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 #include <linux/io.h> 16 #include <linux/mman.h> 17 18 #include <asm/gmap.h> 19 #include <asm/mmu_context.h> 20 #include <asm/sclp.h> 21 #include <asm/nmi.h> 22 #include <asm/dis.h> 23 #include <asm/facility.h> 24 #include "kvm-s390.h" 25 #include "gaccess.h" 26 27 enum vsie_page_flags { 28 VSIE_PAGE_IN_USE = 0, 29 }; 30 31 struct vsie_page { 32 struct kvm_s390_sie_block scb_s; /* 0x0000 */ 33 /* 34 * the backup info for machine check. ensure it's at 35 * the same offset as that in struct sie_page! 36 */ 37 struct mcck_volatile_info mcck_info; /* 0x0200 */ 38 /* 39 * The pinned original scb. Be aware that other VCPUs can modify 40 * it while we read from it. Values that are used for conditions or 41 * are reused conditionally, should be accessed via READ_ONCE. 42 */ 43 struct kvm_s390_sie_block *scb_o; /* 0x0218 */ 44 /* the shadow gmap in use by the vsie_page */ 45 struct gmap *gmap; /* 0x0220 */ 46 /* address of the last reported fault to guest2 */ 47 unsigned long fault_addr; /* 0x0228 */ 48 /* calculated guest addresses of satellite control blocks */ 49 gpa_t sca_gpa; /* 0x0230 */ 50 gpa_t itdba_gpa; /* 0x0238 */ 51 gpa_t gvrd_gpa; /* 0x0240 */ 52 gpa_t riccbd_gpa; /* 0x0248 */ 53 gpa_t sdnx_gpa; /* 0x0250 */ 54 /* 55 * guest address of the original SCB. Remains set for free vsie 56 * pages, so we can properly look them up in our addr_to_page 57 * radix tree. 58 */ 59 gpa_t scb_gpa; /* 0x0258 */ 60 /* 61 * Flags: must be set/cleared atomically after the vsie page can be 62 * looked up by other CPUs. 63 */ 64 unsigned long flags; /* 0x0260 */ 65 __u8 reserved[0x0700 - 0x0268]; /* 0x0268 */ 66 struct kvm_s390_crypto_cb crycb; /* 0x0700 */ 67 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ 68 }; 69 70 /** 71 * gmap_shadow_valid() - check if a shadow guest address space matches the 72 * given properties and is still valid 73 * @sg: pointer to the shadow guest address space structure 74 * @asce: ASCE for which the shadow table is requested 75 * @edat_level: edat level to be used for the shadow translation 76 * 77 * Returns 1 if the gmap shadow is still valid and matches the given 78 * properties, the caller can continue using it. Returns 0 otherwise; the 79 * caller has to request a new shadow gmap in this case. 80 */ 81 int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level) 82 { 83 if (sg->removed) 84 return 0; 85 return sg->orig_asce == asce && sg->edat_level == edat_level; 86 } 87 88 /* trigger a validity icpt for the given scb */ 89 static int set_validity_icpt(struct kvm_s390_sie_block *scb, 90 __u16 reason_code) 91 { 92 scb->ipa = 0x1000; 93 scb->ipb = ((__u32) reason_code) << 16; 94 scb->icptcode = ICPT_VALIDITY; 95 return 1; 96 } 97 98 /* mark the prefix as unmapped, this will block the VSIE */ 99 static void prefix_unmapped(struct vsie_page *vsie_page) 100 { 101 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20); 102 } 103 104 /* mark the prefix as unmapped and wait until the VSIE has been left */ 105 static void prefix_unmapped_sync(struct vsie_page *vsie_page) 106 { 107 prefix_unmapped(vsie_page); 108 if (vsie_page->scb_s.prog0c & PROG_IN_SIE) 109 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags); 110 while (vsie_page->scb_s.prog0c & PROG_IN_SIE) 111 cpu_relax(); 112 } 113 114 /* mark the prefix as mapped, this will allow the VSIE to run */ 115 static void prefix_mapped(struct vsie_page *vsie_page) 116 { 117 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20); 118 } 119 120 /* test if the prefix is mapped into the gmap shadow */ 121 static int prefix_is_mapped(struct vsie_page *vsie_page) 122 { 123 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST); 124 } 125 126 /* copy the updated intervention request bits into the shadow scb */ 127 static void update_intervention_requests(struct vsie_page *vsie_page) 128 { 129 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT; 130 int cpuflags; 131 132 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags); 133 atomic_andnot(bits, &vsie_page->scb_s.cpuflags); 134 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags); 135 } 136 137 /* shadow (filter and validate) the cpuflags */ 138 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 139 { 140 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 141 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 142 int newflags, cpuflags = atomic_read(&scb_o->cpuflags); 143 144 /* we don't allow ESA/390 guests */ 145 if (!(cpuflags & CPUSTAT_ZARCH)) 146 return set_validity_icpt(scb_s, 0x0001U); 147 148 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) 149 return set_validity_icpt(scb_s, 0x0001U); 150 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR)) 151 return set_validity_icpt(scb_s, 0x0007U); 152 153 /* intervention requests will be set later */ 154 newflags = CPUSTAT_ZARCH; 155 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8)) 156 newflags |= CPUSTAT_GED; 157 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) { 158 if (cpuflags & CPUSTAT_GED) 159 return set_validity_icpt(scb_s, 0x0001U); 160 newflags |= CPUSTAT_GED2; 161 } 162 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE)) 163 newflags |= cpuflags & CPUSTAT_P; 164 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS)) 165 newflags |= cpuflags & CPUSTAT_SM; 166 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) 167 newflags |= cpuflags & CPUSTAT_IBS; 168 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) 169 newflags |= cpuflags & CPUSTAT_KSS; 170 171 atomic_set(&scb_s->cpuflags, newflags); 172 return 0; 173 } 174 /* Copy to APCB FORMAT1 from APCB FORMAT0 */ 175 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s, 176 unsigned long crycb_gpa, struct kvm_s390_apcb1 *apcb_h) 177 { 178 struct kvm_s390_apcb0 tmp; 179 unsigned long apcb_gpa; 180 181 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 182 183 if (read_guest_real(vcpu, apcb_gpa, &tmp, 184 sizeof(struct kvm_s390_apcb0))) 185 return -EFAULT; 186 187 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; 188 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; 189 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; 