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 24struct 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 */ 53static 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 */ 63static 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 */ 69static 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 */ 79static 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 */ 85static 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 */ 91static 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 */ 102static 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 */ 139static 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 */ 164static 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, 172 BITS_PER_BYTE * 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 */ 186static 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, 195 BITS_PER_BYTE * sizeof(struct kvm_s390_apcb1)); 196 197 return 0; 198} 199 200/** 201 * setup_apcb - Create a shadow copy of the apcb. 202 * @vcpu: pointer to the virtual CPU 203 * @crycb_s: pointer to shadow crycb 204 * @crycb_o: pointer to original guest crycb 205 * @crycb_h: pointer to the host crycb 206 * @fmt_o: format of the original guest crycb. 207 * @fmt_h: format of the host crycb. 208 * 209 * Checks the compatibility between the guest and host crycb and calls the 210 * appropriate copy function. 211 * 212 * Return 0 or an error number if the guest and host crycb are incompatible. 213 */ 214static int setup_apcb(struct kvm_vcpu *vcpu, struct kvm_s390_crypto_cb *crycb_s, 215 const u32 crycb_o, 216 struct kvm_s390_crypto_cb *crycb_h, 217 int fmt_o, int fmt_h) 218{ 219 struct kvm_s390_crypto_cb *crycb; 220 221 crycb = (struct kvm_s390_crypto_cb *) (unsigned long)crycb_o; 222 223 switch (fmt_o) { 224 case CRYCB_FORMAT2: 225 if ((crycb_o & PAGE_MASK) != ((crycb_o + 256) & PAGE_MASK)) 226 return -EACCES; 227 if (fmt_h != CRYCB_FORMAT2) 228 return -EINVAL; 229 return setup_apcb11(vcpu, (unsigned long *)&crycb_s->apcb1, 230 (unsigned long) &crycb->apcb1, 231 (unsigned long *)&crycb_h->apcb1); 232 case CRYCB_FORMAT1: 233 switch (fmt_h) { 234 case CRYCB_FORMAT2: 235 return setup_apcb10(vcpu, &crycb_s->apcb1, 236 (unsigned long) &crycb->apcb0, 237 &crycb_h->apcb1); 238 case CRYCB_FORMAT1: 239 return setup_apcb00(vcpu, 240 (unsigned long *) &crycb_s->apcb0, 241 (unsigned long) &crycb->apcb0, 242 (unsigned long *) &crycb_h->apcb0); 243 } 244 break; 245 case CRYCB_FORMAT0: 246 if ((crycb_o & PAGE_MASK) != ((crycb_o + 32) & PAGE_MASK)) 247 return -EACCES; 248 249 switch (fmt_h) { 250 case CRYCB_FORMAT2: 251 return setup_apcb10(vcpu, &crycb_s->apcb1, 252 (unsigned long) &crycb->apcb0, 253 &crycb_h->apcb1); 254 case CRYCB_FORMAT1: 255 case CRYCB_FORMAT0: 256 return setup_apcb00(vcpu, 257 (unsigned long *) &crycb_s->apcb0, 258 (unsigned long) &crycb->apcb0, 259 (unsigned long *) &crycb_h->apcb0); 260 } 261 } 262 return -EINVAL; 263} 264 265/** 266 * shadow_crycb - Create a shadow copy of the crycb block 267 * @vcpu: a pointer to the virtual CPU 268 * @vsie_page: a pointer to internal date used for the vSIE 269 * 270 * Create a shadow copy of the crycb block and setup key wrapping, if 271 * requested for guest 3 and enabled for guest 2. 272 * 273 * We accept format-1 or format-2, but we convert format-1 into format-2 274 * in the shadow CRYCB. 275 * Using format-2 enables the firmware to choose the right format when 276 * scheduling the SIE. 277 * There is nothing to do for format-0. 278 * 279 * This function centralize the issuing of set_validity_icpt() for all 280 * the subfunctions working on the crycb. 