1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * kvm nested virtualization support for s390x 4 * 5 * Copyright IBM Corp. 2016, 2018 6 * 7 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com> 8 */ 9 #include <linux/vmalloc.h> 10 #include <linux/kvm_host.h> 11 #include <linux/bug.h> 12 #include <linux/list.h> 13 #include <linux/bitmap.h> 14 #include <linux/sched/signal.h> 15 16 #include <asm/gmap.h> 17 #include <asm/mmu_context.h> 18 #include <asm/sclp.h> 19 #include <asm/nmi.h> 20 #include <asm/dis.h> 21 #include <asm/fpu/api.h> 22 #include "kvm-s390.h" 23 #include "gaccess.h" 24 25 struct vsie_page { 26 struct kvm_s390_sie_block scb_s; /* 0x0000 */ 27 /* 28 * the backup info for machine check. ensure it's at 29 * the same offset as that in struct sie_page! 30 */ 31 struct mcck_volatile_info mcck_info; /* 0x0200 */ 32 /* 33 * The pinned original scb. Be aware that other VCPUs can modify 34 * it while we read from it. Values that are used for conditions or 35 * are reused conditionally, should be accessed via READ_ONCE. 36 */ 37 struct kvm_s390_sie_block *scb_o; /* 0x0218 */ 38 /* the shadow gmap in use by the vsie_page */ 39 struct gmap *gmap; /* 0x0220 */ 40 /* address of the last reported fault to guest2 */ 41 unsigned long fault_addr; /* 0x0228 */ 42 /* calculated guest addresses of satellite control blocks */ 43 gpa_t sca_gpa; /* 0x0230 */ 44 gpa_t itdba_gpa; /* 0x0238 */ 45 gpa_t gvrd_gpa; /* 0x0240 */ 46 gpa_t riccbd_gpa; /* 0x0248 */ 47 gpa_t sdnx_gpa; /* 0x0250 */ 48 __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */ 49 struct kvm_s390_crypto_cb crycb; /* 0x0700 */ 50 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ 51 }; 52 53 /* trigger a validity icpt for the given scb */ 54 static int set_validity_icpt(struct kvm_s390_sie_block *scb, 55 __u16 reason_code) 56 { 57 scb->ipa = 0x1000; 58 scb->ipb = ((__u32) reason_code) << 16; 59 scb->icptcode = ICPT_VALIDITY; 60 return 1; 61 } 62 63 /* mark the prefix as unmapped, this will block the VSIE */ 64 static void prefix_unmapped(struct vsie_page *vsie_page) 65 { 66 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20); 67 } 68 69 /* mark the prefix as unmapped and wait until the VSIE has been left */ 70 static void prefix_unmapped_sync(struct vsie_page *vsie_page) 71 { 72 prefix_unmapped(vsie_page); 73 if (vsie_page->scb_s.prog0c & PROG_IN_SIE) 74 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags); 75 while (vsie_page->scb_s.prog0c & PROG_IN_SIE) 76 cpu_relax(); 77 } 78 79 /* mark the prefix as mapped, this will allow the VSIE to run */ 80 static void prefix_mapped(struct vsie_page *vsie_page) 81 { 82 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20); 83 } 84 85 /* test if the prefix is mapped into the gmap shadow */ 86 static int prefix_is_mapped(struct vsie_page *vsie_page) 87 { 88 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST); 89 } 90 91 /* copy the updated intervention request bits into the shadow scb */ 92 static void update_intervention_requests(struct vsie_page *vsie_page) 93 { 94 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT; 95 int cpuflags; 96 97 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags); 98 atomic_andnot(bits, &vsie_page->scb_s.cpuflags); 99 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags); 100 } 101 102 /* shadow (filter and validate) the cpuflags */ 103 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 104 { 105 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 106 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 107 int newflags, cpuflags = atomic_read(&scb_o->cpuflags); 108 109 /* we don't allow ESA/390 guests */ 110 if (!(cpuflags & CPUSTAT_ZARCH)) 111 return set_validity_icpt(scb_s, 0x0001U); 112 113 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) 114 return set_validity_icpt(scb_s, 0x0001U); 115 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR)) 116 return set_validity_icpt(scb_s, 0x0007U); 117 118 /* intervention requests will be set later */ 119 newflags = CPUSTAT_ZARCH; 120 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8)) 121 newflags |= CPUSTAT_GED; 122 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) { 123 if (cpuflags & CPUSTAT_GED) 124 return set_validity_icpt(scb_s, 0x0001U); 125 newflags |= CPUSTAT_GED2; 126 } 127 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE)) 128 newflags |= cpuflags & CPUSTAT_P; 129 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS)) 130 newflags |= cpuflags & CPUSTAT_SM; 131 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) 132 newflags |= cpuflags & CPUSTAT_IBS; 133 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) 134 newflags |= cpuflags & CPUSTAT_KSS; 135 136 atomic_set(&scb_s->cpuflags, newflags); 137 return 0; 138 } 139 /* Copy to APCB FORMAT1 from APCB FORMAT0 */ 140 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s, 141 unsigned long crycb_gpa, struct kvm_s390_apcb1 *apcb_h) 142 { 143 struct kvm_s390_apcb0 tmp; 144 unsigned long apcb_gpa; 145 146 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 147 148 if (read_guest_real(vcpu, apcb_gpa, &tmp, 149 sizeof(struct kvm_s390_apcb0))) 150 return -EFAULT; 151 152 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; 153 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; 154 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; 155 156 return 0; 157 158 } 159 160 /** 161 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 162 * @vcpu: pointer to the virtual CPU 163 * @apcb_s: pointer to start of apcb in the shadow crycb 164 * @crycb_gpa: guest physical address to start of original guest crycb 165 * @apcb_h: pointer to start of apcb in the guest1 166 * 167 * Returns 0 and -EFAULT on error reading guest apcb 168 */ 169 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 170 unsigned long crycb_gpa, unsigned long *apcb_h) 171 { 172 unsigned long apcb_gpa; 173 174 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 175 176 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 177 sizeof(struct kvm_s390_apcb0))) 178 return -EFAULT; 179 180 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0)); 181 182 return 0; 183 } 184 185 /** 186 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB 187 * @vcpu: pointer to the virtual CPU 188 * @apcb_s: pointer to start of apcb in the shadow crycb 189 * @crycb_gpa: guest physical address to start of original guest crycb 190 * @apcb_h: pointer to start of apcb in the host 191 * 192 * Returns 0 and -EFAULT on error reading guest apcb 193 */ 194 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 195 unsigned long crycb_gpa, 196 unsigned long *apcb_h) 197 { 198 unsigned long apcb_gpa; 199 200 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb1); 201 202 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 203 sizeof(struct kvm_s390_apcb1))) 204 return -EFAULT; 205 206 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1)); 207 208 return 0; 209 } 210 211 /** 212 * setup_apcb - Create a shadow copy of the apcb. 213 * @vcpu: pointer to the virtual CPU 214 * @crycb_s: pointer to shadow crycb 215 * @crycb_gpa: guest physical address of original guest crycb 216 * @crycb_h: pointer to the host crycb 217 * @fmt_o: format of the original guest crycb. 218 * @fmt_h: format of the host crycb. 219 * 220 * Checks the compatibility between the guest and host crycb and calls the 221 * appropriate copy function. 222 * 223 * Return 0 or an error number if the guest and host crycb are incompatible. 224 */ 225 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 226 const u32 crycb_gpa, 227 struct kvm_s390_crypto_cb *crycb_h, 228 int fmt_o, int fmt_h) 229 { 230 switch (fmt_o) { 231 case CRYCB_FORMAT2: 232 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 256) & PAGE_MASK)) 233 return -EACCES; 234 if (fmt_h != CRYCB_FORMAT2) 235 return -EINVAL; 236 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 237 crycb_gpa, 238 (unsigned long *)&crycb_h->apcb1); 239 case CRYCB_FORMAT1: 240 switch (fmt_h) { 241 case CRYCB_FORMAT2: 242 return setup_apcb10(vcpu, &crycb_s->apcb1, 243 crycb_gpa, 244 &crycb_h->apcb1); 245 case CRYCB_FORMAT1: 246 return setup_apcb00(vcpu, 247 (unsigned long *) &crycb_s->apcb0, 248 crycb_gpa, 249 (unsigned long *) &crycb_h->apcb0); 250 } 251 break; 252 case CRYCB_FORMAT0: 253 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 32) & PAGE_MASK)) 254 return -EACCES; 255 256 switch (fmt_h) { 257 case CRYCB_FORMAT2: 258 return setup_apcb10(vcpu, &crycb_s->apcb1, 259 crycb_gpa, 260 &crycb_h->apcb1); 261 case CRYCB_FORMAT1: 262 case CRYCB_FORMAT0: 263 return setup_apcb00(vcpu, 264 (unsigned long *) &crycb_s->apcb0, 265 crycb_gpa, 266 (unsigned long *) &crycb_h->apcb0); 267 } 268 } 269 return -EINVAL; 270 } 271 272 /** 273 * shadow_crycb - Create a shadow copy of the crycb block 274 * @vcpu: a pointer to the virtual CPU 275 * @vsie_page: a pointer to internal date used for the vSIE 276 * 277 * Create a shadow copy of the crycb block and setup key wrapping, if 278 * requested for guest 3 and enabled for guest 2. 279 * 280 * We accept format-1 or format-2, but we convert format-1 into format-2 281 * in the shadow CRYCB. 282 * Using format-2 enables the firmware to choose the right format when 283 * scheduling the SIE. 284 * There is nothing to do for format-0. 285 * 286 * This function centralize the issuing of set_validity_icpt() for all 287 * the subfunctions working on the crycb. 288 * 289 * Returns: - 0 if shadowed or nothing to do 290 * - > 0 if control has to be given to guest 2 291 */ 292 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 293 { 294 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 295 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 296 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 297 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 298 unsigned long *b1, *b2; 299 u8 ecb3_flags; 300 u32 ecd_flags; 301 int apie_h; 302 int apie_s; 303 int key_msk = test_kvm_facility(vcpu->kvm, 76); 304 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 305 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 306 int ret = 0; 307 308 scb_s->crycbd = 0; 309 310 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 311 apie_s = apie_h & scb_o->eca; 312 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 313 return 0; 314 315 if (!crycb_addr) 316 return set_validity_icpt(scb_s, 0x0039U); 317 318 if (fmt_o == CRYCB_FORMAT1) 319 if ((crycb_addr & PAGE_MASK) != 320 ((crycb_addr + 128) & PAGE_MASK)) 321 return set_validity_icpt(scb_s, 0x003CU); 322 323 if (apie_s) { 324 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 325 vcpu->kvm->arch.crypto.crycb, 326 fmt_o, fmt_h); 327 if (ret) 328 goto end; 329 scb_s->eca |= scb_o->eca & ECA_APIE; 330 } 331 332 /* we may only allow it if enabled for guest 2 */ 333 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 334 (ECB3_AES | ECB3_DEA); 335 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; 336 if (!ecb3_flags && !ecd_flags) 337 goto end; 338 339 /* copy only the wrapping keys */ 340 if (read_guest_real(vcpu, crycb_addr + 72, 341 vsie_page->crycb.dea_wrapping_key_mask, 56)) 342 return set_validity_icpt(scb_s, 0x0035U); 343 344 scb_s->ecb3 |= ecb3_flags; 345 scb_s->ecd |= ecd_flags; 346 347 /* xor both blocks in one run */ 348 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 349 b2 = (unsigned long *) 350 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 351 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 352 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 353 end: 354 switch (ret) { 355 case -EINVAL: 356 return set_validity_icpt(scb_s, 0x0022U); 357 case -EFAULT: 358 return set_validity_icpt(scb_s, 0x0035U); 359 