190 191 return 0; 192 193 } 194 195 /** 196 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 197 * @vcpu: pointer to the virtual CPU 198 * @apcb_s: pointer to start of apcb in the shadow crycb 199 * @crycb_gpa: guest physical address to start of original guest crycb 200 * @apcb_h: pointer to start of apcb in the guest1 201 * 202 * Returns 0 and -EFAULT on error reading guest apcb 203 */ 204 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 205 unsigned long crycb_gpa, unsigned long *apcb_h) 206 { 207 unsigned long apcb_gpa; 208 209 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 210 211 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 212 sizeof(struct kvm_s390_apcb0))) 213 return -EFAULT; 214 215 bitmap_and(apcb_s, apcb_s, apcb_h, 216 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb0)); 217 218 return 0; 219 } 220 221 /** 222 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB 223 * @vcpu: pointer to the virtual CPU 224 * @apcb_s: pointer to start of apcb in the shadow crycb 225 * @crycb_gpa: guest physical address to start of original guest crycb 226 * @apcb_h: pointer to start of apcb in the host 227 * 228 * Returns 0 and -EFAULT on error reading guest apcb 229 */ 230 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 231 unsigned long crycb_gpa, 232 unsigned long *apcb_h) 233 { 234 unsigned long apcb_gpa; 235 236 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb1); 237 238 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 239 sizeof(struct kvm_s390_apcb1))) 240 return -EFAULT; 241 242 bitmap_and(apcb_s, apcb_s, apcb_h, 243 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb1)); 244 245 return 0; 246 } 247 248 /** 249 * setup_apcb - Create a shadow copy of the apcb. 250 * @vcpu: pointer to the virtual CPU 251 * @crycb_s: pointer to shadow crycb 252 * @crycb_gpa: guest physical address of original guest crycb 253 * @crycb_h: pointer to the host crycb 254 * @fmt_o: format of the original guest crycb. 255 * @fmt_h: format of the host crycb. 256 * 257 * Checks the compatibility between the guest and host crycb and calls the 258 * appropriate copy function. 259 * 260 * Return 0 or an error number if the guest and host crycb are incompatible. 261 */ 262 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 263 const u32 crycb_gpa, 264 struct kvm_s390_crypto_cb *crycb_h, 265 int fmt_o, int fmt_h) 266 { 267 switch (fmt_o) { 268 case CRYCB_FORMAT2: 269 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 256) & PAGE_MASK)) 270 return -EACCES; 271 if (fmt_h != CRYCB_FORMAT2) 272 return -EINVAL; 273 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 274 crycb_gpa, 275 (unsigned long *)&crycb_h->apcb1); 276 case CRYCB_FORMAT1: 277 switch (fmt_h) { 278 case CRYCB_FORMAT2: 279 return setup_apcb10(vcpu, &crycb_s->apcb1, 280 crycb_gpa, 281 &crycb_h->apcb1); 282 case CRYCB_FORMAT1: 283 return setup_apcb00(vcpu, 284 (unsigned long *) &crycb_s->apcb0, 285 crycb_gpa, 286 (unsigned long *) &crycb_h->apcb0); 287 } 288 break; 289 case CRYCB_FORMAT0: 290 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 32) & PAGE_MASK)) 291 return -EACCES; 292 293 switch (fmt_h) { 294 case CRYCB_FORMAT2: 295 return setup_apcb10(vcpu, &crycb_s->apcb1, 296 crycb_gpa, 297 &crycb_h->apcb1); 298 case CRYCB_FORMAT1: 299 case CRYCB_FORMAT0: 300 return setup_apcb00(vcpu, 301 (unsigned long *) &crycb_s->apcb0, 302 crycb_gpa, 303 (unsigned long *) &crycb_h->apcb0); 304 } 305 } 306 return -EINVAL; 307 } 308 309 /** 310 * shadow_crycb - Create a shadow copy of the crycb block 311 * @vcpu: a pointer to the virtual CPU 312 * @vsie_page: a pointer to internal date used for the vSIE 313 * 314 * Create a shadow copy of the crycb block and setup key wrapping, if 315 * requested for guest 3 and enabled for guest 2. 316 * 317 * We accept format-1 or format-2, but we convert format-1 into format-2 318 * in the shadow CRYCB. 319 * Using format-2 enables the firmware to choose the right format when 320 * scheduling the SIE. 321 * There is nothing to do for format-0. 322 * 323 * This function centralize the issuing of set_validity_icpt() for all 324 * the subfunctions working on the crycb. 325 * 326 * Returns: - 0 if shadowed or nothing to do 327 * - > 0 if control has to be given to guest 2 328 */ 329 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 330 { 331 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 332 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 333 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 334 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 335 unsigned long *b1, *b2; 336 u8 ecb3_flags; 337 u32 ecd_flags; 338 int apie_h; 339 int apie_s; 340 int key_msk = test_kvm_facility(vcpu->kvm, 76); 341 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 342 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 343 int ret = 0; 344 345 scb_s->crycbd = 0; 346 347 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 348 apie_s = apie_h & scb_o->eca; 349 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 350 return 0; 351 352 if (!crycb_addr) 353 return set_validity_icpt(scb_s, 0x0039U); 354 355 if (fmt_o == CRYCB_FORMAT1) 356 if ((crycb_addr & PAGE_MASK) != 357 ((crycb_addr + 128) & PAGE_MASK)) 358 return set_validity_icpt(scb_s, 0x003CU); 359 360 if (apie_s) { 361 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 362 vcpu->kvm->arch.crypto.crycb, 363 fmt_o, fmt_h); 364 if (ret) 365 goto end; 366 scb_s->eca |= scb_o->eca & ECA_APIE; 367 } 368 369 /* we may only allow it if enabled for guest 2 */ 370 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 371 (ECB3_AES | ECB3_DEA); 372 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & 373 (ECD_ECC | ECD_HMAC); 374 if (!ecb3_flags && !ecd_flags) 375 goto end; 376 377 /* copy only the wrapping keys */ 378 if (read_guest_real(vcpu, crycb_addr + 72, 379 vsie_page->crycb.dea_wrapping_key_mask, 56)) 380 return set_validity_icpt(scb_s, 0x0035U); 381 382 scb_s->ecb3 |= ecb3_flags; 383 scb_s->ecd |= ecd_flags; 384 385 /* xor both blocks in one run */ 386 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 387 b2 = (unsigned long *) 388 