x86/time: report correct frequency of Xen PV clocksource

The value of the counter represents the number of nanoseconds
since host boot. That means the correct frequency is always 1GHz.

This inconsistency caused time to go slower in PV shim on most
platforms.

Signed-off-by: Igor Druzhinin <igor.druzhinin@citrix.com>
Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: c52bd545de461127f3ca67c48e8fef7145402035
master date: 2020-02-14 18:01:52 +0000

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index fd4c8bc4f047fdef2dfb7687bc76be39d26fa4c1..44d3b75830283babad6e42281eb512adca531a89 100644 (file)
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -584,9 +584,7 @@ static int64_t __init init_xen_timer(struct platform_timesource *pts)
     if ( !xen_guest )
         return 0;
 
-    pts->frequency = xen_timer_cpu_frequency();
-
-    return pts->frequency;
+    return xen_timer_cpu_frequency();
 }
 
 static always_inline uint64_t read_cycle(const struct vcpu_time_info *info,
@@ -640,6 +638,7 @@ static struct platform_timesource __initdata plt_xen_timer =
 {
     .id = "xen",
     .name = "XEN PV CLOCK",
+    .frequency = 1000000000ULL,
     .read_counter = read_xen_timer,
     .init = init_xen_timer,
     .resume = resume_xen_timer,