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 apcb_o, struct kvm_s390_apcb1 *apcb_h) 142 { 143 struct kvm_s390_apcb0 tmp; 144 145 if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0))) 146 return -EFAULT; 147 148 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; 149 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; 150 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; 151 152 return 0; 153 154 } 155 156 /** 157 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 158 * @vcpu: pointer to the virtual CPU 159 * @apcb_s: pointer to start of apcb in the shadow crycb 160 * @apcb_o: pointer to start of original apcb in the guest2 161 * @apcb_h: pointer to start of apcb in the guest1 162 * 163 * Returns 0 and -EFAULT on error reading guest apcb 164 */ 165 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 166 unsigned long apcb_o, unsigned long *apcb_h) 167 { 168 if (read_guest_real(vcpu, apcb_o, apcb_s, 169 sizeof(struct kvm_s390_apcb0))) 170 return -EFAULT; 171 172 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0)); 173 174 return 0; 175 } 176 177 /** 178 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB 179 * @vcpu: pointer to the virtual CPU 180 * @apcb_s: pointer to start of apcb in the shadow crycb 181 * @apcb_o: pointer to start of original guest apcb 182 * @apcb_h: pointer to start of apcb in the host 183 * 184 * Returns 0 and -EFAULT on error reading guest apcb 185 */ 186 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 187 unsigned long apcb_o, 188 unsigned long *apcb_h) 189 { 190 if (read_guest_real(vcpu, apcb_o, apcb_s, 191 sizeof(struct kvm_s390_apcb1))) 192 return -EFAULT; 193 194 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1)); 195 196 return 0; 197 } 198 199 /** 200 * setup_apcb - Create a shadow copy of the apcb. 201 * @vcpu: pointer to the virtual CPU 202 * @crycb_s: pointer to shadow crycb 203 * @crycb_o: pointer to original guest crycb 204 * @crycb_h: pointer to the host crycb 205 * @fmt_o: format of the original guest crycb. 206 * @fmt_h: format of the host crycb. 207 * 208 * Checks the compatibility between the guest and host crycb and calls the 209 * appropriate copy function. 210 * 211 * Return 0 or an error number if the guest and host crycb are incompatible. 212 */ 213 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 214 const u32 crycb_o, 215 struct kvm_s390_crypto_cb *crycb_h, 216 int fmt_o, int fmt_h) 217 { 218 struct kvm_s390_crypto_cb *crycb; 219 220 crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o; 221 222 switch (fmt_o) { 223 case CRYCB_FORMAT2: 224 if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK)) 225 return -EACCES; 226 if (fmt_h != CRYCB_FORMAT2) 227 return -EINVAL; 228 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 229 (unsigned long) &crycb->apcb1, 230 (unsigned long *)&crycb_h->apcb1); 231 case CRYCB_FORMAT1: 232 switch (fmt_h) { 233 case CRYCB_FORMAT2: 234 return setup_apcb10(vcpu, &crycb_s->apcb1, 235 (unsigned long) &crycb->apcb0, 236 &crycb_h->apcb1); 237 case CRYCB_FORMAT1: 238 return setup_apcb00(vcpu, 239 (unsigned long *) &crycb_s->apcb0, 240 (unsigned long) &crycb->apcb0, 241 (unsigned long *) &crycb_h->apcb0); 242 } 243 break; 244 case CRYCB_FORMAT0: 245 if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK)) 246 return -EACCES; 247 248 switch (fmt_h) { 249 case CRYCB_FORMAT2: 250 return setup_apcb10(vcpu, &crycb_s->apcb1, 251 (unsigned long) &crycb->apcb0, 252 &crycb_h->apcb1); 253 case CRYCB_FORMAT1: 254 case CRYCB_FORMAT0: 255 return setup_apcb00(vcpu, 256 (unsigned long *) &crycb_s->apcb0, 257 (unsigned long) &crycb->apcb0, 258 (unsigned long *) &crycb_h->apcb0); 259 } 260 } 261 return -EINVAL; 262 } 263 264 /** 265 * shadow_crycb - Create a shadow copy of the crycb block 266 * @vcpu: a pointer to the virtual CPU 267 * @vsie_page: a pointer to internal date used for the vSIE 268 * 269 * Create a shadow copy of the crycb block and setup key wrapping, if 270 * requested for guest 3 and enabled for guest 2. 271 * 272 * We accept format-1 or format-2, but we convert format-1 into format-2 273 * in the shadow CRYCB. 274 * Using format-2 enables the firmware to choose the right format when 275 * scheduling the SIE. 276 * There is nothing to do for format-0. 277 * 278 * This function centralize the issuing of set_validity_icpt() for all 279 * the subfunctions working on the crycb. 