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 "kvm-s390.h" 22 #include "gaccess.h" 23 24 struct vsie_page { 25 struct kvm_s390_sie_block scb_s; /* 0x0000 */ 26 /* 27 * the backup info for machine check. ensure it's at 28 * the same offset as that in struct sie_page! 29 */ 30 struct mcck_volatile_info mcck_info; /* 0x0200 */ 31 /* 32 * The pinned original scb. Be aware that other VCPUs can modify 33 * it while we read from it. Values that are used for conditions or 34 * are reused conditionally, should be accessed via READ_ONCE. 35 */ 36 struct kvm_s390_sie_block *scb_o; /* 0x0218 */ 37 /* the shadow gmap in use by the vsie_page */ 38 struct gmap *gmap; /* 0x0220 */ 39 /* address of the last reported fault to guest2 */ 40 unsigned long fault_addr; /* 0x0228 */ 41 /* calculated guest addresses of satellite control blocks */ 42 gpa_t sca_gpa; /* 0x0230 */ 43 gpa_t itdba_gpa; /* 0x0238 */ 44 gpa_t gvrd_gpa; /* 0x0240 */ 45 gpa_t riccbd_gpa; /* 0x0248 */ 46 gpa_t sdnx_gpa; /* 0x0250 */ 47 __u8 reserved[0x0700 - 0x0258]; /* 0x0258 */ 48 struct kvm_s390_crypto_cb crycb; /* 0x0700 */ 49 __u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE]; /* 0x0800 */ 50 }; 51 52 /* trigger a validity icpt for the given scb */ 53 static int set_validity_icpt(struct kvm_s390_sie_block *scb, 54 __u16 reason_code) 55 { 56 scb->ipa = 0x1000; 57 scb->ipb = ((__u32) reason_code) << 16; 58 scb->icptcode = ICPT_VALIDITY; 59 return 1; 60 } 61 62 /* mark the prefix as unmapped, this will block the VSIE */ 63 static void prefix_unmapped(struct vsie_page *vsie_page) 64 { 65 atomic_or(PROG_REQUEST, &vsie_page->scb_s.prog20); 66 } 67 68 /* mark the prefix as unmapped and wait until the VSIE has been left */ 69 static void prefix_unmapped_sync(struct vsie_page *vsie_page) 70 { 71 prefix_unmapped(vsie_page); 72 if (vsie_page->scb_s.prog0c & PROG_IN_SIE) 73 atomic_or(CPUSTAT_STOP_INT, &vsie_page->scb_s.cpuflags); 74 while (vsie_page->scb_s.prog0c & PROG_IN_SIE) 75 cpu_relax(); 76 } 77 78 /* mark the prefix as mapped, this will allow the VSIE to run */ 79 static void prefix_mapped(struct vsie_page *vsie_page) 80 { 81 atomic_andnot(PROG_REQUEST, &vsie_page->scb_s.prog20); 82 } 83 84 /* test if the prefix is mapped into the gmap shadow */ 85 static int prefix_is_mapped(struct vsie_page *vsie_page) 86 { 87 return !(atomic_read(&vsie_page->scb_s.prog20) & PROG_REQUEST); 88 } 89 90 /* copy the updated intervention request bits into the shadow scb */ 91 static void update_intervention_requests(struct vsie_page *vsie_page) 92 { 93 const int bits = CPUSTAT_STOP_INT | CPUSTAT_IO_INT | CPUSTAT_EXT_INT; 94 int cpuflags; 95 96 cpuflags = atomic_read(&vsie_page->scb_o->cpuflags); 97 atomic_andnot(bits, &vsie_page->scb_s.cpuflags); 98 atomic_or(cpuflags & bits, &vsie_page->scb_s.cpuflags); 99 } 100 101 /* shadow (filter and validate) the cpuflags */ 102 static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 103 { 104 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 105 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 106 int newflags, cpuflags = atomic_read(&scb_o->cpuflags); 107 108 /* we don't allow ESA/390 guests */ 109 if (!(cpuflags & CPUSTAT_ZARCH)) 110 return set_validity_icpt(scb_s, 0x0001U); 111 112 if (cpuflags & (CPUSTAT_RRF | CPUSTAT_MCDS)) 113 return set_validity_icpt(scb_s, 0x0001U); 114 else if (cpuflags & (CPUSTAT_SLSV | CPUSTAT_SLSR)) 115 return set_validity_icpt(scb_s, 0x0007U); 116 117 /* intervention requests will be set later */ 118 newflags = CPUSTAT_ZARCH; 119 if (cpuflags & CPUSTAT_GED && test_kvm_facility(vcpu->kvm, 8)) 120 newflags |= CPUSTAT_GED; 121 if (cpuflags & CPUSTAT_GED2 && test_kvm_facility(vcpu->kvm, 78)) { 122 if (cpuflags & CPUSTAT_GED) 123 return set_validity_icpt(scb_s, 0x0001U); 124 newflags |= CPUSTAT_GED2; 125 } 126 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GPERE)) 127 newflags |= cpuflags & CPUSTAT_P; 128 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_GSLS)) 129 newflags |= cpuflags & CPUSTAT_SM; 130 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS)) 131 newflags |= cpuflags & CPUSTAT_IBS; 132 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS)) 133 newflags |= cpuflags & CPUSTAT_KSS; 134 135 atomic_set(&scb_s->cpuflags, newflags); 136 return 0; 137 } 138 /* Copy to APCB FORMAT1 from APCB FORMAT0 */ 139 static int setup_apcb10(struct kvm_vcpu *vcpu, struct kvm_s390_apcb1 *apcb_s, 140 unsigned long apcb_o, struct kvm_s390_apcb1 *apcb_h) 141 { 142 struct kvm_s390_apcb0 tmp; 143 144 if (read_guest_real(vcpu, apcb_o, &tmp, sizeof(struct kvm_s390_apcb0))) 145 return -EFAULT; 146 147 apcb_s->apm[0] = apcb_h->apm[0] & tmp.apm[0]; 148 apcb_s->aqm[0] = apcb_h->aqm[0] & tmp.aqm[0] & 0xffff000000000000UL; 149 apcb_s->adm[0] = apcb_h->adm[0] & tmp.adm[0] & 0xffff000000000000UL; 150 151 return 0; 152 153 } 154 155 /** 156 * setup_apcb00 - Copy to APCB FORMAT0 from APCB FORMAT0 157 * @vcpu: pointer to the virtual CPU 158 * @apcb_s: pointer to start of apcb in the shadow crycb 159 * @apcb_o: pointer to start of original apcb in the guest2 160 * @apcb_h: pointer to start of apcb in the guest1 161 * 162 * Returns 0 and -EFAULT on error reading guest apcb 163 */ 164 static int setup_apcb00(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 165 unsigned long apcb_o, unsigned