[Xen-devel] [PATCH v3 04/13] x86/time.c: Scale host TSC in pvclock properly

[Haozhong Zhang <haozhong.zhang@xxxxxxxxx>]

This patch makes the pvclock return the scaled host TSC and
corresponding scaling parameters to HVM domains if guest TSC is not
emulated and TSC scaling is enabled.

Signed-off-by: Haozhong Zhang <haozhong.zhang@xxxxxxxxx>
---
Changes in v3:
 (addressing Boris Ostrovsky's comments)
 * No changes in fact. tsc_set_info() does not set d->arch.vtsc to 0
   if host_tsc_is_safe() is not satisfied, so it is safe to use
   d->arch.vtsc_to_ns here.

 xen/arch/x86/time.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index d83f068..b31634a 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -815,10 +815,18 @@ static void __update_vcpu_system_time(struct vcpu *v, int 
force)
     }
     else
     {
-        tsc_stamp = t->local_tsc_stamp;
-
-        _u.tsc_to_system_mul = t->tsc_scale.mul_frac;
-        _u.tsc_shift         = (s8)t->tsc_scale.shift;
+        if ( has_hvm_container_domain(d) && cpu_has_tsc_ratio )
+        {
+            tsc_stamp            = hvm_funcs.scale_tsc(v, t->local_tsc_stamp);
+            _u.tsc_to_system_mul = d->arch.vtsc_to_ns.mul_frac;
+            _u.tsc_shift         = d->arch.vtsc_to_ns.shift;
+        }
+        else
+        {
+            tsc_stamp            = t->local_tsc_stamp;
+            _u.tsc_to_system_mul = t->tsc_scale.mul_frac;
+            _u.tsc_shift         = (s8)t->tsc_scale.shift;
+        }
     }
 
     _u.tsc_timestamp = tsc_stamp;
-- 
2.4.8


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