280 * 281 * Returns: - 0 if shadowed or nothing to do 282 * - > 0 if control has to be given to guest 2 283 */ 284 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 285 { 286 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 287 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 288 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 289 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 290 unsigned long *b1, *b2; 291 u8 ecb3_flags; 292 u32 ecd_flags; 293 int apie_h; 294 int apie_s; 295 int key_msk = test_kvm_facility(vcpu->kvm, 76); 296 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 297 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 298 int ret = 0; 299 300 scb_s->crycbd = 0; 301 302 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 303 apie_s = apie_h & scb_o->eca; 304 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 305 return 0; 306 307 if (!crycb_addr) 308 return set_validity_icpt(scb_s, 0x0039U); 309 310 if (fmt_o == CRYCB_FORMAT1) 311 if ((crycb_addr & PAGE_MASK) != 312 ((crycb_addr + 128) & PAGE_MASK)) 313 return set_validity_icpt(scb_s, 0x003CU); 314 315 if (apie_s) { 316 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 317 vcpu->kvm->arch.crypto.crycb, 318 fmt_o, fmt_h); 319 if (ret) 320 goto end; 321 scb_s->eca |= scb_o->eca & ECA_APIE; 322 } 323 324 /* we may only allow it if enabled for guest 2 */ 325 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 326 (ECB3_AES | ECB3_DEA); 327 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; 328 if (!ecb3_flags && !ecd_flags) 329 goto end; 330 331 /* copy only the wrapping keys */ 332 if (read_guest_real(vcpu, crycb_addr + 72, 333 vsie_page->crycb.dea_wrapping_key_mask, 56)) 334 return set_validity_icpt(scb_s, 0x0035U); 335 336 scb_s->ecb3 |= ecb3_flags; 337 scb_s->ecd |= ecd_flags; 338 339 /* xor both blocks in one run */ 340 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 341 b2 = (unsigned long *) 342 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 343 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 344 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 345 end: 346 switch (ret) { 347 case -EINVAL: 348 return set_validity_icpt(scb_s, 0x0022U); 349 case -EFAULT: 350 return set_validity_icpt(scb_s, 0x0035U); 351 case -EACCES: 352 return set_validity_icpt(scb_s, 0x003CU); 353 } 354 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; 355 return 0; 356 } 357 358 /* shadow (round up/down) the ibc to avoid validity icpt */ 359 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 360 { 361 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 362 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 363 /* READ_ONCE does not work on bitfields - use a temporary variable */ 364 const uint32_t __new_ibc = scb_o->ibc; 365 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 366 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 367 368 scb_s->ibc = 0; 369 /* ibc installed in g2 and requested for g3 */ 370 if (vcpu->kvm->arch.model.ibc && new_ibc) { 371 scb_s->ibc = new_ibc; 372 /* takte care of the minimum ibc level of the machine */ 373 if (scb_s->ibc < min_ibc) 374 scb_s->ibc = min_ibc; 375 /* take care of the maximum ibc level set for the guest */ 376 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 377 scb_s->ibc = vcpu->kvm->arch.model.ibc; 378 } 379 } 380 381 /* unshadow the scb, copying parameters back to the real scb */ 382 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 383 { 384 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 385 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 386 387 /* interception */ 388 scb_o->icptcode = scb_s->icptcode; 389 scb_o->icptstatus = scb_s->icptstatus; 390 scb_o->ipa = scb_s->ipa; 391 scb_o->ipb = scb_s->ipb; 392 scb_o->gbea = scb_s->gbea; 393 394 /* timer */ 395 scb_o->cputm = scb_s->cputm; 396 scb_o->ckc = scb_s->ckc; 397 scb_o->todpr = scb_s->todpr; 398 399 /* guest state */ 400 scb_o->gpsw = scb_s->gpsw; 401 scb_o->gg14 = scb_s->gg14; 402 scb_o->gg15 = scb_s->gg15; 403 memcpy(scb_o->gcr, scb_s->gcr, 128); 404 scb_o->pp = scb_s->pp; 405 406 /* branch prediction */ 407 if (test_kvm_facility(vcpu->kvm, 82)) { 408 scb_o->fpf &= ~FPF_BPBC; 409 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 410 } 411 412 /* interrupt intercept */ 413 switch (scb_s->icptcode) { 414 case ICPT_PROGI: 415 case ICPT_INSTPROGI: 416 case ICPT_EXTINT: 417 memcpy((void *)((u64)scb_o + 0xc0), 418 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 419 break; 420 case ICPT_PARTEXEC: 421 /* MVPG only */ 422 memcpy((void *)((u64)scb_o + 0xc0), 423 (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0); 424 break; 425 } 426 427 if (scb_s->ihcpu != 0xffffU) 428 scb_o->ihcpu = scb_s->ihcpu; 429 } 430 431 /* 432 * Setup the shadow scb by copying and checking the relevant parts of the g2 433 * provided scb. 434 * 435 * Returns: - 0 if the scb has been shadowed 436 * - > 0 if control has to be given to guest 2 437 */ 438 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 439 { 440 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 441 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 442 /* READ_ONCE does not work on