palacios/src/palacios/vmm_sym_iface.c

   1 /*
   2  * This file is part of the Palacios Virtual Machine Monitor developed
   3  * by the V3VEE Project with funding from the United States National
   4  * Science Foundation and the Department of Energy.
   5  *
   6  * The V3VEE Project is a joint project between Northwestern University
   7  * and the University of New Mexico.  You can find out more at
   8  * http://www.v3vee.org
   9  *
  10  * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
  11  * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
  12  * All rights reserved.
  13  *
  14  * Author: Jack Lange <jarusl@cs.northwestern.edu>
  15  *
  16  * This is free software.  You are permitted to use,
  17  * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
  18  */
  19
  20
  21 #include <palacios/vmm.h>
  22 #include <palacios/vmm_msr.h>
  23 #include <palacios/vmm_mem.h>
  24 #include <palacios/vmm_hypercall.h>
  25 #include <palacios/vm_guest.h>
  26
  27 #define SYM_PAGE_MSR 0x535
  28
  29 #define SYM_CPUID_NUM 0x90000000
  30
  31 // A succesfull symcall returns via the RET_HCALL, with the return values in registers
  32 // A symcall error returns via the ERR_HCALL with the error code in rbx
  33 #define SYM_CALL_RET_HCALL 0x535
  34 #define SYM_CALL_ERR_HCALL 0x536
  35
  36
  37 /* Notes: We use a combination of SYSCALL and SYSENTER Semantics
  38  * SYSCALL just sets an EIP, CS/SS seg, and GS seg via swapgs
  39  * the RSP is loaded via the structure pointed to by GS
  40  * This is safe because it assumes that system calls are guaranteed to be made with an empty kernel stack.
  41  * We cannot make that assumption with a symcall, so we have to have our own stack area somewhere.
  42  * SYSTENTER does not really use the GS base MSRs, but we do to map to 64 bit kernels
  43  */
  44
  45 #define SYMCALL_RIP_MSR 0x536
  46 #define SYMCALL_RSP_MSR 0x537
  47 #define SYMCALL_CS_MSR  0x538
  48 #define SYMCALL_GS_MSR  0x539
  49 #define SYMCALL_FS_MSR  0x540
  50
  51 static int msr_read(uint_t msr, struct v3_msr * dst, void * priv_data) {
  52     struct guest_info * info = (struct guest_info *)priv_data;
  53     struct v3_sym_state * state = &(info->vm_info->sym_state);
  54
  55     switch (msr) {
  56         case SYM_PAGE_MSR:
  57             dst->value = state->guest_pg_addr;
  58             break;
  59         default:
  60             return -1;
  61     }
  62
  63     return 0;
  64 }
  65
  66 static int symcall_msr_read(uint_t msr, struct v3_msr * dst, void * priv_data) {
  67     struct guest_info * info = (struct guest_info *)priv_data;
  68     struct v3_symcall_state * state = &(info->vm_info->sym_state.symcalls[info->cpu_id]);
  69
  70     switch (msr) {
  71         case SYMCALL_RIP_MSR:
  72             dst->value = state->sym_call_rip;
  73             break;
  74         case SYMCALL_RSP_MSR:
  75             dst->value = state->sym_call_rsp;
  76             break;
  77         case SYMCALL_CS_MSR:
  78             dst->value = state->sym_call_cs;
  79             break;
  80         case SYMCALL_GS_MSR:
  81             dst->value = state->sym_call_gs;
  82             break;
  83         case SYMCALL_FS_MSR:
  84             dst->value = state->sym_call_fs;
  85             break;
  86         default:
  87             return -1;
  88     }
  89
  90     return 0;
  91 }
  92
  93 static int msr_write(uint_t msr, struct v3_msr src, void * priv_data) {
  94     struct guest_info * info = (struct guest_info *)priv_data;
