Patch "xen/xenbus: Update xenbus event channel on resume" has been added to the 4.0-stable tree

Patch "xen/xenbus: Update xenbus event channel on resume" has been added to the 4.0-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    xen/xenbus: Update xenbus event channel on resume

to the 4.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xen-xenbus-update-xenbus-event-channel-on-resume.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 16f1cf3ba7303228372d3756677bf7d10e79cf9f Mon Sep 17 00:00:00 2001
From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Date: Wed, 29 Apr 2015 17:10:13 -0400
Subject: xen/xenbus: Update xenbus event channel on resume

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>

commit 16f1cf3ba7303228372d3756677bf7d10e79cf9f upstream.

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>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/xen/xenbus/xenbus_probe.c |   29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

--- 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 @@ static int __init xenstored_local_init(v
 	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 @@ static int __init xenbus_init(void)
 		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


Patches currently in stable-queue which might be from boris.ostrovsky@oracle.com are

queue-4.0/xen-console-update-console-event-channel-on-resume.patch
queue-4.0/xen-events-set-irq_info-evtchn-before-binding-the-channel-to-cpu-in-__startup_pirq.patch
queue-4.0/xen-xenbus-update-xenbus-event-channel-on-resume.patch
queue-4.0/xen-events-clear-cpu_evtchn_mask-before-resuming.patch