281 * 282 * Returns: - 0 if shadowed or nothing to do 283 * - > 0 if control has to be given to guest 2 284 */ 285static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 286{ 287 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 288 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 289 const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd); 290 const u32 crycb_addr = crycbd_o & 0x7ffffff8U; 291 unsigned long *b1, *b2; 292 u8 ecb3_flags; 293 u32 ecd_flags; 294 int apie_h; 295 int apie_s; 296 int key_msk = test_kvm_facility(vcpu->kvm, 76); 297 int fmt_o = crycbd_o & CRYCB_FORMAT_MASK; 298 int fmt_h = vcpu->arch.sie_block->crycbd & CRYCB_FORMAT_MASK; 299 int ret = 0; 300 301 scb_s->crycbd = 0; 302 303 apie_h = vcpu->arch.sie_block->eca & ECA_APIE; 304 apie_s = apie_h & scb_o->eca; 305 if (!apie_s && (!key_msk || (fmt_o == CRYCB_FORMAT0))) 306 return 0; 307 308 if (!crycb_addr) 309 return set_validity_icpt(scb_s, 0x0039U); 310 311 if (fmt_o == CRYCB_FORMAT1) 312 if ((crycb_addr & PAGE_MASK) != 313 ((crycb_addr + 128) & PAGE_MASK)) 314 return set_validity_icpt(scb_s, 0x003CU); 315 316 if (apie_s) { 317 ret = setup_apcb(vcpu, &vsie_page->crycb, crycb_addr, 318 vcpu->kvm->arch.crypto.crycb, 319 fmt_o, fmt_h); 320 if (ret) 321 goto end; 322 scb_s->eca |= scb_o->eca & ECA_APIE; 323 } 324 325 /* we may only allow it if enabled for guest 2 */ 326 ecb3_flags = scb_o->ecb3 & vcpu->arch.sie_block->ecb3 & 327 (ECB3_AES | ECB3_DEA); 328 ecd_flags = scb_o->ecd & vcpu->arch.sie_block->ecd & ECD_ECC; 329 if (!ecb3_flags && !ecd_flags) 330 goto end; 331 332 /* copy only the wrapping keys */ 333 if (read_guest_real(vcpu, crycb_addr + 72, 334 vsie_page->crycb.dea_wrapping_key_mask, 56)) 335 return set_validity_icpt(scb_s, 0x0035U); 336 337 scb_s->ecb3 |= ecb3_flags; 338 scb_s->ecd |= ecd_flags; 339 340 /* xor both blocks in one run */ 341 b1 = (unsigned long *) vsie_page->crycb.dea_wrapping_key_mask; 342 b2 = (unsigned long *) 343 vcpu->kvm->arch.crypto.crycb->dea_wrapping_key_mask; 344 /* as 56%8 == 0, bitmap_xor won't overwrite any data */ 345 bitmap_xor(b1, b1, b2, BITS_PER_BYTE * 56); 346end: 347 switch (ret) { 348 case -EINVAL: 349 return set_validity_icpt(scb_s, 0x0022U); 350 case -EFAULT: 351 return set_validity_icpt(scb_s, 0x0035U); 352 case -EACCES: 353 return set_validity_icpt(scb_s, 0x003CU); 354 } 355 scb_s->crycbd = ((__u32)(__u64) &vsie_page->crycb) | CRYCB_FORMAT2; 356 return 0; 357} 358 359/* shadow (round up/down) the ibc to avoid validity icpt */ 360static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 361{ 362 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 363 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 364 /* READ_ONCE does not work on bitfields - use a temporary variable */ 365 const uint32_t __new_ibc = scb_o->ibc; 366 const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU; 367 __u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU; 368 369 scb_s->ibc = 0; 370 /* ibc installed in g2 and requested for g3 */ 371 if (vcpu->kvm->arch.model.ibc && new_ibc) { 372 scb_s->ibc = new_ibc; 373 /* takte care of the minimum ibc level of the machine */ 374 if (scb_s->ibc < min_ibc) 375 scb_s->ibc = min_ibc; 376 /* take care of the maximum ibc level set for the guest */ 377 if (scb_s->ibc > vcpu->kvm->arch.model.ibc) 378 scb_s->ibc = vcpu->kvm->arch.model.ibc; 379 } 380} 381 382/* unshadow the scb, copying parameters back to the real scb */ 383static void unshadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 384{ 385 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 386 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 387 388 /* interception */ 389 scb_o->icptcode = scb_s->icptcode; 390 scb_o->icptstatus = scb_s->icptstatus; 391 scb_o->ipa = scb_s->ipa; 392 scb_o->ipb = scb_s->ipb; 393 scb_o->gbea = scb_s->gbea; 394 395 /* timer */ 396 scb_o->cputm = scb_s->cputm; 397 scb_o->ckc = scb_s->ckc; 398 scb_o->todpr = scb_s->todpr; 399 400 /* guest state */ 401 scb_o->gpsw = scb_s->gpsw; 402 scb_o->gg14 = scb_s->gg14; 403 scb_o->gg15 = scb_s->gg15; 404 memcpy(scb_o->gcr, scb_s->gcr, 128); 405 scb_o->pp = scb_s->pp; 406 407 /* branch prediction */ 408 if (test_kvm_facility(vcpu->kvm, 82)) { 409 scb_o->fpf &= ~FPF_BPBC; 410 scb_o->fpf |= scb_s->fpf & FPF_BPBC; 411 } 412 413 /* interrupt intercept */ 414 switch (scb_s->icptcode) { 415 case ICPT_PROGI: 416 case ICPT_INSTPROGI: 417 case ICPT_EXTINT: 418 memcpy((void *)((u64)scb_o + 0xc0), 419 (void *)((u64)scb_s + 0xc0), 0xf0 - 0xc0); 420 break; 421 } 422 423 if (scb_s->ihcpu != 0xffffU) 424 scb_o->ihcpu = scb_s->ihcpu; 425} 426 427/* 428 * Setup the shadow scb by copying and checking the relevant parts of the g2 429 * provided scb. 430 * 431 * Returns: - 0 if the scb has been shadowed 432 * - > 0 if control has to be given to guest 2 433 */ 434static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 435{ 436 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 437 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 438 /* READ_ONCE does not work on bitfields - use a temporary variable */ 439 const uint32_t __new_prefix = scb_o->prefix; 440 const uint32_t new_prefix = READ_ONCE(__new_prefix); 441 const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE; 442 bool had_tx = scb_s->ecb & ECB_TE; 443 unsigned long new_mso = 0; 444 int rc; 445 446 /* make sure we don't have any leftovers when reusing the scb */ 447 scb_s->icptcode = 0; 448 scb_s->eca = 0; 449 scb_s->ecb = 0; 450 scb_s->ecb2 = 0; 451 scb_s->ecb3 = 0; 452 scb_s->ecd = 0; 453 scb_s->fac = 0; 454 scb_s->fpf = 0; 455 456 rc = prepare_cpuflags(vcpu, vsie_page); 457 if (rc) 458 goto out; 459 460 /* timer */ 461 scb_s->cputm = scb_o->cputm; 462 scb_s->ckc = scb_o->ckc; 463 scb_s->todpr = scb_o->todpr; 464 scb_s->epoch = scb_o->epoch; 465 466 /* guest state */ 467 scb_s->gpsw = scb_o->gpsw; 468 scb_s->gg14 = scb_o->gg14; 469 scb_s->gg15 = scb_o->gg15; 470 memcpy(scb_s->gcr, scb_o->gcr, 128); 471 scb_s->pp = scb_o->pp; 472 473 /* interception / execution handling */ 474 scb_s->gbea = scb_o->gbea; 475 scb_s->lctl = scb_o->lctl; 476 scb_s->svcc = scb_o->svcc; 477 scb_s->ictl = scb_o->ictl; 478 /* 479 * SKEY handling functions can't deal with false setting of PTE invalid 480 * bits. Therefore we cannot provide interpretation and would later 481 * have to provide own emulation handlers. 482 */ 483 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS)) 484 scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE; 485 486 scb_s->icpua = scb_o->icpua; 487 488 if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM)) 489 new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL; 490 /* if the hva of the prefix changes, we have to remap the prefix */ 491 if (scb_s->mso != new_mso || scb_s->prefix != new_prefix) 492 prefix_unmapped(vsie_page); 493 /* SIE will do mso/msl validity and exception checks for us */ 494 scb_s->msl = scb_o->msl & 0xfffffffffff00000UL; 495 scb_s->mso = new_mso; 496 scb_s->prefix = new_prefix; 497 498 /* We have to definetly flush the tlb if this scb never ran */ 499 if (scb_s->ihcpu != 0xffffU) 500 scb_s->ihcpu = scb_o->ihcpu; 501 502 /* MVPG and Protection Exception Interpretation are always available */ 503 scb_s->eca |= scb_o->eca & (ECA_MVPGI | ECA_PROTEXCI); 504 /* Host-protection-interruption introduced with ESOP */ 505 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP)) 506 scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT; 507 /* transactional execution */ 508 if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) { 