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 int v3_vmx_handle_cr4_access(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual) {
  81     if (cr_qual->access_type < 2) {
  82
  83         if (cr_qual->access_type == 0) {
  84             if (v3_handle_cr4_write(info) != 0) {
  85                 PrintError("Could not handle CR4 write\n");
  86                 return -1;
  87             }
  88             info->ctrl_regs.cr4 |= 0x2000; // no VMX allowed in guest, so mask CR4.VMXE
  89         } else {
  90             if (v3_handle_cr4_read(info) != 0) {
  91                 PrintError("Could not handle CR4 read\n");
  92                 return -1;
  93             }
  94         }
  95
  96         return 0;
  97     }
  98
  99     PrintError("Invalid CR4 Access type?? (type=%d)\n", cr_qual->access_type);
 100     return -1;
 101 }
 102
 103 static int handle_mov_to_cr3(struct guest_info * info, v3_reg_t * cr3_reg) {
 104
 105     if (info->shdw_pg_mode == SHADOW_PAGING) {
 106
 107         /*
 108         PrintDebug("Old Guest CR3=%p, Old Shadow CR3=%p\n",
 109                    (void *)info->ctrl_regs.cr3,
 110                    (void *)info->shdw_pg_state.guest_cr3);
 111         */
 112
 113         if (info->cpu_mode == LONG) {
 114             info->shdw_pg_state.guest_cr3 = (uint64_t)*cr3_reg;
 115         } else {
 116             info->shdw_pg_state.guest_cr3 = (uint32_t)*cr3_reg;
 117         }
 118
 119
 120         if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
 121             if (v3_activate_shadow_pt(info) == -1) {
 122                 PrintError("Failed to activate 32 bit shadow page table\n");
 123                 return -1;
 124             }
 125         }
 126         /*
 127         PrintDebug("New guest CR3=%p, New shadow CR3=%p\n",
 128                    (void *)info->ctrl_regs.cr3,
 129                    (void *)info->shdw_pg_state.guest_cr3);
 130         */
 131     } else if (info->shdw_pg_mode == NESTED_PAGING) {
 132         PrintError("Nested paging not available in VMX right now!\n");
 133         return -1;
 134     }
 135
 136
 137
 138     return 0;
 139 }
 140
 141 static int handle_mov_from_cr3(struct guest_info * info, v3_reg_t * cr3_reg) {
 142
 143
 144     if (info->shdw_pg_mode == SHADOW_PAGING) {
 145
 146         if ((v3_get_vm_cpu_mode(info) == LONG) ||
 147             (v3_get_vm_cpu_mode(info) == LONG_32_COMPAT)) {
 148
 149             *cr3_reg = (uint64_t)info->shdw_pg_state.guest_cr3;
 150         } else {
 151             *cr3_reg = (uint32_t)info->shdw_pg_state.guest_cr3;
 152         }
 153
 154     } else {
 155         PrintError("Unhandled paging mode\n");
 156         return -1;
 157     }
 158
 159
 160     return 0;
 161 }
 162
 163 static int handle_mov_to_cr0(struct guest_info * info, v3_reg_t * new_cr0, struct vmx_exit_info * exit_info) {
 164     struct cr0_32 * guest_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
 165     struct cr0_32 * shdw_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
 166     struct cr0_32 * new_shdw_cr0 = (struct cr0_32 *)new_cr0;
 167     struct vmx_data * vmx_info = (struct vmx_data *)info->vmm_data;
 168     uint_t paging_transition = 0;
 169
 170     /*
 171       PrintDebug("Old shadow CR0: 0x%x, New shadow CR0: 0x%x\n",
 172       (uint32_t)info->shdw_pg_state.guest_cr0, (uint32_t)*new_cr0);
 173     */
 174
 175     if (new_shdw_cr0->pe != shdw_cr0->pe) {
 176         /*
 177           PrintDebug("Guest CR0: 0x%x\n", *(uint32_t *)guest_cr0);
 178           PrintDebug("Old shadow CR0: 0x%x\n", *(uint32_t *)shdw_cr0);
 179           PrintDebug("New shadow CR0: 0x%x\n", *(uint32_t *)new_shdw_cr0);
 180         */
 181
 182         if (v3_vmxassist_ctx_switch(info) != 0) {
 183             PrintError("Unable to execute VMXASSIST context switch!\n");
 184             return -1;
 185         }
 186
 187         if (vmx_info->assist_state == VMXASSIST_ENABLED) {
 188             PrintDebug("Loading VMXASSIST at RIP: %p\n", (void *)(addr_t)info->rip);
 189         } else {
 190             PrintDebug("Leaving VMXASSIST and entering protected mode at RIP: %p\n",
 191                        (void *)(addr_t)info->rip);
