KVM: MMU: store generation-number into mmio spte

Store the generation-number into bit3 ~ bit11 and bit52 ~ bit61, totally
19 bits can be used, it should be enough for nearly all most common cases

In this patch, the generation-number is always 0, it will be changed in
the later patch

[Gleb: masking generation bits from spte in get_mmio_spte_gfn() and
       get_mmio_spte_access()]

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index da20860..fb50fa6 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -792,7 +792,8 @@
 		pte_access &= gpte_access(vcpu, gpte);
 		protect_clean_gpte(&pte_access, gpte);
 
-		if (sync_mmio_spte(&sp->spt[i], gfn, pte_access, &nr_present))
+		if (sync_mmio_spte(vcpu->kvm, &sp->spt[i], gfn, pte_access,
+		      &nr_present))
 			continue;
 
 		if (gfn != sp->gfns[i]) {