sys/platform/pc64/vmm/vmm_utils.c

   1 /*
   2  * Copyright (c) 2003-2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Mihai Carabas <mihai.carabas@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/types.h>
  36 #include <sys/proc.h>
  37 #include <sys/systm.h>
  38 #include <cpu/lwbuf.h>
  39 #include <vm/vm_page.h>
  40 #include <vm/vm_extern.h>
  41
  42 #include "vmm_utils.h"
  43
  44 int
  45 instr_check(struct instr_decode *instr, void *ip, uint8_t instr_length)
  46 {
  47
  48         uint8_t i;
  49         uint8_t *instr_ip;
  50         uint8_t *instr_opcode;
  51
  52         instr_ip = (uint8_t *) ip;
  53         instr_opcode = (uint8_t *) &instr->opcode;
  54
  55         /*  Skip REX prefix if present */
  56         if (*instr_ip >= 0x40 && *instr_ip <= 0x4F) {
  57                 instr_ip++;
  58                 instr_length--;
  59         }
  60
  61         for (i = 0; i < instr->opcode_bytes; i++) {
  62                 if (i < instr_length) {
  63                         if (instr_ip[i] != instr_opcode[i]) {
  64                                 return -1;
  65                         }
  66                 } else {
  67                         return -1;
  68                 }
  69         }
  70         return 0;
  71 }
  72
  73 static int
  74 get_pt_entry(struct vmspace *vm, pt_entry_t *pte, vm_offset_t addr, int index)
  75 {
  76         struct lwbuf *lwb;
  77         struct lwbuf lwb_cache;
  78         pt_entry_t *pt;
  79         int err = 0;
  80         vm_page_t m;
  81
  82         m = vm_fault_page(&vm->vm_map, trunc_page(addr),
  83                           VM_PROT_READ, VM_FAULT_NORMAL, &err);
  84         if (err) {
  85                 kprintf("%s: could not get addr %llx\n",
  86                     __func__, (unsigned long long)addr);
  87                 goto error;
  88         }
  89         lwb = lwbuf_alloc(m, &lwb_cache);
  90         pt = (pt_entry_t *)lwbuf_kva(lwb) + ((vm_offset_t)addr & PAGE_MASK);
  91
  92         *pte = pt[index];
  93         lwbuf_free(lwb);
  94         vm_page_unhold(m);
  95 error:
  96         return err;
  97 }
  98
  99 int
 100 guest_phys_addr(struct vmspace *vm, register_t *gpa, register_t guest_cr3, vm_offset_t uaddr)
 101 {
 102         pt_entry_t pml4e;
 103         pt_entry_t pdpe;
 104         pt_entry_t pde;
 105         pt_entry_t pte;
 106         int err = 0;
 107
 108         err = get_pt_entry(vm, &pml4e, guest_cr3, uaddr >> PML4SHIFT);
 109         if (err) {
 110                 kprintf("%s: could not get pml4e\n", __func__);
 111                 goto error;
 112         }
 113         if (pml4e & kernel_pmap.pmap_bits[PG_V_IDX]) {
 114                 err = get_pt_entry(vm, &pdpe, pml4e & PG_FRAME, (uaddr & PML4MASK) >> PDPSHIFT);
 115                 if (err) {
 116                         kprintf("%s: could not get pdpe\n", __func__);
 117                         goto error;
 118                 }
 119                 if (pdpe & kernel_pmap.pmap_bits[PG_V_IDX]) {
 120                         if (pdpe & kernel_pmap.pmap_bits[PG_PS_IDX]) {
 121                                 *gpa = (pdpe & PG_FRAME) | (uaddr & PDPMASK);
 122                                 goto out;
 123                         } else {
 124                                 err = get_pt_entry(vm, &pde, pdpe & PG_FRAME, (uaddr & PDPMASK) >> PDRSHIFT);
 125                                 if(err) {
 126                                         kprintf("%s: could not get pdpe\n", __func__);
 127                                         goto error;
 128                                 }
 129                                 if (pde & kernel_pmap.pmap_bits[PG_V_IDX]) {
 130                                         if (pde & kernel_pmap.pmap_bits[PG_PS_IDX]) {
 131                                                 *gpa = (pde & PG_FRAME) | (uaddr & PDRMASK);
 132                                                 goto out;
 133                                         } else {
 134                                                 err = get_pt_entry(vm, &pte, pde & PG_FRAME, (uaddr & PDRMASK) >> PAGE_SHIFT);
 135                                                 if (err) {
 136                                                         kprintf("%s: could not get pte\n", __func__);
 137                                                         goto error;
 138                                                 }
 139                                                 if (pte & kernel_pmap.pmap_bits[PG_V_IDX]) {
 140                                                         *gpa = (pte & PG_FRAME) | (uaddr & PAGE_MASK);
 141                                                 } else {
 142                                                         kprintf("%s: pte not valid\n", __func__);
 143                                                         err = EFAULT;
 144                                                         goto error;
 145                                                 }
 146                                         }
 147                                 } else {
 148                                         kprintf("%s: pde not valid\n", __func__);
 149                                         err = EFAULT;
 150                                         goto error;
 151                                 }
 152                         }
 153                 } else {
 154                         kprintf("%s: pdpe not valid\n", __func__);
 155                         err = EFAULT;
 156                         goto error;
 157                 }
 158         } else {
 159                 kprintf("%s: pml4e not valid\n", __func__);
 160                 err = EFAULT;
 161                 goto error;
 162         }
 163 out:
 164 error:
 165         return err;
 166 }