1 /*- 2 * Copyright (c) 2013 Anish Gupta (akgupt3@gmail.com) 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/cpuset.h> 33 34 #include <machine/segments.h> 35 #include <machine/specialreg.h> 36 #include <machine/vmm.h> 37 38 #include "vmm_ktr.h" 39 40 #include "vmcb.h" 41 #include "svm.h" 42 #include "svm_softc.h" 43 44 /* 45 * The VMCB aka Virtual Machine Control Block is a 4KB aligned page 46 * in memory that describes the virtual machine. 47 * 48 * The VMCB contains: 49 * - instructions or events in the guest to intercept 50 * - control bits that modify execution environment of the guest 51 * - guest processor state (e.g. general purpose registers) 52 */ 53 54 /* 55 * Return VMCB segment area. 56 */ 57 static struct vmcb_segment * 58 vmcb_segptr(struct vmcb *vmcb, int type) 59 { 60 struct vmcb_state *state; 61 struct vmcb_segment *seg; 62 63 state = &vmcb->state; 64 65 switch (type) { 66 case VM_REG_GUEST_CS: 67 seg = &state->cs; 68 break; 69 70 case VM_REG_GUEST_DS: 71 seg = &state->ds; 72 break; 73 74 case VM_REG_GUEST_ES: 75 seg = &state->es; 76 break; 77 78 case VM_REG_GUEST_FS: 79 seg = &state->fs; 80 break; 81 82 case VM_REG_GUEST_GS: 83 seg = &state->gs; 84 break; 85 86 case VM_REG_GUEST_SS: 87 seg = &state->ss; 88 break; 89 90 case VM_REG_GUEST_GDTR: 91 seg = &state->gdt; 92 break; 93 94 case VM_REG_GUEST_IDTR: 95 seg = &state->idt; 96 break; 97 98 case VM_REG_GUEST_LDTR: 99 seg = &state->ldt; 100 break; 101 102 case VM_REG_GUEST_TR: 103 seg = &state->tr; 104 break; 105 106 default: 107 seg = NULL; 108 break; 109 } 110 111 return (seg); 112 } 113 114 static int 115 vmcb_access(struct svm_softc *softc, int vcpu, int write, int ident, 116 uint64_t *val) 117 { 118 struct vmcb *vmcb; 119 int off, bytes; 120 char *ptr; 121 122 vmcb = svm_get_vmcb(softc, vcpu); 123 off = VMCB_ACCESS_OFFSET(ident); 124 bytes = VMCB_ACCESS_BYTES(ident); 125 126 if ((off + bytes) >= sizeof (struct vmcb)) 127 return (EINVAL); 128 129 ptr = (char *)vmcb; 130 131 if (!write) 132 *val = 0; 133 134 switch (bytes) { 135 case 8: 136 case 4: 137 case 2: 138 if (write) 139 memcpy(ptr + off, val, bytes); 140 else 141 memcpy(val, ptr + off, bytes); 142 break; 143 default: 144 VCPU_CTR1(softc->vm, vcpu, 145 "Invalid size %d for VMCB access: %d", bytes); 146 return (EINVAL); 147 } 148 149 /* Invalidate all VMCB state cached by h/w. */ 150 if (write) 151 svm_set_dirty(softc, vcpu, 0xffffffff); 152 153 return (0); 154 } 155 156 /* 157 * Read from segment selector, control and general purpose register of VMCB. 158 */ 159 int 160 vmcb_read(struct svm_softc *sc, int vcpu, int ident, uint64_t *retval) 161 { 162 struct vmcb *vmcb; 163 struct vmcb_state *state; 164 struct vmcb_segment *seg; 165 int err; 166 167 vmcb = svm_get_vmcb(sc, vcpu); 168 state = &vmcb->state; 169 err = 0; 170 171 if (VMCB_ACCESS_OK(ident)) 172 return (vmcb_access(sc, vcpu, 0, ident, retval)); 173 174 switch (ident) { 175 case VM_REG_GUEST_CR0: 176 *retval = state->cr0; 177 break; 178 179 case VM_REG_GUEST_CR2: 180 *retval = state->cr2; 181 break; 182 183 case VM_REG_GUEST_CR3: 