1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * kvm nested virtualization support for s390x 4 * 5 * Copyright IBM Corp. 2016, 2018 6 * 7 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com> 8 */ 9 #include <linux/vmalloc.h> 10 #include <linux/kvm_host.h> 11 #include <linux/bug.h> 12 #include <linux/list.h> 13 #include <linux/bitmap.h> 14 #include <linux/sched/signal.h> 15 16 #include <asm/gmap.h> 17 #include <asm/mmu_context.h> 18 #include <asm/sclp.h> 19 #include <asm/nmi.h> 20 #include <asm/dis.h> 21 #include <asm/fpu/api.h> 22 #include "kvm-s390.h" 23 #include "gaccess.h" 24 25 struct vsie_page { 26 struct kvm_s390_sie_block scb_s; /* 0x0000 */ 27 /* 28 * the backup info for machine check. ensure it's at 29 * the same offset as that in struct sie_page! 30 */ 31 struct mcck_volatile_info mcck_info; /* 0x0200 */ 32 /* 33 * The pinned original scb. Be aware that other VCPUs can modify 34 * it while we read from it. Values that are used for conditions or 35 * are reused conditionally, should be accessed via READ_ONCE. 36 */ 37 struct kvm_s390_sie_block *scb_o; /* 0x0218 */ 38 /* the shadow gmap in use by the vsie_page */ 39 struct gmap *gmap; /* 0x0220 */ 40 /* address of the last reported fault to guest2 */ 41 unsigned long fault_addr; /* 0x0228 */ 42 /* calculated guest addresses of satellite control blocks */ 43 gpa_t sca_gpa; /* 0x0230 */ 44 gpa_t itdba_gpa; /* 0x0238 */ 45 gpa_t gvrd_gpa; /* 0x0240 */ 46 gpa_t riccbd_gpa; /* 0x0248 */ 47 gpa_t sdnx_gpa; /* 0x0250 */ 48 __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */ 49 struct kvm_s390_crypto_cb crycb; /* 0x0700 */ 50 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ 51 }; 52 53 /* trigger a validity icpt for the given scb */ 54 static int set_validity_icpt(struct kvm_s390_sie_block *scb, 55 __u16 reason_code) 56 { 57 scb->ipa = 0x1000; 58 scb->ipb = ((__u32) reason_code) << 16; 59 scb->icptcode = ICPT_VALIDITY; 60 return 1; 61 } 62 63 /* mark the prefix as unmapped, this will block the VSIE */ 64 static void prefix_unmapped(struct vsie_page *vsie_page) 65 { 66 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20); 67 } 68 69 /* mark the prefix as unmapped and wait until the VSIE has been left */ 70 static void prefix_unmapped_sync(struct vsie_page *vsie_page) 71 { 72 prefix_unmapped(vsie_page); 73 if (vsie_page->scb_s.prog0c & PROG_IN_SIE) 74 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags); 75 while (vsie_page->scb_s.prog0c & PROG_IN_SIE) 76 cpu_relax(); 77 } 78 79 /* mark the prefix as mapped, this will allow the VSIE to run */ 80 static void prefix_mapped(struct vsie_page *vsie_page) 81 { 82 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20); 83 } 84 85 /* test if the prefix is mapped into the gmap shadow */ 86 static int prefix_is_mapped(struct vsie_page *vsie_page) 87 { 88 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST); 89 } 90 91 /* copy the updated intervention request bits into the shadow scb */ 92 static void update_intervention_requests(struct vsie_page *vsie_page) 93 { 94 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT; 95 int cpuflags; 96 97 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags); 98 atomic_andnot(bits, &vsie_page->scb_s.cpuflags); 99 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags); 100 } 101 102 /* shadow (filter and validate) the cpuflags */ 103 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 104 { 105 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 106 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 107 int newflags, cpuflags = atomic_read(&scb_o->cpuflags); 108 109 /* we don't allow ESA/390 guests */ 110 if (!(cpuflags & CPUSTAT_ZARCH)) 111 return set_validity_icpt(scb_s, 0x0001U); 112 113 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) 114 return set_validity_icpt(scb_s, 0x0001U); 115 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR)) 116 return set_validity_icpt(scb_s, 0x0007U); 117 118 /* intervention requests will be set later */ 119 newflags = CPUSTAT_ZARCH; 120 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8)) 121 newflags |= CPUSTAT_GED; 122 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) { 123 if (cpuflags & CPUSTAT_GED) 124 return set_validity_icpt(scb_s, 0x0001U); 125 newflags |= CPUSTAT_GED2; 126 } 127 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE)) 128 newflags |= cpuflags & CPUSTAT_P; 129 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS)) 130 newflags |= cpuflags & CPUSTAT_SM; 131 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) 132 newflags |= cpuflags & CPUSTAT_IBS; 133 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) 134 newflags |= cpuflags & CPUSTAT_KSS; 135 136 atomic_set(&scb_s->cpuflags, newflags); 137 return 0; 138 } 139 /* Copy to APCB FORMAT1 from APCB FORMAT0 */ 140 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s, 141 unsigned long crycb_gpa, struct kvm_s390_apcb1 *apcb_h) 142 { 143 struct kvm_s390_apcb0 tmp; 144 unsigned long apcb_gpa; 145 146 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 147 148 if (read_guest_real(vcpu, apcb_gpa, &tmp, 149 sizeof(struct kvm_s390_apcb0))) 150 return -EFAULT; 151 152 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; 153 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; 154 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; 155 156 return 0; 157 158 } 159 160 /** 161 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 162 * @vcpu: pointer to the virtual CPU 163 * @apcb_s: pointer to start of apcb in the shadow crycb 164 * @crycb_gpa: guest physical address to start of original guest crycb 165 * @apcb_h: pointer to start of apcb in the guest1 166 * 167 * Returns 0 and -EFAULT on error reading guest apcb 168 */ 169 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 170 unsigned long crycb_gpa, unsigned long *apcb_h) 171 { 172 unsigned long