509 /* remap the prefix is tx is toggled on */ 510 if (!had_tx) 511 prefix_unmapped(vsie_page); 512 scb_s->ecb |= ECB_TE; 513 } 514 /* branch prediction */ 515 if (test_kvm_facility(vcpu->kvm, 82)) 516 scb_s->fpf |= scb_o->fpf & FPF_BPBC; 517 /* SIMD */ 518 if (test_kvm_facility(vcpu->kvm, 129)) { 519 scb_s->eca |= scb_o->eca & ECA_VX; 520 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 521 } 522 /* Run-time-Instrumentation */ 523 if (test_kvm_facility(vcpu->kvm, 64)) 524 scb_s->ecb3 |= scb_o->ecb3 & ECB3_RI; 525 /* Instruction Execution Prevention */ 526 if (test_kvm_facility(vcpu->kvm, 130)) 527 scb_s->ecb2 |= scb_o->ecb2 & ECB2_IEP; 528 /* Guarded Storage */ 529 if (test_kvm_facility(vcpu->kvm, 133)) { 530 scb_s->ecb |= scb_o->ecb & ECB_GS; 531 scb_s->ecd |= scb_o->ecd & ECD_HOSTREGMGMT; 532 } 533 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIIF)) 534 scb_s->eca |= scb_o->eca & ECA_SII; 535 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IB)) 536 scb_s->eca |= scb_o->eca & ECA_IB; 537 if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_CEI)) 538 scb_s->eca |= scb_o->eca & ECA_CEI; 539 /* Epoch Extension */ 540 if (test_kvm_facility(vcpu->kvm, 139)) { 541 scb_s->ecd |= scb_o->ecd & ECD_MEF; 542 scb_s->epdx = scb_o->epdx; 543 } 544 545 /* etoken */ 546 if (test_kvm_facility(vcpu->kvm, 156)) 547 scb_s->ecd |= scb_o->ecd & ECD_ETOKENF; 548 549 scb_s->hpid = HPID_VSIE; 550 scb_s->cpnc = scb_o->cpnc; 551 552 prepare_ibc(vcpu, vsie_page); 553 rc = shadow_crycb(vcpu, vsie_page); 554out: 555 if (rc) 556 unshadow_scb(vcpu, vsie_page); 557 return rc; 558} 559 560void 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 */ 606static 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, NULL); 622 if (!rc && (scb_s->ecb & ECB_TE)) 623 rc = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, 624 prefix + PAGE_SIZE, NULL); 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 */ 643static 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. */ 655static 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 */ 663static 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 */ 719static 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; 831unpin: 832 unpin_blocks(vcpu, vsie_page); 833 return rc; 834} 835 836/* unpin the scb provided by guest 2, marking it as dirty */ 837static 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 */ 853static 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 */ 875static 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 */ 905static 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, NULL); 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 */ 932static 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, NULL); 938 vsie_page->fault_addr = 0; 939} 940 941static 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 */ 947static 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 */ 969static 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 * Get a register for a nested guest. 986 * @vcpu the vcpu of the guest 987 * @vsie_page the vsie_page for the nested guest 988 * @reg the register number, the upper 4 bits are ignored. 989 * returns: the value of the register. 