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