apcb_gpa; 173 174 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb0); 175 176 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 177 sizeof(struct kvm_s390_apcb0))) 178 return -EFAULT; 179 180 bitmap_and(apcb_s, apcb_s, apcb_h, 181 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb0)); 182 183 return 0; 184 } 185 186 /** 187 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB 188 * @vcpu: pointer to the virtual CPU 189 * @apcb_s: pointer to start of apcb in the shadow crycb 190 * @crycb_gpa: guest physical address to start of original guest crycb 191 * @apcb_h: pointer to start of apcb in the host 192 * 193 * Returns 0 and -EFAULT on error reading guest apcb 194 */ 195 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 196 unsigned long crycb_gpa, 197 unsigned long *apcb_h) 198 { 199 unsigned long apcb_gpa; 200 201 apcb_gpa = crycb_gpa + offsetof(struct kvm_s390_crypto_cb, apcb1); 202 203 if (read_guest_real(vcpu, apcb_gpa, apcb_s, 204 sizeof(struct kvm_s390_apcb1))) 205 return -EFAULT; 206 207 bitmap_and(apcb_s, apcb_s, apcb_h, 208 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb1)); 209 210 return 0; 211 } 212 213 /** 214 * setup_apcb - Create a shadow copy of the apcb. 215 * @vcpu: pointer to the virtual CPU 216 * @crycb_s: pointer to shadow crycb 217 * @crycb_gpa: guest physical address of original guest crycb 218 * @crycb_h: pointer to the host crycb 219 * @fmt_o: format of the original guest crycb. 220 * @fmt_h: format of the host crycb. 221 * 222 * Checks the compatibility between the guest and host crycb and calls the 223 * appropriate copy function. 224 * 225 * Return 0 or an error number if the guest and host crycb are incompatible. 226 */ 227 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 228 const u32 crycb_gpa, 229 struct kvm_s390_crypto_cb *crycb_h, 230 int fmt_o, int fmt_h) 231 { 232 switch (fmt_o) { 233 case CRYCB_FORMAT2: 234 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 256) & PAGE_MASK)) 235 return -EACCES; 236 if (fmt_h != CRYCB_FORMAT2) 237 return -EINVAL; 238 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 239 crycb_gpa, 240 (unsigned long *)&crycb_h->apcb1); 241 case CRYCB_FORMAT1: 242 switch (fmt_h) { 243 case CRYCB_FORMAT2: 244 return setup_apcb10(vcpu, &crycb_s->apcb1, 245 crycb_gpa, 246 &crycb_h->apcb1); 247 case CRYCB_FORMAT1: 248 return setup_apcb00(vcpu, 249 (unsigned long *) &crycb_s->apcb0, 250 crycb_gpa, 251 (unsigned long *) &crycb_h->apcb0); 252 } 253 break; 254 case CRYCB_FORMAT0: 255 if ((crycb_gpa & PAGE_MASK) != ((crycb_gpa + 32) & PAGE_MASK)) 256 return -EACCES; 257 258 switch (fmt_h) { 259 case CRYCB_FORMAT2: 260 return setup_apcb10(vcpu, &crycb_s->apcb1, 261 crycb_gpa, 262 &crycb_h->apcb1); 263 case CRYCB_FORMAT1: 264 case CRYCB_FORMAT0: 265 return setup_apcb00(vcpu, 266 (unsigned long *) &crycb_s->apcb0, 267 crycb_gpa, 268 (unsigned long *) &crycb_h->apcb0); 269 } 270 } 271 return -EINVAL; 272 } 273 274 /** 275 * shadow_crycb - Create a shadow copy of the crycb block 276 * @vcpu: a pointer to the virtual CPU 277 * @vsie_page: a pointer to internal date used for the vSIE 278 * 279 * Create a shadow copy of the crycb block and setup key wrapping, if 280 * requested for guest 3 and enabled for guest 2. 281 * 282 * We accept format-1 or format-2, but we convert format-1 into format-2 283 * in the shadow CRYCB. 284 * Using format-2 enables the firmware to choose the right format when 285 * scheduling the SIE. 286 * There is nothing to do for format-0. 287 * 288 * This function centralize the issuing of set_validity_icpt() for all 289 * the subfunctions working on the crycb. 290 * 291 * Returns: - 0 if shadowed or nothing to do 292 * - > 0 if control has to be given to guest 2 293 */ 294 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 295 { 296 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 297 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 298 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 299 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 300 unsigned long *b1, *b2; 301 u8 ecb3_flags; 302 u32 ecd_flags; 303 int apie_h; 304 int apie_s; 305 int key_msk = test_kvm_facility(vcpu->kvm, 76); 306 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 307 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 308 int ret = 0; 309 310 scb_s->crycbd = 0; 311 312 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 313 apie_s = apie_h & scb_o->eca; 314 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 315 return 0; 316 317 if (!crycb_addr) 318 return set_validity_icpt(scb_s, 0x0039U); 319 320 if (fmt_o == CRYCB_FORMAT1) 321 if ((crycb_addr & PAGE_MASK) != 322 ((crycb_addr + 128) & PAGE_MASK)) 323 return set_validity_icpt(scb_s, 0x003CU); 324 325 if (apie_s) { 326 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 327 vcpu->kvm->arch.crypto.crycb, 328 fmt_o, fmt_h); 329 if (ret) 330 goto end; 331 scb_s->eca |= scb_o->eca & ECA_APIE; 332 } 333 334 /* we may only allow it if enabled for guest 2 */ 335 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 336 (ECB3_AES | ECB3_DEA); 337 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; 338 if (!ecb3_flags && !ecd_flags) 339 goto end; 340 341 /* copy only the wrapping keys */ 342 if (read_guest_real(vcpu, crycb_addr + 72, 343 vsie_page->crycb.dea_wrapping_key_mask, 56)) 344 return set_validity_icpt(scb_s, 0x0035U); 345 346 scb_s->ecb3 |= ecb3_flags; 347 scb_s->ecd |= ecd_flags; 348 349 /* xor both blocks in one run */ 350 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 351 b2 = (unsigned long *) 352 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 353 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 354 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 355 end: 356 switch (ret) { 357 case -EINVAL: 358 return set_validity_icpt(scb_s, 0x0022U); 359 case -EFAULT: 360 return