bitfields - use a temporary variable */ 443 const uint32_t __new_prefix = scb_o->prefix; 444 const uint32_t new_prefix = READ_ONCE(__new_prefix); 445 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 446 bool had_tx = scb_s->ecb & ECB_TE; 447 unsigned long new_mso = 0; 448 int rc; 449 450 /* make sure we don't have any leftovers when reusing the scb */ 451 scb_s->icptcode = 0; 452 scb_s->eca = 0; 453 scb_s->ecb = 0; 454 scb_s->ecb2 = 0; 455 scb_s->ecb3 = 0; 456 scb_s->ecd = 0; 457 scb_s->fac = 0; 458 scb_s->fpf = 0; 459 460 rc = prepare_cpuflags(vcpu, vsie_page); 461 if (rc) 462 goto out; 463 464 /* timer */ 465 scb_s->cputm = scb_o->cputm; 466 scb_s->ckc = scb_o->ckc; 467 scb_s->todpr = scb_o->todpr; 468 scb_s->epoch = scb_o->epoch; 469 470 /* guest state */ 471 scb_s->gpsw = scb_o->gpsw; 472 scb_s->gg14 = scb_o->gg14; 473 scb_s->gg15 = scb_o->gg15; 474 memcpy(scb_s->gcr, scb_o->gcr, 128); 475 scb_s->pp = scb_o->pp; 476 477 /* interception / execution handling */ 478 scb_s->gbea = scb_o->gbea; 479 scb_s->lctl = scb_o->lctl; 480 scb_s->svcc = scb_o->svcc; 481 scb_s->ictl = scb_o->ictl; 482 /* 483 * SKEY handling functions can't deal with false setting of PTE invalid 484 * bits. Therefore we cannot provide interpretation and would later 485 * have to provide own emulation handlers. 486 */ 487 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 488 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 489 490 scb_s->icpua = scb_o->icpua; 491 492 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 493 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 494 /* if the hva of the prefix changes, we have to remap the prefix */ 495 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 496 prefix_unmapped(vsie_page); 497 /* SIE will do mso/msl validity and exception checks for us */ 498 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 499 scb_s->mso = new_mso; 500 scb_s->prefix = new_prefix; 501 502 /* We have to definetly flush the tlb if this scb never ran */ 503 if (scb_s->ihcpu != 0xffffU) 504 scb_s->ihcpu = scb_o->ihcpu; 505 506 /* MVPG and Protection Exception Interpretation are always available */ 507 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 508 /* Host-protection-interruption introduced with ESOP */ 509 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 510 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 511 /* transactional execution */ 512 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 513 /* remap the prefix is tx is toggled on */ 514 if (!had_tx) 515 prefix_unmapped(vsie_page); 516 scb_s->ecb |= ECB_TE; 517 } 518 /* branch prediction */ 519 if (test_kvm_facility(vcpu->kvm, 82)) 520 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 521 /* SIMD */ 522 if (test_kvm_facility(vcpu->kvm, 129)) { 523 scb_s->eca |= scb_o->eca & ECA_VX; 524 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 525 } 526 /* Run-time-Instrumentation */ 527 if (test_kvm_facility(vcpu->kvm, 64)) 528 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 529 /* Instruction Execution Prevention */ 530 if (test_kvm_facility(vcpu->kvm, 130)) 531 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 532 /* Guarded Storage */ 533 if (test_kvm_facility(vcpu->kvm, 133)) { 534 scb_s->ecb |= scb_o->ecb & ECB_GS; 535 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 536 } 537 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 538 scb_s->eca |= scb_o->eca & ECA_SII; 539 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 540 scb_s->eca |= scb_o->eca & ECA_IB; 541 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 542 scb_s->eca |= scb_o->eca & ECA_CEI; 543 /* Epoch Extension */ 544 if (test_kvm_facility(vcpu->kvm, 139)) 545 scb_s->ecd |= scb_o->ecd & ECD_MEF; 546 547 /* etoken */ 548 if (test_kvm_facility(vcpu->kvm, 156)) 549 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 550 551 scb_s->hpid = HPID_VSIE; 552 scb_s->cpnc = scb_o->cpnc; 553 554 prepare_ibc(vcpu, vsie_page); 555 rc = shadow_crycb(vcpu, vsie_page); 556 out: 557 if (rc) 558 unshadow_scb(vcpu, vsie_page); 559 return rc; 560 } 561 562 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 563 unsigned long end) 564 { 565 struct kvm *kvm = gmap->private; 566 struct vsie_page *cur; 567 unsigned long prefix; 568 struct page *page; 569 int i; 570 571 if (!gmap_is_shadow(gmap)) 572 return; 573 if (start >= 1UL << 31) 574 /* We are only interested in prefix pages */ 575 return; 576 577 /* 578 * Only new shadow blocks are added to the list during runtime, 579 * therefore we can safely reference them all the time. 580 */ 581 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 582 page = READ_ONCE(kvm->arch.vsie.pages[i]); 583 if (!page) 584 continue; 585 cur = page_to_virt(page); 586 if (READ_ONCE(cur->gmap) != gmap) 587 continue; 588 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; 589 /* with mso/msl, the prefix lies at an offset */ 590 prefix += cur->scb_s.mso; 591 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) 592 prefix_unmapped_sync(cur); 593 } 594 } 595 596 /* 597 * Map the first prefix page and if tx is enabled also the second prefix page. 598 * 599 * The prefix will be protected, a gmap notifier will inform about unmaps. 