1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corporation, 2018 4 * Authors Suraj Jitindar Singh <sjitindarsingh@gmail.com> 5 * Paul Mackerras <paulus@ozlabs.org> 6 * 7 * Description: KVM functions specific to running nested KVM-HV guests 8 * on Book3S processors (specifically POWER9 and later). 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/kvm_host.h> 13 #include <linux/llist.h> 14 #include <linux/pgtable.h> 15 16 #include <asm/kvm_ppc.h> 17 #include <asm/kvm_book3s.h> 18 #include <asm/mmu.h> 19 #include <asm/pgalloc.h> 20 #include <asm/pte-walk.h> 21 #include <asm/reg.h> 22 23 static struct patb_entry *pseries_partition_tb; 24 25 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp); 26 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free); 27 28 void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) 29 { 30 struct kvmppc_vcore *vc = vcpu->arch.vcore; 31 32 hr->pcr = vc->pcr | PCR_MASK; 33 hr->dpdes = vc->dpdes; 34 hr->hfscr = vcpu->arch.hfscr; 35 hr->tb_offset = vc->tb_offset; 36 hr->dawr0 = vcpu->arch.dawr; 37 hr->dawrx0 = vcpu->arch.dawrx; 38 hr->ciabr = vcpu->arch.ciabr; 39 hr->purr = vcpu->arch.purr; 40 hr->spurr = vcpu->arch.spurr; 41 hr->ic = vcpu->arch.ic; 42 hr->vtb = vc->vtb; 43 hr->srr0 = vcpu->arch.shregs.srr0; 44 hr->srr1 = vcpu->arch.shregs.srr1; 45 hr->sprg[0] = vcpu->arch.shregs.sprg0; 46 hr->sprg[1] = vcpu->arch.shregs.sprg1; 47 hr->sprg[2] = vcpu->arch.shregs.sprg2; 48 hr->sprg[3] = vcpu->arch.shregs.sprg3; 49 hr->pidr = vcpu->arch.pid; 50 hr->cfar = vcpu->arch.cfar; 51 hr->ppr = vcpu->arch.ppr; 52 } 53 54 static void byteswap_pt_regs(struct pt_regs *regs) 55 { 56 unsigned long *addr = (unsigned long *) regs; 57 58 for (; addr < ((unsigned long *) (regs + 1)); addr++) 59 *addr = swab64(*addr); 60 } 61 62 static void byteswap_hv_regs(struct hv_guest_state *hr) 63 { 64 hr->version = swab64(hr->version); 65 hr->lpid = swab32(hr->lpid); 66 hr->vcpu_token = swab32(hr->vcpu_token); 67 hr->lpcr = swab64(hr->lpcr); 68 hr->pcr = swab64(hr->pcr) | PCR_MASK; 69 hr->amor = swab64(hr->amor); 70 hr->dpdes = swab64(hr->dpdes); 71 hr->hfscr = swab64(hr->hfscr); 72 hr->tb_offset = swab64(hr->tb_offset); 73 hr->dawr0 = swab64(hr->dawr0); 74 hr->dawrx0 = swab64(hr->dawrx0); 75 hr->ciabr = swab64(hr->ciabr); 76 hr->hdec_expiry = swab64(hr->hdec_expiry); 77 hr->purr = swab64(hr->purr); 78 hr->spurr = swab64(hr->spurr); 79 hr->ic = swab64(hr->ic); 80 hr->vtb = swab64(hr->vtb); 81 hr->hdar = swab64(hr->hdar); 82 hr->hdsisr = swab64(hr->hdsisr); 83 hr->heir = swab64(hr->heir); 84 hr->asdr = swab64(hr->asdr); 85 hr->srr0 = swab64(hr->srr0); 86 hr->srr1 = swab64(hr->srr1); 87 hr->sprg[0] = swab64(hr->sprg[0]); 88 hr->sprg[1] = swab64(hr->sprg[1]); 89 hr->sprg[2] = swab64(hr->sprg[2]); 90 hr->sprg[3] = swab64(hr->sprg[3]); 91 hr->pidr = swab64(hr->pidr); 92 hr->cfar = swab64(hr->cfar); 93 hr->ppr = swab64(hr->ppr); 94 } 95 96 static void save_hv_return_state(struct