184 *retval = state->cr3; 185 break; 186 187 case VM_REG_GUEST_CR4: 188 *retval = state->cr4; 189 break; 190 191 case VM_REG_GUEST_DR7: 192 *retval = state->dr7; 193 break; 194 195 case VM_REG_GUEST_EFER: 196 *retval = state->efer; 197 break; 198 199 case VM_REG_GUEST_RAX: 200 *retval = state->rax; 201 break; 202 203 case VM_REG_GUEST_RFLAGS: 204 *retval = state->rflags; 205 break; 206 207 case VM_REG_GUEST_RIP: 208 *retval = state->rip; 209 break; 210 211 case VM_REG_GUEST_RSP: 212 *retval = state->rsp; 213 break; 214 215 case VM_REG_GUEST_CS: 216 case VM_REG_GUEST_DS: 217 case VM_REG_GUEST_ES: 218 case VM_REG_GUEST_FS: 219 case VM_REG_GUEST_GS: 220 case VM_REG_GUEST_SS: 221 case VM_REG_GUEST_LDTR: 222 case VM_REG_GUEST_TR: 223 seg = vmcb_segptr(vmcb, ident); 224 KASSERT(seg != NULL, ("%s: unable to get segment %d from VMCB", 225 __func__, ident)); 226 *retval = seg->selector; 227 break; 228 229 case VM_REG_GUEST_GDTR: 230 case VM_REG_GUEST_IDTR: 231 /* GDTR and IDTR don't have segment selectors */ 232 err = EINVAL; 233 break; 234 default: 235 err = EINVAL; 236 break; 237 } 238 239 return (err); 240 } 241 242 /* 243 * Write to segment selector, control and general purpose register of VMCB. 244 */ 245 int 246 vmcb_write(struct svm_softc *sc, int vcpu, int ident, uint64_t val) 247 { 248 struct vmcb *vmcb; 249 struct vmcb_state *state; 250 struct vmcb_segment *seg; 251 int err, dirtyseg; 252 253 vmcb = svm_get_vmcb(sc, vcpu); 254 state = &vmcb->state; 255 dirtyseg = 0; 256 err = 0; 257 258 if (VMCB_ACCESS_OK(ident)) 259 return (vmcb_access(sc, vcpu, 1, ident, &val)); 260 261 switch (ident) { 262 case VM_REG_GUEST_CR0: 263 state->cr0 = val; 264 svm_set_dirty(sc, vcpu, VMCB_CACHE_CR); 265 break; 266 267 case VM_REG_GUEST_CR2: 268 state->cr2 = val; 269 svm_set_dirty(sc, vcpu, VMCB_CACHE_CR2); 270 break; 271 272 case VM_REG_GUEST_CR3: 273 state->cr3 = val; 274 svm_set_dirty(sc, vcpu, VMCB_CACHE_CR); 275 break; 276 277 case VM_REG_GUEST_CR4: 278 state->cr4 = val; 279 svm_set_dirty(sc, vcpu, VMCB_CACHE_CR); 280 break; 281 282 case VM_REG_GUEST_DR7: 283 state->dr7 = val; 284 break; 285 286 case VM_REG_GUEST_EFER: 287 /* EFER_SVM must always be set when the guest is executing */ 288 state->efer = val | EFER_SVM; 289 svm_set_dirty(sc, vcpu, VMCB_CACHE_CR); 290 break; 291 292 case VM_REG_GUEST_RAX: 293 state->rax = val; 294 break; 295 296 case VM_REG_GUEST_RFLAGS: 297 state->rflags = val; 298 break; 299 300 case VM_REG_GUEST_RIP: 301 state->rip = val; 302 break; 303 304 case VM_REG_GUEST_RSP: 305 state->rsp = val; 306 break; 307 308 case VM_REG_GUEST_CS: 309 case VM_REG_GUEST_DS: 310 case VM_REG_GUEST_ES: 311 case VM_REG_GUEST_SS: 312 dirtyseg = 1; /* FALLTHROUGH */ 313 case VM_REG_GUEST_FS: 314 case VM_REG_GUEST_GS: 315 case VM_REG_GUEST_LDTR: 316 case VM_REG_GUEST_TR: 317 seg = vmcb_segptr(vmcb, ident); 318 KASSERT(seg != NULL, ("%s: unable to get segment %d from VMCB", 319 __func__, ident)); 320 seg->selector = val; 321 if (dirtyseg) 322 svm_set_dirty(sc, vcpu, VMCB_CACHE_SEG); 323 break; 324 325 case VM_REG_GUEST_GDTR: 