long *apcb_h) 166 { 167 if (read_guest_real(vcpu, apcb_o, apcb_s, 168 sizeof(struct kvm_s390_apcb0))) 169 return -EFAULT; 170 171 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb0)); 172 173 return 0; 174 } 175 176 /** 177 * setup_apcb11 - Copy the FORMAT1 APCB from the guest to the shadow CRYCB 178 * @vcpu: pointer to the virtual CPU 179 * @apcb_s: pointer to start of apcb in the shadow crycb 180 * @apcb_o: pointer to start of original guest apcb 181 * @apcb_h: pointer to start of apcb in the host 182 * 183 * Returns 0 and -EFAULT on error reading guest apcb 184 */ 185 static int setup_apcb11(struct kvm_vcpu *vcpu, unsigned long *apcb_s, 186 unsigned long apcb_o, 187 unsigned long *apcb_h) 188 { 189 if (read_guest_real(vcpu, apcb_o, apcb_s, 190 sizeof(struct kvm_s390_apcb1))) 191 return -EFAULT; 192 193 bitmap_and(apcb_s, apcb_s, apcb_h, sizeof(struct kvm_s390_apcb1)); 194 195 return 0; 196 } 197 198 /** 199 * setup_apcb - Create a shadow copy of the apcb. 200 * @vcpu: pointer to the virtual CPU 201 * @crycb_s: pointer to shadow crycb 202 * @crycb_o: pointer to original guest crycb 203 * @crycb_h: pointer to the host crycb 204 * @fmt_o: format of the original guest crycb. 205 * @fmt_h: format of the host crycb. 206 * 207 * Checks the compatibility between the guest and host crycb and calls the 208 * appropriate copy function. 209 * 210 * Return 0 or an error number if the guest and host crycb are incompatible. 211 */ 212 static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 213 const u32 crycb_o, 214 struct kvm_s390_crypto_cb *crycb_h, 215 int fmt_o, int fmt_h) 216 { 217 struct kvm_s390_crypto_cb *crycb; 218 219 crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o; 220 221 switch (fmt_o) { 222 case CRYCB_FORMAT2: 223 if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK)) 224 return -EACCES; 225 if (fmt_h != CRYCB_FORMAT2) 226 return -EINVAL; 227 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 228 (unsigned long) &crycb->apcb1, 229 (unsigned long *)&crycb_h->apcb1); 230 case CRYCB_FORMAT1: 231 switch (fmt_h) { 232 case CRYCB_FORMAT2: 233 return setup_apcb10(vcpu, &crycb_s->apcb1, 234 (unsigned long) &crycb->apcb0, 235 &crycb_h->apcb1); 236 case CRYCB_FORMAT1: 237 return setup_apcb00(vcpu, 238 (unsigned long *) &crycb_s->apcb0, 239 (unsigned long) &crycb->apcb0, 240 (unsigned long *) &crycb_h->apcb0); 241 } 242 break; 243 case CRYCB_FORMAT0: 244 if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK)) 245 return -EACCES; 246 247 switch (fmt_h) { 248 case CRYCB_FORMAT2: 249 return setup_apcb10(vcpu, &crycb_s->apcb1, 250 (unsigned long) &crycb->apcb0, 251 &crycb_h->apcb1); 252 case CRYCB_FORMAT1: 253 case CRYCB_FORMAT0: 254 return setup_apcb00(vcpu, 255 (unsigned long *) &crycb_s->apcb0, 256 (unsigned long) &crycb->apcb0, 257 (unsigned long *) &crycb_h->apcb0); 258 } 259 } 260 return -EINVAL; 261 } 262 263 /** 264 * shadow_crycb - Create a shadow copy of the crycb block 265 * @vcpu: a pointer to the virtual CPU 266 * @vsie_page: a pointer to internal date used for the vSIE 267 * 268 * Create a shadow copy of the crycb block and setup key wrapping, if 269 * requested for guest 3 and enabled for guest 2. 270 * 271 * We accept format-1 or format-2, but we convert format-1 into format-2 272 * in the shadow CRYCB. 273 * Using format-2 enables the firmware to choose the right format when 274 * scheduling the SIE. 275 * There is nothing to do for format-0. 276 * 277 * This function centralize the issuing of set_validity_icpt() for all 278 * the subfunctions working on the crycb. 279 * 280 * Returns: - 0 if shadowed or nothing to do 281 * - > 0 if control has to be given to guest 2 282 */ 283 static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 284 { 285 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 286 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 287 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 288 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 289 unsigned long *b1, *b2; 290 u8 ecb3_flags; 291 u32 ecd_flags; 292 int apie_h; 293 int apie_s; 294 int key_msk = test_kvm_facility(vcpu->kvm, 76); 295 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 296 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 297 int ret = 0; 298 299 scb_s->crycbd = 0; 300 301 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 302 apie_s = apie_h & scb_o->eca; 303 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 304 return 0; 305 306 if (!crycb_addr) 307 return set_validity_icpt(scb_s, 0x0039U); 308 309 if (fmt_o == CRYCB_FORMAT1) 310 if ((crycb_addr & PAGE_MASK) != 311 ((crycb_addr + 128) & PAGE_MASK)) 312 return set_validity_icpt(scb_s, 0x003CU); 313 314 if (apie_s) { 315 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 316 vcpu->kvm->arch.crypto.crycb, 317 fmt_o, fmt_h); 318 if (ret) 319 goto end; 320 scb_s->eca |= scb_o->eca & ECA_APIE; 321 } 322 323 /* we may only allow it if enabled for guest 2 */ 324 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 325 (ECB3_AES | ECB3_DEA); 326 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; 327 if (!ecb3_flags && !ecd_flags) 328 goto end; 329 330 /* copy only the wrapping keys */ 331 if (read_guest_real(vcpu, crycb_addr + 72, 332 vsie_page->crycb.dea_wrapping_key_mask, 56)) 333 return