# Commit e95dc6ba69daef6468b3ae5912710727244d6e2f
# Date 2013-11-22 14:47:24 +0100
# Author Tomasz Wroblewski <tomasz.wroblewski@citrix.com>
# Committer Jan Beulich <jbeulich@suse.com>
x86/hvm: reset TSC to 0 after domain resume from S3

Host S3 implicitly resets the host TSC to 0, but the tsc offset for hvm
domains is not recalculated when they resume, causing it to go into
negative values. In Linux guest using tsc clocksource, this results in
a hang after wrap back to positive values since the tsc clocksource
implementation expects it reset.

Signed-off-by: Tomasz Wroblewski <tomasz.wroblewski@citrix.com>

--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3607,7 +3607,13 @@ static void hvm_s3_suspend(struct domain
 static void hvm_s3_resume(struct domain *d)
 {
     if ( test_and_clear_bool(d->arch.hvm_domain.is_s3_suspended) )
+    {
+        struct vcpu *v;
+
+        for_each_vcpu( d, v )
+            hvm_set_guest_tsc(v, 0);
         domain_unpause(d);
+    }
 }
 
 static int hvmop_set_isa_irq_level(