set_validity_icpt(scb_s, 0x0035U); 361 case -EACCES: 362 return set_validity_icpt(scb_s, 0x003CU); 363 } 364 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; 365 return 0; 366 } 367 368 /* shadow (round up/down) the ibc to avoid validity icpt */ 369 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 370 { 371 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 372 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 373 /* READ_ONCE does not work on bitfields - use a temporary variable */ 374 const uint32_t __new_ibc = scb_o->ibc; 375 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 376 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 377 378 scb_s->ibc = 0; 379 /* ibc installed in g2 and requested for g3 */ 380 if (vcpu->kvm->arch.model.ibc && new_ibc) { 381 scb_s->ibc = new_ibc; 382 /* takte care of the minimum ibc level of the machine */ 383 if (scb_s->ibc < min_ibc) 384 scb_s->ibc = min_ibc; 385 /* take care of the maximum ibc level set for the guest */ 386 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 387 scb_s->ibc = vcpu->kvm->arch.model.ibc; 388 } 389 } 390 391 /* unshadow the scb, copying parameters back to the real scb */ 392 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 393 { 394 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 395 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 396 397 /* interception */ 398 scb_o->icptcode = scb_s->icptcode; 399 scb_o->icptstatus = scb_s->icptstatus; 400 scb_o->ipa = scb_s->ipa; 401 scb_o->ipb = scb_s->ipb; 402 scb_o->gbea = scb_s->gbea; 403 404 /* timer */ 405 scb_o->cputm = scb_s->cputm; 406 scb_o->ckc = scb_s->ckc; 407 scb_o->todpr = scb_s->todpr; 408 409 /* guest state */ 410 scb_o->gpsw = scb_s->gpsw; 411 scb_o->gg14 = scb_s->gg14; 412 scb_o->gg15 = scb_s->gg15; 413 memcpy(scb_o->gcr, scb_s->gcr, 128); 414 scb_o->pp = scb_s->pp; 415 416 /* branch prediction */ 417 if (test_kvm_facility(vcpu->kvm, 82)) { 418 scb_o->fpf &= ~FPF_BPBC; 419 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 420 } 421 422 /* interrupt intercept */ 423 switch (scb_s->icptcode) { 424 case ICPT_PROGI: 425 case ICPT_INSTPROGI: 426 case ICPT_EXTINT: 427 memcpy((void *)((u64)scb_o + 0xc0), 428 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 429 break; 430 } 431 432 if (scb_s->ihcpu != 0xffffU) 433 scb_o->ihcpu = scb_s->ihcpu; 434 } 435 436 /* 437 * Setup the shadow scb by copying and checking the relevant parts of the g2 438 * provided scb. 439 * 440 * Returns: - 0 if the scb has been shadowed 441 * - > 0 if control has to be given to guest 2 442 */ 443 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 444 { 445 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 446 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 447 /* READ_ONCE does not work on bitfields - use a temporary variable */ 448 const uint32_t __new_prefix = scb_o->prefix; 449 const uint32_t new_prefix = READ_ONCE(__new_prefix); 450 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 451 bool had_tx = scb_s->ecb & ECB_TE; 452 unsigned long new_mso = 0; 453 int rc; 454 455 /* make sure we don't have any leftovers when reusing the scb */ 456 scb_s->icptcode = 0; 457 scb_s->eca = 0; 458 scb_s->ecb = 0; 459 scb_s->ecb2 = 0; 460 scb_s->ecb3 = 0; 461 scb_s->ecd = 0; 462 scb_s->fac = 0; 463 scb_s->fpf = 0; 464 465 rc = prepare_cpuflags(vcpu, vsie_page); 466 if (rc) 467 goto out; 468 469 /* timer */ 470 scb_s->cputm = scb_o->cputm; 471 scb_s->ckc = scb_o->ckc; 472 scb_s->todpr = scb_o->todpr; 473 scb_s->epoch = scb_o->epoch; 474 475 /* guest state */ 476 scb_s->gpsw = scb_o->gpsw; 477 scb_s->gg14 = scb_o->gg14; 478 scb_s->gg15 = scb_o->gg15; 479 memcpy(scb_s->gcr, scb_o->gcr, 128); 480 scb_s->pp = scb_o->pp; 481 482 /* interception / execution handling */ 483 scb_s->gbea = scb_o->gbea; 484 scb_s->lctl = scb_o->lctl; 485 scb_s->svcc = scb_o->svcc; 486 scb_s->ictl = scb_o->ictl; 487 /* 488 * SKEY handling functions can't deal with false setting of PTE invalid 489 * bits. Therefore we cannot provide interpretation and would later 490 * have to provide own emulation handlers. 491 */ 492 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 493 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 494 495 scb_s->icpua = scb_o->icpua; 496 497 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 498 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 499 /* if the hva of the prefix changes, we have to remap the prefix */ 500 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 501 prefix_unmapped(vsie_page); 502 /* SIE will do mso/msl validity and exception checks for us */ 503 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 504 scb_s->mso = new_mso; 505 scb_s->prefix = new_prefix; 506 507 /* We have to definitely flush the tlb if this scb never ran */ 508 if (scb_s->ihcpu != 0xffffU) 509 scb_s->ihcpu = scb_o->ihcpu; 510 511 /* MVPG and Protection Exception Interpretation are always available */ 512 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 513 /* Host-protection-interruption introduced with ESOP */ 514 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 515 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 516 /* 517 * CPU Topology 518 * This facility only uses the utility field of the SCA and none of 519 * the cpu entries that are problematic with the other interpretation 520 * facilities so we can pass it through 521 */ 522 if (test_kvm_facility(vcpu->kvm, 11)) 523 scb_s->ecb |= scb_o->ecb & ECB_PTF; 524 /* transactional execution */ 525 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 526 /* remap the prefix is tx is toggled on */ 527 if (!had_tx) 528 prefix_unmapped(vsie_page); 529 scb_s->ecb |= ECB_TE; 530 } 531 /* specification exception interpretation */ 532 scb_s->ecb |= scb_o->ecb & ECB_SPECI; 533 /* branch prediction */ 534 if (test_kvm_facility(vcpu->kvm, 82)) 535 