set_validity_icpt(scb_s, 0x0035U); 334 335 scb_s->ecb3 |= ecb3_flags; 336 scb_s->ecd |= ecd_flags; 337 338 /* xor both blocks in one run */ 339 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 340 b2 = (unsigned long *) 341 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 342 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 343 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 344 end: 345 switch (ret) { 346 case -EINVAL: 347 return set_validity_icpt(scb_s, 0x0022U); 348 case -EFAULT: 349 return set_validity_icpt(scb_s, 0x0035U); 350 case -EACCES: 351 return set_validity_icpt(scb_s, 0x003CU); 352 } 353 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; 354 return 0; 355 } 356 357 /* shadow (round up/down) the ibc to avoid validity icpt */ 358 static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 359 { 360 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 361 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 362 /* READ_ONCE does not work on bitfields - use a temporary variable */ 363 const uint32_t __new_ibc = scb_o->ibc; 364 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 365 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 366 367 scb_s->ibc = 0; 368 /* ibc installed in g2 and requested for g3 */ 369 if (vcpu->kvm->arch.model.ibc && new_ibc) { 370 scb_s->ibc = new_ibc; 371 /* takte care of the minimum ibc level of the machine */ 372 if (scb_s->ibc < min_ibc) 373 scb_s->ibc = min_ibc; 374 /* take care of the maximum ibc level set for the guest */ 375 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 376 scb_s->ibc = vcpu->kvm->arch.model.ibc; 377 } 378 } 379 380 /* unshadow the scb, copying parameters back to the real scb */ 381 static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 382 { 383 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 384 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 385 386 /* interception */ 387 scb_o->icptcode = scb_s->icptcode; 388 scb_o->icptstatus = scb_s->icptstatus; 389 scb_o->ipa = scb_s->ipa; 390 scb_o->ipb = scb_s->ipb; 391 scb_o->gbea = scb_s->gbea; 392 393 /* timer */ 394 scb_o->cputm = scb_s->cputm; 395 scb_o->ckc = scb_s->ckc; 396 scb_o->todpr = scb_s->todpr; 397 398 /* guest state */ 399 scb_o->gpsw = scb_s->gpsw; 400 scb_o->gg14 = scb_s->gg14; 401 scb_o->gg15 = scb_s->gg15; 402 memcpy(scb_o->gcr, scb_s->gcr, 128); 403 scb_o->pp = scb_s->pp; 404 405 /* branch prediction */ 406 if (test_kvm_facility(vcpu->kvm, 82)) { 407 scb_o->fpf &= ~FPF_BPBC; 408 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 409 } 410 411 /* interrupt intercept */ 412 switch (scb_s->icptcode) { 413 case ICPT_PROGI: 414 case ICPT_INSTPROGI: 415 case ICPT_EXTINT: 416 memcpy((void *)((u64)scb_o + 0xc0), 417 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 418 break; 419 case ICPT_PARTEXEC: 420 /* MVPG only */ 421 memcpy((void *)((u64)scb_o + 0xc0), 422 (void *)((u64)scb_s + 0xc0), 0xd0 - 0xc0); 423 break; 424 } 425 426 if (scb_s->ihcpu != 0xffffU) 427 scb_o->ihcpu = scb_s->ihcpu; 428 } 429 430 /* 431 * Setup the shadow scb by copying and checking the relevant parts of the g2 432 * provided scb. 433 * 434 * Returns: - 0 if the scb has been shadowed 435 * - > 0 if control has to be given to guest 2 436 */ 437 static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 438 { 439 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 440 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 441 /* READ_ONCE does not work on bitfields - use a temporary variable */ 442 const uint32_t __new_prefix = scb_o->prefix; 443 const uint32_t new_prefix = READ_ONCE(__new_prefix); 444 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 445 bool had_tx = scb_s->ecb & ECB_TE; 446 unsigned long new_mso = 0; 447 int rc; 448 449 /* make sure we don't have any leftovers when reusing the scb */ 450 scb_s->icptcode = 0; 451 scb_s->eca = 0; 452 scb_s->ecb = 0; 453 scb_s->ecb2 = 0; 454 scb_s->ecb3 = 0; 455 scb_s->ecd = 0; 456 scb_s->fac = 0; 457 scb_s->fpf = 0; 458 459 rc = prepare_cpuflags(vcpu, vsie_page); 460 if (rc) 461 goto out; 462 463 /* timer */ 464 scb_s->cputm = scb_o->cputm; 465 scb_s->ckc = scb_o->ckc; 466 scb_s->todpr = scb_o->todpr; 467 scb_s->epoch = scb_o->epoch; 468 469 /* guest state */ 470 scb_s->gpsw = scb_o->gpsw; 471 scb_s->gg14 = scb_o->gg14; 472 scb_s->gg15 = scb_o->gg15; 473 memcpy(scb_s->gcr, scb_o->gcr, 128); 474 scb_s->pp = scb_o->pp; 475 476 /* interception / execution handling */ 477 scb_s->gbea = scb_o->gbea; 478 scb_s->lctl = scb_o->lctl; 479 scb_s->svcc = scb_o->svcc; 480 scb_s->ictl = scb_o->ictl; 481 /* 482 * SKEY handling functions can't deal with false setting of PTE invalid 483 * bits. Therefore we cannot provide interpretation and would later 484 * have to provide own emulation handlers. 