case -EACCES: 360 return set_validity_icpt(scb_s, 0x003CU); 361 } 362 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; 363 return 0; 364 } 365 366 /* shadow (round up/down) the ibc to avoid validity icpt */ 367 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 368 { 369 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 370 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 371 /* READ_ONCE does not work on bitfields - use a temporary variable */ 372 const uint32_t __new_ibc = scb_o->ibc; 373 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 374 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 375 376 scb_s->ibc = 0; 377 /* ibc installed in g2 and requested for g3 */ 378 if (vcpu->kvm->arch.model.ibc && new_ibc) { 379 scb_s->ibc = new_ibc; 380 /* takte care of the minimum ibc level of the machine */ 381 if (scb_s->ibc < min_ibc) 382 scb_s->ibc = min_ibc; 383 /* take care of the maximum ibc level set for the guest */ 384 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 385 scb_s->ibc = vcpu->kvm->arch.model.ibc; 386 } 387 } 388 389 /* unshadow the scb, copying parameters back to the real scb */ 390 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 391 { 392 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 393 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 394 395 /* interception */ 396 scb_o->icptcode = scb_s->icptcode; 397 scb_o->icptstatus = scb_s->icptstatus; 398 scb_o->ipa = scb_s->ipa; 399 scb_o->ipb = scb_s->ipb; 400 scb_o->gbea = scb_s->gbea; 401 402 /* timer */ 403 scb_o->cputm = scb_s->cputm; 404 scb_o->ckc = scb_s->ckc; 405 scb_o->todpr = scb_s->todpr; 406 407 /* guest state */ 408 scb_o->gpsw = scb_s->gpsw; 409 scb_o->gg14 = scb_s->gg14; 410 scb_o->gg15 = scb_s->gg15; 411 memcpy(scb_o->gcr, scb_s->gcr, 128); 412 scb_o->pp = scb_s->pp; 413 414 /* branch prediction */ 415 if (test_kvm_facility(vcpu->kvm, 82)) { 416 scb_o->fpf &= ~FPF_BPBC; 417 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 418 } 419 420 /* interrupt intercept */ 421 switch (scb_s->icptcode) { 422 case ICPT_PROGI: 423 case ICPT_INSTPROGI: 424 case ICPT_EXTINT: 425 memcpy((void *)((u64)scb_o + 0xc0), 426 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 427 break; 428 } 429 430 if (scb_s->ihcpu != 0xffffU) 431 scb_o->ihcpu = scb_s->ihcpu; 432 } 433 434 /* 435 * Setup the shadow scb by copying and checking the relevant parts of the g2 436 * provided scb. 437 * 438 * Returns: - 0 if the scb has been shadowed 439 * - > 0 if control has to be given to guest 2 440 */ 441 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 442 { 443 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 444 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 445 /* READ_ONCE does not work on bitfields - use a temporary variable */ 446 const uint32_t __new_prefix = scb_o->prefix; 447 const uint32_t new_prefix = READ_ONCE(__new_prefix); 448 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 449 bool had_tx = scb_s->ecb & ECB_TE; 450 unsigned long new_mso = 0; 451 int rc; 452 453 /* make sure we don't have any leftovers when reusing the scb */ 454 scb_s->icptcode = 0; 455 scb_s->eca = 0; 456 scb_s->ecb = 0; 457 scb_s->ecb2 = 0; 458 scb_s->ecb3 = 0; 459 scb_s->ecd = 0; 460 scb_s->fac = 0; 461 scb_s->fpf = 0; 462 463 rc = prepare_cpuflags(vcpu, vsie_page); 464 if (rc) 465 goto out; 466 467 /* timer */ 468 scb_s->cputm = scb_o->cputm; 469 scb_s->ckc = scb_o->ckc; 470 scb_s->todpr = scb_o->todpr; 471 scb_s->epoch = scb_o->epoch; 472 473 /* guest state */ 474 scb_s->gpsw = scb_o->gpsw; 475 scb_s->gg14 = scb_o->gg14; 476 scb_s->gg15 = scb_o->gg15; 477 memcpy(scb_s->gcr, scb_o->gcr, 128); 478 scb_s->pp = scb_o->pp; 479 480 /* interception / execution handling */ 481 scb_s->gbea = scb_o->gbea; 482 scb_s->lctl = scb_o->lctl; 483 scb_s->svcc = scb_o->svcc; 484 scb_s->ictl = scb_o->ictl; 485 /* 486 * SKEY handling functions can't deal with false setting of PTE invalid 487 * bits. Therefore we cannot provide interpretation and would later 488 * have to provide own emulation handlers. 489 */ 490 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 491 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 492 493 scb_s->icpua = scb_o->icpua; 494 495 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 496 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 497 /* if the hva of the prefix changes, we have to remap the prefix */ 498 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 499 prefix_unmapped(vsie_page); 500 /* SIE will do mso/msl validity and exception checks for us */ 501 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 502 scb_s->mso = new_mso; 503 scb_s->prefix = new_prefix; 504 505 /* We have to definetly flush the tlb if this scb never ran */ 506 if (scb_s->ihcpu != 0xffffU) 507 scb_s->ihcpu = scb_o->ihcpu; 508 509 /* MVPG and Protection Exception Interpretation are always available */ 510 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 511 /* Host-protection-interruption introduced with ESOP */ 512 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 513 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 514 /* 515 * CPU Topology 516 * This facility only uses the utility field of the SCA and none of 517 * the cpu entries that are problematic with the other interpretation 518 * facilities so we can pass it through 519 */ 520 if (test_kvm_facility(vcpu->kvm, 11)) 521 scb_s->ecb |= scb_o->ecb & ECB_PTF; 522 /* transactional execution */ 523 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 524 /* remap the prefix is tx is toggled on */ 525 if (!had_tx) 526 prefix_unmapped(vsie_page); 527 scb_s->ecb |= ECB_TE; 528 } 529 /* specification exception interpretation */ 530 scb_s->ecb |= scb_o->ecb & ECB_SPECI; 531 /* branch prediction */ 532 if (test_kvm_facility(vcpu->kvm, 82)) 533 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 