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 389 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 390 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 391 end: 392 switch (ret) { 393 case -EINVAL: 394 return set_validity_icpt(scb_s, 0x0022U); 395 case -EFAULT: 396 return set_validity_icpt(scb_s, 0x0035U); 397 case -EACCES: 398 return set_validity_icpt(scb_s, 0x003CU); 399 } 400 scb_s->crycbd = (u32)virt_to_phys(&vsie_page->crycb) | CRYCB_FORMAT2; 401 return 0; 402 } 403 404 /* shadow (round up/down) the ibc to avoid validity icpt */ 405 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 406 { 407 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 408 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 409 /* READ_ONCE does not work on bitfields - use a temporary variable */ 410 const uint32_t __new_ibc = scb_o->ibc; 411 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 412 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 413 414 scb_s->ibc = 0; 415 /* ibc installed in g2 and requested for g3 */ 416 if (vcpu->kvm->arch.model.ibc && new_ibc) { 417 scb_s->ibc = new_ibc; 418 /* takte care of the minimum ibc level of the machine */ 419 if (scb_s->ibc < min_ibc) 420 scb_s->ibc = min_ibc; 421 /* take care of the maximum ibc level set for the guest */ 422 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 423 scb_s->ibc = vcpu->kvm->arch.model.ibc; 424 } 425 } 426 427 /* unshadow the scb, copying parameters back to the real scb */ 428 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 429 { 430 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 431 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 432 433 /* interception */ 434 scb_o->icptcode = scb_s->icptcode; 435 scb_o->icptstatus = scb_s->icptstatus; 436 scb_o->ipa = scb_s->ipa; 437 scb_o->ipb = scb_s->ipb; 438 scb_o->gbea = scb_s->gbea; 439 440 /* timer */ 441 scb_o->cputm = scb_s->cputm; 442 scb_o->ckc = scb_s->ckc; 443 scb_o->todpr = scb_s->todpr; 444 445 /* guest state */ 446 scb_o->gpsw = scb_s->gpsw; 447 scb_o->gg14 = scb_s->gg14; 448 scb_o->gg15 = scb_s->gg15; 449 memcpy(scb_o->gcr, scb_s->gcr, 128); 450 scb_o->pp = scb_s->pp; 451 452 /* branch prediction */ 453 if (test_kvm_facility(vcpu->kvm, 82)) { 454 scb_o->fpf &= ~FPF_BPBC; 455 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 456 } 457 458 /* interrupt intercept */ 459 switch (scb_s->icptcode) { 460 case ICPT_PROGI: 461 case ICPT_INSTPROGI: 462 case ICPT_EXTINT: 463 memcpy((void *)((u64)scb_o + 0xc0), 464 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 465 break; 466 } 467 468 if (scb_s->ihcpu != 0xffffU) 469 scb_o->ihcpu = scb_s->ihcpu; 470 } 471 472 /* 473 * Setup the shadow scb by copying and checking the relevant parts of the g2 474 * provided scb. 475 * 476 * Returns: - 0 if the scb has been shadowed 477 * - > 0 if control has to be given to guest 2 478 */ 479 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 480 { 481 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 482 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 483 /* READ_ONCE does not work on bitfields - use a temporary variable */ 484 const uint32_t __new_prefix = scb_o->prefix; 485 const uint32_t new_prefix = READ_ONCE(__new_prefix); 486 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 487 bool had_tx = scb_s->ecb & ECB_TE; 488 unsigned long new_mso = 0; 489 int rc; 490 491 /* make sure we don't have any leftovers when reusing the scb */ 492 scb_s->icptcode = 0; 493 scb_s->eca = 0; 494 scb_s->ecb = 0; 495 scb_s->ecb2 = 0; 496 scb_s->ecb3 = 0; 497 scb_s->ecd = 0; 498 scb_s->fac = 0; 499 scb_s->fpf = 0; 500 501 rc = prepare_cpuflags(vcpu, vsie_page); 502 if (rc) 503 goto out; 504 505 /* timer */ 506 scb_s->cputm = scb_o->cputm; 507 scb_s->ckc = scb_o->ckc; 508 scb_s->todpr = scb_o->todpr; 509 scb_s->epoch = scb_o->epoch; 510 511 /* guest state */ 512 scb_s->gpsw = scb_o->gpsw; 513 scb_s->gg14 = scb_o->gg14; 514 scb_s->gg15 = scb_o->gg15; 515 memcpy(scb_s->gcr, scb_o->gcr, 128); 516 scb_s->pp = scb_o->pp; 517 518 /* interception / execution handling */ 519 scb_s->gbea = scb_o->gbea; 520 scb_s->lctl = scb_o->lctl; 521 scb_s->svcc = scb_o->svcc; 522 scb_s->ictl = scb_o->ictl; 523 /* 524 * SKEY handling functions can't deal with false setting of PTE invalid 525 * bits. Therefore we cannot provide interpretation and would later 526 * have to provide own emulation handlers. 527 */ 528 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 529 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 530 531 scb_s->icpua = scb_o->icpua; 532 533 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 534 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 535 /* if the hva of the prefix changes, we have to remap the prefix */ 536 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 537 prefix_unmapped(vsie_page); 538 /* SIE will do mso/msl validity and exception checks for us */ 539 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 540 scb_s->mso = new_mso; 541 scb_s->prefix = new_prefix; 542 543 /* We have to definitely flush the tlb if this scb never ran */ 544 if (scb_s->ihcpu != 0xffffU) 545 scb_s->ihcpu = scb_o->ihcpu; 546 547 /* MVPG and Protection Exception Interpretation are always available */ 548 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 549 /* Host-protection-interruption introduced with ESOP */ 550 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 551 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 552 /* 553 * CPU Topology 554 * This facility only uses the utility field of the SCA and none of 555 * the cpu entries that are problematic with the other interpretation 556 * facilities so we can pass it through 557 */ 558 if (test_kvm_facility(vcpu->kvm, 11)) 559 scb_s->ecb |= scb_o->ecb & ECB_PTF; 560 /* transactional execution */ 561 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 562 /* remap the prefix is tx is toggled on */ 563 if (!had_tx) 564 prefix_unmapped(vsie_page); 565 scb_s->ecb |= ECB_TE; 566 } 567 /* specification exception interpretation */ 568 scb_s->ecb |= scb_o->ecb & ECB_SPECI; 569 /* branch prediction */ 570 if (test_kvm_facility(vcpu->kvm, 82)) 571 