diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index fd32600ae3..3c17464550 100644
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -1669,6 +1669,7 @@ const struct hvm_function_table * __init start_svm(void)
 
     if ( _svm_cpu_up(true) )
     {
+        setup_clear_cpu_cap(X86_FEATURE_SVM);
         printk("SVM: failed to initialise.\n");
         return NULL;
     }
diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index bcbecc6945..b5ecc51b43 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -2163,6 +2163,23 @@ int __init vmx_vmcs_init(void)
 
     if ( !ret )
         register_keyhandler('v', vmcs_dump, "dump VT-x VMCSs", 1);
+    else
+    {
+        setup_clear_cpu_cap(X86_FEATURE_VMX);
+
+        /*
+         * _vmx_vcpu_up() may have made it past feature identification.
+         * Make sure all dependent features are off as well.
+         */
+        vmx_basic_msr              = 0;
+        vmx_pin_based_exec_control = 0;
+        vmx_cpu_based_exec_control = 0;
+        vmx_secondary_exec_control = 0;
+        vmx_vmexit_control         = 0;
+        vmx_vmentry_control        = 0;
+        vmx_ept_vpid_cap           = 0;
+        vmx_vmfunc                 = 0;
+    }
 
     return ret;
 }