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 536 /* SIMD */ 537 if (test_kvm_facility(vcpu->kvm, 129)) { 538 scb_s->eca |= scb_o->eca & ECA_VX; 539 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 540 } 541 /* Run-time-Instrumentation */ 542 if (test_kvm_facility(vcpu->kvm, 64)) 543 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 544 /* Instruction Execution Prevention */ 545 if (test_kvm_facility(vcpu->kvm, 130)) 546 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 547 /* Guarded Storage */ 548 if (test_kvm_facility(vcpu->kvm, 133)) { 549 scb_s->ecb |= scb_o->ecb & ECB_GS; 550 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 551 } 552 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 553 scb_s->eca |= scb_o->eca & ECA_SII; 554 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 555 scb_s->eca |= scb_o->eca & ECA_IB; 556 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 557 scb_s->eca |= scb_o->eca & ECA_CEI; 558 /* Epoch Extension */ 559 if (test_kvm_facility(vcpu->kvm, 139)) { 560 scb_s->ecd |= scb_o->ecd & ECD_MEF; 561 scb_s->epdx = scb_o->epdx; 562 } 563 564 /* etoken */ 565 if (test_kvm_facility(vcpu->kvm, 156)) 566 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 567 568 scb_s->hpid = HPID_VSIE; 569 scb_s->cpnc = scb_o->cpnc; 570 571 prepare_ibc(vcpu, vsie_page); 572 rc = shadow_crycb(vcpu, vsie_page); 573 out: 574 if (rc) 575 unshadow_scb(vcpu, vsie_page); 576 return rc; 577 } 578 579 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 580 unsigned long end) 581 { 582 struct kvm *kvm = gmap->private; 583 struct vsie_page *cur; 584 unsigned long prefix; 585 struct page *page; 586 int i; 587 588 if (!gmap_is_shadow(gmap)) 589 return; 590 if (start >= 1UL << 31) 591 /* We are only interested in prefix pages */ 592 return; 593 594 /* 595 * Only new shadow blocks are added to the list during runtime, 596 * therefore we can safely reference them all the time. 597 */ 598 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 599 page = READ_ONCE(kvm->arch.vsie.pages[i]); 600 if (!page) 601 continue; 602 cur = page_to_virt(page); 603 if (READ_ONCE(cur->gmap) != gmap) 604 continue; 605 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; 606 /* with mso/msl, the prefix lies at an offset */ 607 prefix += cur->scb_s.mso; 608 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) 609 prefix_unmapped_sync(cur); 610 } 611 } 612 613 /* 614 * Map the first prefix page and if tx is enabled also the second prefix page. 615 * 616 * The prefix will be protected, a gmap notifier will inform about unmaps. 617 * The shadow scb must not be executed until the prefix is remapped, this is 618 * guaranteed by properly handling PROG_REQUEST. 619 * 620 * Returns: - 0 on if successfully mapped or already mapped 621 * - > 0 if control has to be given to guest 2 622 * - -EAGAIN if the caller can retry immediately 623 * - -ENOMEM if out of memory 624 */ 625 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 626 { 627 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 628 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 629 int rc; 630 631 if (prefix_is_mapped(vsie_page)) 632 return 0; 633 634 /* mark it as mapped so we can catch any concurrent unmappers */ 635 prefix_mapped(vsie_page); 636 637 /* with mso/msl, the prefix lies at offset *mso* */ 638 prefix += scb_s->mso; 639 640 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix, NULL); 641 if (!rc && (scb_s->ecb & ECB_TE)) 642 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 643 prefix + PAGE_SIZE, NULL); 644 /* 645 * We don't have to mprotect, we will be called for all unshadows. 646 * SIE will detect if protection applies and trigger a validity. 647 */ 648 if (rc) 649 prefix_unmapped(vsie_page); 650 if (rc > 0 || rc == -EFAULT) 651 rc = set_validity_icpt(scb_s, 0x0037U); 652 return rc; 653 } 654 655 /* 656 * Pin the guest page given by gpa and set hpa to the pinned host address. 657 * Will always be pinned writable. 658 * 659 * Returns: - 0 on success 660 * - -EINVAL if the gpa is not valid guest storage 661 */ 662 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) 663 { 664 struct page *page; 665 666 page = gfn_to_page(kvm, gpa_to_gfn(gpa)); 667 if (is_error_page(page)) 668 return -EINVAL; 669 *hpa = (hpa_t)page_to_phys(page) + (gpa & ~PAGE_MASK); 670 return 0; 671 } 672 673 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ 674 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) 675 { 676 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT); 677 /* mark the page always as dirty for migration */ 678 mark_page_dirty(kvm, gpa_to_gfn(gpa)); 679 } 680 681 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ 682 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 683 { 684 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 685 hpa_t hpa; 686 687 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; 688 if (hpa) { 689 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); 690 vsie_page->sca_gpa = 0; 691 scb_s->scaol = 0; 692 scb_s->scaoh = 0; 693 } 694 695 hpa = scb_s->itdba; 696 if (hpa) { 697 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); 698 vsie_page->itdba_gpa = 0; 699 scb_s->itdba = 0; 700 } 701 702 hpa = scb_s->gvrd; 703 if (hpa) { 704 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); 705 vsie_page->gvrd_gpa = 0; 706 scb_s->gvrd = 0; 707 } 708 709 hpa = scb_s->riccbd; 710 if (hpa) { 711 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); 712 vsie_page->riccbd_gpa = 0; 713 scb_s->riccbd = 0; 714 } 715 716 hpa = scb_s->sdnxo; 717 if (hpa) { 718 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); 719 vsie_page->sdnx_gpa = 0; 720 scb_s->sdnxo = 0; 721 } 722 } 723 724 /* 725 * Instead of shadowing some blocks, we can simply forward them because the 726 * addresses in the scb are 64 bit long. 727 * 728 * This works as long as the data lies in one page. If blocks ever exceed one 729 * page, we have to fall back to shadowing. 