534 /* SIMD */ 535 if (test_kvm_facility(vcpu->kvm, 129)) { 536 scb_s->eca |= scb_o->eca & ECA_VX; 537 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 538 } 539 /* Run-time-Instrumentation */ 540 if (test_kvm_facility(vcpu->kvm, 64)) 541 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 542 /* Instruction Execution Prevention */ 543 if (test_kvm_facility(vcpu->kvm, 130)) 544 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 545 /* Guarded Storage */ 546 if (test_kvm_facility(vcpu->kvm, 133)) { 547 scb_s->ecb |= scb_o->ecb & ECB_GS; 548 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 549 } 550 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 551 scb_s->eca |= scb_o->eca & ECA_SII; 552 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 553 scb_s->eca |= scb_o->eca & ECA_IB; 554 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 555 scb_s->eca |= scb_o->eca & ECA_CEI; 556 /* Epoch Extension */ 557 if (test_kvm_facility(vcpu->kvm, 139)) { 558 scb_s->ecd |= scb_o->ecd & ECD_MEF; 559 scb_s->epdx = scb_o->epdx; 560 } 561 562 /* etoken */ 563 if (test_kvm_facility(vcpu->kvm, 156)) 564 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 565 566 scb_s->hpid = HPID_VSIE; 567 scb_s->cpnc = scb_o->cpnc; 568 569 prepare_ibc(vcpu, vsie_page); 570 rc = shadow_crycb(vcpu, vsie_page); 571 out: 572 if (rc) 573 unshadow_scb(vcpu, vsie_page); 574 return rc; 575 } 576 577 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 578 unsigned long end) 579 { 580 struct kvm *kvm = gmap->private; 581 struct vsie_page *cur; 582 unsigned long prefix; 583 struct page *page; 584 int i; 585 586 if (!gmap_is_shadow(gmap)) 587 return; 588 if (start >= 1UL << 31) 589 /* We are only interested in prefix pages */ 590 return; 591 592 /* 593 * Only new shadow blocks are added to the list during runtime, 594 * therefore we can safely reference them all the time. 595 */ 596 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 597 page = READ_ONCE(kvm->arch.vsie.pages[i]); 598 if (!page) 599 continue; 600 cur = page_to_virt(page); 601 if (READ_ONCE(cur->gmap) != gmap) 602 continue; 603 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; 604 /* with mso/msl, the prefix lies at an offset */ 605 prefix += cur->scb_s.mso; 606 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) 607 prefix_unmapped_sync(cur); 608 } 609 } 610 611 /* 612 * Map the first prefix page and if tx is enabled also the second prefix page. 613 * 614 * The prefix will be protected, a gmap notifier will inform about unmaps. 615 * The shadow scb must not be executed until the prefix is remapped, this is 616 * guaranteed by properly handling PROG_REQUEST. 617 * 618 * Returns: - 0 on if successfully mapped or already mapped 619 * - > 0 if control has to be given to guest 2 620 * - -EAGAIN if the caller can retry immediately 621 * - -ENOMEM if out of memory 622 */ 623 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 624 { 625 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 626 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 627 int rc; 628 629 if (prefix_is_mapped(vsie_page)) 630 return 0; 631 632 /* mark it as mapped so we can catch any concurrent unmappers */ 633 prefix_mapped(vsie_page); 634 635 /* with mso/msl, the prefix lies at offset *mso* */ 636 prefix += scb_s->mso; 637 638 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL); 639 if (!rc && (scb_s->ecb & ECB_TE)) 640 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 641 prefix + PAGE_SIZE, NULL); 642 /* 643 * We don't have to mprotect, we will be called for all unshadows. 644 * SIE will detect if protection applies and trigger a validity. 645 */ 646 if (rc) 647 prefix_unmapped(vsie_page); 648 if (rc > 0 || rc == -EFAULT) 649 rc = set_validity_icpt(scb_s, 0x0037U); 650 return rc; 651 } 652 653 /* 654 * Pin the guest page given by gpa and set hpa to the pinned host address. 655 * Will always be pinned writable. 656 * 657 * Returns: - 0 on success 658 * - -EINVAL if the gpa is not valid guest storage 659 */ 660 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) 661 { 662 struct page *page; 663 664 page = gfn_to_page(kvm, gpa_to_gfn(gpa)); 665 if (is_error_page(page)) 666 return -EINVAL; 667 *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK); 668 return 0; 669 } 670 671 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ 672 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) 673 { 674 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT); 675 /* mark the page always as dirty for migration */ 676 mark_page_dirty(kvm, gpa_to_gfn(gpa)); 677 } 678 679 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ 680 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 681 { 682 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 683 hpa_t hpa; 684 685 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; 686 if (hpa) { 687 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); 688 vsie_page->sca_gpa = 0; 689 scb_s->scaol = 0; 690 scb_s->scaoh = 0; 691 } 692 693 hpa = scb_s->itdba; 694 if (hpa) { 695 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); 696 vsie_page->itdba_gpa = 0; 697 scb_s->itdba = 0; 698 } 699 700 hpa = scb_s->gvrd; 701 if (hpa) { 702 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); 703 vsie_page->gvrd_gpa = 0; 704 scb_s->gvrd = 0; 705 } 706 707 hpa = scb_s->riccbd; 708 if (hpa) { 709 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); 710 vsie_page->riccbd_gpa = 0; 711 scb_s->riccbd = 0; 712 } 713 714 hpa = scb_s->sdnxo; 715 if (hpa) { 716 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); 717 vsie_page->sdnx_gpa = 0; 718 scb_s->sdnxo = 0; 719 } 720 } 721 722 /* 723 * Instead of shadowing some blocks, we can simply forward them because the 724 * addresses in the scb are 64 bit long. 725 * 726 * This works as long as the data lies in one page. If blocks ever exceed one 727 * page, we have to fall back to shadowing. 