palacios/src/palacios/vmx_ctrl_regs.c

   1
   2 /*
   3  * This file is part of the Palacios Virtual Machine Monitor developed
   4  * by the V3VEE Project with funding from the United States National
   5  * Science Foundation and the Department of Energy.
   6  *
   7  * The V3VEE Project is a joint project between Northwestern University
   8  * and the University of New Mexico.  You can find out more at
   9  * http://www.v3vee.org
  10  *
  11  * Copyright (c) 2008, Andy Gocke <agocke@gmail.com>
  12  * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
  13  * All rights reserved.
  14  *
  15  * Author: Andy Gocke <agocke@gmail.com>
  16  *
  17  * This is free software.  You are permitted to use,
  18  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  19  */
  20
  21 #include <palacios/vmx_ctrl_regs.h>
  22 #include <palacios/vmm.h>
  23 #include <palacios/vmx_lowlevel.h>
  24 #include <palacios/vmx.h>
  25 #include <palacios/vmx_assist.h>
  26 #include <palacios/vm_guest_mem.h>
  27 #include <palacios/vmm_direct_paging.h>
  28 #include <palacios/vmm_ctrl_regs.h>
  29
  30 #ifndef V3_CONFIG_DEBUG_VMX
  31 #undef PrintDebug
  32 #define PrintDebug(fmt, args...)
  33 #endif
  34
  35 static v3_reg_t * get_reg_ptr(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual);
  36 static int handle_mov_to_cr0(struct guest_info * info, v3_reg_t * new_val, struct vmx_exit_info * exit_info);
  37 static int handle_mov_to_cr3(struct guest_info * info, v3_reg_t * cr3_reg);
  38 static int handle_mov_from_cr3(struct guest_info * info, v3_reg_t * cr3_reg);
  39
  40 int v3_vmx_handle_cr0_access(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual, struct vmx_exit_info * exit_info) {
  41
  42     if (cr_qual->access_type < 2) {
  43         v3_reg_t * reg = get_reg_ptr(info, cr_qual);
  44
  45         if (cr_qual->access_type == 0) {
  46
  47             if (handle_mov_to_cr0(info, reg, exit_info) != 0) {
  48                 PrintError("Could not handle CR0 write\n");
  49                 return -1;
  50             }
  51         } else {
  52             // Mov from cr
  53             PrintError("Mov From CR0 not handled\n");
  54             return -1;
  55         }
  56
  57         return 0;
  58     }
  59
  60     PrintError("Invalid CR0 Access type?? (type=%d)\n", cr_qual->access_type);
  61     return -1;
  62 }
  63
  64 int v3_vmx_handle_cr3_access(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual) {
  65
  66     if (cr_qual->access_type < 2) {
  67         v3_reg_t * reg = get_reg_ptr(info, cr_qual);
  68
  69         if (cr_qual->access_type == 0) {
  70             return handle_mov_to_cr3(info, reg);
  71         } else {
  72             return handle_mov_from_cr3(info, reg);
  73         }
  74     }
  75
  76     PrintError("Invalid CR3 Access type?? (type=%d)\n", cr_qual->access_type);
  77     return -1;
  78 }
  79
  80 static int handle_mov_to_cr3(struct guest_info * info, v3_reg_t * cr3_reg) {
  81
  82     if (info->shdw_pg_mode == SHADOW_PAGING) {
  83
  84         /*
  85         PrintDebug("Old Guest CR3=%p, Old Shadow CR3=%p\n",
  86                    (void *)info->ctrl_regs.cr3,
  87                    (void *)info->shdw_pg_state.guest_cr3);
  88         */
  89
  90         if (info->cpu_mode == LONG) {
  91             info->shdw_pg_state.guest_cr3 = (uint64_t)*cr3_reg;
  92         } else {
  93             info->shdw_pg_state.guest_cr3 = (uint32_t)*cr3_reg;
  94         }
  95
  96
  97         if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
  98             if (v3_activate_shadow_pt(info) == -1) {
  99                 PrintError("Failed to activate 32 bit shadow page table\n");
 100                 return -1;
 101             }
 102         }
 103         /*
 104         PrintDebug("New guest CR3=%p, New shadow CR3=%p\n",
 105                    (void *)info->ctrl_regs.cr3,
 106                    (void *)info->shdw_pg_state.guest_cr3);
 107         */
 108     } else if (info->shdw_pg_mode == NESTED_PAGING) {
 109         PrintError("Nested paging not available in VMX right now!\n");
 110         return -1;
 111     }
 112
 113
 114
 115     return 0;
 116 }
 117
 118 static int handle_mov_from_cr3(struct guest_info * info, v3_reg_t * cr3_reg) {
 119
 120
 121     if (info->shdw_pg_mode == SHADOW_PAGING) {
 122
 123         if ((v3_get_vm_cpu_mode(info) == LONG) ||
 124             (v3_get_vm_cpu_mode(info) == LONG_32_COMPAT)) {
 125
 126             *cr3_reg = (uint64_t)info->shdw_pg_state.guest_cr3;
 127         } else {
 128             *cr3_reg = (uint32_t)info->shdw_pg_state.guest_cr3;
 129         }
 130
 131     } else {
 132         PrintError("Unhandled paging mode\n");
 133         return -1;
 134     }
 135
 136
 137     return 0;
 138 }
 139
 140 static int handle_mov_to_cr0(struct guest_info * info, v3_reg_t * new_cr0, struct vmx_exit_info * exit_info) {
 141     struct cr0_32 * guest_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
 142     struct cr0_32 * shdw_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
 143     struct cr0_32 * new_shdw_cr0 = (struct cr0_32 *)new_cr0;