 192         }
 193
 194         // PE switches modify the RIP directly, so we clear the instr_len field to avoid catastrophe
 195         exit_info->instr_len = 0;
 196
 197         //      v3_vmx_restore_vmcs(info);
 198         //      v3_print_vmcs(info);
 199
 200     } else {
 201
 202         if (new_shdw_cr0->pg != shdw_cr0->pg) {
 203             paging_transition = 1;
 204         }
 205
 206         // The shadow always reflects the new value
 207         *shdw_cr0 = *new_shdw_cr0;
 208
 209         // We don't care about most of the flags, so lets go for it
 210         // and set them to the guest values
 211         *guest_cr0 = *shdw_cr0;
 212
 213         // Except PG, PE, and NE, which are always set
 214         guest_cr0->pe = 1;
 215         guest_cr0->pg = 1;
 216         guest_cr0->ne = 1;
 217
 218         if ((paging_transition)) {
 219             // Paging transition
 220
 221             if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
 222                 struct efer_64 * vm_efer = (struct efer_64 *)&(info->shdw_pg_state.guest_efer);
 223                 struct efer_64 * hw_efer = (struct efer_64 *)&(info->ctrl_regs.efer);
 224
 225                 if (vm_efer->lme) {
 226                     //     PrintDebug("Enabling long mode\n");
 227
 228                     hw_efer->lma = 1;
 229                     hw_efer->lme = 1;
 230
 231                     vmx_info->entry_ctrls.guest_ia32e = 1;
 232                 }
 233
 234                 //            PrintDebug("Activating Shadow Page tables\n");
 235
 236                 if (info->shdw_pg_mode == SHADOW_PAGING) {
 237                     if (v3_activate_shadow_pt(info) == -1) {
 238                         PrintError("Failed to activate shadow page tables\n");
 239                         return -1;
 240                     }
 241                 }
 242
 243             } else {
 244
 245                 if (info->shdw_pg_mode == SHADOW_PAGING) {
 246                     if (v3_activate_passthrough_pt(info) == -1) {
 247                         PrintError("Failed to activate passthrough page tables\n");
 248                         return -1;
 249                     }
 250                 } else {
 251                     // This is hideous... Let's hope that the 1to1 page table has not been nuked...
 252                     info->ctrl_regs.cr3 = VMXASSIST_1to1_PT;
 253                 }
 254             }
 255         }
 256     }
 257
 258     return 0;
 259 }
 260
 261 static v3_reg_t * get_reg_ptr(struct guest_info * info, struct vmx_exit_cr_qual * cr_qual) {
 262     v3_reg_t * reg = NULL;
 263
 264     switch (cr_qual->gpr) {
 265         case 0:
 266             reg = &(info->vm_regs.rax);
 267             break;
 268         case 1:
 269             reg = &(info->vm_regs.rcx);
 270             break;
 271         case 2:
 272             reg = &(info->vm_regs.rdx);
 273             break;
 274         case 3:
 275             reg = &(info->vm_regs.rbx);
 276             break;
 277         case 4:
 278             reg = &(info->vm_regs.rsp);
 279             break;
 280         case 5:
 281             reg = &(info->vm_regs.rbp);
 282             break;
 283         case 6:
 284             reg = &(info->vm_regs.rsi);
 285             break;
 286         case 7:
 287             reg = &(info->vm_regs.rdi);
 288             break;
 289         case 8:
 290             reg = &(info->vm_regs.r8);
 291             break;
 292         case 9:
 293             reg = &(info->vm_regs.r9);
 294             break;
 295         case 10:
 296             reg = &(info->vm_regs.r10);
 297             break;
 298         case 11:
 299             reg = &(info->vm_regs.r11);
 300             break;
 301         case 12:
 302             reg = &(info->vm_regs.r11);
 303             break;
 304         case 13:
 305             reg = &(info->vm_regs.r13);
 306             break;
 307         case 14:
 308             reg = &(info->vm_regs.r14);
 309             break;
 310         case 15:
 311             reg = &(info->vm_regs.r15);
 312             break;
 313     }
 314
 315     return reg;
 316 }
 317
 318