  95     struct v3_sym_state * state = &(info->vm_info->sym_state);
  96
  97     if (msr == SYM_PAGE_MSR) {
  98         PrintDebug("Symbiotic MSR write for page %p\n", (void *)src.value);
  99
 100         if (state->active == 1) {
 101             // unmap page
 102             struct v3_shadow_region * old_reg = v3_get_shadow_region(info->vm_info, (addr_t)state->guest_pg_addr);
 103
 104             if (old_reg == NULL) {
 105                 PrintError("Could not find previously active symbiotic page (%p)\n", (void *)state->guest_pg_addr);
 106                 return -1;
 107             }
 108
 109             v3_delete_shadow_region(info->vm_info, old_reg);
 110         }
 111
 112         state->guest_pg_addr = src.value;
 113         state->guest_pg_addr &= ~0xfffLL;
 114
 115         state->active = 1;
 116
 117         // map page
 118         v3_add_shadow_mem(info->vm_info, (addr_t)state->guest_pg_addr,
 119                           (addr_t)(state->guest_pg_addr + PAGE_SIZE_4KB - 1),
 120                           state->sym_page_pa);
 121     } else {
 122         PrintError("Invalid Symbiotic MSR write (0x%x)\n", msr);
 123         return -1;
 124     }
 125
 126     return 0;
 127 }
 128
 129
 130 static int symcall_msr_write(uint_t msr, struct v3_msr src, void * priv_data) {
 131     struct guest_info * info = (struct guest_info *)priv_data;
 132     struct v3_symcall_state * state = &(info->vm_info->sym_state.symcalls[info->cpu_id]);
 133
 134     switch (msr) {
 135         case SYMCALL_RIP_MSR:
 136             state->sym_call_rip = src.value;
 137             break;
 138         case SYMCALL_RSP_MSR:
 139             state->sym_call_rsp = src.value;
 140             break;
 141         case SYMCALL_CS_MSR:
 142             state->sym_call_cs = src.value;
 143             break;
 144         case SYMCALL_GS_MSR:
 145             state->sym_call_gs = src.value;
 146             break;
 147         case SYMCALL_FS_MSR:
 148             state->sym_call_fs = src.value;
 149             break;
 150         default:
 151             PrintError("Invalid Symbiotic MSR write (0x%x)\n", msr);
 152             return -1;
 153     }
 154     return 0;
 155 }
 156
 157 static int cpuid_fn(struct guest_info * info, uint32_t cpuid,
 158                     uint32_t * eax, uint32_t * ebx,
 159                     uint32_t * ecx, uint32_t * edx,
 160                     void * private_data) {
 161     extern v3_cpu_arch_t v3_cpu_types[];
 162
 163     *eax = *(uint32_t *)"V3V";
 164
 165     if ((v3_cpu_types[info->cpu_id] == V3_SVM_CPU) ||
 166         (v3_cpu_types[info->cpu_id] == V3_SVM_REV3_CPU)) {
 167         *ebx = *(uint32_t *)"SVM";
 168     } else if ((v3_cpu_types[info->cpu_id] == V3_VMX_CPU) ||
 169                (v3_cpu_types[info->cpu_id] == V3_VMX_EPT_CPU)) {
 170         *ebx = *(uint32_t *)"VMX";
 171     }
 172
 173
 174     return 0;
 175 }
 176
 177
 178 static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data);
 179 static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data);
 180
 181
 182
 183 int v3_init_sym_iface(struct v3_vm_info * vm) {
 184     struct v3_sym_state * state = &(vm->sym_state);
 185     memset(state, 0, sizeof(struct v3_sym_state));
 186
 187     state->sym_page_pa = (addr_t)V3_AllocPages(1);
 188     state->sym_page = (struct v3_sym_interface *)V3_VAddr((void *)state->sym_page_pa);
 189     memset(state->sym_page, 0, PAGE_SIZE_4KB);
 190
 191
 192     memcpy(&(state->sym_page->magic), "V3V", 3);
