1 /* 2 * handling privileged instructions 3 * 4 * Copyright IBM Corp. 2008 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License (version 2 only) 8 * as published by the Free Software Foundation. 9 * 10 * Author(s): Carsten Otte <cotte@de.ibm.com> 11 * Christian Borntraeger <borntraeger@de.ibm.com> 12 */ 13 14 #include <linux/kvm.h> 15 #include <linux/gfp.h> 16 #include <linux/errno.h> 17 #include <linux/compat.h> 18 #include <asm/asm-offsets.h> 19 #include <asm/current.h> 20 #include <asm/debug.h> 21 #include <asm/ebcdic.h> 22 #include <asm/sysinfo.h> 23 #include <asm/ptrace.h> 24 #include <asm/compat.h> 25 #include "gaccess.h" 26 #include "kvm-s390.h" 27 #include "trace.h" 28 29 static int handle_set_prefix(struct kvm_vcpu *vcpu) 30 { 31 u64 operand2; 32 u32 address = 0; 33 u8 tmp; 34 35 vcpu->stat.instruction_spx++; 36 37 operand2 = kvm_s390_get_base_disp_s(vcpu); 38 39 /* must be word boundary */ 40 if (operand2 & 3) 41 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 42 43 /* get the value */ 44 if (get_guest(vcpu, address, (u32 __user *) operand2)) 45 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 46 47 address = address & 0x7fffe000u; 48 49 /* make sure that the new value is valid memory */ 50 if (copy_from_guest_absolute(vcpu, &tmp, address, 1) || 51 (copy_from_guest_absolute(vcpu, &tmp, address + PAGE_SIZE, 1))) 52 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 53 54 kvm_s390_set_prefix(vcpu, address); 55 56 VCPU_EVENT(vcpu, 5, "setting prefix to %x", address); 57 trace_kvm_s390_handle_prefix(vcpu, 1, address); 58 return 0; 59 } 60 61 static int handle_store_prefix(struct kvm_vcpu *vcpu) 62 { 63 u64 operand2; 64 u32 address; 65 66 vcpu->stat.instruction_stpx++; 67 68 operand2 = kvm_s390_get_base_disp_s(vcpu); 69 70 /* must be word boundary */ 71 if (operand2 & 3) 72 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 73 74 address = vcpu->arch.sie_block->prefix; 75 address = address & 0x7fffe000u; 76 77 /* get the value */ 78 if (put_guest(vcpu, address, (u32 __user *)operand2)) 79 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 80 81 VCPU_EVENT(vcpu, 5, "storing prefix to %x", address); 82 trace_kvm_s390_handle_prefix(vcpu, 0, address); 83 return 0; 84 } 85 86 static int handle_store_cpu_address(struct kvm_vcpu *vcpu) 87 { 88 u64 useraddr; 89 90 vcpu->stat.instruction_stap++; 91 92 useraddr = kvm_s390_get_base_disp_s(vcpu); 93 94 if (useraddr & 1) 95 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 96 97 if (put_guest(vcpu, vcpu->vcpu_id, (u16 __user *)useraddr)) 98 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 99 100 VCPU_EVENT(vcpu, 5, "storing cpu address to %llx", useraddr); 101 trace_kvm_s390_handle_stap(vcpu, useraddr); 102 return 0; 103 } 104 105 static int handle_skey(struct kvm_vcpu *vcpu) 106 { 107 vcpu->stat.instruction_storage_key++; 108 vcpu->arch.sie_block->gpsw.addr -= 4; 109 VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation"); 110 return 0; 111 } 112 113 static int handle_tpi(struct kvm_vcpu *vcpu) 114 { 115 struct kvm_s390_interrupt_info *inti; 116 u64 addr; 117 int cc; 118 119 addr = kvm_s390_get_base_disp_s(vcpu); 120 if (addr & 3) 121 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 122 cc = 0; 123 inti = kvm_s390_get_io_int(vcpu->kvm, vcpu->run->s.regs.crs[6], 0); 124 if (!inti) 125 goto no_interrupt; 126 cc = 1; 127 if (addr) { 128 /* 129 * Store the two-word I/O interruption code into the 130 * provided area. 131 */ 132 put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) addr); 