990 */ 991static u64 vsie_get_register(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page, u8 reg) 992{ 993 /* no need to validate the parameter and/or perform error handling */ 994 reg &= 0xf; 995 switch (reg) { 996 case 15: 997 return vsie_page->scb_s.gg15; 998 case 14: 999 return vsie_page->scb_s.gg14; 1000 default: 1001 return vcpu->run->s.regs.gprs[reg]; 1002 } 1003} 1004 1005static int vsie_handle_mvpg(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1006{ 1007 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1008 unsigned long pei_dest, pei_src, src, dest, mask, prefix; 1009 u64 *pei_block = &vsie_page->scb_o->mcic; 1010 int edat, rc_dest, rc_src; 1011 union ctlreg0 cr0; 1012 1013 cr0.val = vcpu->arch.sie_block->gcr[0]; 1014 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1015 mask = _kvm_s390_logical_to_effective(&scb_s->gpsw, PAGE_MASK); 1016 prefix = scb_s->prefix << GUEST_PREFIX_SHIFT; 1017 1018 dest = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 20) & mask; 1019 dest = _kvm_s390_real_to_abs(prefix, dest) + scb_s->mso; 1020 src = vsie_get_register(vcpu, vsie_page, scb_s->ipb >> 16) & mask; 1021 src = _kvm_s390_real_to_abs(prefix, src) + scb_s->mso; 1022 1023 rc_dest = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, dest, &pei_dest); 1024 rc_src = kvm_s390_shadow_fault(vcpu, vsie_page->gmap, src, &pei_src); 1025 /* 1026 * Either everything went well, or something non-critical went wrong 1027 * e.g. because of a race. In either case, simply retry. 1028 */ 1029 if (rc_dest == -EAGAIN || rc_src == -EAGAIN || (!rc_dest && !rc_src)) { 1030 retry_vsie_icpt(vsie_page); 1031 return -EAGAIN; 1032 } 1033 /* Something more serious went wrong, propagate the error */ 1034 if (rc_dest < 0) 1035 return rc_dest; 1036 if (rc_src < 0) 1037 return rc_src; 1038 1039 /* The only possible suppressing exception: just deliver it */ 1040 if (rc_dest == PGM_TRANSLATION_SPEC || rc_src == PGM_TRANSLATION_SPEC) { 1041 clear_vsie_icpt(vsie_page); 1042 rc_dest = kvm_s390_inject_program_int(vcpu, PGM_TRANSLATION_SPEC); 1043 WARN_ON_ONCE(rc_dest); 1044 return 1; 1045 } 1046 1047 /* 1048 * Forward the PEI intercept to the guest if it was a page fault, or 1049 * also for segment and region table faults if EDAT applies. 1050 */ 1051 if (edat) { 1052 rc_dest = rc_dest == PGM_ASCE_TYPE ? rc_dest : 0; 1053 rc_src = rc_src == PGM_ASCE_TYPE ? rc_src : 0; 1054 } else { 1055 rc_dest = rc_dest != PGM_PAGE_TRANSLATION ? rc_dest : 0; 1056 rc_src = rc_src != PGM_PAGE_TRANSLATION ? rc_src : 0; 1057 } 1058 if (!rc_dest && !rc_src) { 1059 pei_block[0] = pei_dest; 1060 pei_block[1] = pei_src; 1061 return 1; 1062 } 1063 1064 retry_vsie_icpt(vsie_page); 1065 1066 /* 1067 * The host has edat, and the guest does not, or it was an ASCE type 1068 * exception. The host needs to inject the appropriate DAT interrupts 1069 * into the guest. 1070 */ 1071 if (rc_dest) 1072 return inject_fault(vcpu, rc_dest, dest, 1); 1073 return inject_fault(vcpu, rc_src, src, 0); 1074} 1075 1076/* 1077 * Run the vsie on a shadow scb and a shadow gmap, without any further 1078 * sanity checks, handling SIE faults. 1079 * 1080 * Returns: - 0 everything went fine 1081 * - > 0 if control has to be given to guest 2 1082 * - < 0 if an error occurred 1083 */ 1084static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1085 __releases(vcpu->kvm->srcu) 1086 __acquires(vcpu->kvm->srcu) 1087{ 1088 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1089 struct kvm_s390_sie_block *scb_o = vsie_page->scb_o; 1090 int guest_bp_isolation; 1091 int rc = 0; 1092 1093 handle_last_fault(vcpu, vsie_page); 1094 1095 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); 1096 1097 /* save current guest state of bp isolation override */ 1098 guest_bp_isolation = test_thread_flag(TIF_ISOLATE_BP_GUEST); 1099 1100 /* 1101 * The guest is running with BPBC, so we have to force it on for our 1102 * nested guest. This is done by enabling BPBC globally, so the BPBC 1103 * control in the SCB (which the nested guest can modify) is simply 1104 * ignored. 