485 */ 486 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 487 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 488 489 scb_s->icpua = scb_o->icpua; 490 491 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 492 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 493 /* if the hva of the prefix changes, we have to remap the prefix */ 494 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 495 prefix_unmapped(vsie_page); 496 /* SIE will do mso/msl validity and exception checks for us */ 497 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 498 scb_s->mso = new_mso; 499 scb_s->prefix = new_prefix; 500 501 /* We have to definetly flush the tlb if this scb never ran */ 502 if (scb_s->ihcpu != 0xffffU) 503 scb_s->ihcpu = scb_o->ihcpu; 504 505 /* MVPG and Protection Exception Interpretation are always available */ 506 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 507 /* Host-protection-interruption introduced with ESOP */ 508 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 509 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 510 /* transactional execution */ 511 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 512 /* remap the prefix is tx is toggled on */ 513 if (!had_tx) 514 prefix_unmapped(vsie_page); 515 scb_s->ecb |= ECB_TE; 516 } 517 /* branch prediction */ 518 if (test_kvm_facility(vcpu->kvm, 82)) 519 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 520 /* SIMD */ 521 if (test_kvm_facility(vcpu->kvm, 129)) { 522 scb_s->eca |= scb_o->eca & ECA_VX; 523 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 524 } 525 /* Run-time-Instrumentation */ 526 if (test_kvm_facility(vcpu->kvm, 64)) 527 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 528 /* Instruction Execution Prevention */ 529 if (test_kvm_facility(vcpu->kvm, 130)) 530 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 531 /* Guarded Storage */ 532 if (test_kvm_facility(vcpu->kvm, 133)) { 533 scb_s->ecb |= scb_o->ecb & ECB_GS; 534 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 535 } 536 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 537 scb_s->eca |= scb_o->eca & ECA_SII; 538 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 539 scb_s->eca |= scb_o->eca & ECA_IB; 540 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 541 scb_s->eca |= scb_o->eca & ECA_CEI; 542 /* Epoch Extension */ 543 if (test_kvm_facility(vcpu->kvm, 139)) 544 scb_s->ecd |= scb_o->ecd & ECD_MEF; 545 546 /* etoken */ 547 if (test_kvm_facility(vcpu->kvm, 156)) 548 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 549 550 scb_s->hpid = HPID_VSIE; 551 552 prepare_ibc(vcpu, vsie_page); 553 rc = shadow_crycb(vcpu, vsie_page); 554 out: 555 if (rc) 556 unshadow_scb(vcpu, vsie_page); 557 return rc; 558 } 559 560 void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 561 unsigned long end) 562 { 563 struct kvm *kvm = gmap->private; 564 struct vsie_page *cur; 565 unsigned long prefix; 566 struct page *page; 567 int i; 568 569 if (!gmap_is_shadow(gmap)) 570 return; 571 if (start >= 1UL << 31) 572 /* We are only interested in prefix pages */ 573 return; 574 575 /* 576 * Only new shadow blocks are added to the list during runtime, 577 * therefore we can safely reference them all the time. 578 */ 579 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 580 page = READ_ONCE(kvm->arch.vsie.pages[i]); 581 if (!page) 582 continue; 583 cur = page_to_virt(page); 584 if (READ_ONCE(cur->gmap) != gmap) 585 continue; 586 prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT; 587 /* with mso/msl, the prefix lies at an offset */ 588 prefix += cur->scb_s.mso; 589 if (prefix <= end && start <= prefix + 2 * PAGE_SIZE - 1) 590 prefix_unmapped_sync(cur); 591 } 592 } 593 594 /* 595 * Map the first prefix page and if tx is enabled also the second prefix page. 596 * 597 * The prefix will be protected, a gmap notifier will inform about unmaps. 598 * The shadow scb must not be executed until the prefix is remapped, this is 599 * guaranteed by properly handling PROG_REQUEST. 600 * 601 * Returns: - 0 on if successfully mapped or already mapped 602 * - > 0 if control has to be given to guest 2 603 * - -EAGAIN if the caller can retry immediately 604 * - -ENOMEM if out of memory 605 */ 606 static int map_prefix(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 607 { 608 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 609 u64 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 610 int rc; 611 612 if (prefix_is_mapped(vsie_page)) 613 return 0; 614 615 /* mark it as mapped so we can catch any concurrent unmappers */ 616 prefix_mapped(vsie_page); 617 618 /* with mso/msl, the prefix lies at offset *mso* */ 619 prefix += scb_s->mso; 620 621 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, prefix); 622 if (!rc && (scb_s->ecb & ECB_TE)) 623 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 624 prefix + PAGE_SIZE); 625 /* 626 * We don't have to mprotect, we will be called for all unshadows. 627 * SIE will detect if protection applies and trigger a validity. 628 */ 629 if (rc) 630 prefix_unmapped(vsie_page); 631 if (rc > 0 || rc == -EFAULT) 632 rc = set_validity_icpt(scb_s, 0x0037U); 633 return rc; 634 } 635 636 /* 637 * Pin the guest page given by gpa and set hpa to the pinned host address. 638 * Will always be pinned writable. 