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
  52 static int msr_read(uint_t msr, struct v3_msr * dst, void * priv_data) {
  53     struct guest_info * info = (struct guest_info *)priv_data;
  54     struct v3_sym_state * state = &(info->sym_state);
  55
  56     switch (msr) {
  57         case SYM_PAGE_MSR:
  58             dst->value = state->guest_pg_addr;
  59             break;
  60         case SYMCALL_RIP_MSR:
  61             dst->value = state->sym_call_rip;
  62             break;
  63         case SYMCALL_RSP_MSR:
  64             dst->value = state->sym_call_rsp;
  65             break;
  66         case SYMCALL_CS_MSR:
  67             dst->value = state->sym_call_cs;
  68             break;
  69         case SYMCALL_GS_MSR:
  70             dst->value = state->sym_call_gs;
  71             break;
  72         case SYMCALL_FS_MSR:
  73             dst->value = state->sym_call_fs;
  74             break;
  75         default:
  76             return -1;
  77     }
  78
  79     return 0;
  80 }
  81
  82 static int msr_write(uint_t msr, struct v3_msr src, void * priv_data) {
  83     struct guest_info * info = (struct guest_info *)priv_data;
  84     struct v3_sym_state * state = &(info->sym_state);
  85
  86     if (msr == SYM_PAGE_MSR) {
  87         PrintDebug("Symbiotic MSR write for page %p\n", (void *)src.value);
  88
  89         if (state->active == 1) {
  90             // unmap page
  91             struct v3_shadow_region * old_reg = v3_get_shadow_region(info, (addr_t)state->guest_pg_addr);
  92
  93             if (old_reg == NULL) {
  94                 PrintError("Could not find previously active symbiotic page (%p)\n", (void *)state->guest_pg_addr);
  95                 return -1;
  96             }
  97
  98             v3_delete_shadow_region(info, old_reg);
  99         }
 100
 101         state->guest_pg_addr = src.value;
 102         state->guest_pg_addr &= ~0xfffLL;
 103
 104         state->active = 1;
 105
 106         // map page
 107         v3_add_shadow_mem(info, (addr_t)state->guest_pg_addr,
 108                           (addr_t)(state->guest_pg_addr + PAGE_SIZE_4KB - 1),
 109                           state->sym_page_pa);
 110
 111
 112     } else if (msr == SYMCALL_RIP_MSR) {
 113         state->sym_call_rip = src.value;
 114     } else if (msr == SYMCALL_RSP_MSR) {
 115         state->sym_call_rsp = src.value;
 116     } else if (msr == SYMCALL_CS_MSR) {
 117         state->sym_call_cs = src.value;
 118     } else if (msr == SYMCALL_GS_MSR) {
 119         state->sym_call_gs = src.value;
 120     } else if (msr == SYMCALL_FS_MSR) {
 121         state->sym_call_fs = src.value;
 122     } else {
 123         PrintError("Invalid Symbiotic MSR write (0x%x)\n", msr);
 124         return -1;
 125     }
 126
 127     return 0;
 128 }
 129
 130 static int cpuid_fn(struct guest_info * info, uint32_t cpuid,
 131                     uint32_t * eax, uint32_t * ebx,
 132                     uint32_t * ecx, uint32_t * edx,
 133                     void * private_data) {
 134     extern v3_cpu_arch_t v3_cpu_types[];
 135
 136     *eax = *(uint32_t *)"V3V";
 137
 138     if ((v3_cpu_types[info->cpu_id] == V3_SVM_CPU) ||
 139         (v3_cpu_types[info->cpu_id] == V3_SVM_REV3_CPU)) {
 140         *ebx = *(uint32_t *)"SVM";
 141     } else if ((v3_cpu_types[info->cpu_id] == V3_VMX_CPU) ||
 142                (v3_cpu_types[info->cpu_id] == V3_VMX_EPT_CPU)) {
 143         *ebx = *(uint32_t *)"VMX";
 144     }
 145
 146
 147     return 0;
 148 }
 149
 150
 151 static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data);
