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