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 572 /* SIMD */ 573 if (test_kvm_facility(vcpu->kvm, 129)) { 574 scb_s->eca |= scb_o->eca & ECA_VX; 575 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 576 } 577 /* Run-time-Instrumentation */ 578 if (test_kvm_facility(vcpu->kvm, 64)) 579 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 580 /* Instruction Execution Prevention */ 581 if (test_kvm_facility(vcpu->kvm, 130)) 582 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 583 /* Guarded Storage */ 584 if (test_kvm_facility(vcpu->kvm, 133)) { 585 scb_s->ecb |= scb_o->ecb & ECB_GS; 586 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 587 } 588 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 589 scb_s->eca |= scb_o->eca & ECA_SII; 590 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 591 scb_s->eca |= scb_o->eca & ECA_IB; 592 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 593 scb_s->eca |= scb_o->eca & ECA_CEI; 594 /* Epoch Extension */ 595 if (test_kvm_facility(vcpu->kvm, 139)) { 596 scb_s->ecd |= scb_o->ecd & ECD_MEF; 597 scb_s->epdx = scb_o->epdx; 598 } 599 600 /* etoken */ 601 if (test_kvm_facility(vcpu->kvm, 156)) 602 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 603 604 scb_s->hpid = HPID_VSIE; 605 scb_s->cpnc = scb_o->cpnc; 606 607 prepare_ibc(vcpu, vsie_page); 608 rc = shadow_crycb(vcpu, vsie_page); 609 out: 610 if (rc) 611 unshadow_scb(vcpu, vsie_page); 612 return rc; 613 } 614 615 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 616 unsigned long end) 617 { 618 struct kvm *kvm = gmap->private; 619 struct vsie_page *cur; 620 unsigned long prefix; 621 int i; 622 623 if (!gmap_is_shadow(gmap)) 624 return; 625 /* 626 * Only new shadow blocks are added to the list during runtime, 627 * therefore we can safely reference them all the time. 628 */ 629 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 630 cur = READ_ONCE(kvm->arch.vsie.pages[i]); 631 if (!cur) 632 continue; 633 if (READ_ONCE(cur->gmap) != gmap) 634 continue; 635 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; 636 /* with mso/msl, the prefix lies at an offset */ 637 prefix += cur->scb_s.mso; 638 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) 639 prefix_unmapped_sync(cur); 640 } 641 } 642 643 /* 644 * Map the first prefix page and if tx is enabled also the second prefix page. 645 * 646 * The prefix will be protected, a gmap notifier will inform about unmaps. 647 * The shadow scb must not be executed until the prefix is remapped, this is 648 * guaranteed by properly handling PROG_REQUEST. 649 * 650 * Returns: - 0 on if successfully mapped or already mapped 651 * - > 0 if control has to be given to guest 2 652 * - -EAGAIN if the caller can retry immediately 653 * - -ENOMEM if out of memory 654 */ 655 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 656 { 657 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 658 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 659 int rc; 660 661 if (prefix_is_mapped(vsie_page)) 662 return 0; 663 664 /* mark it as mapped so we can catch any concurrent unmappers */ 665 prefix_mapped(vsie_page); 666 667 /* with mso/msl, the prefix lies at offset *mso* */ 668 prefix += scb_s->mso; 669 670 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL); 671 if (!rc && (scb_s->ecb & ECB_TE)) 672 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 673 prefix + PAGE_SIZE, NULL); 674 /* 675 * We don't have to mprotect, we will be called for all unshadows. 676 * SIE will detect if protection applies and trigger a validity. 677 */ 678 if (rc) 679 prefix_unmapped(vsie_page); 680 if (rc > 0 || rc == -EFAULT) 681 rc = set_validity_icpt(scb_s, 0x0037U); 682 return rc; 683 } 684 685 /* 686 * Pin the guest page given by gpa and set hpa to the pinned host address. 687 * Will always be pinned writable. 688 * 689 * Returns: - 0 on success 690 * - -EINVAL if the gpa is not valid guest storage 691 */ 692 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) 693 { 694 struct page *page; 695 696 page = gfn_to_page(kvm, gpa_to_gfn(gpa)); 697 if (!page) 698 return -EINVAL; 699 *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK); 700 return 0; 701 } 702 703 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ 704 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) 705 { 706 kvm_release_page_dirty(pfn_to_page(hpa >> PAGE_SHIFT)); 707 /* mark the page always as dirty for migration */ 708 mark_page_dirty(kvm, gpa_to_gfn(gpa)); 709 } 710 711 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ 712 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 713 { 714 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 715 hpa_t hpa; 716 717 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; 718 if (hpa) { 719 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); 720 vsie_page->sca_gpa = 0; 721 scb_s->scaol = 0; 722 scb_s->scaoh = 0; 723 } 724 725 hpa = scb_s->itdba; 726 if (hpa) { 727 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); 728 vsie_page->itdba_gpa = 0; 729 scb_s->itdba = 0; 730 } 731 732 hpa = scb_s->gvrd; 733 if (hpa) { 734 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); 735 vsie_page->gvrd_gpa = 0; 736 scb_s->gvrd = 0; 737 } 738 739 hpa = scb_s->riccbd; 740 if (hpa) { 741 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); 742 vsie_page->riccbd_gpa = 0; 743 scb_s->riccbd = 0; 744 } 745 746 hpa = scb_s->sdnxo; 747 if (hpa) { 748 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); 749 vsie_page->sdnx_gpa = 0; 750 scb_s->sdnxo = 0; 751 } 752 } 753 754 /* 755 * Instead of shadowing some blocks, we can simply forward them because the 756 * addresses in the scb are 64 bit long. 757 * 758 * This works as long as the data lies in one page. If blocks ever exceed one 759 * page, we have to fall back to shadowing. 760 * 761 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must 762 * therefore not enable any facilities that access these pointers (e.g. SIGPIF). 763 * 764 * Returns: - 0 if all blocks were pinned. 