1 files changed, 10 insertions, 3 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0b7553cbc529..bd74229081c3 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -168,7 +168,9 @@ static void __init xen_banner(void)
 {
         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
                pv_info.name);
-        printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic);
+        printk(KERN_INFO "Hypervisor signature: %s%s\n",
+               xen_start_info->magic,
+               xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
 }
 
 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
@@ -1243,6 +1245,8 @@ asmlinkage void __init xen_start_kernel(void)
 
         BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
 
+        xen_setup_features();
+
         /* Install Xen paravirt ops */
         pv_info = xen_info;
         pv_init_ops = xen_init_ops;
@@ -1252,14 +1256,17 @@ asmlinkage void __init xen_start_kernel(void)
         pv_apic_ops = xen_apic_ops;
         pv_mmu_ops = xen_mmu_ops;
 
+        if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
+                pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
+                pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
+        }
+
         machine_ops = xen_machine_ops;
 
 #ifdef CONFIG_SMP
         smp_ops = xen_smp_ops;
 #endif
 
-        xen_setup_features();
-
         /* Get mfn list */
         if (!xen_feature(XENFEAT_auto_translated_physmap))
                 xen_build_dynamic_phys_to_machine();