639 * 640 * Returns: - 0 on success 641 * - -EINVAL if the gpa is not valid guest storage 642 */ 643 static int pin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t *hpa) 644 { 645 struct page *page; 646 647 page = gfn_to_page(kvm, gpa_to_gfn(gpa)); 648 if (is_error_page(page)) 649 return -EINVAL; 650 *hpa = (hpa_t) page_to_virt(page) + (gpa & ~PAGE_MASK); 651 return 0; 652 } 653 654 /* Unpins a page previously pinned via pin_guest_page, marking it as dirty. */ 655 static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa) 656 { 657 kvm_release_pfn_dirty(hpa >> PAGE_SHIFT); 658 /* mark the page always as dirty for migration */ 659 mark_page_dirty(kvm, gpa_to_gfn(gpa)); 660 } 661 662 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */ 663 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 664 { 665 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 666 hpa_t hpa; 667 668 hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol; 669 if (hpa) { 670 unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa); 671 vsie_page->sca_gpa = 0; 672 scb_s->scaol = 0; 673 scb_s->scaoh = 0; 674 } 675 676 hpa = scb_s->itdba; 677 if (hpa) { 678 unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa); 679 vsie_page->itdba_gpa = 0; 680 scb_s->itdba = 0; 681 } 682 683 hpa = scb_s->gvrd; 684 if (hpa) { 685 unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa); 686 vsie_page->gvrd_gpa = 0; 687 scb_s->gvrd = 0; 688 } 689 690 hpa = scb_s->riccbd; 691 if (hpa) { 692 unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa); 693 vsie_page->riccbd_gpa = 0; 694 scb_s->riccbd = 0; 695 } 696 697 hpa = scb_s->sdnxo; 698 if (hpa) { 699 unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa); 700 vsie_page->sdnx_gpa = 0; 701 scb_s->sdnxo = 0; 702 } 703 } 704 705 /* 706 * Instead of shadowing some blocks, we can simply forward them because the 707 * addresses in the scb are 64 bit long. 708 * 709 * This works as long as the data lies in one page. If blocks ever exceed one 710 * page, we have to fall back to shadowing. 711 * 712 * As we reuse the sca, the vcpu pointers contained in it are invalid. We must 713 * therefore not enable any facilities that access these pointers (e.g. SIGPIF). 714 * 715 * Returns: - 0 if all blocks were pinned. 716 * - > 0 if control has to be given to guest 2 717 * - -ENOMEM if out of memory 718 */ 719 static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 720 { 721 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 722 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 723 hpa_t hpa; 724 gpa_t gpa; 725 int rc = 0; 726 727 gpa = READ_ONCE(scb_o->scaol) & ~0xfUL; 728 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO)) 729 gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32; 730 if (gpa) { 731 if (gpa < 2 * PAGE_SIZE) 732 rc = set_validity_icpt(scb_s, 0x0038U); 733 else if ((gpa & ~0x1fffUL) == kvm_s390_get_prefix(vcpu)) 734 rc = set_validity_icpt(scb_s, 0x0011U); 735 else if ((gpa & PAGE_MASK) != 736 ((gpa + sizeof(struct bsca_block) - 1) & PAGE_MASK)) 737 rc = set_validity_icpt(scb_s, 0x003bU); 738 if (!rc) { 739 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 740 if (rc) 741 rc = set_validity_icpt(scb_s, 0x0034U); 742 } 743 if (rc) 744 goto unpin; 745 vsie_page->sca_gpa = gpa; 746 scb_s->scaoh = (u32)((u64)hpa >> 32); 747 scb_s->scaol = (u32)(u64)hpa; 748 } 749 750 gpa = READ_ONCE(scb_o->itdba) & ~0xffUL; 751 if (gpa && (scb_s->ecb & ECB_TE)) { 752 if (gpa < 2 * PAGE_SIZE) { 753 rc = set_validity_icpt(scb_s, 0x0080U); 754 goto unpin; 755 } 756 /* 256 bytes cannot cross page boundaries */ 757 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 758 if (rc) { 759 rc = set_validity_icpt(scb_s, 0x0080U); 760 goto unpin; 761 } 762 vsie_page->itdba_gpa = gpa; 763 scb_s->itdba = hpa; 764 } 765 766 gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL; 767 if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) { 768 if (gpa < 2 * PAGE_SIZE) { 769 rc = set_validity_icpt(scb_s, 0x1310U); 770 goto unpin; 771 } 772 /* 773 * 512 bytes vector registers cannot cross page boundaries 774 * if this block gets bigger, we have to shadow it. 775 */ 776 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 777 if (rc) { 778 rc = set_validity_icpt(scb_s, 0x1310U); 779 goto unpin; 780 } 781 vsie_page->gvrd_gpa = gpa; 782 scb_s->gvrd = hpa; 783 } 784 785 gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL; 786 if (gpa && (scb_s->ecb3 & ECB3_RI)) { 787 if (gpa < 2 * PAGE_SIZE) { 788 rc = set_validity_icpt(scb_s, 0x0043U); 789 goto unpin; 790 } 791 /* 64 bytes cannot cross page boundaries */ 792 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 793 if (rc) { 794 rc = set_validity_icpt(scb_s, 0x0043U); 795 goto unpin; 796 } 797 /* Validity 0x0044 will be checked by SIE */ 798 vsie_page->riccbd_gpa = gpa; 799 scb_s->riccbd = hpa; 800 } 801 if (((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) || 802 (scb_s->ecd & ECD_ETOKENF)) { 803 unsigned long sdnxc; 804 805 gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL; 806 sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL; 807 if (!gpa || gpa < 2 * PAGE_SIZE) { 808 rc = set_validity_icpt(scb_s, 0x10b0U); 809 goto unpin; 810 } 811 if (sdnxc < 6 || sdnxc > 12) { 812 rc = set_validity_icpt(scb_s, 0x10b1U); 813 goto unpin; 814 } 815 if (gpa & ((1 << sdnxc) - 1)) { 816 rc = set_validity_icpt(scb_s, 0x10b2U); 817 goto unpin; 818 } 819 /* Due to alignment rules (checked above) this cannot 820 * cross page boundaries 821 */ 822 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 823 if (rc) { 824 rc = set_validity_icpt(scb_s, 0x10b0U); 825 goto unpin; 826 } 827 vsie_page->sdnx_gpa = gpa; 828 scb_s->sdnxo = hpa | sdnxc; 829 } 830 return 0; 831 unpin: 832 unpin_blocks(vcpu, vsie_page); 833 return rc; 834 } 835 836 /* unpin the scb provided by guest 2, marking it as dirty */ 837 static void unpin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 838 gpa_t gpa) 839 { 840 hpa_t hpa = (hpa_t) vsie_page->scb_o; 841 842 if (hpa) 843 unpin_guest_page(vcpu->kvm, gpa, hpa); 844 vsie_page->scb_o = NULL; 845 } 846 847 /* 848 * Pin the scb at gpa provided by guest 2 at vsie_page->scb_o. 849 * 850 * Returns: - 0 if the scb was pinned. 