765 * - > 0 if control has to be given to guest 2 766 * - -ENOMEM if out of memory 767 */ 768 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 769 { 770 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 771 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 772 hpa_t hpa; 773 gpa_t gpa; 774 int rc = 0; 775 776 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; 777 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) 778 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; 779 if (gpa) { 780 if (gpa < 2 * PAGE_SIZE) 781 rc = set_validity_icpt(scb_s, 0x0038U); 782 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) 783 rc = set_validity_icpt(scb_s, 0x0011U); 784 else if ((gpa & PAGE_MASK) != 785 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) 786 rc = set_validity_icpt(scb_s, 0x003bU); 787 if (!rc) { 788 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 789 if (rc) 790 rc = set_validity_icpt(scb_s, 0x0034U); 791 } 792 if (rc) 793 goto unpin; 794 vsie_page->sca_gpa = gpa; 795 scb_s->scaoh = (u32)((u64)hpa >> 32); 796 scb_s->scaol = (u32)(u64)hpa; 797 } 798 799 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; 800 if (gpa && (scb_s->ecb & ECB_TE)) { 801 if (gpa < 2 * PAGE_SIZE) { 802 rc = set_validity_icpt(scb_s, 0x0080U); 803 goto unpin; 804 } 805 /* 256 bytes cannot cross page boundaries */ 806 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 807 if (rc) { 808 rc = set_validity_icpt(scb_s, 0x0080U); 809 goto unpin; 810 } 811 vsie_page->itdba_gpa = gpa; 812 scb_s->itdba = hpa; 813 } 814 815 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; 816 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { 817 if (gpa < 2 * PAGE_SIZE) { 818 rc = set_validity_icpt(scb_s, 0x1310U); 819 goto unpin; 820 } 821 /* 822 * 512 bytes vector registers cannot cross page boundaries 823 * if this block gets bigger, we have to shadow it. 824 */ 825 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 826 if (rc) { 827 rc = set_validity_icpt(scb_s, 0x1310U); 828 goto unpin; 829 } 830 vsie_page->gvrd_gpa = gpa; 831 scb_s->gvrd = hpa; 832 } 833 834 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; 835 if (gpa && (scb_s->ecb3 & ECB3_RI)) { 836 if (gpa < 2 * PAGE_SIZE) { 837 rc = set_validity_icpt(scb_s, 0x0043U); 838 goto unpin; 839 } 840 /* 64 bytes cannot cross page boundaries */ 841 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 842 if (rc) { 843 rc = set_validity_icpt(scb_s, 0x0043U); 844 goto unpin; 845 } 846 /* Validity 0x0044 will be checked by SIE */ 847 vsie_page->riccbd_gpa = gpa; 848 scb_s->riccbd = hpa; 849 } 850 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || 851 (scb_s->ecd & ECD_ETOKENF)) { 852 unsigned long sdnxc; 853 854 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; 855 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; 856 if (!gpa || gpa < 2 * PAGE_SIZE) { 857 rc = set_validity_icpt(scb_s, 0x10b0U); 858 goto unpin; 859 } 860 if (sdnxc < 6 || sdnxc > 12) { 861 rc = set_validity_icpt(scb_s, 0x10b1U); 862 goto unpin; 863 } 864 if (gpa & ((1 << sdnxc) - 1)) { 865 rc = set_validity_icpt(scb_s, 0x10b2U); 866 goto unpin; 867 } 868 /* Due to alignment rules (checked above) this cannot 869 * cross page boundaries 870 */ 871 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 872 if (rc) { 873 rc = set_validity_icpt(scb_s, 0x10b0U); 874 goto unpin; 875 } 876 vsie_page->sdnx_gpa = gpa; 877 scb_s->sdnxo = hpa | sdnxc; 878 } 879 return 0; 880 unpin: 881 unpin_blocks(vcpu, vsie_page); 882 return rc; 883 } 884 885 /* unpin the scb provided by guest 2, marking it as dirty */ 886 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 887 gpa_t gpa) 888 { 889 hpa_t hpa = virt_to_phys(vsie_page->scb_o); 890 891 if (hpa) 892 unpin_guest_page(vcpu->kvm, gpa, hpa); 893 vsie_page->scb_o = NULL; 894 } 895 896 /* 897 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. 898 * 899 * Returns: - 0 if the scb was pinned. 900 * - > 0 if control has to be given to guest 2 901 */ 902 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 903 gpa_t gpa) 904 { 905 hpa_t hpa; 906 int rc; 907 908 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 909 if (rc) { 910 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 911 WARN_ON_ONCE(rc); 912 return 1; 913 } 914 vsie_page->scb_o = phys_to_virt(hpa); 915 return 0; 916 } 917 918 /* 919 * Inject a fault into guest 2. 920 * 921 * Returns: - > 0 if control has to be given to guest 2 922 * < 0 if an error occurred during injection. 923 */ 924 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, 925 bool write_flag) 926 { 927 struct kvm_s390_pgm_info pgm = { 928 .code = code, 929 .trans_exc_code = 930 /* 0-51: virtual address */ 931 (vaddr & 0xfffffffffffff000UL) | 932 /* 52-53: store / fetch */ 933 (((unsigned int) !write_flag) + 1) << 10, 934 /* 62-63: asce id (always primary == 0) */ 935 .exc_access_id = 0, /* always primary */ 936 .op_access_id = 0, /* not MVPG */ 937 }; 938 int rc; 939 940 if (code == PGM_PROTECTION) 941 pgm.trans_exc_code |= 0x4UL; 942 943 rc = kvm_s390_inject_prog_irq(vcpu, &pgm); 944 return rc ? rc : 1; 945 } 946 947 /* 948 * Handle a fault during vsie execution on a gmap shadow. 949 * 950 * Returns: - 0 if the fault was resolved 951 * - > 0 if control has to be given to guest 2 952 * - < 0 if an error occurred 953 */ 954 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 955 { 956 int rc; 957 958 if ((current->thread.gmap_int_code & PGM_INT_CODE_MASK) == PGM_PROTECTION) 959 /* we can directly forward all protection exceptions */ 960 return inject_fault(vcpu, PGM_PROTECTION, 961 current->thread.gmap_teid.addr * PAGE_SIZE, 1); 962 963 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 964 current->thread.gmap_teid.addr * PAGE_SIZE, NULL); 965 if (rc > 0) { 966 rc = inject_fault(vcpu, rc, 967 current->thread.gmap_teid.addr * PAGE_SIZE, 968 kvm_s390_cur_gmap_fault_is_write()); 969 if (rc >= 0) 970 vsie_page->fault_addr = current->thread.gmap_teid.addr * PAGE_SIZE; 971 } 972 return rc; 973 } 974 975 /* 976 * Retry the previous fault that required guest 2 intervention. This avoids 977 * one superfluous SIE re-entry and direct exit. 978 * 979 * Will ignore any errors. The next SIE fault will do proper fault handling. 