Home | History | Annotate | Line # | Download | only in libkvm 
      1 /* $NetBSD: kvm_i386pae.c,v 1.4 2023/08/23 14:00:11 rin Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2010 Jean-Yves Migeon.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     16  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     17  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     19  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     25  * POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #include <sys/cdefs.h>
     29 __RCSID("$NetBSD: kvm_i386pae.c,v 1.4 2023/08/23 14:00:11 rin Exp $");
     30 
     31 /*
     32  * This will expose PAE functions, macros, definitions and constants.
     33  * Note: this affects all virtual memory related functions. Only their
     34  * PAE versions can be used below.
     35  */
     36 #define PAE
     37 
     38 #include <sys/param.h>
     39 #include <sys/stat.h>
     40 #include <sys/kcore.h>
     41 #include <sys/types.h>
     42 
     43 #include <stdlib.h>
     44 #include <unistd.h>
     45 #include <nlist.h>
     46 #include <kvm.h>
     47 
     48 #include <uvm/uvm_extern.h>
     49 
     50 #include <limits.h>
     51 #include <db.h>
     52 
     53 #include "kvm_private.h"
     54 
     55 #include <i386/kcore.h>
     56 #include <i386/pmap.h>
     57 #include <i386/pte.h>
     58 #include <i386/vmparam.h>
     59 
     60 int _kvm_kvatop_i386pae(kvm_t *, vaddr_t, paddr_t *);
     61 
     62 /*
     63  * Used to translate a virtual address to a physical address for systems
     64  * running under PAE mode. Three levels of virtual memory pages are handled
     65  * here: the per-CPU L3 page, the 4 L2 PDs and the PTs.
     66  */
     67 int
     68 _kvm_kvatop_i386pae(kvm_t *kd, vaddr_t va, paddr_t *pa)
     69 {
     70 	cpu_kcore_hdr_t *cpu_kh;
     71 	u_long page_off;
     72 	pd_entry_t pde;
     73 	pt_entry_t pte;
     74 	paddr_t pde_pa, pte_pa;
     75 
     76 	cpu_kh = kd->cpu_data;
     77 	page_off = va & PGOFSET;
     78 
     79 	/*
     80 	 * Find and read the PDE. Ignore the L3, as it is only a per-CPU
     81 	 * page, not needed for kernel VA => PA translations.
     82 	 * Remember that the 4 L2 pages are contiguous, so it is safe
     83 	 * to increment pdppaddr to compute the address of the PDE.
     84 	 * pdppaddr being PAGE_SIZE aligned, we mask the option bits.
     85 	 */
     86 	pde_pa = (cpu_kh->pdppaddr & PTE_FRAME) + (pl2_pi(va) * sizeof(pde));
     87 	if (_kvm_pread(kd, kd->pmfd, (void *)&pde, sizeof(pde),
     88 	    _kvm_pa2off(kd, pde_pa)) != sizeof(pde)) {
     89 		_kvm_syserr(kd, 0, "could not read PDE");
     90 		goto lose;
     91 	}
     92 
     93 	/*
     94 	 * Find and read the page table entry.
     95 	 */
     96 	if ((pde & PTE_P) == 0) {
     97 		_kvm_err(kd, 0, "invalid translation (invalid PDE)");
     98 		goto lose;
     99 	}
    100 	if ((pde & PTE_PS) != 0) {
    101 		/*
    102 		 * This is a 2MB page.
    103 		 */
    104 		page_off = va & ((vaddr_t)~PTE_LGFRAME);
    105 		*pa = (pde & PTE_LGFRAME) + page_off;
    106 		return (int)(NBPD_L2 - page_off);
    107 	}
    108 
    109 	pte_pa = (pde & PTE_FRAME) + (pl1_pi(va) * sizeof(pt_entry_t));
    110 	if (_kvm_pread(kd, kd->pmfd, (void *) &pte, sizeof(pte),
    111 	    _kvm_pa2off(kd, pte_pa)) != sizeof(pte)) {
    112 		_kvm_syserr(kd, 0, "could not read PTE");
    113 		goto lose;
    114 	}
    115 
    116 	/*
    117 	 * Validate the PTE and return the physical address.
    118 	 */
    119 	if ((pte & PTE_P) == 0) {
    120 		_kvm_err(kd, 0, "invalid translation (invalid PTE)");
    121 		goto lose;
    122 	}
    123 	*pa = (pte & PTE_FRAME) + page_off;
    124 	return (int)(NBPG - page_off);
    125 
    126 lose:
    127 	*pa = (paddr_t)~0L;
    128 	return 0;
    129 
    130 }
    131