730 * 731 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must 732 * therefore not enable any facilities that access these pointers (e.g. SIGPIF). 733 * 734 * Returns: - 0 if all blocks were pinned. 735 * - > 0 if control has to be given to guest 2 736 * - -ENOMEM if out of memory 737 */ 738 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 739 { 740 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 741 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 742 hpa_t hpa; 743 gpa_t gpa; 744 int rc = 0; 745 746 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; 747 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) 748 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; 749 if (gpa) { 750 if (gpa < 2 * PAGE_SIZE) 751 rc = set_validity_icpt(scb_s, 0x0038U); 752 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) 753 rc = set_validity_icpt(scb_s, 0x0011U); 754 else if ((gpa & PAGE_MASK) != 755 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) 756 rc = set_validity_icpt(scb_s, 0x003bU); 757 if (!rc) { 758 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 759 if (rc) 760 rc = set_validity_icpt(scb_s, 0x0034U); 761 } 762 if (rc) 763 goto unpin; 764 vsie_page->sca_gpa = gpa; 765 scb_s->scaoh = (u32)((u64)hpa >> 32); 766 scb_s->scaol = (u32)(u64)hpa; 767 } 768 769 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; 770 if (gpa && (scb_s->ecb & ECB_TE)) { 771 if (gpa < 2 * PAGE_SIZE) { 772 rc = set_validity_icpt(scb_s, 0x0080U); 773 goto unpin; 774 } 775 /* 256 bytes cannot cross page boundaries */ 776 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 777 if (rc) { 778 rc = set_validity_icpt(scb_s, 0x0080U); 779 goto unpin; 780 } 781 vsie_page->itdba_gpa = gpa; 782 scb_s->itdba = hpa; 783 } 784 785 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; 786 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { 787 if (gpa < 2 * PAGE_SIZE) { 788 rc = set_validity_icpt(scb_s, 0x1310U); 789 goto unpin; 790 } 791 /* 792 * 512 bytes vector registers cannot cross page boundaries 793 * if this block gets bigger, we have to shadow it. 794 */ 795 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 796 if (rc) { 797 rc = set_validity_icpt(scb_s, 0x1310U); 798 goto unpin; 799 } 800 vsie_page->gvrd_gpa = gpa; 801 scb_s->gvrd = hpa; 802 } 803 804 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; 805 if (gpa && (scb_s->ecb3 & ECB3_RI)) { 806 if (gpa < 2 * PAGE_SIZE) { 807 rc = set_validity_icpt(scb_s, 0x0043U); 808 goto unpin; 809 } 810 /* 64 bytes cannot cross page boundaries */ 811 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 812 if (rc) { 813 rc = set_validity_icpt(scb_s, 0x0043U); 814 goto unpin; 815 } 816 /* Validity 0x0044 will be checked by SIE */ 817 vsie_page->riccbd_gpa = gpa; 818 scb_s->riccbd = hpa; 819 } 820 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || 821 (scb_s->ecd & ECD_ETOKENF)) { 822 unsigned long sdnxc; 823 824 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; 825 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; 826 if (!gpa || gpa < 2 * PAGE_SIZE) { 827 rc = set_validity_icpt(scb_s, 0x10b0U); 828 goto unpin; 829 } 830 if (sdnxc < 6 || sdnxc > 12) { 831 rc = set_validity_icpt(scb_s, 0x10b1U); 832 goto unpin; 833 } 834 if (gpa & ((1 << sdnxc) - 1)) { 835 rc = set_validity_icpt(scb_s, 0x10b2U); 836 goto unpin; 837 } 838 /* Due to alignment rules (checked above) this cannot 839 * cross page boundaries 840 */ 841 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 842 if (rc) { 843 rc = set_validity_icpt(scb_s, 0x10b0U); 844 goto unpin; 845 } 846 vsie_page->sdnx_gpa = gpa; 847 scb_s->sdnxo = hpa | sdnxc; 848 } 849 return 0; 850 unpin: 851 unpin_blocks(vcpu, vsie_page); 852 return rc; 853 } 854 855 /* unpin the scb provided by guest 2, marking it as dirty */ 856 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 857 gpa_t gpa) 858 { 859 hpa_t hpa = (hpa_t) vsie_page->scb_o; 860 861 if (hpa) 862 unpin_guest_page(vcpu->kvm, gpa, hpa); 863 vsie_page->scb_o = NULL; 864 } 865 866 /* 867 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. 868 * 869 * Returns: - 0 if the scb was pinned. 870 * - > 0 if control has to be given to guest 2 871 */ 872 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 873 gpa_t gpa) 874 { 875 hpa_t hpa; 876 int rc; 877 878 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 879 if (rc) { 880 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 881 WARN_ON_ONCE(rc); 882 return 1; 883 } 884 vsie_page->scb_o = phys_to_virt(hpa); 885 return 0; 886 } 887 888 /* 889 * Inject a fault into guest 2. 890 * 891 * Returns: - > 0 if control has to be given to guest 2 892 * < 0 if an error occurred during injection. 893 */ 894 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, 895 bool write_flag) 896 { 897 struct kvm_s390_pgm_info pgm = { 898 .code = code, 899 .trans_exc_code = 900 /* 0-51: virtual address */ 901 (vaddr & 0xfffffffffffff000UL) | 902 /* 52-53: store / fetch */ 903 (((unsigned int) !write_flag) + 1) << 10, 904 /* 62-63: asce id (always primary == 0) */ 905 .exc_access_id = 0, /* always primary */ 906 .op_access_id = 0, /* not MVPG */ 907 }; 908 int rc; 909 910 if (code == PGM_PROTECTION) 911 pgm.trans_exc_code |= 0x4UL; 912 913 rc = kvm_s390_inject_prog_irq(vcpu, &pgm); 914 return rc ? rc : 1; 915 } 916 917 /* 918 * Handle a fault during vsie execution on a gmap shadow. 