728 * 729 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must 730 * therefore not enable any facilities that access these pointers (e.g. SIGPIF). 731 * 732 * Returns: - 0 if all blocks were pinned. 733 * - > 0 if control has to be given to guest 2 734 * - -ENOMEM if out of memory 735 */ 736 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 737 { 738 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 739 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 740 hpa_t hpa; 741 gpa_t gpa; 742 int rc = 0; 743 744 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; 745 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) 746 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; 747 if (gpa) { 748 if (gpa < 2 * PAGE_SIZE) 749 rc = set_validity_icpt(scb_s, 0x0038U); 750 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) 751 rc = set_validity_icpt(scb_s, 0x0011U); 752 else if ((gpa & PAGE_MASK) != 753 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) 754 rc = set_validity_icpt(scb_s, 0x003bU); 755 if (!rc) { 756 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 757 if (rc) 758 rc = set_validity_icpt(scb_s, 0x0034U); 759 } 760 if (rc) 761 goto unpin; 762 vsie_page->sca_gpa = gpa; 763 scb_s->scaoh = (u32)((u64)hpa >> 32); 764 scb_s->scaol = (u32)(u64)hpa; 765 } 766 767 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; 768 if (gpa && (scb_s->ecb & ECB_TE)) { 769 if (gpa < 2 * PAGE_SIZE) { 770 rc = set_validity_icpt(scb_s, 0x0080U); 771 goto unpin; 772 } 773 /* 256 bytes cannot cross page boundaries */ 774 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 775 if (rc) { 776 rc = set_validity_icpt(scb_s, 0x0080U); 777 goto unpin; 778 } 779 vsie_page->itdba_gpa = gpa; 780 scb_s->itdba = hpa; 781 } 782 783 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; 784 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { 785 if (gpa < 2 * PAGE_SIZE) { 786 rc = set_validity_icpt(scb_s, 0x1310U); 787 goto unpin; 788 } 789 /* 790 * 512 bytes vector registers cannot cross page boundaries 791 * if this block gets bigger, we have to shadow it. 792 */ 793 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 794 if (rc) { 795 rc = set_validity_icpt(scb_s, 0x1310U); 796 goto unpin; 797 } 798 vsie_page->gvrd_gpa = gpa; 799 scb_s->gvrd = hpa; 800 } 801 802 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; 803 if (gpa && (scb_s->ecb3 & ECB3_RI)) { 804 if (gpa < 2 * PAGE_SIZE) { 805 rc = set_validity_icpt(scb_s, 0x0043U); 806 goto unpin; 807 } 808 /* 64 bytes cannot cross page boundaries */ 809 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 810 if (rc) { 811 rc = set_validity_icpt(scb_s, 0x0043U); 812 goto unpin; 813 } 814 /* Validity 0x0044 will be checked by SIE */ 815 vsie_page->riccbd_gpa = gpa; 816 scb_s->riccbd = hpa; 817 } 818 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || 819 (scb_s->ecd & ECD_ETOKENF)) { 820 unsigned long sdnxc; 821 822 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; 823 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; 824 if (!gpa || gpa < 2 * PAGE_SIZE) { 825 rc = set_validity_icpt(scb_s, 0x10b0U); 826 goto unpin; 827 } 828 if (sdnxc < 6 || sdnxc > 12) { 829 rc = set_validity_icpt(scb_s, 0x10b1U); 830 goto unpin; 831 } 832 if (gpa & ((1 << sdnxc) - 1)) { 833 rc = set_validity_icpt(scb_s, 0x10b2U); 834 goto unpin; 835 } 836 /* Due to alignment rules (checked above) this cannot 837 * cross page boundaries 838 */ 839 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 840 if (rc) { 841 rc = set_validity_icpt(scb_s, 0x10b0U); 842 goto unpin; 843 } 844 vsie_page->sdnx_gpa = gpa; 845 scb_s->sdnxo = hpa | sdnxc; 846 } 847 return 0; 848 unpin: 849 unpin_blocks(vcpu, vsie_page); 850 return rc; 851 } 852 853 /* unpin the scb provided by guest 2, marking it as dirty */ 854 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 855 gpa_t gpa) 856 { 857 hpa_t hpa = (hpa_t) vsie_page->scb_o; 858 859 if (hpa) 860 unpin_guest_page(vcpu->kvm, gpa, hpa); 861 vsie_page->scb_o = NULL; 862 } 863 864 /* 865 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. 866 * 867 * Returns: - 0 if the scb was pinned. 868 * - > 0 if control has to be given to guest 2 869 */ 870 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 871 gpa_t gpa) 872 { 873 hpa_t hpa; 874 int rc; 875 876 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 877 if (rc) { 878 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 879 WARN_ON_ONCE(rc); 880 return 1; 881 } 882 vsie_page->scb_o = phys_to_virt(hpa); 883 return 0; 884 } 885 886 /* 887 * Inject a fault into guest 2. 888 * 889 * Returns: - > 0 if control has to be given to guest 2 890 * < 0 if an error occurred during injection. 891 */ 892 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, 893 bool write_flag) 894 { 895 struct kvm_s390_pgm_info pgm = { 896 .code = code, 897 .trans_exc_code = 898 /* 0-51: virtual address */ 899 (vaddr & 0xfffffffffffff000UL) | 900 /* 52-53: store / fetch */ 901 (((unsigned int) !write_flag) + 1) << 10, 902 /* 62-63: asce id (alway primary == 0) */ 903 .exc_access_id = 0, /* always primary */ 904 .op_access_id = 0, /* not MVPG */ 905 }; 906 int rc; 907 908 if (code == PGM_PROTECTION) 909 pgm.trans_exc_code |= 0x4UL; 910 911 rc = kvm_s390_inject_prog_irq(vcpu, &pgm); 912 return rc ? rc : 1; 913 } 914 915 /* 916 * Handle a fault during vsie execution on a gmap shadow. 