980 */ 981 static void handle_last_fault(struct kvm_vcpu *vcpu, 982 struct vsie_page *vsie_page) 983 { 984 if (vsie_page->fault_addr) 985 kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 986 vsie_page->fault_addr, NULL); 987 vsie_page->fault_addr = 0; 988 } 989 990 static inline void clear_vsie_icpt(struct vsie_page *vsie_page) 991 { 992 vsie_page->scb_s.icptcode = 0; 993 } 994 995 /* rewind the psw and clear the vsie icpt, so we can retry execution */ 996 static void retry_vsie_icpt(struct vsie_page *vsie_page) 997 { 998 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 999 int ilen = insn_length(scb_s->ipa >> 8); 1000 1001 /* take care of EXECUTE instructions */ 1002 if (scb_s->icptstatus & 1) { 1003 ilen = (scb_s->icptstatus >> 4) & 0x6; 1004 if (!ilen) 1005 ilen = 4; 1006 } 1007 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); 1008 clear_vsie_icpt(vsie_page); 1009 } 1010 1011 /* 1012 * Try to shadow + enable the guest 2 provided facility list. 1013 * Retry instruction execution if enabled for and provided by guest 2. 1014 * 1015 * Returns: - 0 if handled (retry or guest 2 icpt) 1016 * - > 0 if control has to be given to guest 2 1017 */ 1018 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1019 { 1020 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1021 __u32 fac = READ_ONCE(vsie_page->scb_o->fac); 1022 1023 /* 1024 * Alternate-STFLE-Interpretive-Execution facilities are not supported 1025 * -> format-0 flcb 1026 */ 1027 if (fac && test_kvm_facility(vcpu->kvm, 7)) { 1028 retry_vsie_icpt(vsie_page); 1029 /* 1030 * The facility list origin (FLO) is in bits 1 - 28 of the FLD 1031 * so we need to mask here before reading. 1032 */ 1033 fac = fac & 0x7ffffff8U; 1034 /* 1035 * format-0 -> size of nested guest's facility list == guest's size 1036 * guest's size == host's size, since STFLE is interpretatively executed 1037 * using a format-0 for the guest, too. 1038 */ 1039 if (read_guest_real(vcpu, fac, &vsie_page->fac, 1040 stfle_size() * sizeof(u64))) 1041 return set_validity_icpt(scb_s, 0x1090U); 1042 scb_s->fac = (u32)virt_to_phys(&vsie_page->fac); 1043 } 1044 return 0; 1045 } 1046 1047 /* 1048 * Get a register for a nested guest. 1049 * @vcpu the vcpu of the guest 1050 * @vsie_page the vsie_page for the nested guest 1051 * @reg the register number, the upper 4 bits are ignored. 1052 * returns: the value of the register. 1053 */ 1054 static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) 1055 { 1056 /* no need to validate the parameter and/or perform error handling */ 1057 reg &= 0xf; 1058 switch (reg) { 1059 case 15: 1060 return vsie_page->scb_s.gg15; 1061 case 14: 1062 return vsie_page->scb_s.gg14; 1063 default: 1064 return vcpu->run->s.regs.gprs[reg]; 1065 } 1066 } 1067 1068 static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1069 { 1070 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1071 unsigned long pei_dest, pei_src, src, dest, mask, prefix; 1072 u64 *pei_block = &vsie_page->scb_o->mcic; 1073 int edat, rc_dest, rc_src; 1074 union ctlreg0 cr0; 1075 1076 cr0.val = vcpu->arch.sie_block->gcr[0]; 1077 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1078 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK); 1079 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 1080 1081 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; 1082 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso; 1083 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; 1084 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso; 1085 1086 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest); 1087 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src); 1088 /* 1089 * Either everything went well, or something non-critical went wrong 1090 * e.g. because of a race. In either case, simply retry. 1091 */ 1092 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { 1093 retry_vsie_icpt(vsie_page); 1094 return -EAGAIN; 1095 } 1096 /* Something more serious went wrong, propagate the error */ 1097 if (rc_dest < 0) 1098 return rc_dest; 1099 if (rc_src < 0) 1100 return rc_src; 1101 1102 /* The only possible suppressing exception: just deliver it */ 1103 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) { 1104 clear_vsie_icpt(vsie_page); 1105 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC); 1106 WARN_ON_ONCE(rc_dest); 1107 return 1; 1108 } 1109 1110 /* 1111 * Forward the PEI intercept to the guest if it was a page fault, or 1112 * also for segment and region table faults if EDAT applies. 1113 */ 1114 if (edat) { 1115 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0; 1116 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0; 1117 } else { 1118 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0; 1119 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0; 1120 } 1121 if (!rc_dest && !rc_src) { 1122 pei_block[0] = pei_dest; 1123 pei_block[1] = pei_src; 1124 return 1; 1125 } 1126 1127 retry_vsie_icpt(vsie_page); 1128 1129 /* 1130 * The host has edat, and the guest does not, or it was an ASCE type 1131 * exception. The host needs to inject the appropriate DAT interrupts 1132 * into the guest. 1133 */ 1134 if (rc_dest) 1135 return inject_fault(vcpu, rc_dest, dest, 1); 1136 return inject_fault(vcpu, rc_src, src, 0); 1137 } 1138 1139 /* 1140 * Run the vsie on a shadow scb and a shadow gmap, without any further 1141 * sanity checks, handling SIE faults. 1142 * 1143 * Returns: - 0 everything went fine 1144 * - > 0 if control has to be given to guest 2 1145 * - < 0 if an error occurred 1146 */ 1147 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1148 __releases(vcpu->kvm->srcu) 1149 __acquires(vcpu->kvm->srcu) 1150 { 1151 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1152 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 1153 int guest_bp_isolation; 1154 int rc = 0; 1155 1156 handle_last_fault(vcpu, vsie_page); 1157 1158 kvm_vcpu_srcu_read_unlock(vcpu); 1159 1160 /* save current guest state of bp isolation override */ 1161 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1162 1163 /* 1164 * The guest is running with BPBC, so we have to force it on for our 1165 * nested guest. This is done by enabling BPBC globally, so the BPBC 1166 * control in the SCB (which the nested guest can modify) is simply 1167 * ignored. 