851 * - > 0 if control has to be given to guest 2 852 */ 853 static int pin_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, 854 gpa_t gpa) 855 { 856 hpa_t hpa; 857 int rc; 858 859 rc = pin_guest_page(vcpu->kvm, gpa, &hpa); 860 if (rc) { 861 rc = kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); 862 WARN_ON_ONCE(rc); 863 return 1; 864 } 865 vsie_page->scb_o = (struct kvm_s390_sie_block *) hpa; 866 return 0; 867 } 868 869 /* 870 * Inject a fault into guest 2. 871 * 872 * Returns: - > 0 if control has to be given to guest 2 873 * < 0 if an error occurred during injection. 874 */ 875 static int inject_fault(struct kvm_vcpu *vcpu, __u16 code, __u64 vaddr, 876 bool write_flag) 877 { 878 struct kvm_s390_pgm_info pgm = { 879 .code = code, 880 .trans_exc_code = 881 /* 0-51: virtual address */ 882 (vaddr & 0xfffffffffffff000UL) | 883 /* 52-53: store / fetch */ 884 (((unsigned int) !write_flag) + 1) << 10, 885 /* 62-63: asce id (alway primary == 0) */ 886 .exc_access_id = 0, /* always primary */ 887 .op_access_id = 0, /* not MVPG */ 888 }; 889 int rc; 890 891 if (code == PGM_PROTECTION) 892 pgm.trans_exc_code |= 0x4UL; 893 894 rc = kvm_s390_inject_prog_irq(vcpu, &pgm); 895 return rc ? rc : 1; 896 } 897 898 /* 899 * Handle a fault during vsie execution on a gmap shadow. 900 * 901 * Returns: - 0 if the fault was resolved 902 * - > 0 if control has to be given to guest 2 903 * - < 0 if an error occurred 904 */ 905 static int handle_fault(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 906 { 907 int rc; 908 909 if (current->thread.gmap_int_code == PGM_PROTECTION) 910 /* we can directly forward all protection exceptions */ 911 return inject_fault(vcpu, PGM_PROTECTION, 912 current->thread.gmap_addr, 1); 913 914 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 915 current->thread.gmap_addr); 916 if (rc > 0) { 917 rc = inject_fault(vcpu, rc, 918 current->thread.gmap_addr, 919 current->thread.gmap_write_flag); 920 if (rc >= 0) 921 vsie_page->fault_addr = current->thread.gmap_addr; 922 } 923 return rc; 924 } 925 926 /* 927 * Retry the previous fault that required guest 2 intervention. This avoids 928 * one superfluous SIE re-entry and direct exit. 929 * 930 * Will ignore any errors. The next SIE fault will do proper fault handling. 931 */ 932 static void handle_last_fault(struct kvm_vcpu *vcpu, 933 struct vsie_page *vsie_page) 934 { 935 if (vsie_page->fault_addr) 936 kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 937 vsie_page->fault_addr); 938 vsie_page->fault_addr = 0; 939 } 940 941 static inline void clear_vsie_icpt(struct vsie_page *vsie_page) 942 { 943 vsie_page->scb_s.icptcode = 0; 944 } 945 946 /* rewind the psw and clear the vsie icpt, so we can retry execution */ 947 static void retry_vsie_icpt(struct vsie_page *vsie_page) 948 { 949 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 950 int ilen = insn_length(scb_s->ipa >> 8); 951 952 /* take care of EXECUTE instructions */ 953 if (scb_s->icptstatus & 1) { 954 ilen = (scb_s->icptstatus >> 4) & 0x6; 955 if (!ilen) 956 ilen = 4; 957 } 958 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, ilen); 959 clear_vsie_icpt(vsie_page); 960 } 961 962 /* 963 * Try to shadow + enable the guest 2 provided facility list. 964 * Retry instruction execution if enabled for and provided by guest 2. 965 * 966 * Returns: - 0 if handled (retry or guest 2 icpt) 967 * - > 0 if control has to be given to guest 2 968 */ 969 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 970 { 971 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 972 __u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U; 973 974 if (fac && test_kvm_facility(vcpu->kvm, 7)) { 975 retry_vsie_icpt(vsie_page); 976 if (read_guest_real(vcpu, fac, &vsie_page->fac, 977 sizeof(vsie_page->fac))) 978 return set_validity_icpt(scb_s, 0x1090U); 979 scb_s->fac = (__u32)(__u64) &vsie_page->fac; 980 } 981 return 0; 982 } 983 984 /* 985 * Run the vsie on a shadow scb and a shadow gmap, without any further 986 * sanity checks, handling SIE faults. 987 * 988 * Returns: - 0 everything went fine 989 * - > 0 if control has to be given to guest 2 990 * - < 0 if an error occurred 991 */ 992 static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 993 __releases(vcpu->kvm->srcu) 994 __acquires(vcpu->kvm->srcu) 995 { 996 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 997 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 998 int guest_bp_isolation; 999 int rc = 0; 1000 1001 handle_last_fault(vcpu, vsie_page); 1002 1003 if (need_resched()) 1004 schedule(); 1005 if (test_cpu_flag(CIF_MCCK_PENDING)) 1006 s390_handle_mcck(); 1007 1008 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); 1009 1010 /* save current guest state of bp isolation override */ 1011 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1012 1013 /* 1014 * The guest is running with BPBC, so we have to force it on for our 1015 * nested guest. This is done by enabling BPBC globally, so the BPBC 1016 * control in the SCB (which the nested guest can modify) is simply 1017 * ignored. 