KVM: Replace kvmclock open-coded get_cpu_var() with the real thing

Suggested by Ingo Molnar.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8beccaa17690..ffbb2c818d78 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -631,16 +631,17 @@ static void kvm_write_guest_time(struct kvm_vcpu *v)
         unsigned long flags;
         struct kvm_vcpu_arch *vcpu = &v->arch;
         void *shared_kaddr;
+        unsigned long this_tsc_khz;
 
         if ((!vcpu->time_page))
                 return;
 
-        preempt_disable();
-        if (unlikely(vcpu->hv_clock_tsc_khz != __get_cpu_var(cpu_tsc_khz))) {
-                kvm_set_time_scale(__get_cpu_var(cpu_tsc_khz), &vcpu->hv_clock);
-                vcpu->hv_clock_tsc_khz = __get_cpu_var(cpu_tsc_khz);
+        this_tsc_khz = get_cpu_var(cpu_tsc_khz);
+        if (unlikely(vcpu->hv_clock_tsc_khz != this_tsc_khz)) {
+                kvm_set_time_scale(this_tsc_khz, &vcpu->hv_clock);
+                vcpu->hv_clock_tsc_khz = this_tsc_khz;
         }
-        preempt_enable();
+        put_cpu_var(cpu_tsc_khz);
 
         /* Keep irq disabled to prevent changes to the clock */
         local_irq_save(flags);