kvm_vcpu *vcpu, int trap, 97 struct hv_guest_state *hr) 98 { 99 struct kvmppc_vcore *vc = vcpu->arch.vcore; 100 101 hr->dpdes = vc->dpdes; 102 hr->hfscr = vcpu->arch.hfscr; 103 hr->purr = vcpu->arch.purr; 104 hr->spurr = vcpu->arch.spurr; 105 hr->ic = vcpu->arch.ic; 106 hr->vtb = vc->vtb; 107 hr->srr0 = vcpu->arch.shregs.srr0; 108 hr->srr1 = vcpu->arch.shregs.srr1; 109 hr->sprg[0] = vcpu->arch.shregs.sprg0; 110 hr->sprg[1] = vcpu->arch.shregs.sprg1; 111 hr->sprg[2] = vcpu->arch.shregs.sprg2; 112 hr->sprg[3] = vcpu->arch.shregs.sprg3; 113 hr->pidr = vcpu->arch.pid; 114 hr->cfar = vcpu->arch.cfar; 115 hr->ppr = vcpu->arch.ppr; 116 switch (trap) { 117 case BOOK3S_INTERRUPT_H_DATA_STORAGE: 118 hr->hdar = vcpu->arch.fault_dar; 119 hr->hdsisr = vcpu->arch.fault_dsisr; 120 hr->asdr = vcpu->arch.fault_gpa; 121 break; 122 case BOOK3S_INTERRUPT_H_INST_STORAGE: 123 hr->asdr = vcpu->arch.fault_gpa; 124 break; 125 case BOOK3S_INTERRUPT_H_EMUL_ASSIST: 126 hr->heir = vcpu->arch.emul_inst; 127 break; 128 } 129 } 130 131 static void sanitise_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) 132 { 133 /* 134 * Don't let L1 enable features for L2 which we've disabled for L1, 135 * but preserve the interrupt cause field. 136 */ 137 hr->hfscr &= (HFSCR_INTR_CAUSE | vcpu->arch.hfscr); 138 139 /* Don't let data address watchpoint match in hypervisor state */ 140 hr->dawrx0 &= ~DAWRX_HYP; 141 142 /* Don't let completed instruction address breakpt match in HV state */ 143 if ((hr->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER) 144 hr->ciabr &= ~CIABR_PRIV; 145 } 146 147 static void restore_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr) 148 { 149 struct kvmppc_vcore *vc = vcpu->arch.vcore; 150 151 vc->pcr = hr->pcr | PCR_MASK; 152 vc->dpdes = hr->dpdes; 153 vcpu->arch.hfscr = hr->hfscr; 154 vcpu->arch.dawr = hr->dawr0; 155 vcpu->arch.dawrx = hr->dawrx0; 156 vcpu->arch.ciabr = hr->ciabr; 157 vcpu->arch.purr = hr->purr; 158 vcpu->arch.spurr = hr->spurr; 159 vcpu->arch.ic = hr->ic; 160 vc->vtb = hr->vtb; 161 vcpu->arch.shregs.srr0 = hr->srr0; 162 vcpu->arch.shregs.srr1 = hr->srr1; 163 vcpu->arch.shregs.sprg0 = hr->sprg[0]; 164 vcpu->arch.shregs.sprg1 = hr->sprg[1]; 165 vcpu->arch.shregs.sprg2 = hr->sprg[2]; 166 vcpu->arch.shregs.sprg3 = hr->sprg[3]; 167 vcpu->arch.pid = hr->pidr; 168 vcpu->arch.cfar = hr->cfar; 169 vcpu->arch.ppr = hr->ppr; 170 } 171 172 void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu, 173 struct hv_guest_state *hr) 174 { 175 struct kvmppc_vcore *vc = vcpu->arch.vcore; 176 177 vc->dpdes = hr->dpdes; 178 vcpu->arch.hfscr = hr->hfscr; 179 vcpu->arch.purr = hr->purr; 180 vcpu->arch.spurr = hr->spurr; 181 vcpu->arch.ic = hr->ic; 182 vc->vtb = hr->vtb; 183 vcpu->arch.fault_dar = hr->hdar; 184 vcpu->arch.fault_dsisr = hr->hdsisr; 185 vcpu->arch.fault_gpa = hr->asdr; 186 vcpu->arch.emul_inst = hr->heir; 187 vcpu->arch.shregs.srr0 = hr->srr0; 188 vcpu->arch.shregs.srr1 = hr->srr1; 189 vcpu->arch.shregs.sprg0 = hr->sprg[0]; 190 vcpu->arch.shregs.sprg1 = hr->sprg[1]; 191 vcpu->arch.shregs.sprg2 = hr->sprg[2]; 192 vcpu->arch.shregs.sprg3 = hr->sprg[3]; 193 vcpu->arch.pid = hr->pidr; 194 vcpu->arch.cfar = hr->cfar; 195 vcpu->arch.ppr = hr->ppr; 196 } 197 198 static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr) 199 { 200 /* No need to reflect the page fault to L1, we've handled it */ 201 vcpu->arch.trap = 0; 202 203 /* 204 * Since the L2 gprs have already been written back into L1 memory when 205 * we complete the mmio, store the L1 memory location of the L2 gpr 206 * being loaded into by the mmio so that the loaded value can be 207 * written there in kvmppc_complete_mmio_load() 208 */ 209 if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR) 210 && (vcpu->mmio_is_write == 0)) { 211 vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr + 212 offsetof(struct pt_regs, 213 gpr[vcpu->arch.io_gpr]); 214 vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR; 215 } 216 } 217 218 long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu) 219 { 220 long int err, r; 221 struct kvm_nested_guest *l2; 222 struct pt_regs l2_regs, saved_l1_regs; 223 struct hv_guest_state l2_hv, saved_l1_hv; 224 struct kvmppc_vcore *vc = vcpu->arch.vcore; 225 u64 hv_ptr, regs_ptr; 226 u64 hdec_exp; 227 s64 delta_purr, delta_spurr, delta_ic, delta_vtb; 228 u64 mask; 229 unsigned long lpcr; 230 231 if (vcpu->kvm->arch.l1_ptcr == 0) 232 return H_NOT_AVAILABLE; 233 234 /* copy parameters in */ 235 hv_ptr = kvmppc_get_gpr(vcpu, 4); 236 err = kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv, 237 sizeof(struct hv_guest_state)); 238 if (err) 239 return H_PARAMETER; 240 if (kvmppc_need_byteswap(vcpu)) 241 byteswap_hv_regs(&l2_hv); 242 if (l2_hv.version != HV_GUEST_STATE_VERSION) 243 return H_P2; 244 245 regs_ptr = kvmppc_get_gpr(vcpu, 5); 246 err = kvm_vcpu_read_guest(vcpu, regs_ptr, &l2_regs, 247 sizeof(struct pt_regs)); 248 if (err) 249 return H_PARAMETER; 250 if (kvmppc_need_byteswap(vcpu)) 251 byteswap_pt_regs(&l2_regs); 252 if (l2_hv.vcpu_token >= NR_CPUS) 253 return H_PARAMETER; 254 255 /* translate lpid */ 256 l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true); 257 if (!l2) 258 return H_PARAMETER; 259 if (!l2->l1_gr_to_hr) { 260 mutex_lock(&l2->tlb_lock); 261 kvmhv_update_ptbl_cache(l2); 262 mutex_unlock(&l2->tlb_lock); 263 } 264 265 /* save l1 values of things */ 266 vcpu->arch.regs.msr = vcpu->arch.shregs.msr; 267 saved_l1_regs = vcpu->arch.regs; 268 kvmhv_save_hv_regs(vcpu, &saved_l1_hv); 269 270 /* convert TB values/offsets to host (L0) values */ 271 hdec_exp = l2_hv.hdec_expiry - vc->tb_offset; 272 vc->tb_offset += l2_hv.tb_offset; 273 274 /* set L1 state to L2 state */ 275 vcpu->arch.nested = l2; 276 vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token; 277 vcpu->arch.regs = l2_regs; 278 vcpu->arch.shregs.msr = vcpu->arch.regs.msr; 279 mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD | 280 LPCR_LPES | LPCR_MER; 281 lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask); 282 sanitise_hv_regs(vcpu, &l2_hv); 283 restore_hv_regs(vcpu, &l2_hv); 284 285 vcpu->arch.ret = RESUME_GUEST; 286 vcpu->arch.trap = 0; 287 do { 288 if (mftb() >= hdec_exp) { 289 vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER; 290 r = RESUME_HOST; 291 break; 292 } 293 r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr); 294 } while (is_kvmppc_resume_guest(r)); 295 296 /* save L2 state for return */ 297 l2_regs = vcpu->arch.regs; 298 l2_regs.msr = vcpu->arch.shregs.msr; 299 delta_purr = vcpu->arch.purr - l2_hv.purr; 300 delta_spurr = vcpu->arch.spurr - l2_hv.spurr; 301 delta_ic = vcpu->arch.ic - l2_hv.ic; 302 delta_vtb = vc->vtb - l2_hv.vtb; 303 save_hv_return_state(vcpu, vcpu->arch.trap, &l2_hv); 304 305 /* restore L1 state */ 306 vcpu->arch.nested = NULL; 307 vcpu->arch.regs = saved_l1_regs; 308 vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK; 309 /* set L1 MSR TS field according to L2 transaction state */ 310 if (l2_regs.msr & MSR_TS_MASK) 311 vcpu->arch.shregs.msr |= MSR_TS_S; 312 vc->tb_offset = saved_l1_hv.tb_offset; 313 restore_hv_regs(vcpu, &saved_l1_hv); 314 vcpu->arch.purr += delta_purr; 315 vcpu->arch.spurr += delta_spurr; 316 vcpu->arch.ic += delta_ic; 317 vc->vtb += delta_vtb; 318 319 kvmhv_put_nested(l2); 320 321 /* copy l2_hv_state and regs back to guest */ 322 if (kvmppc_need_byteswap(vcpu)) { 323 byteswap_hv_regs(&l2_hv); 324 byteswap_pt_regs(&l2_regs); 325 } 326 err = kvm_vcpu_write_guest(vcpu, hv_ptr, &l2_hv, 327 sizeof(struct hv_guest_state)); 328 if (err) 329 return H_AUTHORITY; 330 err = kvm_vcpu_write_guest(vcpu, regs_ptr, &l2_regs, 331 sizeof(struct pt_regs)); 332 if (err) 333 return H_AUTHORITY; 334 335 if (r == -EINTR) 336 return H_INTERRUPT; 337 338 if (vcpu->mmio_needed) { 339 kvmhv_nested_mmio_needed(vcpu, regs_ptr); 340 return H_TOO_HARD; 341 } 342 343 return vcpu->arch.trap; 344 } 345 346 long kvmhv_nested_init(void) 347 { 348 long int ptb_order; 349 unsigned long ptcr; 350 long rc; 351 352 if (!kvmhv_on_pseries()) 353 return 0; 354 if (!radix_enabled()) 355 return -ENODEV; 356 357 /* find log base 2 of KVMPPC_NR_LPIDS, rounding up */ 358 ptb_order = __ilog2(KVMPPC_NR_LPIDS - 1) + 1; 359 if (ptb_order < 8) 360 ptb_order = 8; 361 pseries_partition_tb = kmalloc(sizeof(struct patb_entry) << ptb_order, 362 GFP_KERNEL); 363 if (!pseries_partition_tb) { 364 pr_err("kvm-hv: failed to allocated nested partition table\n"); 365 return -ENOMEM; 366 } 367 368 ptcr = __pa(pseries_partition_tb) | (ptb_order - 8); 369 rc = plpar_hcall_norets(H_SET_PARTITION_TABLE, ptcr); 370 if (rc != H_SUCCESS) { 371 pr_err("kvm-hv: Parent hypervisor does not support nesting (rc=%ld)\n", 372 rc); 373 kfree(pseries_partition_tb); 374 pseries_partition_tb = NULL; 375 return -ENODEV; 376 } 377 378 return 0; 379 } 380 381 