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

Suggested by Ingo Molnar.

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

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8beccaa..ffbb2c8 100644 (file)
--- 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);