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

*** 19,29 ****
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2015 by Delphix. All rights reserved.
!  * Copyright 2016 Joyent, Inc.
   */
  
  /*      Copyright (c) 1988 AT&T */
  /*        All Rights Reserved   */
  
--- 19,29 ----
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright (c) 2015 by Delphix. All rights reserved.
!  * Copyright 2018 Joyent, Inc.
   */
  
  /*      Copyright (c) 1988 AT&T */
  /*        All Rights Reserved   */
  
*** 291,311 ****
  #define USERLIMIT32     USERLIMIT
  
  #endif  /* __i386 */
  
  /*
!  * Reserve pages just below KERNEL_TEXT for the GDT, IDT, TSS and debug info.
   *
   * For now, DEBUG_INFO_VA must be first in this list for "xm" initiated dumps
   * of solaris domUs to be usable with mdb. Relying on a fixed VA is not viable
   * long term, but it's the best we've got for now.
   */
  #if !defined(_ASM)
  #define DEBUG_INFO_VA   (KERNEL_TEXT - MMU_PAGESIZE)
  #define GDT_VA          (DEBUG_INFO_VA - MMU_PAGESIZE)
  #define IDT_VA          (GDT_VA - MMU_PAGESIZE)
! #define KTSS_VA         (IDT_VA - MMU_PAGESIZE)
  #define DFTSS_VA        (KTSS_VA - MMU_PAGESIZE)
  #define MISC_VA_BASE    (DFTSS_VA)
  #define MISC_VA_SIZE    (KERNEL_TEXT - MISC_VA_BASE)
  #endif /* !_ASM */
  
--- 291,313 ----
  #define USERLIMIT32     USERLIMIT
  
  #endif  /* __i386 */
  
  /*
!  * Reserve pages just below KERNEL_TEXT for the GDT, IDT, LDT, TSS and debug
!  * info.
   *
   * For now, DEBUG_INFO_VA must be first in this list for "xm" initiated dumps
   * of solaris domUs to be usable with mdb. Relying on a fixed VA is not viable
   * long term, but it's the best we've got for now.
   */
  #if !defined(_ASM)
  #define DEBUG_INFO_VA   (KERNEL_TEXT - MMU_PAGESIZE)
  #define GDT_VA          (DEBUG_INFO_VA - MMU_PAGESIZE)
  #define IDT_VA          (GDT_VA - MMU_PAGESIZE)
! #define LDT_VA          (IDT_VA - (16 * MMU_PAGESIZE))
! #define KTSS_VA         (LDT_VA - MMU_PAGESIZE)
  #define DFTSS_VA        (KTSS_VA - MMU_PAGESIZE)
  #define MISC_VA_BASE    (DFTSS_VA)
  #define MISC_VA_SIZE    (KERNEL_TEXT - MISC_VA_BASE)
  #endif /* !_ASM */