[Xen-changelog] [xen stable-4.3] x86/hvm: fix restart of RTC periodic timer with vpt_align=1

[patchbot@xxxxxxx]

commit cd766e12d4c914f3928537acb64595f5044d43bf
Author:     Kouya Shimura <kouya@xxxxxxxxxxxxxx>
AuthorDate: Fri Nov 15 11:25:46 2013 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Nov 15 11:25:46 2013 +0100

    x86/hvm: fix restart of RTC periodic timer with vpt_align=1
    
    The commit 58afa7ef "x86/hvm: Run the RTC periodic timer on a
    consistent time series" aligns the RTC periodic timer to the VM's boot time.
    However, it's aligned later again to the system time in 
create_periodic_time()
    with vpt_align=1. The next tick might be skipped.
    
    Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Tim Deegan <tim@xxxxxxx>
    master commit: 48535f5798e3e237d9920a74c1ce3802958136c0
    master date: 2013-11-08 11:07:14 +0100
---
 xen/arch/x86/hvm/rtc.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c
index d1a6848..cdedefe 100644
--- a/xen/arch/x86/hvm/rtc.c
+++ b/xen/arch/x86/hvm/rtc.c
@@ -130,7 +130,10 @@ static void rtc_timer_update(RTCState *s)
                 s->pt_code = period_code;
                 period = 1 << (period_code - 1); /* period in 32 Khz cycles */
                 period = DIV_ROUND(period * 1000000000ULL, 32768); /* in ns */
-                delta = period - ((NOW() - s->start_time) % period);
+                if ( v->domain->arch.hvm_domain.params[HVM_PARAM_VPT_ALIGN] )
+                    delta = 0;
+                else
+                    delta = period - ((NOW() - s->start_time) % period);
                 create_periodic_time(v, &s->pt, delta, period,
                                      RTC_IRQ, NULL, s);
             }
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.3

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