133 put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) (addr + 2)); 134 put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) (addr + 4)); 135 } else { 136 /* 137 * Store the three-word I/O interruption code into 138 * the appropriate lowcore area. 139 */ 140 put_guest(vcpu, inti->io.subchannel_id, (u16 __user *) __LC_SUBCHANNEL_ID); 141 put_guest(vcpu, inti->io.subchannel_nr, (u16 __user *) __LC_SUBCHANNEL_NR); 142 put_guest(vcpu, inti->io.io_int_parm, (u32 __user *) __LC_IO_INT_PARM); 143 put_guest(vcpu, inti->io.io_int_word, (u32 __user *) __LC_IO_INT_WORD); 144 } 145 kfree(inti); 146 no_interrupt: 147 /* Set condition code and we're done. */ 148 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); 149 vcpu->arch.sie_block->gpsw.mask |= (cc & 3ul) << 44; 150 return 0; 151 } 152 153 static int handle_tsch(struct kvm_vcpu *vcpu) 154 { 155 struct kvm_s390_interrupt_info *inti; 156 157 inti = kvm_s390_get_io_int(vcpu->kvm, 0, 158 vcpu->run->s.regs.gprs[1]); 159 160 /* 161 * Prepare exit to userspace. 162 * We indicate whether we dequeued a pending I/O interrupt 163 * so that userspace can re-inject it if the instruction gets 164 * a program check. While this may re-order the pending I/O 165 * interrupts, this is no problem since the priority is kept 166 * intact. 167 */ 168 vcpu->run->exit_reason = KVM_EXIT_S390_TSCH; 169 vcpu->run->s390_tsch.dequeued = !!inti; 170 if (inti) { 171 vcpu->run->s390_tsch.subchannel_id = inti->io.subchannel_id; 172 vcpu->run->s390_tsch.subchannel_nr = inti->io.subchannel_nr; 173 vcpu->run->s390_tsch.io_int_parm = inti->io.io_int_parm; 174 vcpu->run->s390_tsch.io_int_word = inti->io.io_int_word; 175 } 176 vcpu->run->s390_tsch.ipb = vcpu->arch.sie_block->ipb; 177 kfree(inti); 178 return -EREMOTE; 179 } 180 181 static int handle_io_inst(struct kvm_vcpu *vcpu) 182 { 183 VCPU_EVENT(vcpu, 4, "%s", "I/O instruction"); 184 185 if (vcpu->kvm->arch.css_support) { 186 /* 187 * Most I/O instructions will be handled by userspace. 188 * Exceptions are tpi and the interrupt portion of tsch. 189 */ 190 if (vcpu->arch.sie_block->ipa == 0xb236) 191 return handle_tpi(vcpu); 192 if (vcpu->arch.sie_block->ipa == 0xb235) 193 return handle_tsch(vcpu); 194 /* Handle in userspace. */ 195 return -EOPNOTSUPP; 196 } else { 197 /* 198 * Set condition code 3 to stop the guest from issueing channel 199 * I/O instructions. 200 */ 201 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); 202 vcpu->arch.sie_block->gpsw.mask |= (3 & 3ul) << 44; 203 return 0; 204 } 205 } 206 207 static int handle_stfl(struct kvm_vcpu *vcpu) 208 { 209 unsigned int facility_list; 210 int rc; 211 212 vcpu->stat.instruction_stfl++; 213 /* only pass the facility bits, which we can handle */ 214 facility_list = S390_lowcore.stfl_fac_list & 0xff00fff3; 215 216 rc = copy_to_guest(vcpu, offsetof(struct _lowcore, stfl_fac_list), 217 &facility_list, sizeof(facility_list)); 218 if (rc) 219 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 220 VCPU_EVENT(vcpu, 5, "store facility list value %x", facility_list); 221 trace_kvm_s390_handle_stfl(vcpu, facility_list); 222 return 0; 223 } 224 225 static void handle_new_psw(struct kvm_vcpu *vcpu) 226 { 227 /* Check whether the new psw is enabled for machine checks. */ 228 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK) 229 kvm_s390_deliver_pending_machine_checks(vcpu); 230 } 231 232 #define PSW_MASK_ADDR_MODE (PSW_MASK_EA | PSW_MASK_BA) 233 #define PSW_MASK_UNASSIGNED 0xb80800fe7fffffffUL 234 #define PSW_ADDR_24 0x0000000000ffffffUL 235 #define PSW_ADDR_31 0x000000007fffffffUL 236 237 static int is_valid_psw(psw_t *psw) { 238 if (psw->mask & PSW_MASK_UNASSIGNED) 239 return 0; 240 if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_BA) { 241 if (psw->addr & ~PSW_ADDR_31) 242 return 0; 243 } 244 if (!