600 * The shadow scb must not be executed until the prefix is remapped, this is 601 * guaranteed by properly handling PROG_REQUEST. 602 * 603 * Returns: - 0 on if successfully mapped or already mapped 604 * - > 0 if control has to be given to guest 2 605 * - -EAGAIN if the caller can retry immediately 606 * - -ENOMEM if out of memory 607 */ 608 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 609 { 610 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 611 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 612 int rc; 613 614 if (prefix_is_mapped(vsie_page)) 615 return 0; 616 617 /* mark it as mapped so we can catch any concurrent unmappers */ 618 prefix_mapped(vsie_page); 619 620 /* with mso/msl, the prefix lies at offset *mso* */ 621 prefix += scb_s->mso; 622 623 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix); 624 if (!rc && (scb_s->ecb & ECB_TE)) 625 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 626 prefix + PAGE_SIZE); 627 /* 628 * We don't have to mprotect, we will be called for all unshadows. 629 * SIE will detect if protection applies and trigger a validity. 630 */ 631 if (rc) 632 prefix_unmapped(vsie_page); 633 if (rc > 0 || rc == -EFAULT) 634 rc = set_validity_icpt(scb_s, 0x0037U); 635 return rc; 636 } 637 638 /* 639 * Pin the guest page given by gpa and set hpa to the pinned host address. 640 * Will always be pinned writable. 641 * 642 * Returns: - 0 on success 643 * - -EINVAL if the gpa is not valid guest storage 644 */ 645 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) 646 { 647 struct page *page; 648 649 page = gfn_to_page(kvm, gpa_to_gfn(gpa)); 650 if (is_error_page(page)) 651 return -EINVAL; 652 *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK); 653 return 0; 654 } 655 656 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ 657 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) 658 { 659 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT); 660 /* mark the page always as dirty for migration */ 661 mark_page_dirty(kvm, gpa_to_gfn(gpa)); 662 } 663 664 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ 665 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 666 { 667 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 668 hpa_t hpa; 669 670 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; 671 if (hpa) { 672 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); 673 vsie_page->sca_gpa = 0; 674 scb_s->scaol = 0; 675 scb_s->scaoh = 0; 676 } 677 678 hpa = scb_s->itdba; 679 if (hpa) { 680 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); 681 vsie_page->itdba_gpa = 0; 682 scb_s->itdba = 0; 683 } 684 685 hpa = scb_s->gvrd; 686 if (hpa) { 687 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); 688 vsie_page->gvrd_gpa = 0; 689 scb_s->gvrd = 0; 690 } 691 692 hpa = scb_s->riccbd; 693 if (hpa) { 694 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); 695 vsie_page->riccbd_gpa = 0; 696 scb_s->riccbd = 0; 697 } 698 699 hpa = scb_s->sdnxo; 700 if (hpa) { 701 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); 702 vsie_page->sdnx_gpa = 0; 703 scb_s->sdnxo = 0; 704 } 705 } 706 707 /* 708 * Instead of shadowing some blocks, we can simply forward them because the 709 * addresses in the scb are 64 bit long. 710 * 711 * This works as long as the data lies in one page. If blocks ever exceed one 712 * page, we have to fall back to shadowing. 713 * 714 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must 715 * therefore not enable any facilities that access these pointers (e.g. SIGPIF). 716 * 717 * Returns: - 0 if all blocks were pinned. 718 * - > 0 if control has to be given to guest 2 719 * - -ENOMEM if out of memory 720 */ 721 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 722 { 723 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 724 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 725 hpa_t hpa; 726 gpa_t gpa; 727 int rc = 0; 728 729 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; 730 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) 731 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; 732 if (gpa) { 733 if (gpa < 2 * PAGE_SIZE) 734 rc = set_validity_icpt(scb_s, 0x0038U); 735 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) 736 rc = set_validity_icpt(scb_s, 0x0011U); 737 else if ((gpa & PAGE_MASK) != 738 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) 