326 case VM_REG_GUEST_IDTR: 327 /* GDTR and IDTR don't have segment selectors */ 328 err = EINVAL; 329 break; 330 default: 331 err = EINVAL; 332 break; 333 } 334 335 return (err); 336 } 337 338 int 339 vmcb_seg(struct vmcb *vmcb, int ident, struct vmcb_segment *seg2) 340 { 341 struct vmcb_segment *seg; 342 343 seg = vmcb_segptr(vmcb, ident); 344 if (seg != NULL) { 345 bcopy(seg, seg2, sizeof(struct vmcb_segment)); 346 return (0); 347 } else { 348 return (EINVAL); 349 } 350 } 351 352 int 353 vmcb_setdesc(void *arg, int vcpu, int reg, struct seg_desc *desc) 354 { 355 struct vmcb *vmcb; 356 struct svm_softc *sc; 357 struct vmcb_segment *seg; 358 uint16_t attrib; 359 360 sc = arg; 361 vmcb = svm_get_vmcb(sc, vcpu); 362 363 seg = vmcb_segptr(vmcb, reg); 364 KASSERT(seg != NULL, ("%s: invalid segment descriptor %d", 365 __func__, reg)); 366 367 seg->base = desc->base; 368 seg->limit = desc->limit; 369 if (reg != VM_REG_GUEST_GDTR && reg != VM_REG_GUEST_IDTR) { 370 /* 371 * Map seg_desc access to VMCB attribute format. 372 * 373 * SVM uses the 'P' bit in the segment attributes to indicate a 374 * NULL segment so clear it if the segment is marked unusable. 375 */ 376 attrib = ((desc->access & 0xF000) >> 4) | (desc->access & 0xFF); 377 if (SEG_DESC_UNUSABLE(desc->access)) { 378 attrib &= ~0x80; 379 } 380 seg->attrib = attrib; 381 } 382 383 VCPU_CTR4(sc->vm, vcpu, "Setting desc %d: base (%#lx), limit (%#x), " 384 "attrib (%#x)", reg, seg->base, seg->limit, seg->attrib); 385 386 switch (reg) { 387 case VM_REG_GUEST_CS: 388 case VM_REG_GUEST_DS: 389 case VM_REG_GUEST_ES: 390 case VM_REG_GUEST_SS: 391 svm_set_dirty(sc, vcpu, VMCB_CACHE_SEG); 392 break; 393 case VM_REG_GUEST_GDTR: 394 case VM_REG_GUEST_IDTR: 395 svm_set_dirty(sc, vcpu, VMCB_CACHE_DT); 396 break; 397 default: 398 break; 399 } 400 401 return (0); 402 } 403 404 int 405 vmcb_getdesc(void *arg, int vcpu, int reg, struct seg_desc *desc) 406 { 407 struct vmcb *vmcb; 408 struct svm_softc *sc; 409 struct vmcb_segment *seg; 410 411 sc = arg; 412 vmcb = svm_get_vmcb(sc, vcpu); 413 seg = vmcb_segptr(vmcb, reg); 414 KASSERT(seg != NULL, ("%s: invalid segment descriptor %d", 415 __func__, reg)); 416 417 desc->base = seg->base; 418 desc->limit = seg->limit; 419 desc->access = 0; 420 421 if (reg != VM_REG_GUEST_GDTR && reg != VM_REG_GUEST_IDTR) { 422 /* Map seg_desc access to VMCB attribute format */ 423 desc->access = ((seg->attrib & 0xF00) << 4) | 424 (seg->attrib & 0xFF); 425 426 /* 427 * VT-x uses bit 16 to indicate a segment that has been loaded 428 * with a NULL selector (aka unusable). The 'desc->access' 429 * field is interpreted in the VT-x format by the 430 * processor-independent code. 431 * 432 * SVM uses the 'P' bit to convey the same information so 433 * convert it into the VT-x format. For more details refer to 434 * section "Segment State in the VMCB" in APMv2. 435 */ 436 if (reg != VM_REG_GUEST_CS && reg != VM_REG_GUEST_TR) { 437 if ((desc->access & 0x80) == 0) 438 desc->access |= 0x10000; /* Unusable segment */ 439 } 440 } 441 442 return (0); 443 } 444