917 * 918 * Returns: - 0 if the fault was resolved 919 * - > 0 if control has to be given to guest 2 920 * - < 0 if an error occurred 921 */ 922 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 923 { 924 int rc; 925 926 if (current->thread.gmap_int_code == PGM_PROTECTION) 927 /* we can directly forward all protection exceptions */ 928 return inject_fault(vcpu, PGM_PROTECTION, 929 current->thread.gmap_addr, 1); 930 931 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 932 current->thread.gmap_addr, NULL); 933 if (rc > 0) { 934 rc = inject_fault(vcpu, rc, 935 current->thread.gmap_addr, 936 current->thread.gmap_write_flag); 937 if (rc >= 0) 938 vsie_page->fault_addr = current->thread.gmap_addr; 939 } 940 return rc; 941 } 942 943 /* 944 * Retry the previous fault that required guest 2 intervention. This avoids 945 * one superfluous SIE re-entry and direct exit. 946 * 947 * Will ignore any errors. The next SIE fault will do proper fault handling. 948 */ 949 static void handle_last_fault(struct kvm_vcpu *vcpu, 950 struct vsie_page *vsie_page) 951 { 952 if (vsie_page->fault_addr) 953 kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 954 vsie_page->fault_addr, NULL); 955 vsie_page->fault_addr = 0; 956 } 957 958 static inline void clear_vsie_icpt(struct vsie_page *vsie_page) 959 { 960 vsie_page->scb_s.icptcode = 0; 961 } 962 963 /* rewind the psw and clear the vsie icpt, so we can retry execution */ 964 static void retry_vsie_icpt(struct vsie_page *vsie_page) 965 { 966 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 967 int ilen = insn_length(scb_s->ipa >> 8); 968 969 /* take care of EXECUTE instructions */ 970 if (scb_s->icptstatus & 1) { 971 ilen = (scb_s->icptstatus >> 4) & 0x6; 972 if (!ilen) 973 ilen = 4; 974 } 975 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); 976 clear_vsie_icpt(vsie_page); 977 } 978 979 /* 980 * Try to shadow + enable the guest 2 provided facility list. 981 * Retry instruction execution if enabled for and provided by guest 2. 982 * 983 * Returns: - 0 if handled (retry or guest 2 icpt) 984 * - > 0 if control has to be given to guest 2 985 */ 986 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 987 { 988 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 989 __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; 990 991 if (fac && test_kvm_facility(vcpu->kvm, 7)) { 992 retry_vsie_icpt(vsie_page); 993 if (read_guest_real(vcpu, fac, &vsie_page->fac, 994 sizeof(vsie_page->fac))) 995 return set_validity_icpt(scb_s, 0x1090U); 996 scb_s->fac = (__u32)(__u64) &vsie_page->fac; 997 } 998 return 0; 999 } 1000 1001 /* 1002 * Get a register for a nested guest. 1003 * @vcpu the vcpu of the guest 1004 * @vsie_page the vsie_page for the nested guest 1005 * @reg the register number, the upper 4 bits are ignored. 1006 * returns: the value of the register. 1007 */ 1008 static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) 1009 { 1010 /* no need to validate the parameter and/or perform error handling */ 1011 reg &= 0xf; 1012 switch (reg) { 1013 case 15: 1014 return vsie_page->scb_s.gg15; 1015 case 14: 1016 return vsie_page->scb_s.gg14; 1017 default: 1018 return vcpu->run->s.regs.gprs[reg]; 1019 } 1020 } 1021 1022 static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1023 { 1024 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1025 unsigned long pei_dest, pei_src, src, dest, mask, prefix; 1026 u64 *pei_block = &vsie_page->scb_o->mcic; 1027 int edat, rc_dest, rc_src; 1028 union ctlreg0 cr0; 1029 1030 cr0.val = vcpu->arch.sie_block->gcr[0]; 1031 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1032 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK); 1033 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 1034 1035 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; 1036 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso; 1037 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; 1038 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso; 1039 1040 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest); 1041 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src); 1042 /* 1043 * Either everything went well, or something non-critical went wrong 1044 * e.g. because of a race. In either case, simply retry. 1045 */ 1046 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { 1047 retry_vsie_icpt(vsie_page); 1048 return -EAGAIN; 1049 } 1050 /* Something more serious went wrong, propagate the error */ 1051 if (rc_dest < 0) 1052 return rc_dest; 1053 if (rc_src < 0) 1054 return rc_src; 1055 1056 /* The only possible suppressing exception: just deliver it */ 1057 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) { 1058 clear_vsie_icpt(vsie_page); 1059 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC); 1060 WARN_ON_ONCE(rc_dest); 1061 return 1; 1062 } 1063 1064 /* 1065 * Forward the PEI intercept to the guest if it was a page fault, or 1066 * also for segment and region table faults if EDAT applies. 1067 */ 1068 if (edat) { 1069 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0; 1070 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0; 1071 } else { 1072 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0; 1073 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0; 1074 } 1075 if (!rc_dest && !rc_src) { 1076 pei_block[0] = pei_dest; 1077 pei_block[1] = pei_src; 1078 return 1; 1079 } 1080 1081 retry_vsie_icpt(vsie_page); 1082 1083 /* 1084 * The host has edat, and the guest does not, or it was an ASCE type 1085 * exception. The host needs to inject the appropriate DAT interrupts 1086 * into the guest. 1087 */ 1088 if (rc_dest) 1089 return inject_fault(vcpu, rc_dest, dest, 1); 1090 return inject_fault(vcpu, rc_src, src, 0); 1091 } 1092 1093 /* 1094 * Run the vsie on a shadow scb and a shadow gmap, without any further 1095 * sanity checks, handling SIE faults. 