739 rc = set_validity_icpt(scb_s, 0x003bU); 740 if (!rc) { 741 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 742 if (rc) 743 rc = set_validity_icpt(scb_s, 0x0034U); 744 } 745 if (rc) 746 goto unpin; 747 vsie_page->sca_gpa = gpa; 748 scb_s->scaoh = (u32)((u64)hpa >> 32); 749 scb_s->scaol = (u32)(u64)hpa; 750 } 751 752 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; 753 if (gpa && (scb_s->ecb & ECB_TE)) { 754 if (gpa < 2 * PAGE_SIZE) { 755 rc = set_validity_icpt(scb_s, 0x0080U); 756 goto unpin; 757 } 758 /* 256 bytes cannot cross page boundaries */ 759 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 760 if (rc) { 761 rc = set_validity_icpt(scb_s, 0x0080U); 762 goto unpin; 763 } 764 vsie_page->itdba_gpa = gpa; 765 scb_s->itdba = hpa; 766 } 767 768 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; 769 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { 770 if (gpa < 2 * PAGE_SIZE) { 771 rc = set_validity_icpt(scb_s, 0x1310U); 772 goto unpin; 773 } 774 /* 775 * 512 bytes vector registers cannot cross page boundaries 776 * if this block gets bigger, we have to shadow it. 777 */ 778 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 779 if (rc) { 780 rc = set_validity_icpt(scb_s, 0x1310U); 781 goto unpin; 782 } 783 vsie_page->gvrd_gpa = gpa; 784 scb_s->gvrd = hpa; 785 } 786 787 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; 788 if (gpa && (scb_s->ecb3 & ECB3_RI)) { 789 if (gpa < 2 * PAGE_SIZE) { 790 rc = set_validity_icpt(scb_s, 0x0043U); 791 goto unpin; 792 } 793 /* 64 bytes cannot cross page boundaries */ 794 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 795 if (rc) { 796 rc = set_validity_icpt(scb_s, 0x0043U); 797 goto unpin; 798 } 799 /* Validity 0x0044 will be checked by SIE */ 800 vsie_page->riccbd_gpa = gpa; 801 scb_s->riccbd = hpa; 802 } 803 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || 804 (scb_s->ecd & ECD_ETOKENF)) { 805 unsigned long sdnxc; 806 807 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; 808 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; 809 if (!gpa || gpa < 2 * PAGE_SIZE) { 810 rc = set_validity_icpt(scb_s, 0x10b0U); 811 goto unpin; 812 } 813 if (sdnxc < 6 || sdnxc > 12) { 814 rc = set_validity_icpt(scb_s, 0x10b1U); 815 goto unpin; 816 } 817 if (gpa & ((1 << sdnxc) - 1)) { 818 rc = set_validity_icpt(scb_s, 0x10b2U); 819 goto unpin; 820 } 821 /* Due to alignment rules (checked above) this cannot 822 * cross page boundaries 823 */ 824 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 825 if (rc) { 826 rc = set_validity_icpt(scb_s, 0x10b0U); 827 goto unpin; 828 } 829 vsie_page->sdnx_gpa = gpa; 830 scb_s->sdnxo = hpa | sdnxc; 831 } 832 return 0; 833 unpin: 834 unpin_blocks(vcpu, vsie_page); 835 return rc; 836 } 837 838 /* unpin the scb provided by guest 2, marking it as dirty */ 839 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 840 gpa_t gpa) 841 { 842 hpa_t hpa = (hpa_t) vsie_page->scb_o; 843 844 if (hpa) 845 unpin_guest_page(vcpu->kvm, gpa, hpa); 846 vsie_page->scb_o = NULL; 847 } 848 849 /* 850 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. 851 * 852 * Returns: - 0 if the scb was pinned. 853 * - > 0 if control has to be given to guest 2 854 */ 855 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 856 gpa_t gpa) 857 { 858 hpa_t hpa; 859 int rc; 860 861 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 862 if (rc) { 863 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 864 WARN_ON_ONCE(rc); 865 return 1; 866 } 867 vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa; 868 return 0; 869 } 870 871 /* 872 * Inject a fault into guest 2. 873 * 874 * Returns: - > 0 if control has to be given to guest 2 875 * < 0 if an error occurred during injection. 876 */ 877 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, 878 bool write_flag) 879 { 880 struct kvm_s390_pgm_info pgm = { 881 .code = code, 882 .trans_exc_code = 883 /* 0-51: virtual address */ 884 (vaddr & 0xfffffffffffff000UL) | 885 /* 52-53: store / fetch */ 886 (((unsigned int) !write_flag) + 1) << 10, 887 /* 62-63: asce id (alway primary == 0) */ 888 .exc_access_id = 0, /* always primary */ 889 .op_access_id = 0, /* not MVPG */ 890 }; 891 int rc; 892 893 if (code == PGM_PROTECTION) 894 pgm.trans_exc_code |= 0x4UL; 895 896 rc = kvm_s390_inject_prog_irq(vcpu, &pgm); 897 return rc ? rc : 1; 898 } 899 900 /* 901 * Handle a fault during vsie execution on a gmap shadow. 