 193
 194     v3_hook_msr(vm, SYM_PAGE_MSR, msr_read, msr_write, info);
 195
 196     v3_hook_cpuid(vm, SYM_CPUID_NUM, cpuid_fn, info);
 197
 198     v3_hook_msr(vm, SYMCALL_RIP_MSR, symcall_msr_read, msr_write, info);
 199     v3_hook_msr(vm, SYMCALL_RSP_MSR, symcall_msr_read, msr_write, info);
 200     v3_hook_msr(vm, SYMCALL_CS_MSR, symcall_msr_read, msr_write, info);
 201     v3_hook_msr(vm, SYMCALL_GS_MSR, symcall_msr_read, msr_write, info);
 202     v3_hook_msr(vm, SYMCALL_FS_MSR, symcall_msr_read, msr_write, info);
 203
 204     v3_register_hypercall(vm, SYM_CALL_RET_HCALL, sym_call_ret, NULL);
 205     v3_register_hypercall(vm, SYM_CALL_ERR_HCALL, sym_call_err, NULL);
 206
 207     return 0;
 208 }
 209
 210 int v3_sym_map_pci_passthrough(struct v3_vm_info * vm, uint_t bus, uint_t dev, uint_t fn) {
 211     struct v3_sym_state * state = &(vm->sym_state);
 212     uint_t dev_index = (bus << 8) + (dev << 3) + fn;
 213     uint_t major = dev_index / 8;
 214     uint_t minor = dev_index % 8;
 215
 216     if (bus > 3) {
 217         PrintError("Invalid PCI bus %d\n", bus);
 218         return -1;
 219     }
 220
 221     PrintDebug("Setting passthrough pci map for index=%d\n", dev_index);
 222
 223     state->sym_page->pci_pt_map[major] |= 0x1 << minor;
 224
 225     PrintDebug("pt_map entry=%x\n",   state->sym_page->pci_pt_map[major]);
 226
 227     PrintDebug("pt map vmm addr=%p\n", state->sym_page->pci_pt_map);
 228
 229     return 0;
 230 }
 231
 232 int v3_sym_unmap_pci_passthrough(struct v3_vm_info * vm, uint_t bus, uint_t dev, uint_t fn) {
 233     struct v3_sym_state * state = &(vm->sym_state);
 234     uint_t dev_index = (bus << 8) + (dev << 3) + fn;
 235     uint_t major = dev_index / 8;
 236     uint_t minor = dev_index % 8;
 237
 238     if (bus > 3) {
 239         PrintError("Invalid PCI bus %d\n", bus);
 240         return -1;
 241     }
 242
 243     state->sym_page->pci_pt_map[major] &= ~(0x1 << minor);
 244
 245     return 0;
 246 }
 247
 248
 249 static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data) {
 250     struct v3_symcall_state * state = (struct v3_symcall_state *)&(info->sym_state.symcalls[info->cpu_id]);
 251
 252     PrintError("sym call error\n");
 253
 254     state->sym_call_errno = (int)info->vm_regs.rbx;
 255     v3_print_guest_state(info);
 256     v3_print_mem_map(info);
 257
 258     // clear sym flags
 259     state->sym_call_error = 1;
 260     state->sym_call_returned = 1;
 261
 262     return -1;
 263 }
 264
 265 static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data) {
 266     struct v3_symcall_state * state = (struct v3_symcall_state *)&(info->vm_info->sym_state.symcalls[info->cpu_id]);
 267
 268     //    PrintError("Return from sym call (ID=%x)\n", hcall_id);
 269     //   v3_print_guest_state(info);
 270
 271     state->sym_call_returned = 1;
 272
 273     return 0;
 274 }
 275
 276 static int execute_symcall(struct guest_info * info) {
 277     struct v3_symcall_state * state = (struct v3_symcall_state *)&(info->vm_info->sym_state.symcalls[info->cpu_id]);
 278
 279     while (state->sym_call_returned == 0) {
 280         if (v3_vm_enter(info) == -1) {
 281             PrintError("Error in Sym call\n");
 282             return -1;
 283         }
 284     }
 285
 286     return 0;
 287 }
 288
 289
 290 int v3_sym_call(struct guest_info * info,
 291                 uint64_t call_num, sym_arg_t * arg0,
 292                 sym_arg_t * arg1, sym_arg_t * arg2,