1096 * 1097 * Returns: - 0 everything went fine 1098 * - > 0 if control has to be given to guest 2 1099 * - < 0 if an error occurred 1100 */ 1101 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1102 __releases(vcpu->kvm->srcu) 1103 __acquires(vcpu->kvm->srcu) 1104 { 1105 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1106 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 1107 int guest_bp_isolation; 1108 int rc = 0; 1109 1110 handle_last_fault(vcpu, vsie_page); 1111 1112 kvm_vcpu_srcu_read_unlock(vcpu); 1113 1114 /* save current guest state of bp isolation override */ 1115 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1116 1117 /* 1118 * The guest is running with BPBC, so we have to force it on for our 1119 * nested guest. This is done by enabling BPBC globally, so the BPBC 1120 * control in the SCB (which the nested guest can modify) is simply 1121 * ignored. 1122 */ 1123 if (test_kvm_facility(vcpu->kvm, 82) && 1124 vcpu->arch.sie_block->fpf & FPF_BPBC) 1125 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1126 1127 local_irq_disable(); 1128 guest_enter_irqoff(); 1129 local_irq_enable(); 1130 1131 /* 1132 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1133 * and VCPU requests also hinder the vSIE from running and lead 1134 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1135 * also kick the vSIE. 1136 */ 1137 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1138 barrier(); 1139 if (test_cpu_flag(CIF_FPU)) 1140 load_fpu_regs(); 1141 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) 1142 rc = sie64a(scb_s, vcpu->run->s.regs.gprs); 1143 barrier(); 1144 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1145 1146 local_irq_disable(); 1147 guest_exit_irqoff(); 1148 local_irq_enable(); 1149 1150 /* restore guest state for bp isolation override */ 1151 if (!guest_bp_isolation) 1152 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1153 1154 kvm_vcpu_srcu_read_lock(vcpu); 1155 1156 if (rc == -EINTR) { 1157 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1158 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1159 return 0; 1160 } 1161 1162 if (rc > 0) 1163 rc = 0; /* we could still have an icpt */ 1164 else if (rc == -EFAULT) 1165 return handle_fault(vcpu, vsie_page); 1166 1167 switch (scb_s->icptcode) { 1168 case ICPT_INST: 1169 if (scb_s->ipa == 0xb2b0) 1170 rc = handle_stfle(vcpu, vsie_page); 1171 break; 1172 case ICPT_STOP: 1173 /* stop not requested by g2 - must have been a kick */ 1174 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1175 clear_vsie_icpt(vsie_page); 1176 break; 1177 case ICPT_VALIDITY: 1178 if ((scb_s->ipa & 0xf000) != 0xf000) 1179 scb_s->ipa += 0x1000; 1180 break; 1181 case ICPT_PARTEXEC: 1182 if (scb_s->ipa == 0xb254) 1183 rc = vsie_handle_mvpg(vcpu, vsie_page); 1184 break; 1185 } 1186 return rc; 1187 } 1188 1189 static void release_gmap_shadow(struct vsie_page *vsie_page) 1190 { 1191 if (vsie_page->gmap) 1192 gmap_put(vsie_page->gmap); 1193 WRITE_ONCE(vsie_page->gmap, NULL); 1194 prefix_unmapped(vsie_page); 1195 } 1196 1197 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1198 struct vsie_page *vsie_page) 1199 { 1200 unsigned long asce; 1201 union ctlreg0 cr0; 1202 struct gmap *gmap; 1203 int edat; 1204 1205 asce = vcpu->arch.sie_block->gcr[1]; 1206 cr0.val = vcpu->arch.sie_block->gcr[0]; 1207 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1208 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1209 1210 /* 1211 * ASCE or EDAT could have changed since last icpt, or the gmap 1212 * we're holding has been unshadowed. If the gmap is still valid, 1213 * we can safely reuse it. 1214 */ 1215 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) 1216 return 0; 1217 1218 /* release the old shadow - if any, and mark the prefix as unmapped */ 1219 release_gmap_shadow(vsie_page); 1220 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1221 if (IS_ERR(gmap)) 1222 return PTR_ERR(gmap); 1223 gmap->private = vcpu->kvm; 1224 WRITE_ONCE(vsie_page->gmap, gmap); 1225 return 0; 1226 } 1227 1228 /* 1229 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1230 */ 1231 static void register_shadow_scb(struct kvm_vcpu *vcpu, 1232 struct vsie_page *vsie_page) 1233 { 1234 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1235 1236 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1237 /* 1238 * External calls have to lead to a kick of the vcpu and 1239 * therefore the vsie -> Simulate Wait state. 1240 */ 1241 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1242 /* 1243 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1244 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1245 */ 1246 preempt_disable(); 1247 scb_s->epoch += vcpu->kvm->arch.epoch; 1248 1249 if (scb_s->ecd & ECD_MEF) { 1250 scb_s->epdx += vcpu->kvm->arch.epdx; 1251 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1252 scb_s->epdx += 1; 1253 } 1254 1255 preempt_enable(); 1256 } 1257 1258 /* 1259 * Unregister a shadow scb from a VCPU. 1260 */ 1261 static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1262 { 1263 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1264 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1265 } 1266 1267 /* 1268 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1269 * prefix pages and faults. 1270 * 1271 * Returns: - 0 if no errors occurred 1272 * - > 0 if control has to be given to guest 2 1273 * - -ENOMEM if out of memory 1274 */ 1275 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1276 { 1277 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1278 int rc = 0; 1279 1280 while (1) { 1281 rc = acquire_gmap_shadow(vcpu, vsie_page); 1282 if (!rc) 1283 rc = map_prefix(vcpu, vsie_page); 1284 if (!rc) { 1285 gmap_enable(vsie_page->gmap); 1286 update_intervention_requests(vsie_page); 1287 rc = do_vsie_run(vcpu, vsie_page); 1288 gmap_enable(vcpu->arch.gmap); 1289 } 1290 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1291 1292 if (rc == -EAGAIN) 1293 rc = 0; 1294 if (rc || scb_s->icptcode || signal_pending(current) || 1295 kvm_s390_vcpu_has_irq(vcpu, 0) || 1296 kvm_s390_vcpu_sie_inhibited(vcpu)) 1297 break; 1298 cond_resched(); 1299 } 1300 1301 if (rc == -EFAULT) { 1302 /* 1303 * Addressing exceptions are always presentes as intercepts. 