1168 */ 1169 if (test_kvm_facility(vcpu->kvm, 82) && 1170 vcpu->arch.sie_block->fpf & FPF_BPBC) 1171 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1172 1173 /* 1174 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1175 * and VCPU requests also hinder the vSIE from running and lead 1176 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1177 * also kick the vSIE. 1178 */ 1179 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1180 current->thread.gmap_int_code = 0; 1181 barrier(); 1182 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) { 1183 local_irq_disable(); 1184 guest_timing_enter_irqoff(); 1185 rc = kvm_s390_enter_exit_sie(scb_s, vcpu->run->s.regs.gprs, vsie_page->gmap->asce); 1186 guest_timing_exit_irqoff(); 1187 local_irq_enable(); 1188 } 1189 barrier(); 1190 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1191 1192 /* restore guest state for bp isolation override */ 1193 if (!guest_bp_isolation) 1194 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1195 1196 kvm_vcpu_srcu_read_lock(vcpu); 1197 1198 if (rc == -EINTR) { 1199 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1200 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1201 return 0; 1202 } 1203 1204 if (rc > 0) 1205 rc = 0; /* we could still have an icpt */ 1206 else if (current->thread.gmap_int_code) 1207 return handle_fault(vcpu, vsie_page); 1208 1209 switch (scb_s->icptcode) { 1210 case ICPT_INST: 1211 if (scb_s->ipa == 0xb2b0) 1212 rc = handle_stfle(vcpu, vsie_page); 1213 break; 1214 case ICPT_STOP: 1215 /* stop not requested by g2 - must have been a kick */ 1216 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1217 clear_vsie_icpt(vsie_page); 1218 break; 1219 case ICPT_VALIDITY: 1220 if ((scb_s->ipa & 0xf000) != 0xf000) 1221 scb_s->ipa += 0x1000; 1222 break; 1223 case ICPT_PARTEXEC: 1224 if (scb_s->ipa == 0xb254) 1225 rc = vsie_handle_mvpg(vcpu, vsie_page); 1226 break; 1227 } 1228 return rc; 1229 } 1230 1231 static void release_gmap_shadow(struct vsie_page *vsie_page) 1232 { 1233 if (vsie_page->gmap) 1234 gmap_put(vsie_page->gmap); 1235 WRITE_ONCE(vsie_page->gmap, NULL); 1236 prefix_unmapped(vsie_page); 1237 } 1238 1239 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1240 struct vsie_page *vsie_page) 1241 { 1242 unsigned long asce; 1243 union ctlreg0 cr0; 1244 struct gmap *gmap; 1245 int edat; 1246 1247 asce = vcpu->arch.sie_block->gcr[1]; 1248 cr0.val = vcpu->arch.sie_block->gcr[0]; 1249 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1250 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1251 1252 /* 1253 * ASCE or EDAT could have changed since last icpt, or the gmap 1254 * we're holding has been unshadowed. If the gmap is still valid, 1255 * we can safely reuse it. 1256 */ 1257 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) { 1258 vcpu->kvm->stat.gmap_shadow_reuse++; 1259 return 0; 1260 } 1261 1262 /* release the old shadow - if any, and mark the prefix as unmapped */ 1263 release_gmap_shadow(vsie_page); 1264 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1265 if (IS_ERR(gmap)) 1266 return PTR_ERR(gmap); 1267 vcpu->kvm->stat.gmap_shadow_create++; 1268 WRITE_ONCE(vsie_page->gmap, gmap); 1269 return 0; 1270 } 1271 1272 /* 1273 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1274 */ 1275 static void register_shadow_scb(struct kvm_vcpu *vcpu, 1276 struct vsie_page *vsie_page) 1277 { 1278 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1279 1280 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1281 /* 1282 * External calls have to lead to a kick of the vcpu and 1283 * therefore the vsie -> Simulate Wait state. 1284 */ 1285 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1286 /* 1287 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1288 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1289 */ 1290 preempt_disable(); 1291 scb_s->epoch += vcpu->kvm->arch.epoch; 1292 1293 if (scb_s->ecd & ECD_MEF) { 1294 scb_s->epdx += vcpu->kvm->arch.epdx; 1295 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1296 scb_s->epdx += 1; 1297 } 1298 1299 preempt_enable(); 1300 } 1301 1302 /* 1303 * Unregister a shadow scb from a VCPU. 1304 */ 1305 static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1306 { 1307 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1308 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1309 } 1310 1311 /* 1312 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1313 * prefix pages and faults. 1314 * 1315 * Returns: - 0 if no errors occurred 1316 * - > 0 if control has to be given to guest 2 1317 * - -ENOMEM if out of memory 1318 */ 1319 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1320 { 1321 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1322 int rc = 0; 1323 1324 while (1) { 1325 rc = acquire_gmap_shadow(vcpu, vsie_page); 1326 if (!rc) 1327 rc = map_prefix(vcpu, vsie_page); 1328 if (!rc) { 1329 update_intervention_requests(vsie_page); 1330 rc = do_vsie_run(vcpu, vsie_page); 1331 } 1332 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1333 1334 if (rc == -EAGAIN) 1335 rc = 0; 1336 1337 /* 1338 * Exit the loop if the guest needs to process the intercept 1339 */ 1340 if (rc || scb_s->icptcode) 1341 break; 1342 1343 /* 1344 * Exit the loop if the host needs to process an intercept, 1345 * but rewind the PSW to re-enter SIE once that's completed 1346 * instead of passing a "no action" intercept to the guest. 1347 */ 1348 if (signal_pending(current) || 1349 kvm_s390_vcpu_has_irq(vcpu, 0) || 1350 kvm_s390_vcpu_sie_inhibited(vcpu)) { 1351 kvm_s390_rewind_psw(vcpu, 4); 1352 break; 1353 } 1354 cond_resched(); 1355 } 1356 1357 if (rc == -EFAULT) { 1358 /* 1359 * Addressing exceptions are always presentes as intercepts. 1360 * As addressing exceptions are suppressing and our guest 3 PSW 1361 * points at the responsible instruction, we have to 1362 * forward the PSW and set the ilc. If we can't read guest 3 1363 * instruction, we can use an arbitrary ilc. Let's always use 1364 * ilen = 4 for now, so we can avoid reading in guest 3 virtual 1365 * memory. (we could also fake the shadow so the hardware 1366 * handles it). 