 144     struct vmx_data * vmx_info = (struct vmx_data *)info->vmm_data;
 145     uint_t paging_transition = 0;
 146
 147     /*
 148       PrintDebug("Old shadow CR0: 0x%x, New shadow CR0: 0x%x\n",
 149       (uint32_t)info->shdw_pg_state.guest_cr0, (uint32_t)*new_cr0);
 150     */
 151
 152     if (new_shdw_cr0->pe != shdw_cr0->pe) {
 153         /*
 154           PrintDebug("Guest CR0: 0x%x\n", *(uint32_t *)guest_cr0);
 155           PrintDebug("Old shadow CR0: 0x%x\n", *(uint32_t *)shdw_cr0);
 156           PrintDebug("New shadow CR0: 0x%x\n", *(uint32_t *)new_shdw_cr0);
 157         */
 158
 159         if (v3_vmxassist_ctx_switch(info) != 0) {
 160             PrintError("Unable to execute VMXASSIST context switch!\n");
 161             return -1;
 162         }
 163
 164         if (vmx_info->assist_state == VMXASSIST_ENABLED) {
 165             PrintDebug("Loading VMXASSIST at RIP: %p\n", (void *)(addr_t)info->rip);
 166         } else {
 167             PrintDebug("Leaving VMXASSIST and entering protected mode at RIP: %p\n",
 168                        (void *)(addr_t)info->rip);
 169         }
 170
 171         // PE switches modify the RIP directly, so we clear the instr_len field to avoid catastrophe
 172         exit_info->instr_len = 0;
 173
 174         //      v3_vmx_restore_vmcs(info);
 175         //      v3_print_vmcs(info);
 176
 177     } else {
 178
 179         if (new_shdw_cr0->pg != shdw_cr0->pg) {
 180             paging_transition = 1;
 181         }
 182
 183         // The shadow always reflects the new value
 184         *shdw_cr0 = *new_shdw_cr0;
 185
 186         // We don't care about most of the flags, so lets go for it
 187         // and set them to the guest values
 188         *guest_cr0 = *shdw_cr0;
 189
 190         // Except PG, PE, and NE, which are always set
 191         guest_cr0->pe = 1;
 192         guest_cr0->pg = 1;
 193         guest_cr0->ne = 1;
 194
 195         if ((paging_transition)) {
 196             // Paging transition
 197
 198             if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
 199                 struct efer_64 * guest_efer = (struct efer_64 *)&(info->ctrl_regs.efer);
 200
 201                 if (guest_efer->lme == 1) {
 202                     //     PrintDebug("Enabling long mode\n");
 203
 204                     guest_efer->lma = 1;
 205                     guest_efer->lme = 1;
 206
 207                     vmx_info->entry_ctrls.guest_ia32e = 1;
 208                 }
 209
 210                 //            PrintDebug("Activating Shadow Page tables\n");
 211
 212                 if (info->shdw_pg_mode == SHADOW_PAGING) {
 213                     if (v3_activate_shadow_pt(info) == -1) {
 214                         PrintError("Failed to activate shadow page tables\n");
 215                         return -1;
 216                     }
 217                 }
 218
 219             } else {
 220
 221                 if (info->shdw_pg_mode == SHADOW_PAGING) {
 222                     if (v3_activate_passthrough_pt(info) == -1) {
 223                         PrintError("Failed to activate passthrough page tables\n");
 224                         return -1;
 225                     }
 226                 } else {
 227                     // This is hideous... Let's hope that the 1to1 page table has not been nuked...
 228                     info->ctrl_regs.cr3 = VMXASSIST_1to1_PT;
 229                 }
 230             }
 231         }
 232     }
 233
 234     return 0;
 235 }
 236
 237 static v3_reg_t * get_reg_ptr(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual) {
 238     v3_reg_t * reg = NULL;
 239
 240     switch (cr_qual->gpr) {
 241         case 0:
 242             reg = &(info->vm_regs.rax);
 243             break;
 244         case 1:
 245             reg = &(info->vm_regs.rcx);
 246             break;
 247         case 2:
 248             reg = &(info->vm_regs.rdx);
 249             break;
 250         case 3:
 251             reg = &(info->vm_regs.rbx);
 252             break;
 253         case 4:
 254             reg = &(info->vm_regs.rsp);
 255             break;
 256         case 5:
 257             reg = &(info->vm_regs.rbp);
 258             break;
 259         case 6:
 260             reg = &(info->vm_regs.rsi);
 261             break;
 262         case 7:
 263             reg = &(info->vm_regs.rdi);
 264             break;
 265         case 8:
 266             reg = &(info->vm_regs.r8);
 267             break;
 268         case 9:
 269             reg = &(info->vm_regs.r9);
 270             break;
 271         case 10:
 272             reg = &(info->vm_regs.r10);
 273             break;
 274         case 11:
 275             reg = &(info->vm_regs.r11);
 276             break;
 277         case 12:
 278             reg = &(info->vm_regs.r11);
 279             break;
 280         case 13:
 281             reg = &(info->vm_regs.r13);
 282             break;
 283         case 14:
 284             reg = &(info->vm_regs.r14);
 285             break;
 286         case 15:
 287             reg = &(info->vm_regs.r15);
 288             break;
 289     }
 290
 291     return reg;
 292 }
 293
 294