1304 * As addressing exceptions are suppressing and our guest 3 PSW 1305 * points at the responsible instruction, we have to 1306 * forward the PSW and set the ilc. If we can't read guest 3 1307 * instruction, we can use an arbitrary ilc. Let's always use 1308 * ilen = 4 for now, so we can avoid reading in guest 3 virtual 1309 * memory. (we could also fake the shadow so the hardware 1310 * handles it). 1311 */ 1312 scb_s->icptcode = ICPT_PROGI; 1313 scb_s->iprcc = PGM_ADDRESSING; 1314 scb_s->pgmilc = 4; 1315 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); 1316 rc = 1; 1317 } 1318 return rc; 1319 } 1320 1321 /* 1322 * Get or create a vsie page for a scb address. 1323 * 1324 * Returns: - address of a vsie page (cached or new one) 1325 * - NULL if the same scb address is already used by another VCPU 1326 * - ERR_PTR(-ENOMEM) if out of memory 1327 */ 1328 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1329 { 1330 struct vsie_page *vsie_page; 1331 struct page *page; 1332 int nr_vcpus; 1333 1334 rcu_read_lock(); 1335 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1336 rcu_read_unlock(); 1337 if (page) { 1338 if (page_ref_inc_return(page) == 2) 1339 return page_to_virt(page); 1340 page_ref_dec(page); 1341 } 1342 1343 /* 1344 * We want at least #online_vcpus shadows, so every VCPU can execute 1345 * the VSIE in parallel. 1346 */ 1347 nr_vcpus = atomic_read(&kvm->online_vcpus); 1348 1349 mutex_lock(&kvm->arch.vsie.mutex); 1350 if (kvm->arch.vsie.page_count < nr_vcpus) { 1351 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); 1352 if (!page) { 1353 mutex_unlock(&kvm->arch.vsie.mutex); 1354 return ERR_PTR(-ENOMEM); 1355 } 1356 page_ref_inc(page); 1357 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; 1358 kvm->arch.vsie.page_count++; 1359 } else { 1360 /* reuse an existing entry that belongs to nobody */ 1361 while (true) { 1362 page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1363 if (page_ref_inc_return(page) == 2) 1364 break; 1365 page_ref_dec(page); 1366 kvm->arch.vsie.next++; 1367 kvm->arch.vsie.next %= nr_vcpus; 1368 } 1369 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1370 } 1371 page->index = addr; 1372 /* double use of the same address */ 1373 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { 1374 page_ref_dec(page); 1375 mutex_unlock(&kvm->arch.vsie.mutex); 1376 return NULL; 1377 } 1378 mutex_unlock(&kvm->arch.vsie.mutex); 1379 1380 vsie_page = page_to_virt(page); 1381 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1382 release_gmap_shadow(vsie_page); 1383 vsie_page->fault_addr = 0; 1384 vsie_page->scb_s.ihcpu = 0xffffU; 1385 return vsie_page; 1386 } 1387 1388 /* put a vsie page acquired via get_vsie_page */ 1389 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) 1390 { 1391 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); 1392 1393 page_ref_dec(page); 1394 } 1395 1396 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1397 { 1398 struct vsie_page *vsie_page; 1399 unsigned long scb_addr; 1400 int rc; 1401 1402 vcpu->stat.instruction_sie++; 1403 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1404 return -EOPNOTSUPP; 1405 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1406 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1407 1408 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1409 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1410 1411 /* 512 byte alignment */ 1412 if (unlikely(scb_addr & 0x1ffUL)) 1413 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1414 1415 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1416 kvm_s390_vcpu_sie_inhibited(vcpu)) 1417 return 0; 1418 1419 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1420 if (IS_ERR(vsie_page)) 1421 return PTR_ERR(vsie_page); 1422 else if (!vsie_page) 1423 /* double use of sie control block - simply do nothing */ 1424 return 0; 1425 1426 rc = pin_scb(vcpu, vsie_page, scb_addr); 1427 if (rc) 1428 goto out_put; 1429 rc = shadow_scb(vcpu, vsie_page); 1430 if (rc) 1431 goto out_unpin_scb; 1432 rc = pin_blocks(vcpu, vsie_page); 1433 if (rc) 1434 goto out_unshadow; 1435 register_shadow_scb(vcpu, vsie_page); 1436 rc = vsie_run(vcpu, vsie_page); 1437 unregister_shadow_scb(vcpu); 1438 unpin_blocks(vcpu, vsie_page); 1439 out_unshadow: 1440 unshadow_scb(vcpu, vsie_page); 1441 out_unpin_scb: 1442 unpin_scb(vcpu, vsie_page, scb_addr); 1443 out_put: 1444 put_vsie_page(vcpu->kvm, vsie_page); 1445 1446 return rc < 0 ? rc : 0; 1447 } 1448 1449 /* Init the vsie data structures. To be called when a vm is initialized. */ 1450 void kvm_s390_vsie_init(struct kvm *kvm) 1451 { 1452 mutex_init(&kvm->arch.vsie.mutex); 1453 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT); 1454 } 1455 1456 /* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1457 void kvm_s390_vsie_destroy(struct kvm *kvm) 1458 { 1459 struct vsie_page *vsie_page; 1460 struct page *page; 1461 int i; 1462 1463 mutex_lock(&kvm->arch.vsie.mutex); 1464 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1465 page = kvm->arch.vsie.pages[i]; 1466 kvm->arch.vsie.pages[i] = NULL; 1467 vsie_page = page_to_virt(page); 1468 release_gmap_shadow(vsie_page); 1469 /* free the radix tree entry */ 1470 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1471 __free_page(page); 1472 } 1473 kvm->arch.vsie.page_count = 0; 1474 mutex_unlock(&kvm->arch.vsie.mutex); 1475 } 1476 1477 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1478 { 1479 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1480 1481 /* 1482 * Even if the VCPU lets go of the shadow sie block reference, it is 1483 * still valid in the cache. So we can safely kick it. 1484 */ 1485 if (scb) { 1486 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1487 if (scb->prog0c & PROG_IN_SIE) 1488 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1489 } 1490 } 1491