diff mbox

[v4,02/10] x86/time.c: Scale host TSC in pvclock properly

Message ID 1453067939-9121-3-git-send-email-haozhong.zhang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Haozhong Zhang Jan. 17, 2016, 9:58 p.m. UTC 
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@intel.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
Changes in v4:
 (addressing Jan Beulich's comments)
 * Remove unnecessary cast (u8) in __update_vcpu_system_time().

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

Comments

Jan Beulich Jan. 18, 2016, 1:42 p.m. UTC | #1 
>>> On 17.01.16 at 22:58, <haozhong.zhang@intel.com> wrote:
> 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@intel.com>

This doesn't look to be dependent on patch 1, and I would have
gone apply it right away if that had been stated anywhere
explicitly.

Jan
Haozhong Zhang Jan. 19, 2016, 12:29 a.m. UTC | #2 
On 01/18/16 06:42, Jan Beulich wrote:
> >>> On 17.01.16 at 22:58, <haozhong.zhang@intel.com> wrote:
> > 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@intel.com>
> 
> This doesn't look to be dependent on patch 1, and I would have
> gone apply it right away if that had been stated anywhere
> explicitly.
>

This one uses hvm_funcs.scale_tsc() added in patch 1.

Haozhong
diff mbox

Patch

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index ec3f33e..988403a 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         = t->tsc_scale.shift;
+        }
     }
 
     _u.tsc_timestamp = tsc_stamp;