/xenbus_probe_frontend.c
+++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
@@ -135,7 +135,7 @@ static int read_backend_details(struct xenbus_device *xendev)
         return xenbus_read_otherend_details(xendev, "backend-id", "backend");
 }
 
-static int is_device_connecting(struct device *dev, void *data)
+static int is_device_connecting(struct device *dev, void *data, bool ignore_nonessential)
 {
         struct xenbus_device *xendev = to_xenbus_device(dev);
         struct device_driver *drv = data;
@@ -152,16 +152,41 @@ static int is_device_connecting(struct device *dev, void *data)
         if (drv && (dev->driver != drv))
                 return 0;
 
+        if (ignore_nonessential) {
+                /* With older QEMU, for PVonHVM guests the guest config files
+                 * could contain: vfb = [ 'vnc=1, vnclisten=0.0.0.0']
+                 * which is nonsensical as there is no PV FB (there can be
+                 * a PVKB) running as HVM guest. */
+
+                if ((strncmp(xendev->nodename, "device/vkbd", 11) == 0))
+                        return 0;
+
+                if ((strncmp(xendev->nodename, "device/vfb", 10) == 0))
+                        return 0;
+        }
         xendrv = to_xenbus_driver(dev->driver);
         return (xendev->state < XenbusStateConnected ||
                 (xendev->state == XenbusStateConnected &&
                  xendrv->is_ready && !xendrv->is_ready(xendev)));
 }
+static int essential_device_connecting(struct device *dev, void *data)
+{
+        return is_device_connecting(dev, data, true /* ignore PV[KBB+FB] */);
+}
+static int non_essential_device_connecting(struct device *dev, void *data)
+{
+        return is_device_connecting(dev, data, false);
+}
 
-static int exists_connecting_device(struct device_driver *drv)
+static int exists_essential_connecting_device(struct device_driver *drv)
 {
         return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv,
-                                is_device_connecting);
+                                essential_device_connecting);
+}
+static int exists_non_essential_connecting_device(struct device_driver *drv)
+{
+        return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv,
+                                non_essential_device_connecting);
 }
 
 static int print_device_status(struct device *dev, void *data)
@@ -192,6 +217,23 @@ static int print_device_status(struct device *dev, void *data)
 /* We only wait for device setup after most initcalls have run. */
 static int ready_to_wait_for_devices;
 
+static bool wait_loop(unsigned long start, unsigned int max_delay,
+                     unsigned int *seconds_waited)
+{
+        if (time_after(jiffies, start + (*seconds_waited+5)*HZ)) {
+                if (!*seconds_waited)
+                        printk(KERN_WARNING "XENBUS: Waiting for "
+                               "devices to initialise: ");
+                *seconds_waited += 5;
+                printk("%us...", max_delay - *seconds_waited);
+                if (*seconds_waited == max_delay)
+                        return true;
+        }
+
+        schedule_timeout_interruptible(HZ/10);
+
+        return false;
+}
 /*
  * On a 5-minute timeout, wait for all devices currently configured.  We need
  * to do this to guarantee that the filesystems and / or network devices
@@ -215,19 +257,14 @@ static void wait_for_devices(struct xenbus_driver *xendrv)
         if (!ready_to_wait_for_devices || !xen_domain())
                 return;
 
-        while (exists_connecting_device(drv)) {
-                if (time_after(jiffies, start + (seconds_waited+5)*HZ)) {
-                        if (!seconds_waited)
-                                printk(KERN_WARNING "XENBUS: Waiting for "
-                                       "devices to initialise: ");
-                        seconds_waited += 5;
-                        printk("%us...", 300 - seconds_waited);
-                        if (seconds_waited == 300)
-                                break;
-                }
-
-                schedule_timeout_interruptible(HZ/10);
-        }
+        while (exists_non_essential_connecting_device(drv))
+                if (wait_loop(start, 30, &seconds_waited))
+                        break;
+
+        /* Skips PVKB and PVFB check.*/
+        while (exists_essential_connecting_device(drv))
+                if (wait_loop(start, 270, &seconds_waited))
+                        break;
 
         if (seconds_waited)
                 printk("\n");