From: Ouyang Zhaowei (Charles) <ouyangzhaowei@huawei.com>
Date: Wed, 6 May 2015 01:47:04 +0000 (+0800)
Subject: x86/xen: don't reset vcpu_info on a cancelled suspend
X-Git-Tag: firefly_0821_release~3391^2~187
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7d391345b037f3834c851906ba05cc2fb5e266dc;p=firefly-linux-kernel-4.4.55.git

x86/xen: don't reset vcpu_info on a cancelled suspend

commit 6a1f513776b78c994045287073e55bae44ed9f8c upstream.

On a cancelled suspend the vcpu_info location does not change (it's
still in the per-cpu area registered by xen_vcpu_setup()).  So do not
call xen_hvm_init_shared_info() which would make the kernel think its
back in the shared info.  With the wrong vcpu_info, events cannot be
received and the domain will hang after a cancelled suspend.

Signed-off-by: Charles Ouyang <ouyangzhaowei@huawei.com>
Reviewed-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>
---

diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
index df0c40559583..7f664c416faf 100644
--- a/arch/x86/xen/suspend.c
+++ b/arch/x86/xen/suspend.c
@@ -34,7 +34,8 @@ static void xen_hvm_post_suspend(int suspend_cancelled)
 {
 #ifdef CONFIG_XEN_PVHVM
 	int cpu;
-	xen_hvm_init_shared_info();
+	if (!suspend_cancelled)
+	    xen_hvm_init_shared_info();
 	xen_callback_vector();
 	xen_unplug_emulated_devices();
 	if (xen_feature(XENFEAT_hvm_safe_pvclock)) {