(psw->mask & PSW_MASK_ADDR_MODE) && (psw->addr & ~PSW_ADDR_24)) 245 return 0; 246 if ((psw->mask & PSW_MASK_ADDR_MODE) == PSW_MASK_EA) 247 return 0; 248 return 1; 249 } 250 251 int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu) 252 { 253 psw_t *gpsw = &vcpu->arch.sie_block->gpsw; 254 psw_compat_t new_psw; 255 u64 addr; 256 257 if (gpsw->mask & PSW_MASK_PSTATE) 258 return kvm_s390_inject_program_int(vcpu, 259 PGM_PRIVILEGED_OPERATION); 260 addr = kvm_s390_get_base_disp_s(vcpu); 261 if (addr & 7) 262 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 263 if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw))) 264 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 265 if (!(new_psw.mask & PSW32_MASK_BASE)) 266 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 267 gpsw->mask = (new_psw.mask & ~PSW32_MASK_BASE) << 32; 268 gpsw->mask |= new_psw.addr & PSW32_ADDR_AMODE; 269 gpsw->addr = new_psw.addr & ~PSW32_ADDR_AMODE; 270 if (!is_valid_psw(gpsw)) 271 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 272 handle_new_psw(vcpu); 273 return 0; 274 } 275 276 static int handle_lpswe(struct kvm_vcpu *vcpu) 277 { 278 psw_t new_psw; 279 u64 addr; 280 281 addr = kvm_s390_get_base_disp_s(vcpu); 282 if (addr & 7) 283 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 284 if (copy_from_guest(vcpu, &new_psw, addr, sizeof(new_psw))) 285 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 286 vcpu->arch.sie_block->gpsw = new_psw; 287 if (!is_valid_psw(&vcpu->arch.sie_block->gpsw)) 288 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 289 handle_new_psw(vcpu); 290 return 0; 291 } 292 293 static int handle_stidp(struct kvm_vcpu *vcpu) 294 { 295 u64 operand2; 296 297 vcpu->stat.instruction_stidp++; 298 299 operand2 = kvm_s390_get_base_disp_s(vcpu); 300 301 if (operand2 & 7) 302 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 303 304 if (put_guest(vcpu, vcpu->arch.stidp_data, (u64 __user *)operand2)) 305 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 306 307 VCPU_EVENT(vcpu, 5, "%s", "store cpu id"); 308 return 0; 309 } 310 311 static void handle_stsi_3_2_2(struct kvm_vcpu *vcpu, struct sysinfo_3_2_2 *mem) 312 { 313 struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int; 314 int cpus = 0; 315 int n; 316 317 spin_lock(&fi->lock); 318 for (n = 0; n < KVM_MAX_VCPUS; n++) 319 if (fi->local_int[n]) 320 cpus++; 321 spin_unlock(&fi->lock); 322 323 /* deal with other level 3 hypervisors */ 324 if (stsi(mem, 3, 2, 2)) 325 mem->count = 0; 326 if (mem->count < 8) 327 mem->count++; 328 for (n = mem->count - 1; n > 0 ; n--) 329 memcpy(&mem->vm[n], &mem->vm[n - 1], sizeof(mem->vm[0])); 330 331 mem->vm[0].cpus_total = cpus; 332 mem->vm[0].cpus_configured = cpus; 333 mem->vm[0].cpus_standby = 0; 334 mem->vm[0].cpus_reserved = 0; 335 mem->vm[0].caf = 1000; 336 memcpy(mem->vm[0].name, "KVMguest", 8); 337 ASCEBC(mem->vm[0].name, 8); 338 memcpy(mem->vm[0].cpi, "KVM/Linux ", 16); 339 ASCEBC(mem->vm[0].cpi, 16); 340 } 341 342 static int handle_stsi(struct kvm_vcpu *vcpu) 343 { 344 int fc = (vcpu->run->s.regs.gprs[0] & 0xf0000000) >> 28; 345 int sel1 = vcpu->run->s.regs.gprs[0] & 0xff; 346 int sel2 = vcpu->run->s.regs.gprs[1] & 