KVM: x86: Fix SVM VMCB reset

On reset, VMCB TSC should be set to zero.  Instead, code was setting
tsc_offset to zero, which passes through the underlying TSC.
Signed-off-by: Zachary Amsden <zamsden@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/svm.c

@@ -766,7 +766,7 @@ static void init_vmcb(struct vcpu_svm *svm)
 
 	control->iopm_base_pa = iopm_base;
 	control->msrpm_base_pa = __pa(svm->msrpm);
-	control->tsc_offset = 0;
+	control->tsc_offset = 0-native_read_tsc();
 	control->int_ctl = V_INTR_MASKING_MASK;
 
 	init_seg(&save->es);