919 * 920 * Returns: - 0 if the fault was resolved 921 * - > 0 if control has to be given to guest 2 922 * - < 0 if an error occurred 923 */ 924 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 925 { 926 int rc; 927 928 if (current->thread.gmap_int_code == PGM_PROTECTION) 929 /* we can directly forward all protection exceptions */ 930 return inject_fault(vcpu, PGM_PROTECTION, 931 current->thread.gmap_addr, 1); 932 933 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 934 current->thread.gmap_addr, NULL); 935 if (rc > 0) { 936 rc = inject_fault(vcpu, rc, 937 current->thread.gmap_addr, 938 current->thread.gmap_write_flag); 939 if (rc >= 0) 940 vsie_page->fault_addr = current->thread.gmap_addr; 941 } 942 return rc; 943 } 944 945 /* 946 * Retry the previous fault that required guest 2 intervention. This avoids 947 * one superfluous SIE re-entry and direct exit. 948 * 949 * Will ignore any errors. The next SIE fault will do proper fault handling. 950 */ 951 static void handle_last_fault(struct kvm_vcpu *vcpu, 952 struct vsie_page *vsie_page) 953 { 954 if (vsie_page->fault_addr) 955 kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 956 vsie_page->fault_addr, NULL); 957 vsie_page->fault_addr = 0; 958 } 959 960 static inline void clear_vsie_icpt(struct vsie_page *vsie_page) 961 { 962 vsie_page->scb_s.icptcode = 0; 963 } 964 965 /* rewind the psw and clear the vsie icpt, so we can retry execution */ 966 static void retry_vsie_icpt(struct vsie_page *vsie_page) 967 { 968 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 969 int ilen = insn_length(scb_s->ipa >> 8); 970 971 /* take care of EXECUTE instructions */ 972 if (scb_s->icptstatus & 1) { 973 ilen = (scb_s->icptstatus >> 4) & 0x6; 974 if (!ilen) 975 ilen = 4; 976 } 977 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); 978 clear_vsie_icpt(vsie_page); 979 } 980 981 /* 982 * Try to shadow + enable the guest 2 provided facility list. 983 * Retry instruction execution if enabled for and provided by guest 2. 984 * 985 * Returns: - 0 if handled (retry or guest 2 icpt) 986 * - > 0 if control has to be given to guest 2 987 */ 988 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 989 { 990 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 991 __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; 992 993 if (fac && test_kvm_facility(vcpu->kvm, 7)) { 994 retry_vsie_icpt(vsie_page); 995 if (read_guest_real(vcpu, fac, &vsie_page->fac, 996 sizeof(vsie_page->fac))) 997 return set_validity_icpt(scb_s, 0x1090U); 998 scb_s->fac = (__u32)(__u64) &vsie_page->fac; 999 } 1000 return 0; 1001 } 1002 1003 /* 1004 * Get a register for a nested guest. 1005 * @vcpu the vcpu of the guest 1006 * @vsie_page the vsie_page for the nested guest 1007 * @reg the register number, the upper 4 bits are ignored. 1008 * returns: the value of the register. 1009 */ 1010 static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) 1011 { 1012 /* no need to validate the parameter and/or perform error handling */ 1013 reg &= 0xf; 1014 switch (reg) { 1015 case 15: 1016 return vsie_page->scb_s.gg15; 1017 case 14: 1018 return vsie_page->scb_s.gg14; 1019 default: 1020 return vcpu->run->s.regs.gprs[reg]; 1021 } 1022 } 1023 1024 static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1025 { 1026 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1027 unsigned long pei_dest, pei_src, src, dest, mask, prefix; 1028 u64 *pei_block = &vsie_page->scb_o->mcic; 1029 int edat, rc_dest, rc_src; 1030 union ctlreg0 cr0; 1031 1032 cr0.val = vcpu->arch.sie_block->gcr[0]; 1033 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1034 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK); 1035 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 1036 1037 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; 1038 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso; 1039 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; 1040 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso; 1041 1042 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest); 1043 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src); 1044 /* 1045 * Either everything went well, or something non-critical went wrong 1046 * e.g. because of a race. In either case, simply retry. 1047 */ 1048 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { 1049 retry_vsie_icpt(vsie_page); 1050 return -EAGAIN; 1051 } 1052 /* Something more serious went wrong, propagate the error */ 1053 if (rc_dest < 0) 1054 return rc_dest; 1055 if (rc_src < 0) 1056 return rc_src; 1057 1058 /* The only possible suppressing exception: just deliver it */ 1059 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) { 1060 clear_vsie_icpt(vsie_page); 1061 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC); 1062 WARN_ON_ONCE(rc_dest); 1063 return 1; 1064 } 1065 1066 /* 1067 * Forward the PEI intercept to the guest if it was a page fault, or 1068 * also for segment and region table faults if EDAT applies. 1069 */ 1070 if (edat) { 1071 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0; 1072 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0; 1073 } else { 1074 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0; 1075 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0; 1076 } 1077 if (!rc_dest && !rc_src) { 1078 pei_block[0] = pei_dest; 1079 pei_block[1] = pei_src; 1080 return 1; 1081 } 1082 1083 retry_vsie_icpt(vsie_page); 1084 1085 /* 1086 * The host has edat, and the guest does not, or it was an ASCE type 1087 * exception. The host needs to inject the appropriate DAT interrupts 1088 * into the guest. 1089 */ 1090 if (rc_dest) 1091 return inject_fault(vcpu, rc_dest, dest, 1); 1092 return inject_fault(vcpu, rc_src, src, 0); 1093 } 1094 1095 /* 1096 * Run the vsie on a shadow scb and a shadow gmap, without any further 1097 * sanity checks, handling SIE faults. 