 152 static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data);
 153
 154
 155
 156 int v3_init_sym_iface(struct guest_info * info) {
 157     struct v3_sym_state * state = &(info->sym_state);
 158     memset(state, 0, sizeof(struct v3_sym_state));
 159
 160     state->sym_page_pa = (addr_t)V3_AllocPages(1);
 161     state->sym_page = (struct v3_sym_interface *)V3_VAddr((void *)state->sym_page_pa);
 162     memset(state->sym_page, 0, PAGE_SIZE_4KB);
 163
 164
 165     memcpy(&(state->sym_page->magic), "V3V", 3);
 166
 167     v3_hook_msr(info, SYM_PAGE_MSR, msr_read, msr_write, info);
 168
 169     v3_hook_cpuid(info, SYM_CPUID_NUM, cpuid_fn, info);
 170
 171     v3_hook_msr(info, SYMCALL_RIP_MSR, msr_read, msr_write, info);
 172     v3_hook_msr(info, SYMCALL_RSP_MSR, msr_read, msr_write, info);
 173     v3_hook_msr(info, SYMCALL_CS_MSR, msr_read, msr_write, info);
 174     v3_hook_msr(info, SYMCALL_GS_MSR, msr_read, msr_write, info);
 175     v3_hook_msr(info, SYMCALL_FS_MSR, msr_read, msr_write, info);
 176
 177     v3_register_hypercall(info, SYM_CALL_RET_HCALL, sym_call_ret, NULL);
 178     v3_register_hypercall(info, SYM_CALL_ERR_HCALL, sym_call_err, NULL);
 179
 180     return 0;
 181 }
 182
 183 int v3_sym_map_pci_passthrough(struct guest_info * info, uint_t bus, uint_t dev, uint_t fn) {
 184     struct v3_sym_state * state = &(info->sym_state);
 185     uint_t dev_index = (bus << 8) + (dev << 3) + fn;
 186     uint_t major = dev_index / 8;
 187     uint_t minor = dev_index % 8;
 188
 189     if (bus > 3) {
 190         PrintError("Invalid PCI bus %d\n", bus);
 191         return -1;
 192     }
 193
 194     PrintDebug("Setting passthrough pci map for index=%d\n", dev_index);
 195
 196     state->sym_page->pci_pt_map[major] |= 0x1 << minor;
 197
 198     PrintDebug("pt_map entry=%x\n",   state->sym_page->pci_pt_map[major]);
 199
 200     PrintDebug("pt map vmm addr=%p\n", state->sym_page->pci_pt_map);
 201
 202     return 0;
 203 }
 204
 205 int v3_sym_unmap_pci_passthrough(struct guest_info * info, uint_t bus, uint_t dev, uint_t fn) {
 206     struct v3_sym_state * state = &(info->sym_state);
 207     uint_t dev_index = (bus << 8) + (dev << 3) + fn;
 208     uint_t major = dev_index / 8;
 209     uint_t minor = dev_index % 8;
 210
 211     if (bus > 3) {
 212         PrintError("Invalid PCI bus %d\n", bus);
 213         return -1;
 214     }
 215
 216     state->sym_page->pci_pt_map[major] &= ~(0x1 << minor);
 217
 218     return 0;
 219 }
 220
 221
 222 static int sym_call_err(struct guest_info * info, uint_t hcall_id, void * private_data) {
 223     struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
 224
 225     PrintError("sym call error\n");
 226
 227     state->sym_call_errno = (int)info->vm_regs.rbx;
 228     v3_print_guest_state(info);
 229     v3_print_mem_map(info);
 230
 231     // clear sym flags
 232     state->sym_call_error = 1;
 233     state->sym_call_returned = 1;
 234
 235     return -1;
 236 }
 237
 238 static int sym_call_ret(struct guest_info * info, uint_t hcall_id, void * private_data) {
 239     struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
 240
 241     //    PrintError("Return from sym call\n");
 242     //   v3_print_guest_state(info);
 243
 244     state->sym_call_returned = 1;
 245
 246     return 0;
 247 }
 248
 249 static int execute_symcall(struct guest_info * info) {
 250
 251     while (info->sym_state.sym_call_returned == 0) {
 252         if (v3_vm_enter(info) == -1) {
 253             PrintError("Error in Sym call\n");
 254             return -1;
 255         }
 256     }
 257