1367 */ 1368 scb_s->icptcode = ICPT_PROGI; 1369 scb_s->iprcc = PGM_ADDRESSING; 1370 scb_s->pgmilc = 4; 1371 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); 1372 rc = 1; 1373 } 1374 return rc; 1375 } 1376 1377 /* Try getting a given vsie page, returning "true" on success. */ 1378 static inline bool try_get_vsie_page(struct vsie_page *vsie_page) 1379 { 1380 if (test_bit(VSIE_PAGE_IN_USE, &vsie_page->flags)) 1381 return false; 1382 return !test_and_set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); 1383 } 1384 1385 /* Put a vsie page acquired through get_vsie_page / try_get_vsie_page. */ 1386 static void put_vsie_page(struct vsie_page *vsie_page) 1387 { 1388 clear_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); 1389 } 1390 1391 /* 1392 * Get or create a vsie page for a scb address. 1393 * 1394 * Returns: - address of a vsie page (cached or new one) 1395 * - NULL if the same scb address is already used by another VCPU 1396 * - ERR_PTR(-ENOMEM) if out of memory 1397 */ 1398 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1399 { 1400 struct vsie_page *vsie_page; 1401 int nr_vcpus; 1402 1403 rcu_read_lock(); 1404 vsie_page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1405 rcu_read_unlock(); 1406 if (vsie_page) { 1407 if (try_get_vsie_page(vsie_page)) { 1408 if (vsie_page->scb_gpa == addr) 1409 return vsie_page; 1410 /* 1411 * We raced with someone reusing + putting this vsie 1412 * page before we grabbed it. 1413 */ 1414 put_vsie_page(vsie_page); 1415 } 1416 } 1417 1418 /* 1419 * We want at least #online_vcpus shadows, so every VCPU can execute 1420 * the VSIE in parallel. 1421 */ 1422 nr_vcpus = atomic_read(&kvm->online_vcpus); 1423 1424 mutex_lock(&kvm->arch.vsie.mutex); 1425 if (kvm->arch.vsie.page_count < nr_vcpus) { 1426 vsie_page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); 1427 if (!vsie_page) { 1428 mutex_unlock(&kvm->arch.vsie.mutex); 1429 return ERR_PTR(-ENOMEM); 1430 } 1431 __set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags); 1432 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = vsie_page; 1433 kvm->arch.vsie.page_count++; 1434 } else { 1435 /* reuse an existing entry that belongs to nobody */ 1436 while (true) { 1437 vsie_page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1438 if (try_get_vsie_page(vsie_page)) 1439 break; 1440 kvm->arch.vsie.next++; 1441 kvm->arch.vsie.next %= nr_vcpus; 1442 } 1443 if (vsie_page->scb_gpa != ULONG_MAX) 1444 radix_tree_delete(&kvm->arch.vsie.addr_to_page, 1445 vsie_page->scb_gpa >> 9); 1446 } 1447 /* Mark it as invalid until it resides in the tree. */ 1448 vsie_page->scb_gpa = ULONG_MAX; 1449 1450 /* Double use of the same address or allocation failure. */ 1451 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, 1452 vsie_page)) { 1453 put_vsie_page(vsie_page); 1454 mutex_unlock(&kvm->arch.vsie.mutex); 1455 return NULL; 1456 } 1457 vsie_page->scb_gpa = addr; 1458 mutex_unlock(&kvm->arch.vsie.mutex); 1459 1460 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1461 release_gmap_shadow(vsie_page); 1462 vsie_page->fault_addr = 0; 1463 vsie_page->scb_s.ihcpu = 0xffffU; 1464 return vsie_page; 1465 } 1466 1467 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1468 { 1469 struct vsie_page *vsie_page; 1470 unsigned long scb_addr; 1471 int rc; 1472 1473 vcpu->stat.instruction_sie++; 1474 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1475 return -EOPNOTSUPP; 1476 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1477 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1478 1479 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1480 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1481 1482 /* 512 byte alignment */ 1483 if (unlikely(scb_addr & 0x1ffUL)) 1484 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1485 1486 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1487 kvm_s390_vcpu_sie_inhibited(vcpu)) { 1488 kvm_s390_rewind_psw(vcpu, 4); 1489 return 0; 1490 } 1491 1492 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1493 if (IS_ERR(vsie_page)) 1494 return PTR_ERR(vsie_page); 1495 else if (!vsie_page) 1496 /* double use of sie control block - simply do nothing */ 1497 return 0; 1498 1499 rc = pin_scb(vcpu, vsie_page, scb_addr); 1500 if (rc) 1501 goto out_put; 1502 rc = shadow_scb(vcpu, vsie_page); 1503 if (rc) 1504 goto out_unpin_scb; 1505 rc = pin_blocks(vcpu, vsie_page); 1506 if (rc) 1507 goto out_unshadow; 1508 register_shadow_scb(vcpu, vsie_page); 1509 rc = vsie_run(vcpu, vsie_page); 1510 unregister_shadow_scb(vcpu); 1511 unpin_blocks(vcpu, vsie_page); 1512 out_unshadow: 1513 unshadow_scb(vcpu, vsie_page); 1514 out_unpin_scb: 1515 unpin_scb(vcpu, vsie_page, scb_addr); 1516 out_put: 1517 put_vsie_page(vsie_page); 1518 1519 return rc < 0 ? rc : 0; 1520 } 1521 1522 /* Init the vsie data structures. To be called when a vm is initialized. */ 1523 void kvm_s390_vsie_init(struct kvm *kvm) 1524 { 1525 mutex_init(&kvm->arch.vsie.mutex); 1526 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT); 1527 } 1528 1529 /* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1530 void kvm_s390_vsie_destroy(struct kvm *kvm) 1531 { 1532 struct vsie_page *vsie_page; 1533 int i; 1534 1535 mutex_lock(&kvm->arch.vsie.mutex); 1536 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1537 vsie_page = kvm->arch.vsie.pages[i]; 1538 kvm->arch.vsie.pages[i] = NULL; 1539 release_gmap_shadow(vsie_page); 1540 /* free the radix tree entry */ 1541 if (vsie_page->scb_gpa != ULONG_MAX) 1542 radix_tree_delete(&kvm->arch.vsie.addr_to_page, 1543 vsie_page->scb_gpa >> 9); 1544 free_page((unsigned long)vsie_page); 1545 } 1546 kvm->arch.vsie.page_count = 0; 1547 mutex_unlock(&kvm->arch.vsie.mutex); 1548 } 1549 1550 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1551 { 1552 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1553 1554 /* 1555 * Even if the VCPU lets go of the shadow sie block reference, it is 1556 * still valid in the cache. So we can safely kick it. 1557 */ 1558 if (scb) { 1559 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1560 if (scb->prog0c & PROG_IN_SIE) 1561 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1562 } 1563 } 1564