1098 * 1099 * Returns: - 0 everything went fine 1100 * - > 0 if control has to be given to guest 2 1101 * - < 0 if an error occurred 1102 */ 1103 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1104 __releases(vcpu->kvm->srcu) 1105 __acquires(vcpu->kvm->srcu) 1106 { 1107 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1108 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 1109 int guest_bp_isolation; 1110 int rc = 0; 1111 1112 handle_last_fault(vcpu, vsie_page); 1113 1114 kvm_vcpu_srcu_read_unlock(vcpu); 1115 1116 /* save current guest state of bp isolation override */ 1117 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1118 1119 /* 1120 * The guest is running with BPBC, so we have to force it on for our 1121 * nested guest. This is done by enabling BPBC globally, so the BPBC 1122 * control in the SCB (which the nested guest can modify) is simply 1123 * ignored. 1124 */ 1125 if (test_kvm_facility(vcpu->kvm, 82) && 1126 vcpu->arch.sie_block->fpf & FPF_BPBC) 1127 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1128 1129 local_irq_disable(); 1130 guest_enter_irqoff(); 1131 local_irq_enable(); 1132 1133 /* 1134 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1135 * and VCPU requests also hinder the vSIE from running and lead 1136 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1137 * also kick the vSIE. 1138 */ 1139 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1140 barrier(); 1141 if (test_cpu_flag(CIF_FPU)) 1142 load_fpu_regs(); 1143 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) 1144 rc = sie64a(scb_s, vcpu->run->s.regs.gprs); 1145 barrier(); 1146 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1147 1148 local_irq_disable(); 1149 guest_exit_irqoff(); 1150 local_irq_enable(); 1151 1152 /* restore guest state for bp isolation override */ 1153 if (!guest_bp_isolation) 1154 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1155 1156 kvm_vcpu_srcu_read_lock(vcpu); 1157 1158 if (rc == -EINTR) { 1159 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1160 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1161 return 0; 1162 } 1163 1164 if (rc > 0) 1165 rc = 0; /* we could still have an icpt */ 1166 else if (rc == -EFAULT) 1167 return handle_fault(vcpu, vsie_page); 1168 1169 switch (scb_s->icptcode) { 1170 case ICPT_INST: 1171 if (scb_s->ipa == 0xb2b0) 1172 rc = handle_stfle(vcpu, vsie_page); 1173 break; 1174 case ICPT_STOP: 1175 /* stop not requested by g2 - must have been a kick */ 1176 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1177 clear_vsie_icpt(vsie_page); 1178 break; 1179 case ICPT_VALIDITY: 1180 if ((scb_s->ipa & 0xf000) != 0xf000) 1181 scb_s->ipa += 0x1000; 1182 break; 1183 case ICPT_PARTEXEC: 1184 if (scb_s->ipa == 0xb254) 1185 rc = vsie_handle_mvpg(vcpu, vsie_page); 1186 break; 1187 } 1188 return rc; 1189 } 1190 1191 static void release_gmap_shadow(struct vsie_page *vsie_page) 1192 { 1193 if (vsie_page->gmap) 1194 gmap_put(vsie_page->gmap); 1195 WRITE_ONCE(vsie_page->gmap, NULL); 1196 prefix_unmapped(vsie_page); 1197 } 1198 1199 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1200 struct vsie_page *vsie_page) 1201 { 1202 unsigned long asce; 1203 union ctlreg0 cr0; 1204 struct gmap *gmap; 1205 int edat; 1206 1207 asce = vcpu->arch.sie_block->gcr[1]; 1208 cr0.val = vcpu->arch.sie_block->gcr[0]; 1209 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1210 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1211 1212 /* 1213 * ASCE or EDAT could have changed since last icpt, or the gmap 1214 * we're holding has been unshadowed. If the gmap is still valid, 1215 * we can safely reuse it. 1216 */ 1217 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) { 1218 vcpu->kvm->stat.gmap_shadow_reuse++; 1219 return 0; 1220 } 1221 1222 /* release the old shadow - if any, and mark the prefix as unmapped */ 1223 release_gmap_shadow(vsie_page); 1224 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1225 if (IS_ERR(gmap)) 1226 return PTR_ERR(gmap); 1227 gmap->private = vcpu->kvm; 1228 vcpu->kvm->stat.gmap_shadow_create++; 1229 WRITE_ONCE(vsie_page->gmap, gmap); 1230 return 0; 1231 } 1232 1233 /* 1234 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1235 */ 1236 static void register_shadow_scb(struct kvm_vcpu *vcpu, 1237 struct vsie_page *vsie_page) 1238 { 1239 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1240 1241 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1242 /* 1243 * External calls have to lead to a kick of the vcpu and 1244 * therefore the vsie -> Simulate Wait state. 1245 */ 1246 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1247 /* 1248 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1249 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1250 */ 1251 preempt_disable(); 1252 scb_s->epoch += vcpu->kvm->arch.epoch; 1253 1254 if (scb_s->ecd & ECD_MEF) { 1255 scb_s->epdx += vcpu->kvm->arch.epdx; 1256 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1257 scb_s->epdx += 1; 1258 } 1259 1260 preempt_enable(); 1261 } 1262 1263 /* 1264 * Unregister a shadow scb from a VCPU. 1265 */ 1266 static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1267 { 1268 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1269 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1270 } 1271 1272 /* 1273 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1274 * prefix pages and faults. 1275 * 1276 * Returns: - 0 if no errors occurred 1277 * - > 0 if control has to be given to guest 2 1278 * - -ENOMEM if out of memory 1279 */ 1280 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1281 { 1282 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1283 int rc = 0; 1284 1285 while (1) { 1286 rc = acquire_gmap_shadow(vcpu, vsie_page); 1287 if (!rc) 1288 rc = map_prefix(vcpu, vsie_page); 1289 if (!rc) { 1290 gmap_enable(vsie_page->gmap); 1291 update_intervention_requests(vsie_page); 1292 rc = do_vsie_run(vcpu, vsie_page); 1293 gmap_enable(vcpu->arch.gmap); 1294 } 1295 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1296 1297 if (rc == -EAGAIN) 1298 rc = 0; 1299 if (rc || scb_s->icptcode || signal_pending(current) || 1300 kvm_s390_vcpu_has_irq(vcpu, 0) || 1301 kvm_s390_vcpu_sie_inhibited(vcpu)) 1302 break; 1303 cond_resched(); 1304 } 1305 1306 if (rc == -EFAULT) { 1307 /* 1308 * Addressing exceptions are always presentes as intercepts. 