 258     return 0;
 259 }
 260
 261
 262 int v3_sym_call(struct guest_info * info,
 263                 uint64_t call_num, sym_arg_t * arg0,
 264                 sym_arg_t * arg1, sym_arg_t * arg2,
 265                 sym_arg_t * arg3, sym_arg_t * arg4) {
 266     struct v3_sym_state * state = (struct v3_sym_state *)&(info->sym_state);
 267     struct v3_sym_context * old_ctx = (struct v3_sym_context *)&(state->old_ctx);
 268     struct v3_segment sym_cs;
 269     struct v3_segment sym_ss;
 270     uint64_t trash_args[5] = { [0 ... 4] = 0 };
 271
 272     //   PrintDebug("Making Sym call\n");
 273     //    v3_print_guest_state(info);
 274
 275     if ((state->sym_page->sym_call_enabled == 0) ||
 276         (state->sym_call_active == 1)) {
 277         return -1;
 278     }
 279
 280     if (!arg0) arg0 = &trash_args[0];
 281     if (!arg1) arg1 = &trash_args[1];
 282     if (!arg2) arg2 = &trash_args[2];
 283     if (!arg3) arg3 = &trash_args[3];
 284     if (!arg4) arg4 = &trash_args[4];
 285
 286     // Save the old context
 287     memcpy(&(old_ctx->vm_regs), &(info->vm_regs), sizeof(struct v3_gprs));
 288     memcpy(&(old_ctx->cs), &(info->segments.cs), sizeof(struct v3_segment));
 289     memcpy(&(old_ctx->ss), &(info->segments.ss), sizeof(struct v3_segment));
 290     old_ctx->gs_base = info->segments.gs.base;
 291     old_ctx->fs_base = info->segments.fs.base;
 292     old_ctx->rip = info->rip;
 293     old_ctx->cpl = info->cpl;
 294     old_ctx->flags = info->ctrl_regs.rflags;
 295
 296     // Setup the sym call context
 297     info->rip = state->sym_call_rip;
 298     info->vm_regs.rsp = state->sym_call_rsp; // old contest rsp is saved in vm_regs
 299
 300     v3_translate_segment(info, state->sym_call_cs, &sym_cs);
 301     memcpy(&(info->segments.cs), &sym_cs, sizeof(struct v3_segment));
 302
 303     v3_translate_segment(info, state->sym_call_cs + 8, &sym_ss);
 304     memcpy(&(info->segments.ss), &sym_ss, sizeof(struct v3_segment));
 305
 306     info->segments.gs.base = state->sym_call_gs;
 307     info->segments.fs.base = state->sym_call_fs;
 308     info->cpl = 0;
 309
 310     info->vm_regs.rax = call_num;
 311     info->vm_regs.rbx = *arg0;
 312     info->vm_regs.rcx = *arg1;
 313     info->vm_regs.rdx = *arg2;
 314     info->vm_regs.rsi = *arg3;
 315     info->vm_regs.rdi = *arg4;
 316
 317     // Mark sym call as active
 318     state->sym_call_active = 1;
 319     state->sym_call_returned = 0;
 320
 321     //    PrintDebug("Sym state\n");
 322     //  v3_print_guest_state(info);
 323
 324     // Do the sym call entry
 325     if (execute_symcall(info) == -1) {
 326         PrintError("SYMCALL error\n");
 327         return -1;
 328     }
 329
 330     // clear sym flags
 331     state->sym_call_active = 0;
 332
 333     *arg0 = info->vm_regs.rbx;
 334     *arg1 = info->vm_regs.rcx;
 335     *arg2 = info->vm_regs.rdx;
 336     *arg3 = info->vm_regs.rsi;
 337     *arg4 = info->vm_regs.rdi;
 338
 339     // restore guest state
 340     memcpy(&(info->vm_regs), &(old_ctx->vm_regs), sizeof(struct v3_gprs));
 341     memcpy(&(info->segments.cs), &(old_ctx->cs), sizeof(struct v3_segment));
 342     memcpy(&(info->segments.ss), &(old_ctx->ss), sizeof(struct v3_segment));
 343     info->segments.gs.base = old_ctx->gs_base;
 344     info->segments.fs.base = old_ctx->fs_base;
 345     info->rip = old_ctx->rip;
 346     info->cpl = old_ctx->cpl;
 347     info->ctrl_regs.rflags = old_ctx->flags;
 348
 349
 350
 351     //    PrintDebug("restoring guest state\n");
 352     //    v3_print_guest_state(info);
 353
 354     return 0;
 355 }
 356
 357