902 * 903 * Returns: - 0 if the fault was resolved 904 * - > 0 if control has to be given to guest 2 905 * - < 0 if an error occurred 906 */ 907 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 908 { 909 int rc; 910 911 if (current->thread.gmap_int_code == PGM_PROTECTION) 912 /* we can directly forward all protection exceptions */ 913 return inject_fault(vcpu, PGM_PROTECTION, 914 current->thread.gmap_addr, 1); 915 916 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 917 current->thread.gmap_addr); 918 if (rc > 0) { 919 rc = inject_fault(vcpu, rc, 920 current->thread.gmap_addr, 921 current->thread.gmap_write_flag); 922 if (rc >= 0) 923 vsie_page->fault_addr = current->thread.gmap_addr; 924 } 925 return rc; 926 } 927 928 /* 929 * Retry the previous fault that required guest 2 intervention. This avoids 930 * one superfluous SIE re-entry and direct exit. 931 * 932 * Will ignore any errors. The next SIE fault will do proper fault handling. 933 */ 934 static void handle_last_fault(struct kvm_vcpu *vcpu, 935 struct vsie_page *vsie_page) 936 { 937 if (vsie_page->fault_addr) 938 kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 939 vsie_page->fault_addr); 940 vsie_page->fault_addr = 0; 941 } 942 943 static inline void clear_vsie_icpt(struct vsie_page *vsie_page) 944 { 945 vsie_page->scb_s.icptcode = 0; 946 } 947 948 /* rewind the psw and clear the vsie icpt, so we can retry execution */ 949 static void retry_vsie_icpt(struct vsie_page *vsie_page) 950 { 951 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 952 int ilen = insn_length(scb_s->ipa >> 8); 953 954 /* take care of EXECUTE instructions */ 955 if (scb_s->icptstatus & 1) { 956 ilen = (scb_s->icptstatus >> 4) & 0x6; 957 if (!ilen) 958 ilen = 4; 959 } 960 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); 961 clear_vsie_icpt(vsie_page); 962 } 963 964 /* 965 * Try to shadow + enable the guest 2 provided facility list. 966 * Retry instruction execution if enabled for and provided by guest 2. 967 * 968 * Returns: - 0 if handled (retry or guest 2 icpt) 969 * - > 0 if control has to be given to guest 2 970 */ 971 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 972 { 973 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 974 __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; 975 976 if (fac && test_kvm_facility(vcpu->kvm, 7)) { 977 retry_vsie_icpt(vsie_page); 978 if (read_guest_real(vcpu, fac, &vsie_page->fac, 979 sizeof(vsie_page->fac))) 980 return set_validity_icpt(scb_s, 0x1090U); 981 scb_s->fac = (__u32)(__u64) &vsie_page->fac; 982 } 983 return 0; 984 } 985 986 /* 987 * Run the vsie on a shadow scb and a shadow gmap, without any further 988 * sanity checks, handling SIE faults. 989 * 990 * Returns: - 0 everything went fine 991 * - > 0 if control has to be given to guest 2 992 * - < 0 if an error occurred 993 */ 994 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 995 __releases(vcpu->kvm->srcu) 996 __acquires(vcpu->kvm->srcu) 997 { 998 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 999 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 1000 int guest_bp_isolation; 1001 int rc = 0; 1002 1003 handle_last_fault(vcpu, vsie_page); 1004 1005 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); 1006 1007 /* save current guest state of bp isolation override */ 1008 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1009 1010 /* 1011 * The guest is running with BPBC, so we have to force it on for our 1012 * nested guest. This is done by enabling BPBC globally, so the BPBC 1013 * control in the SCB (which the nested guest can modify) is simply 1014 * ignored. 1015 */ 1016 if (test_kvm_facility(vcpu->kvm, 82) && 1017 vcpu->arch.sie_block->fpf & FPF_BPBC) 1018 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1019 1020 local_irq_disable(); 1021 guest_enter_irqoff(); 1022 local_irq_enable(); 1023 1024 /* 1025 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1026 * and VCPU requests also hinder the vSIE from running and lead 1027 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1028 * also kick the vSIE. 1029 */ 1030 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1031 barrier(); 1032 if (test_cpu_flag(CIF_FPU)) 1033 load_fpu_regs(); 1034 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) 1035 rc = sie64a(scb_s, vcpu->run->s.regs.gprs); 1036 barrier(); 1037 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1038 1039 local_irq_disable(); 1040 guest_exit_irqoff(); 1041 local_irq_enable(); 1042 1043 /* restore guest state for bp isolation override */ 1044 if (!guest_bp_isolation) 1045 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1046 1047 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); 1048 1049 if (rc == -EINTR) { 1050 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1051 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1052 return 0; 1053 } 1054 1055 if (rc > 0) 1056 rc = 0; /* we could still have an icpt */ 1057 else if (rc == -EFAULT) 1058 return handle_fault(vcpu, vsie_page); 1059 1060 switch (scb_s->icptcode) { 1061 case ICPT_INST: 1062 if (scb_s->ipa == 0xb2b0) 1063 rc = handle_stfle(vcpu, vsie_page); 1064 break; 1065 