1309 * As addressing exceptions are suppressing and our guest 3 PSW 1310 * points at the responsible instruction, we have to 1311 * forward the PSW and set the ilc. If we can't read guest 3 1312 * instruction, we can use an arbitrary ilc. Let's always use 1313 * ilen = 4 for now, so we can avoid reading in guest 3 virtual 1314 * memory. (we could also fake the shadow so the hardware 1315 * handles it). 1316 */ 1317 scb_s->icptcode = ICPT_PROGI; 1318 scb_s->iprcc = PGM_ADDRESSING; 1319 scb_s->pgmilc = 4; 1320 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); 1321 rc = 1; 1322 } 1323 return rc; 1324 } 1325 1326 /* 1327 * Get or create a vsie page for a scb address. 1328 * 1329 * Returns: - address of a vsie page (cached or new one) 1330 * - NULL if the same scb address is already used by another VCPU 1331 * - ERR_PTR(-ENOMEM) if out of memory 1332 */ 1333 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1334 { 1335 struct vsie_page *vsie_page; 1336 struct page *page; 1337 int nr_vcpus; 1338 1339 rcu_read_lock(); 1340 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1341 rcu_read_unlock(); 1342 if (page) { 1343 if (page_ref_inc_return(page) == 2) 1344 return page_to_virt(page); 1345 page_ref_dec(page); 1346 } 1347 1348 /* 1349 * We want at least #online_vcpus shadows, so every VCPU can execute 1350 * the VSIE in parallel. 1351 */ 1352 nr_vcpus = atomic_read(&kvm->online_vcpus); 1353 1354 mutex_lock(&kvm->arch.vsie.mutex); 1355 if (kvm->arch.vsie.page_count < nr_vcpus) { 1356 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); 1357 if (!page) { 1358 mutex_unlock(&kvm->arch.vsie.mutex); 1359 return ERR_PTR(-ENOMEM); 1360 } 1361 page_ref_inc(page); 1362 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; 1363 kvm->arch.vsie.page_count++; 1364 } else { 1365 /* reuse an existing entry that belongs to nobody */ 1366 while (true) { 1367 page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1368 if (page_ref_inc_return(page) == 2) 1369 break; 1370 page_ref_dec(page); 1371 kvm->arch.vsie.next++; 1372 kvm->arch.vsie.next %= nr_vcpus; 1373 } 1374 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1375 } 1376 page->index = addr; 1377 /* double use of the same address */ 1378 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { 1379 page_ref_dec(page); 1380 mutex_unlock(&kvm->arch.vsie.mutex); 1381 return NULL; 1382 } 1383 mutex_unlock(&kvm->arch.vsie.mutex); 1384 1385 vsie_page = page_to_virt(page); 1386 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1387 release_gmap_shadow(vsie_page); 1388 vsie_page->fault_addr = 0; 1389 vsie_page->scb_s.ihcpu = 0xffffU; 1390 return vsie_page; 1391 } 1392 1393 /* put a vsie page acquired via get_vsie_page */ 1394 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) 1395 { 1396 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); 1397 1398 page_ref_dec(page); 1399 } 1400 1401 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1402 { 1403 struct vsie_page *vsie_page; 1404 unsigned long scb_addr; 1405 int rc; 1406 1407 vcpu->stat.instruction_sie++; 1408 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1409 return -EOPNOTSUPP; 1410 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1411 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1412 1413 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1414 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1415 1416 /* 512 byte alignment */ 1417 if (unlikely(scb_addr & 0x1ffUL)) 1418 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1419 1420 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1421 kvm_s390_vcpu_sie_inhibited(vcpu)) 1422 return 0; 1423 1424 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1425 if (IS_ERR(vsie_page)) 1426 return PTR_ERR(vsie_page); 1427 else if (!vsie_page) 1428 /* double use of sie control block - simply do nothing */ 1429 return 0; 1430 1431 rc = pin_scb(vcpu, vsie_page, scb_addr); 1432 if (rc) 1433 goto out_put; 1434 rc = shadow_scb(vcpu, vsie_page); 1435 if (rc) 1436 goto out_unpin_scb; 1437 rc = pin_blocks(vcpu, vsie_page); 1438 if (rc) 1439 goto out_unshadow; 1440 register_shadow_scb(vcpu, vsie_page); 1441 rc = vsie_run(vcpu, vsie_page); 1442 unregister_shadow_scb(vcpu); 1443 unpin_blocks(vcpu, vsie_page); 1444 out_unshadow: 1445 unshadow_scb(vcpu, vsie_page); 1446 out_unpin_scb: 1447 unpin_scb(vcpu, vsie_page, scb_addr); 1448 out_put: 1449 put_vsie_page(vcpu->kvm, vsie_page); 1450 1451 return rc < 0 ? rc : 0; 1452 } 1453 1454 /* Init the vsie data structures. To be called when a vm is initialized. */ 1455 void kvm_s390_vsie_init(struct kvm *kvm) 1456 { 1457 mutex_init(&kvm->arch.vsie.mutex); 1458 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT); 1459 } 1460 1461 /* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1462 void kvm_s390_vsie_destroy(struct kvm *kvm) 1463 { 1464 struct vsie_page *vsie_page; 1465 struct page *page; 1466 int i; 1467 1468 mutex_lock(&kvm->arch.vsie.mutex); 1469 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1470 page = kvm->arch.vsie.pages[i]; 1471 kvm->arch.vsie.pages[i] = NULL; 1472 vsie_page = page_to_virt(page); 1473 release_gmap_shadow(vsie_page); 1474 /* free the radix tree entry */ 1475 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1476 __free_page(page); 1477 } 1478 kvm->arch.vsie.page_count = 0; 1479 mutex_unlock(&kvm->arch.vsie.mutex); 1480 } 1481 1482 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1483 { 1484 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1485 1486 /* 1487 * Even if the VCPU lets go of the shadow sie block reference, it is 1488 * still valid in the cache. So we can safely kick it. 1489 */ 1490 if (scb) { 1491 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1492 if (scb->prog0c & PROG_IN_SIE) 1493 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1494 } 1495 } 1496