1105 */ 1106 if (test_kvm_facility(vcpu->kvm, 82) && 1107 vcpu->arch.sie_block->fpf & FPF_BPBC) 1108 set_thread_flag(TIF_ISOLATE_BP_GUEST); 1109 1110 local_irq_disable(); 1111 guest_enter_irqoff(); 1112 local_irq_enable(); 1113 1114 /* 1115 * Simulate a SIE entry of the VCPU (see sie64a), so VCPU blocking 1116 * and VCPU requests also hinder the vSIE from running and lead 1117 * to an immediate exit. kvm_s390_vsie_kick() has to be used to 1118 * also kick the vSIE. 1119 */ 1120 vcpu->arch.sie_block->prog0c |= PROG_IN_SIE; 1121 barrier(); 1122 if (!kvm_s390_vcpu_sie_inhibited(vcpu)) 1123 rc = sie64a(scb_s, vcpu->run->s.regs.gprs); 1124 barrier(); 1125 vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE; 1126 1127 local_irq_disable(); 1128 guest_exit_irqoff(); 1129 local_irq_enable(); 1130 1131 /* restore guest state for bp isolation override */ 1132 if (!guest_bp_isolation) 1133 clear_thread_flag(TIF_ISOLATE_BP_GUEST); 1134 1135 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); 1136 1137 if (rc == -EINTR) { 1138 VCPU_EVENT(vcpu, 3, "%s", "machine check"); 1139 kvm_s390_reinject_machine_check(vcpu, &vsie_page->mcck_info); 1140 return 0; 1141 } 1142 1143 if (rc > 0) 1144 rc = 0; /* we could still have an icpt */ 1145 else if (rc == -EFAULT) 1146 return handle_fault(vcpu, vsie_page); 1147 1148 switch (scb_s->icptcode) { 1149 case ICPT_INST: 1150 if (scb_s->ipa == 0xb2b0) 1151 rc = handle_stfle(vcpu, vsie_page); 1152 break; 1153 case ICPT_STOP: 1154 /* stop not requested by g2 - must have been a kick */ 1155 if (!(atomic_read(&scb_o->cpuflags) & CPUSTAT_STOP_INT)) 1156 clear_vsie_icpt(vsie_page); 1157 break; 1158 case ICPT_VALIDITY: 1159 if ((scb_s->ipa & 0xf000) != 0xf000) 1160 scb_s->ipa += 0x1000; 1161 break; 1162 case ICPT_PARTEXEC: 1163 if (scb_s->ipa == 0xb254) 1164 rc = vsie_handle_mvpg(vcpu, vsie_page); 1165 break; 1166 } 1167 return rc; 1168} 1169 1170static void release_gmap_shadow(struct vsie_page *vsie_page) 1171{ 1172 if (vsie_page->gmap) 1173 gmap_put(vsie_page->gmap); 1174 WRITE_ONCE(vsie_page->gmap, NULL); 1175 prefix_unmapped(vsie_page); 1176} 1177 1178static int acquire_gmap_shadow(struct kvm_vcpu *vcpu, 1179 struct vsie_page *vsie_page) 1180{ 1181 unsigned long asce; 1182 union ctlreg0 cr0; 1183 struct gmap *gmap; 1184 int edat; 1185 1186 asce = vcpu->arch.sie_block->gcr[1]; 1187 cr0.val = vcpu->arch.sie_block->gcr[0]; 1188 edat = cr0.edat && test_kvm_facility(vcpu->kvm, 8); 1189 edat += edat && test_kvm_facility(vcpu->kvm, 78); 1190 1191 /* 1192 * ASCE or EDAT could have changed since last icpt, or the gmap 1193 * we're holding has been unshadowed. If the gmap is still valid, 1194 * we can safely reuse it. 1195 */ 1196 if (vsie_page->gmap && gmap_shadow_valid(vsie_page->gmap, asce, edat)) 1197 return 0; 1198 1199 /* release the old shadow - if any, and mark the prefix as unmapped */ 1200 release_gmap_shadow(vsie_page); 1201 gmap = gmap_shadow(vcpu->arch.gmap, asce, edat); 1202 if (IS_ERR(gmap)) 1203 return PTR_ERR(gmap); 1204 gmap->private = vcpu->kvm; 1205 WRITE_ONCE(vsie_page->gmap, gmap); 1206 return 0; 1207} 1208 1209/* 1210 * Register the shadow scb at the VCPU, e.g. for kicking out of vsie. 1211 */ 1212static void register_shadow_scb(struct kvm_vcpu *vcpu, 1213 struct vsie_page *vsie_page) 1214{ 1215 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1216 1217 WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 1218 /* 1219 * External calls have to lead to a kick of the vcpu and 1220 * therefore the vsie -> Simulate Wait state. 1221 */ 1222 kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT); 1223 /* 1224 * We have to adjust the g3 epoch by the g2 epoch. The epoch will 1225 * automatically be adjusted on tod clock changes via kvm_sync_clock. 