xen/xenbus: Update xenbus event channel on resume
After a resume the hypervisor/tools may change xenbus event
channel number. We should re-query it.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 564b315..5390a67 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -57,6 +57,7 @@
#include <xen/xen.h>
#include <xen/xenbus.h>
#include <xen/events.h>
+#include <xen/xen-ops.h>
#include <xen/page.h>
#include <xen/hvm.h>
@@ -735,6 +736,30 @@
return err;
}
+static int xenbus_resume_cb(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ int err = 0;
+
+ if (xen_hvm_domain()) {
+ uint64_t v;
+
+ err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v);
+ if (!err && v)
+ xen_store_evtchn = v;
+ else
+ pr_warn("Cannot update xenstore event channel: %d\n",
+ err);
+ } else
+ xen_store_evtchn = xen_start_info->store_evtchn;
+
+ return err;
+}
+
+static struct notifier_block xenbus_resume_nb = {
+ .notifier_call = xenbus_resume_cb,
+};
+
static int __init xenbus_init(void)
{
int err = 0;
@@ -793,6 +818,10 @@
goto out_error;
}
+ if ((xen_store_domain_type != XS_LOCAL) &&
+ (xen_store_domain_type != XS_UNKNOWN))
+ xen_resume_notifier_register(&xenbus_resume_nb);
+
#ifdef CONFIG_XEN_COMPAT_XENFS
/*
* Create xenfs mountpoint in /proc for compatibility with