 293                 sym_arg_t * arg3, sym_arg_t * arg4) {
 294     struct v3_sym_state * sym_state = (struct v3_sym_state *)&(info->vm_info->sym_sate);
 295     struct v3_symcall_state * state = (struct v3_symcall_state *)&(sym_state->symcalls[info->cpu_id]);
 296     struct v3_sym_context * old_ctx = (struct v3_sym_context *)&(state->old_ctx);
 297     struct v3_segment sym_cs;
 298     struct v3_segment sym_ss;
 299     uint64_t trash_args[5] = { [0 ... 4] = 0 };
 300
 301     //   PrintDebug("Making Sym call\n");
 302     //    v3_print_guest_state(info);
 303
 304     if ((sym_state->sym_page->sym_call_enabled == 0) ||
 305         (state->sym_call_active == 1)) {
 306         return -1;
 307     }
 308
 309     if (!arg0) arg0 = &trash_args[0];
 310     if (!arg1) arg1 = &trash_args[1];
 311     if (!arg2) arg2 = &trash_args[2];
 312     if (!arg3) arg3 = &trash_args[3];
 313     if (!arg4) arg4 = &trash_args[4];
 314
 315     // Save the old context
 316     memcpy(&(old_ctx->vm_regs), &(info->vm_regs), sizeof(struct v3_gprs));
 317     memcpy(&(old_ctx->cs), &(info->segments.cs), sizeof(struct v3_segment));
 318     memcpy(&(old_ctx->ss), &(info->segments.ss), sizeof(struct v3_segment));
 319     old_ctx->gs_base = info->segments.gs.base;
 320     old_ctx->fs_base = info->segments.fs.base;
 321     old_ctx->rip = info->rip;
 322     old_ctx->cpl = info->cpl;
 323     old_ctx->flags = info->ctrl_regs.rflags;
 324
 325     // Setup the sym call context
 326     info->rip = state->sym_call_rip;
 327     info->vm_regs.rsp = state->sym_call_rsp; // old contest rsp is saved in vm_regs
 328
 329     v3_translate_segment(info, state->sym_call_cs, &sym_cs);
 330     memcpy(&(info->segments.cs), &sym_cs, sizeof(struct v3_segment));
 331
 332     v3_translate_segment(info, state->sym_call_cs + 8, &sym_ss);
 333     memcpy(&(info->segments.ss), &sym_ss, sizeof(struct v3_segment));
 334
 335     info->segments.gs.base = state->sym_call_gs;
 336     info->segments.fs.base = state->sym_call_fs;
 337     info->cpl = 0;
 338
 339     info->vm_regs.rax = call_num;
 340     info->vm_regs.rbx = *arg0;
 341     info->vm_regs.rcx = *arg1;
 342     info->vm_regs.rdx = *arg2;
 343     info->vm_regs.rsi = *arg3;
 344     info->vm_regs.rdi = *arg4;
 345
 346     // Mark sym call as active
 347     state->sym_call_active = 1;
 348     state->sym_call_returned = 0;
 349
 350     //    PrintDebug("Sym state\n");
 351     //  v3_print_guest_state(info);
 352
 353     // Do the sym call entry
 354     if (execute_symcall(info) == -1) {
 355         PrintError("SYMCALL error\n");
 356         return -1;
 357     }
 358
 359     // clear sym flags
 360     state->sym_call_active = 0;
 361
 362     *arg0 = info->vm_regs.rbx;
 363     *arg1 = info->vm_regs.rcx;
 364     *arg2 = info->vm_regs.rdx;
 365     *arg3 = info->vm_regs.rsi;
 366     *arg4 = info->vm_regs.rdi;
 367
 368     // restore guest state
 369     memcpy(&(info->vm_regs), &(old_ctx->vm_regs), sizeof(struct v3_gprs));
 370     memcpy(&(info->segments.cs), &(old_ctx->cs), sizeof(struct v3_segment));
 371     memcpy(&(info->segments.ss), &(old_ctx->ss), sizeof(struct v3_segment));
 372     info->segments.gs.base = old_ctx->gs_base;
 373     info->segments.fs.base = old_ctx->fs_base;
 374     info->rip = old_ctx->rip;
 375     info->cpl = old_ctx->cpl;
 376     info->ctrl_regs.rflags = old_ctx->flags;
 377
 378
 379
 380     //    PrintError("restoring guest state\n");
 381     //    v3_print_guest_state(info);
 382
 383     return 0;
 384 }
 385
 386