case ICPT_STOP: 1066 /* stop not requested by g2 - must have been a kick */ 1067 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1068 clear_vsie_icpt(vsie_page); 1069 break; 1070 case ICPT_VALIDITY: 1071 if ((scb_s->ipa & 0xf000) != 0xf000) 1072 scb_s->ipa += 0x1000; 1073 break; 1074 } 1075 return rc; 1076 } 1077 1078 static void release_gmap_shadow(struct vsie_page *vsie_page) 1079 { 1080 if (vsie_page->gmap) 1081 gmap_put(vsie_page->gmap); 1082 WRITE_ONCE(vsie_page->gmap, NULL); 1083 prefix_unmapped(vsie_page); 1084 } 1085 1086 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1087 struct vsie_page *vsie_page) 1088 { 1089 unsigned long asce; 1090 union ctlreg0 cr0; 1091 struct gmap *gmap; 1092 int edat; 1093 1094 asce = vcpu->arch.sie_block->gcr[1]; 1095 cr0.val = vcpu->arch.sie_block->gcr[0]; 1096 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1097 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1098 1099 /* 1100 * ASCE or EDAT could have changed since last icpt, or the gmap 1101 * we're holding has been unshadowed. If the gmap is still valid, 1102 * we can safely reuse it. 1103 */ 1104 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) 1105 return 0; 1106 1107 /* release the old shadow - if any, and mark the prefix as unmapped */ 1108 release_gmap_shadow(vsie_page); 1109 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1110 if (IS_ERR(gmap)) 1111 return PTR_ERR(gmap); 1112 gmap->private = vcpu->kvm; 1113 WRITE_ONCE(vsie_page->gmap, gmap); 1114 return 0; 1115 } 1116 1117 /* 1118 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1119 */ 1120 static void register_shadow_scb(struct kvm_vcpu *vcpu, 1121 struct vsie_page *vsie_page) 1122 { 1123 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1124 1125 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1126 /* 1127 * External calls have to lead to a kick of the vcpu and 1128 * therefore the vsie -> Simulate Wait state. 1129 */ 1130 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1131 /* 1132 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1133 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1134 */ 1135 preempt_disable(); 1136 scb_s->epoch += vcpu->kvm->arch.epoch; 1137 1138 if (scb_s->ecd & ECD_MEF) { 1139 scb_s->epdx += vcpu->kvm->arch.epdx; 1140 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1141 scb_s->epdx += 1; 1142 } 1143 1144 preempt_enable(); 1145 } 1146 1147 /* 1148 * Unregister a shadow scb from a VCPU. 1149 */ 1150 static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1151 { 1152 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1153 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1154 } 1155 1156 /* 1157 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1158 * prefix pages and faults. 1159 * 1160 * Returns: - 0 if no errors occurred 1161 * - > 0 if control has to be given to guest 2 1162 * - -ENOMEM if out of memory 1163 */ 1164 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1165 { 1166 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1167 int rc = 0; 1168 1169 while (1) { 1170 rc = acquire_gmap_shadow(vcpu, vsie_page); 1171 if (!rc) 1172 rc = map_prefix(vcpu, vsie_page); 1173 if (!rc) { 1174 gmap_enable(vsie_page->gmap); 1175 update_intervention_requests(vsie_page); 1176 rc = do_vsie_run(vcpu, vsie_page); 1177 gmap_enable(vcpu->arch.gmap); 1178 } 1179 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1180 1181 if (rc == -EAGAIN) 1182 rc = 0; 1183 if (rc || scb_s->icptcode || signal_pending(current) || 1184 kvm_s390_vcpu_has_irq(vcpu, 0) || 1185 kvm_s390_vcpu_sie_inhibited(vcpu)) 1186 break; 1187 cond_resched(); 1188 } 1189 1190 if (rc == -EFAULT) { 1191 /* 1192 * Addressing exceptions are always presentes as intercepts. 1193 * As addressing exceptions are suppressing and our guest 3 PSW 1194 * points at the responsible instruction, we have to 1195 * forward the PSW and set the ilc. If we can't read guest 3 1196 * instruction, we can use an arbitrary ilc. Let's always use 1197 * ilen = 4 for now, so we can avoid reading in guest 3 virtual 1198 * memory. (we could also fake the shadow so the hardware 1199 * handles it). 1200 */ 1201 scb_s->icptcode = ICPT_PROGI; 1202 scb_s->iprcc = PGM_ADDRESSING; 1203 scb_s->pgmilc = 4; 1204 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); 1205 rc = 1; 1206 } 1207 return rc; 1208 } 1209 1210 /* 1211 * Get or create a vsie page for a scb address. 1212 * 1213 * Returns: - address of a vsie page (cached or new one) 1214 * - NULL if the same scb address is already used by another VCPU 1215 * - ERR_PTR(-ENOMEM) if out of memory 1216 */ 1217 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1218 { 1219 struct vsie_page *vsie_page; 1220 struct page *page; 1221 int nr_vcpus; 1222 1223 rcu_read_lock(); 1224 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1225 rcu_read_unlock(); 1226 if (page) { 1227 if (page_ref_inc_return(page) == 2) 1228 return page_to_virt(page); 1229 page_ref_dec(page); 1230 } 1231 1232 /* 1233 * We want at least #online_vcpus shadows, so every VCPU can execute 1234 * the VSIE in parallel. 