1018 */ 1019 if (test_kvm_facility(vcpu->kvm, 82) && 1020 vcpu->arch.sie_block->fpf & FPF_BPBC) 1021 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1022 1023 local_irq_disable(); 1024 guest_enter_irqoff(); 1025 local_irq_enable(); 1026 1027 /* 1028 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1029 * and VCPU requests also hinder the vSIE from running and lead 1030 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1031 * also kick the vSIE. 1032 */ 1033 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1034 barrier(); 1035 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) 1036 rc = sie64a(scb_s, vcpu->run->s.regs.gprs); 1037 barrier(); 1038 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1039 1040 local_irq_disable(); 1041 guest_exit_irqoff(); 1042 local_irq_enable(); 1043 1044 /* restore guest state for bp isolation override */ 1045 if (!guest_bp_isolation) 1046 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1047 1048 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); 1049 1050 if (rc == -EINTR) { 1051 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1052 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1053 return 0; 1054 } 1055 1056 if (rc > 0) 1057 rc = 0; /* we could still have an icpt */ 1058 else if (rc == -EFAULT) 1059 return handle_fault(vcpu, vsie_page); 1060 1061 switch (scb_s->icptcode) { 1062 case ICPT_INST: 1063 if (scb_s->ipa == 0xb2b0) 1064 rc = handle_stfle(vcpu, vsie_page); 1065 break; 1066 case ICPT_STOP: 1067 /* stop not requested by g2 - must have been a kick */ 1068 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1069 clear_vsie_icpt(vsie_page); 1070 break; 1071 case ICPT_VALIDITY: 1072 if ((scb_s->ipa & 0xf000) != 0xf000) 1073 scb_s->ipa += 0x1000; 1074 break; 1075 } 1076 return rc; 1077 } 1078 1079 static void release_gmap_shadow(struct vsie_page *vsie_page) 1080 { 1081 if (vsie_page->gmap) 1082 gmap_put(vsie_page->gmap); 1083 WRITE_ONCE(vsie_page->gmap, NULL); 1084 prefix_unmapped(vsie_page); 1085 } 1086 1087 static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1088 struct vsie_page *vsie_page) 1089 { 1090 unsigned long asce; 1091 union ctlreg0 cr0; 1092 struct gmap *gmap; 1093 int edat; 1094 1095 asce = vcpu->arch.sie_block->gcr[1]; 1096 cr0.val = vcpu->arch.sie_block->gcr[0]; 1097 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1098 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1099 1100 /* 1101 * ASCE or EDAT could have changed since last icpt, or the gmap 1102 * we're holding has been unshadowed. If the gmap is still valid, 1103 * we can safely reuse it. 1104 */ 1105 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) 1106 return 0; 1107 1108 /* release the old shadow - if any, and mark the prefix as unmapped */ 1109 release_gmap_shadow(vsie_page); 1110 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1111 if (IS_ERR(gmap)) 1112 return PTR_ERR(gmap); 1113 gmap->private = vcpu->kvm; 1114 WRITE_ONCE(vsie_page->gmap, gmap); 1115 return 0; 1116 } 1117 1118 /* 1119 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1120 */ 1121 static void register_shadow_scb(struct kvm_vcpu *vcpu, 1122 struct vsie_page *vsie_page) 1123 { 1124 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1125 1126 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1127 /* 1128 * External calls have to lead to a kick of the vcpu and 1129 * therefore the vsie -> Simulate Wait state. 1130 */ 1131 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1132 /* 1133 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1134 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1135 */ 1136 preempt_disable(); 1137 scb_s->epoch += vcpu->kvm->arch.epoch; 1138 1139 if (scb_s->ecd & ECD_MEF) { 1140 scb_s->epdx += vcpu->kvm->arch.epdx; 1141 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1142 scb_s->epdx += 1; 1143 } 1144 1145 preempt_enable(); 1146 } 1147 1148 /* 1149 * Unregister a shadow scb from a VCPU. 1150 */ 1151 static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1152 { 1153 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1154 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1155 } 1156 1157 /* 1158 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1159 * prefix pages and faults. 1160 * 1161 * Returns: - 0 if no errors occurred 1162 * - > 0 if control has to be given to guest 2 1163 * - -ENOMEM if out of memory 1164 */ 1165 static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1166 { 1167 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1168 int rc = 0; 1169 1170 while (1) { 1171 rc = acquire_gmap_shadow(vcpu, vsie_page); 1172 if (!rc) 1173 rc = map_prefix(vcpu, vsie_page); 1174 if (!rc) { 1175 gmap_enable(vsie_page->gmap); 1176 update_intervention_requests(vsie_page); 1177 rc = do_vsie_run(vcpu, vsie_page); 1178 gmap_enable(vcpu->arch.gmap); 1179 } 1180 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1181 1182 if (rc == -EAGAIN) 1183 rc = 0; 1184 if (rc || scb_s->icptcode || signal_pending(current) || 1185 kvm_s390_vcpu_has_irq(vcpu, 0) || 1186 kvm_s390_vcpu_sie_inhibited(vcpu)) 1187 break; 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 } 1206 return rc; 1207 } 1208 1209 /* 1210 * Get or create a vsie page for a scb address. 