1226 */ 1227 preempt_disable(); 1228 scb_s->epoch += vcpu->kvm->arch.epoch; 1229 1230 if (scb_s->ecd & ECD_MEF) { 1231 scb_s->epdx += vcpu->kvm->arch.epdx; 1232 if (scb_s->epoch < vcpu->kvm->arch.epoch) 1233 scb_s->epdx += 1; 1234 } 1235 1236 preempt_enable(); 1237} 1238 1239/* 1240 * Unregister a shadow scb from a VCPU. 1241 */ 1242static void unregister_shadow_scb(struct kvm_vcpu *vcpu) 1243{ 1244 kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT); 1245 WRITE_ONCE(vcpu->arch.vsie_block, NULL); 1246} 1247 1248/* 1249 * Run the vsie on a shadowed scb, managing the gmap shadow, handling 1250 * prefix pages and faults. 1251 * 1252 * Returns: - 0 if no errors occurred 1253 * - > 0 if control has to be given to guest 2 1254 * - -ENOMEM if out of memory 1255 */ 1256static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) 1257{ 1258 struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s; 1259 int rc = 0; 1260 1261 while (1) { 1262 rc = acquire_gmap_shadow(vcpu, vsie_page); 1263 if (!rc) 1264 rc = map_prefix(vcpu, vsie_page); 1265 if (!rc) { 1266 gmap_enable(vsie_page->gmap); 1267 update_intervention_requests(vsie_page); 1268 rc = do_vsie_run(vcpu, vsie_page); 1269 gmap_enable(vcpu->arch.gmap); 1270 } 1271 atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20); 1272 1273 if (rc == -EAGAIN) 1274 rc = 0; 1275 if (rc || scb_s->icptcode || signal_pending(current) || 1276 kvm_s390_vcpu_has_irq(vcpu, 0) || 1277 kvm_s390_vcpu_sie_inhibited(vcpu)) 1278 break; 1279 cond_resched(); 1280 } 1281 1282 if (rc == -EFAULT) { 1283 /* 1284 * Addressing exceptions are always presentes as intercepts. 1285 * As addressing exceptions are suppressing and our guest 3 PSW 1286 * points at the responsible instruction, we have to 1287 * forward the PSW and set the ilc. If we can't read guest 3 1288 * instruction, we can use an arbitrary ilc. Let's always use 1289 * ilen = 4 for now, so we can avoid reading in guest 3 virtual 1290 * memory. (we could also fake the shadow so the hardware 1291 * handles it). 1292 */ 1293 scb_s->icptcode = ICPT_PROGI; 1294 scb_s->iprcc = PGM_ADDRESSING; 1295 scb_s->pgmilc = 4; 1296 scb_s->gpsw.addr = __rewind_psw(scb_s->gpsw, 4); 1297 rc = 1; 1298 } 1299 return rc; 1300} 1301 1302/* 1303 * Get or create a vsie page for a scb address. 1304 * 1305 * Returns: - address of a vsie page (cached or new one) 1306 * - NULL if the same scb address is already used by another VCPU 1307 * - ERR_PTR(-ENOMEM) if out of memory 1308 */ 1309static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 1310{ 1311 struct vsie_page *vsie_page; 1312 struct page *page; 1313 int nr_vcpus; 1314 1315 rcu_read_lock(); 1316 page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9); 1317 rcu_read_unlock(); 1318 if (page) { 1319 if (page_ref_inc_return(page) == 2) 1320 return page_to_virt(page); 1321 page_ref_dec(page); 1322 } 1323 1324 /* 1325 * We want at least #online_vcpus shadows, so every VCPU can execute 1326 * the VSIE in parallel. 1327 */ 1328 nr_vcpus = atomic_read(&kvm->online_vcpus); 1329 1330 mutex_lock(&kvm->arch.vsie.mutex); 1331 if (kvm->arch.vsie.page_count < nr_vcpus) { 1332 page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA); 1333 if (!page) { 1334 mutex_unlock(&kvm->arch.vsie.mutex); 1335 return ERR_PTR(-ENOMEM); 1336 } 1337 page_ref_inc(page); 1338 kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page; 1339 kvm->arch.vsie.page_count++; 1340 } else { 1341 /* reuse an existing entry that belongs to nobody */ 1342 while (true) { 1343 page = kvm->arch.vsie.pages[kvm->arch.vsie.next]; 1344 if (page_ref_inc_return(page) == 2) 1345 break; 1346 page_ref_dec(page); 1347 kvm->arch.vsie.next++; 1348 kvm->arch.vsie.next %= nr_vcpus; 1349 } 1350 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1351 } 1352 page->index = addr; 1353 /* double use