OS-7125 Need mitigation of L1TF (CVE-2018-3646)
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 21,30 ****
--- 21,31 ----
  
  /*
   * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2012 by Delphix. All rights reserved.
   * Copyright 2014 Igor Kozhukhov <ikozhukhov@gmail.com>.
+  * Copyright 2018 Joyent, Inc.
   * Copyright 2017 RackTop Systems.
   */
  
  #ifndef _SYS_CPUVAR_H
  #define _SYS_CPUVAR_H
*** 570,586 ****
  #else
  #define CPU             (curthread->t_cpu)      /* Pointer to current CPU */
  #endif
  
  /*
!  * CPU_CURRENT indicates to thread_affinity_set to use CPU->cpu_id
!  * as the target and to grab cpu_lock instead of requiring the caller
!  * to grab it.
   */
  #define CPU_CURRENT     -3
  
  /*
   * Per-CPU statistics
   *
   * cpu_stats_t contains numerous system and VM-related statistics, in the form
   * of gauges or monotonically-increasing event occurrence counts.
   */
--- 571,593 ----
  #else
  #define CPU             (curthread->t_cpu)      /* Pointer to current CPU */
  #endif
  
  /*
!  * CPU_CURRENT indicates to thread_affinity_set() to use whatever curthread's
!  * current CPU is; holding cpu_lock is not required.
   */
  #define CPU_CURRENT     -3
  
  /*
+  * CPU_BEST can be used by thread_affinity_set() callers to set affinity to a
+  * good CPU (in particular, an ht_acquire()-friendly choice); holding cpu_lock
+  * is not required.
+  */
+ #define CPU_BEST        -4
+ 
+ /*
   * Per-CPU statistics
   *
   * cpu_stats_t contains numerous system and VM-related statistics, in the form
   * of gauges or monotonically-increasing event occurrence counts.
   */