1235 */ 1236 nr_vcpus = atomic_read(&kvm->online_vcpus); 1237 1238 mutex_lock(&kvm->arch.vsie.mutex); 1239 if (kvm->arch.vsie.page_count < nr_vcpus) { 1240 page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA); 1241 if (!page) { 1242 mutex_unlock(&kvm->arch.vsie.mutex); 1243 return ERR_PTR(-ENOMEM); 1244 } 1245 page_ref_inc(page); 1246 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; 1247 kvm->arch.vsie.page_count++; 1248 } else { 1249 /* reuse an existing entry that belongs to nobody */ 1250 while (true) { 1251 page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1252 if (page_ref_inc_return(page) == 2) 1253 break; 1254 page_ref_dec(page); 1255 kvm->arch.vsie.next++; 1256 kvm->arch.vsie.next %= nr_vcpus; 1257 } 1258 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1259 } 1260 page->index = addr; 1261 /* double use of the same address */ 1262 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { 1263 page_ref_dec(page); 1264 mutex_unlock(&kvm->arch.vsie.mutex); 1265 return NULL; 1266 } 1267 mutex_unlock(&kvm->arch.vsie.mutex); 1268 1269 vsie_page = page_to_virt(page); 1270 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1271 release_gmap_shadow(vsie_page); 1272 vsie_page->fault_addr = 0; 1273 vsie_page->scb_s.ihcpu = 0xffffU; 1274 return vsie_page; 1275 } 1276 1277 /* put a vsie page acquired via get_vsie_page */ 1278 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) 1279 { 1280 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); 1281 1282 page_ref_dec(page); 1283 } 1284 1285 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1286 { 1287 struct vsie_page *vsie_page; 1288 unsigned long scb_addr; 1289 int rc; 1290 1291 vcpu->stat.instruction_sie++; 1292 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1293 return -EOPNOTSUPP; 1294 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1295 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1296 1297 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1298 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1299 1300 /* 512 byte alignment */ 1301 if (unlikely(scb_addr & 0x1ffUL)) 1302 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1303 1304 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1305 kvm_s390_vcpu_sie_inhibited(vcpu)) 1306 return 0; 1307 1308 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1309 if (IS_ERR(vsie_page)) 1310 return PTR_ERR(vsie_page); 1311 else if (!vsie_page) 1312 /* double use of sie control block - simply do nothing */ 1313 return 0; 1314 1315 rc = pin_scb(vcpu, vsie_page, scb_addr); 1316 if (rc) 1317 goto out_put; 1318 rc = shadow_scb(vcpu, vsie_page); 1319 if (rc) 1320 goto out_unpin_scb; 1321 rc = pin_blocks(vcpu, vsie_page); 1322 if (rc) 1323 goto out_unshadow; 1324 register_shadow_scb(vcpu, vsie_page); 1325 rc = vsie_run(vcpu, vsie_page); 1326 unregister_shadow_scb(vcpu); 1327 unpin_blocks(vcpu, vsie_page); 1328 out_unshadow: 1329 unshadow_scb(vcpu, vsie_page); 1330 out_unpin_scb: 1331 unpin_scb(vcpu, vsie_page, scb_addr); 1332 out_put: 1333 put_vsie_page(vcpu->kvm, vsie_page); 1334 1335 return rc < 0 ? rc : 0; 1336 } 1337 1338 /* Init the vsie data structures. To be called when a vm is initialized. */ 1339 void kvm_s390_vsie_init(struct kvm *kvm) 1340 { 1341 mutex_init(&kvm->arch.vsie.mutex); 1342 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL_ACCOUNT); 1343 } 1344 1345 /* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1346 void kvm_s390_vsie_destroy(struct kvm *kvm) 1347 { 1348 struct vsie_page *vsie_page; 1349 struct page *page; 1350 int i; 1351 1352 mutex_lock(&kvm->arch.vsie.mutex); 1353 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1354 page = kvm->arch.vsie.pages[i]; 1355 kvm->arch.vsie.pages[i] = NULL; 1356 vsie_page = page_to_virt(page); 1357 release_gmap_shadow(vsie_page); 1358 /* free the radix tree entry */ 1359 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1360 __free_page(page); 1361 } 1362 kvm->arch.vsie.page_count = 0; 1363 mutex_unlock(&kvm->arch.vsie.mutex); 1364 } 1365 1366 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1367 { 1368 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1369 1370 /* 1371 * Even if the VCPU lets go of the shadow sie block reference, it is 1372 * still valid in the cache. So we can safely kick it. 1373 */ 1374 if (scb) { 1375 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1376 if (scb->prog0c & PROG_IN_SIE) 1377 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1378 } 1379 } 1380