8956 Implement KPTI
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 24,34 ****
  /*
   * Copyright (c) 2010, Intel Corporation.
   * All rights reserved.
   */
  /*
!  * Copyright 2011 Joyent, Inc. All rights reserved.
   */
  
  #ifndef _SYS_RM_PLATTER_H
  #define _SYS_RM_PLATTER_H
  
--- 24,34 ----
  /*
   * Copyright (c) 2010, Intel Corporation.
   * All rights reserved.
   */
  /*
!  * Copyright 2018 Joyent, Inc.
   */
  
  #ifndef _SYS_RM_PLATTER_H
  #define _SYS_RM_PLATTER_H
  
*** 111,121 ****
   *
   * Note: the tss should be 16 byte aligned for best performance on amd64
   * Since DEFAULTSTKSIZE is a multiple of PAGESIZE tss will be aligned.
   */
  struct cpu_tables {
!         char            ct_stack[DEFAULTSTKSZ];
          tss_t           ct_tss;
  };
  
  /*
   * gdt entries are 8 bytes long, ensure that we have an even no. of them.
--- 111,126 ----
   *
   * Note: the tss should be 16 byte aligned for best performance on amd64
   * Since DEFAULTSTKSIZE is a multiple of PAGESIZE tss will be aligned.
   */
  struct cpu_tables {
!         /* IST stacks */
!         char            ct_stack1[DEFAULTSTKSZ];        /* dblfault */
! #if !defined(__xpv)
!         char            ct_stack2[DEFAULTSTKSZ];        /* nmi */
!         char            ct_stack3[DEFAULTSTKSZ];        /* mce */
! #endif
          tss_t           ct_tss;
  };
  
  /*
   * gdt entries are 8 bytes long, ensure that we have an even no. of them.