1211 * 1212 * Returns: - address of a vsie page (cached or new one) 1213 * - NULL if the same scb address is already used by another VCPU 1214 * - ERR_PTR(-ENOMEM) if out of memory 1215 */ 1216 static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1217 { 1218 struct vsie_page *vsie_page; 1219 struct page *page; 1220 int nr_vcpus; 1221 1222 rcu_read_lock(); 1223 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1224 rcu_read_unlock(); 1225 if (page) { 1226 if (page_ref_inc_return(page) == 2) 1227 return page_to_virt(page); 1228 page_ref_dec(page); 1229 } 1230 1231 /* 1232 * We want at least #online_vcpus shadows, so every VCPU can execute 1233 * the VSIE in parallel. 1234 */ 1235 nr_vcpus = atomic_read(&kvm->online_vcpus); 1236 1237 mutex_lock(&kvm->arch.vsie.mutex); 1238 if (kvm->arch.vsie.page_count < nr_vcpus) { 1239 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA); 1240 if (!page) { 1241 mutex_unlock(&kvm->arch.vsie.mutex); 1242 return ERR_PTR(-ENOMEM); 1243 } 1244 page_ref_inc(page); 1245 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; 1246 kvm->arch.vsie.page_count++; 1247 } else { 1248 /* reuse an existing entry that belongs to nobody */ 1249 while (true) { 1250 page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1251 if (page_ref_inc_return(page) == 2) 1252 break; 1253 page_ref_dec(page); 1254 kvm->arch.vsie.next++; 1255 kvm->arch.vsie.next %= nr_vcpus; 1256 } 1257 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1258 } 1259 page->index = addr; 1260 /* double use of the same address */ 1261 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { 1262 page_ref_dec(page); 1263 mutex_unlock(&kvm->arch.vsie.mutex); 1264 return NULL; 1265 } 1266 mutex_unlock(&kvm->arch.vsie.mutex); 1267 1268 vsie_page = page_to_virt(page); 1269 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1270 release_gmap_shadow(vsie_page); 1271 vsie_page->fault_addr = 0; 1272 vsie_page->scb_s.ihcpu = 0xffffU; 1273 return vsie_page; 1274 } 1275 1276 /* put a vsie page acquired via get_vsie_page */ 1277 static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) 1278 { 1279 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); 1280 1281 page_ref_dec(page); 1282 } 1283 1284 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1285 { 1286 struct vsie_page *vsie_page; 1287 unsigned long scb_addr; 1288 int rc; 1289 1290 vcpu->stat.instruction_sie++; 1291 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1292 return -EOPNOTSUPP; 1293 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1294 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1295 1296 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1297 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1298 1299 /* 512 byte alignment */ 1300 if (unlikely(scb_addr & 0x1ffUL)) 1301 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1302 1303 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1304 kvm_s390_vcpu_sie_inhibited(vcpu)) 1305 return 0; 1306 1307 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1308 if (IS_ERR(vsie_page)) 1309 return PTR_ERR(vsie_page); 1310 else if (!vsie_page) 1311 /* double use of sie control block - simply do nothing */ 1312 return 0; 1313 1314 rc = pin_scb(vcpu, vsie_page, scb_addr); 1315 if (rc) 1316 goto out_put; 1317 rc = shadow_scb(vcpu, vsie_page); 1318 if (rc) 1319 goto out_unpin_scb; 1320 rc = pin_blocks(vcpu, vsie_page); 1321 if (rc) 1322 goto out_unshadow; 1323 register_shadow_scb(vcpu, vsie_page); 1324 rc = vsie_run(vcpu, vsie_page); 1325 unregister_shadow_scb(vcpu); 1326 unpin_blocks(vcpu, vsie_page); 1327 out_unshadow: 1328 unshadow_scb(vcpu, vsie_page); 1329 out_unpin_scb: 1330 unpin_scb(vcpu, vsie_page, scb_addr); 1331 out_put: 1332 put_vsie_page(vcpu->kvm, vsie_page); 1333 1334 return rc < 0 ? rc : 0; 1335 } 1336 1337 /* Init the vsie data structures. To be called when a vm is initialized. */ 1338 void kvm_s390_vsie_init(struct kvm *kvm) 1339 { 1340 mutex_init(&kvm->arch.vsie.mutex); 1341 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL); 1342 } 1343 1344 /* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1345 void kvm_s390_vsie_destroy(struct kvm *kvm) 1346 { 1347 struct vsie_page *vsie_page; 1348 struct page *page; 1349 int i; 1350 1351 mutex_lock(&kvm->arch.vsie.mutex); 1352 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1353 page = kvm->arch.vsie.pages[i]; 1354 kvm->arch.vsie.pages[i] = NULL; 1355 vsie_page = page_to_virt(page); 1356 release_gmap_shadow(vsie_page); 1357 /* free the radix tree entry */ 1358 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1359 __free_page(page); 1360 } 1361 kvm->arch.vsie.page_count = 0; 1362 mutex_unlock(&kvm->arch.vsie.mutex); 1363 } 1364 1365 void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1366 { 1367 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1368 1369 /* 1370 * Even if the VCPU lets go of the shadow sie block reference, it is 1371 * still valid in the cache. So we can safely kick it. 1372 */ 1373 if (scb) { 1374 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1375 if (scb->prog0c & PROG_IN_SIE) 1376 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1377 } 1378 } 1379