of the same address */ 1354 if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) { 1355 page_ref_dec(page); 1356 mutex_unlock(&kvm->arch.vsie.mutex); 1357 return NULL; 1358 } 1359 mutex_unlock(&kvm->arch.vsie.mutex); 1360 1361 vsie_page = page_to_virt(page); 1362 memset(&vsie_page->scb_s, 0, sizeof(struct kvm_s390_sie_block)); 1363 release_gmap_shadow(vsie_page); 1364 vsie_page->fault_addr = 0; 1365 vsie_page->scb_s.ihcpu = 0xffffU; 1366 return vsie_page; 1367} 1368 1369/* put a vsie page acquired via get_vsie_page */ 1370static void put_vsie_page(struct kvm *kvm, struct vsie_page *vsie_page) 1371{ 1372 struct page *page = pfn_to_page(__pa(vsie_page) >> PAGE_SHIFT); 1373 1374 page_ref_dec(page); 1375} 1376 1377int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu) 1378{ 1379 struct vsie_page *vsie_page; 1380 unsigned long scb_addr; 1381 int rc; 1382 1383 vcpu->stat.instruction_sie++; 1384 if (!test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_SIEF2)) 1385 return -EOPNOTSUPP; 1386 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 1387 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 1388 1389 BUILD_BUG_ON(sizeof(struct vsie_page) != PAGE_SIZE); 1390 scb_addr = kvm_s390_get_base_disp_s(vcpu, NULL); 1391 1392 /* 512 byte alignment */ 1393 if (unlikely(scb_addr & 0x1ffUL)) 1394 return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION); 1395 1396 if (signal_pending(current) || kvm_s390_vcpu_has_irq(vcpu, 0) || 1397 kvm_s390_vcpu_sie_inhibited(vcpu)) 1398 return 0; 1399 1400 vsie_page = get_vsie_page(vcpu->kvm, scb_addr); 1401 if (IS_ERR(vsie_page)) 1402 return PTR_ERR(vsie_page); 1403 else if (!vsie_page) 1404 /* double use of sie control block - simply do nothing */ 1405 return 0; 1406 1407 rc = pin_scb(vcpu, vsie_page, scb_addr); 1408 if (rc) 1409 goto out_put; 1410 rc = shadow_scb(vcpu, vsie_page); 1411 if (rc) 1412 goto out_unpin_scb; 1413 rc = pin_blocks(vcpu, vsie_page); 1414 if (rc) 1415 goto out_unshadow; 1416 register_shadow_scb(vcpu, vsie_page); 1417 rc = vsie_run(vcpu, vsie_page); 1418 unregister_shadow_scb(vcpu); 1419 unpin_blocks(vcpu, vsie_page); 1420out_unshadow: 1421 unshadow_scb(vcpu, vsie_page); 1422out_unpin_scb: 1423 unpin_scb(vcpu, vsie_page, scb_addr); 1424out_put: 1425 put_vsie_page(vcpu->kvm, vsie_page); 1426 1427 return rc < 0 ? rc : 0; 1428} 1429 1430/* Init the vsie data structures. To be called when a vm is initialized. */ 1431void kvm_s390_vsie_init(struct kvm *kvm) 1432{ 1433 mutex_init(&kvm->arch.vsie.mutex); 1434 INIT_RADIX_TREE(&kvm->arch.vsie.addr_to_page, GFP_KERNEL); 1435} 1436 1437/* Destroy the vsie data structures. To be called when a vm is destroyed. */ 1438void kvm_s390_vsie_destroy(struct kvm *kvm) 1439{ 1440 struct vsie_page *vsie_page; 1441 struct page *page; 1442 int i; 1443 1444 mutex_lock(&kvm->arch.vsie.mutex); 1445 for (i = 0; i < kvm->arch.vsie.page_count; i++) { 1446 page = kvm->arch.vsie.pages[i]; 1447 kvm->arch.vsie.pages[i] = NULL; 1448 vsie_page = page_to_virt(page); 1449 release_gmap_shadow(vsie_page); 1450 /* free the radix tree entry */ 1451 radix_tree_delete(&kvm->arch.vsie.addr_to_page, page->index >> 9); 1452 __free_page(page); 1453 } 1454 kvm->arch.vsie.page_count = 0; 1455 mutex_unlock(&kvm->arch.vsie.mutex); 1456} 1457 1458void kvm_s390_vsie_kick(struct kvm_vcpu *vcpu) 1459{ 1460 struct kvm_s390_sie_block *scb = READ_ONCE(vcpu->arch.vsie_block); 1461 1462 /* 1463 * Even if the VCPU lets go of the shadow sie block reference, it is 1464 * still valid in the cache. So we can safely kick it. 1465 */ 1466 if (scb) { 1467 atomic_or(PROG_BLOCK_SIE, &scb->prog20); 1468 if (scb->prog0c & PROG_IN_SIE) 1469 atomic_or(CPUSTAT_STOP_INT, &scb->cpuflags); 1470 } 1471} 1472