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

*** 20,29 ****
--- 20,31 ----
   */
  
  /*
   * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
+  *
+  * Copyright 2018 Joyent, Inc.
   */
  
  /*
   * HAT interfaces used by the kernel debugger to interact with the VM system.
   * These interfaces are invoked when the world is stopped.  As such, no blocking
*** 175,185 ****
           * kdi_pread() to walk the page tables
           */
  #if defined(__xpv)
          *pap = pfn_to_pa(CPU->cpu_current_hat->hat_htable->ht_pfn);
  #else
!         *pap = getcr3() & MMU_PAGEMASK;
  #endif
          for (level = mmu.max_level; ; --level) {
                  index = (va >> LEVEL_SHIFT(level)) & (mmu.ptes_per_table - 1);
                  *pap += index << mmu.pte_size_shift;
                  pte = 0;
--- 177,187 ----
           * kdi_pread() to walk the page tables
           */
  #if defined(__xpv)
          *pap = pfn_to_pa(CPU->cpu_current_hat->hat_htable->ht_pfn);
  #else
!         *pap = getcr3_pa();
  #endif
          for (level = mmu.max_level; ; --level) {
                  index = (va >> LEVEL_SHIFT(level)) & (mmu.ptes_per_table - 1);
                  *pap += index << mmu.pte_size_shift;
                  pte = 0;
*** 247,257 ****
  #else
                  else if (hat_kdi_use_pae)
                          *hat_kdi_pte = pte;
                  else
                          *(x86pte32_t *)hat_kdi_pte = pte;
!                 mmu_tlbflush_entry((caddr_t)hat_kdi_page);
  #endif
  
                  bcopy(from, to, sz);
  
                  /*
--- 249,259 ----
  #else
                  else if (hat_kdi_use_pae)
                          *hat_kdi_pte = pte;
                  else
                          *(x86pte32_t *)hat_kdi_pte = pte;
!                 mmu_flush_tlb_kpage(hat_kdi_page);
  #endif
  
                  bcopy(from, to, sz);
  
                  /*
*** 266,276 ****
  #else
                  else if (hat_kdi_use_pae)
                          *hat_kdi_pte = 0;
                  else
                          *(x86pte32_t *)hat_kdi_pte = 0;
!                 mmu_tlbflush_entry((caddr_t)hat_kdi_page);
  #endif
  
                  buf += sz;
                  pa += sz;
                  nbytes -= sz;
--- 268,278 ----
  #else
                  else if (hat_kdi_use_pae)
                          *hat_kdi_pte = 0;
                  else
                          *(x86pte32_t *)hat_kdi_pte = 0;
!                 mmu_flush_tlb_kpage(hat_kdi_page);
  #endif
  
                  buf += sz;
                  pa += sz;
                  nbytes -= sz;
*** 294,303 ****
--- 296,318 ----
  kdi_pwrite(caddr_t buf, size_t nbytes, uint64_t addr, size_t *ncopiedp)
  {
          return (kdi_prw(buf, nbytes, addr, ncopiedp, 0));
  }
  
+ #if !defined(__xpv)
+ /*
+  * This gets used for flushing the TLB on all the slaves just prior to doing a
+  * kdi_prw().  It's unclear why this was originally done, since kdi_prw() itself
+  * will flush any lingering hat_kdi_page mappings, but let's presume it was a
+  * good idea.
+  */
+ void
+ kdi_flush_caches(void)
+ {
+         mmu_flush_tlb(FLUSH_TLB_ALL, NULL);
+ }
+ #endif
  
  /*
   * Return the number of bytes, relative to the beginning of a given range, that
   * are non-toxic (can be read from and written to with relative impunity).
   */