0xffff; 347 unsigned long mem = 0; 348 u64 operand2; 349 int rc = 0; 350 351 vcpu->stat.instruction_stsi++; 352 VCPU_EVENT(vcpu, 4, "stsi: fc: %x sel1: %x sel2: %x", fc, sel1, sel2); 353 354 operand2 = kvm_s390_get_base_disp_s(vcpu); 355 356 if (operand2 & 0xfff && fc > 0) 357 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 358 359 switch (fc) { 360 case 0: 361 vcpu->run->s.regs.gprs[0] = 3 << 28; 362 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); 363 return 0; 364 case 1: /* same handling for 1 and 2 */ 365 case 2: 366 mem = get_zeroed_page(GFP_KERNEL); 367 if (!mem) 368 goto out_no_data; 369 if (stsi((void *) mem, fc, sel1, sel2)) 370 goto out_no_data; 371 break; 372 case 3: 373 if (sel1 != 2 || sel2 != 2) 374 goto out_no_data; 375 mem = get_zeroed_page(GFP_KERNEL); 376 if (!mem) 377 goto out_no_data; 378 handle_stsi_3_2_2(vcpu, (void *) mem); 379 break; 380 default: 381 goto out_no_data; 382 } 383 384 if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) { 385 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 386 goto out_exception; 387 } 388 trace_kvm_s390_handle_stsi(vcpu, fc, sel1, sel2, operand2); 389 free_page(mem); 390 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); 391 vcpu->run->s.regs.gprs[0] = 0; 392 return 0; 393 out_no_data: 394 /* condition code 3 */ 395 vcpu->arch.sie_block->gpsw.mask |= 3ul << 44; 396 out_exception: 397 free_page(mem); 398 return rc; 399 } 400 401 static const intercept_handler_t b2_handlers[256] = { 402 [0x02] = handle_stidp, 403 [0x10] = handle_set_prefix, 404 [0x11] = handle_store_prefix, 405 [0x12] = handle_store_cpu_address, 406 [0x29] = handle_skey, 407 [0x2a] = handle_skey, 408 [0x2b] = handle_skey, 409 [0x30] = handle_io_inst, 410 [0x31] = handle_io_inst, 411 [0x32] = handle_io_inst, 412 [0x33] = handle_io_inst, 413 [0x34] = handle_io_inst, 414 [0x35] = handle_io_inst, 415 [0x36] = handle_io_inst, 416 [0x37] = handle_io_inst, 417 [0x38] = handle_io_inst, 418 [0x39] = handle_io_inst, 419 [0x3a] = handle_io_inst, 420 [0x3b] = handle_io_inst, 421 [0x3c] = handle_io_inst, 422 [0x5f] = handle_io_inst, 423 [0x74] = handle_io_inst, 424 [0x76] = handle_io_inst, 425 [0x7d] = handle_stsi, 426 [0xb1] = handle_stfl, 427 [0xb2] = handle_lpswe, 428 }; 429 430 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu) 431 { 432 intercept_handler_t handler; 433 434 /* 435 * a lot of B2 instructions are priviledged. We first check for 436 * the privileged ones, that we can handle in the kernel. If the 437 * kernel can handle this instruction, we check for the problem 438 * state bit and (a) handle the instruction or (b) send a code 2 439 * program check. 440 * Anything else goes to userspace.*/ 441 handler = b2_handlers[vcpu->arch.sie_block->ipa & 0x00ff]; 442 if (handler) { 443 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 444 return kvm_s390_inject_program_int(vcpu, 445 PGM_PRIVILEGED_OPERATION); 446 else 447 return handler(vcpu); 448 } 449 return -EOPNOTSUPP; 450 } 451 452 static int handle_epsw(struct kvm_vcpu *vcpu) 453 { 454 int reg1, reg2; 455 456 reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24; 457 reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16; 458 459 /* This basically extracts the mask half of the psw. */ 460 vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000; 461 vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32; 462 if (reg2) { 463 vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000; 464 vcpu->run->s.regs.gprs[reg2] |= 465 vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff; 466 } 467 return 0; 468 } 469 470 static const intercept_handler_t b9_handlers[256] = { 471 [0x8d] = handle_epsw, 472 [0x9c] = handle_io_inst, 473 }; 474 475 int kvm_s390_handle_b9(struct kvm_vcpu *vcpu) 476 { 477 intercept_handler_t handler; 478 479 /* This is handled just as for the B2 instructions. */ 480 handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff]; 481 if (handler) { 482 if ((handler != handle_epsw) && 483 (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)) 484 return kvm_s390_inject_program_int(vcpu, 485 PGM_PRIVILEGED_OPERATION); 486 else 487 return handler(vcpu); 488 } 489 return -EOPNOTSUPP; 490 } 491 492 static const intercept_handler_t eb_handlers[256] = { 493 [0x8a] = handle_io_inst, 494 }; 495 496 int kvm_s390_handle_priv_eb(struct kvm_vcpu *vcpu) 497 { 498 intercept_handler_t handler; 499 500 /* All eb instructions that end up here are privileged. */ 501 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 502 return kvm_s390_inject_program_int(vcpu, 503 PGM_PRIVILEGED_OPERATION); 504 handler = eb_handlers[vcpu->arch.sie_block->ipb & 0xff]; 505 if (handler) 506 return handler(vcpu); 507 return -EOPNOTSUPP; 508 } 509 510 static int handle_tprot(struct kvm_vcpu *vcpu) 511 { 512 u64 address1, address2; 513 struct vm_area_struct *vma; 514 unsigned long user_address; 515 516 vcpu->stat.instruction_tprot++; 517 518 kvm_s390_get_base_disp_sse(vcpu, &address1, &address2); 519 520 /* we only handle the Linux memory detection case: 521 * access key == 0 522 * guest DAT == off 523 * everything else goes to userspace. */ 524 if (address2 & 0xf0) 525 return -EOPNOTSUPP; 526 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT) 527 return -EOPNOTSUPP; 528 529 down_read(¤t->mm->mmap_sem); 530 user_address = __gmap_translate(address1, vcpu->arch.gmap); 531 if (IS_ERR_VALUE(user_address)) 532 goto out_inject; 533 vma = find_vma(current->mm, user_address); 534 if (!vma) 535 goto out_inject; 536 vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44); 537 if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ)) 538 vcpu->arch.sie_block->gpsw.mask |= (1ul << 44); 539 if (!(vma->vm_flags & VM_WRITE) && !(vma->vm_flags & VM_READ)) 540 vcpu->arch.sie_block->gpsw.mask |= (2ul << 44); 541 542 up_read(¤t->mm->mmap_sem); 543 return 0; 544 545 out_inject: 546 up_read(¤t->mm->mmap_sem); 547 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 548 } 549 550 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu) 551 { 552 /* For e5xx... instructions we only handle TPROT */ 553 if ((vcpu->arch.sie_block->ipa & 0x00ff) == 0x01) 554 return handle_tprot(vcpu); 555 return -EOPNOTSUPP; 556 } 557 558 static int handle_sckpf(struct kvm_vcpu *vcpu) 559 { 560 u32 value; 561 562 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 563 return kvm_s390_inject_program_int(vcpu, 564 PGM_PRIVILEGED_OPERATION); 565 566 if (vcpu->run->s.regs.gprs[0] & 0x00000000ffff0000) 567 return kvm_s390_inject_program_int(vcpu, 568 PGM_SPECIFICATION); 569 570 value = vcpu->run->s.regs.gprs[0] & 0x000000000000ffff; 571 vcpu->arch.sie_block->todpr = value; 572 573 return 0; 574 } 575 576 static const intercept_handler_t x01_handlers[256] = { 577 [0x07] = handle_sckpf, 578 }; 579 580 int kvm_s390_handle_01(struct kvm_vcpu *vcpu) 581 { 582 intercept_handler_t handler; 583 584 handler = x01_handlers[vcpu->arch.sie_block->ipa & 0x00ff]; 585 if (handler) 586 return handler(vcpu); 587 return -EOPNOTSUPP; 588 } 589