void kvmhv_nested_exit(void) 382 { 383 /* 384 * N.B. the kvmhv_on_pseries() test is there because it enables 385 * the compiler to remove the call to plpar_hcall_norets() 386 * when CONFIG_PPC_PSERIES=n. 387 */ 388 if (kvmhv_on_pseries() && pseries_partition_tb) { 389 plpar_hcall_norets(H_SET_PARTITION_TABLE, 0); 390 kfree(pseries_partition_tb); 391 pseries_partition_tb = NULL; 392 } 393 } 394 395 static void kvmhv_flush_lpid(unsigned int lpid) 396 { 397 long rc; 398 399 if (!kvmhv_on_pseries()) { 400 radix__flush_all_lpid(lpid); 401 return; 402 } 403 404 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(2, 0, 1), 405 lpid, TLBIEL_INVAL_SET_LPID); 406 if (rc) 407 pr_err("KVM: TLB LPID invalidation hcall failed, rc=%ld\n", rc); 408 } 409 410 void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1) 411 { 412 if (!kvmhv_on_pseries()) { 413 mmu_partition_table_set_entry(lpid, dw0, dw1, true); 414 return; 415 } 416 417 pseries_partition_tb[lpid].patb0 = cpu_to_be64(dw0); 418 pseries_partition_tb[lpid].patb1 = cpu_to_be64(dw1); 419 /* L0 will do the necessary barriers */ 420 kvmhv_flush_lpid(lpid); 421 } 422 423 static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp) 424 { 425 unsigned long dw0; 426 427 dw0 = PATB_HR | radix__get_tree_size() | 428 __pa(gp->shadow_pgtable) | RADIX_PGD_INDEX_SIZE; 429 kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table); 430 } 431 432 void kvmhv_vm_nested_init(struct kvm *kvm) 433 { 434 kvm->arch.max_nested_lpid = -1; 435 } 436 437 /* 438 * Handle the H_SET_PARTITION_TABLE hcall. 439 * r4 = guest real address of partition table + log_2(size) - 12 440 * (formatted as for the PTCR). 441 */ 442 long kvmhv_set_partition_table(struct kvm_vcpu *vcpu) 443 { 444 struct kvm *kvm = vcpu->kvm; 445 unsigned long ptcr = kvmppc_get_gpr(vcpu, 4); 446 int srcu_idx; 447 long ret = H_SUCCESS; 448 449 srcu_idx = srcu_read_lock(&kvm->srcu); 450 /* 451 * Limit the partition table to 4096 entries (because that's what 452 * hardware supports), and check the base address. 453 */ 454 if ((ptcr & PRTS_MASK) > 12 - 8 || 455 !kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT)) 456 ret = H_PARAMETER; 457 srcu_read_unlock(&kvm->srcu, srcu_idx); 458 if (ret == H_SUCCESS) 459 kvm->arch.l1_ptcr = ptcr; 460 return ret; 461 } 462 463 /* 464 * Handle the H_COPY_TOFROM_GUEST hcall. 465 * r4 = L1 lpid of nested guest 466 * r5 = pid 467 * r6 = eaddr to access 468 * r7 = to buffer (L1 gpa) 469 * r8 = from buffer (L1 gpa) 470 * r9 = n bytes to copy 471 */ 472 long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu) 473 { 474 struct kvm_nested_guest *gp; 475 int l1_lpid = kvmppc_get_gpr(vcpu, 4); 476 int pid = kvmppc_get_gpr(vcpu, 5); 477 gva_t eaddr = kvmppc_get_gpr(vcpu, 6); 478 gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7); 479 gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8); 480 void *buf; 481 unsigned long n = kvmppc_get_gpr(vcpu, 9); 482 bool is_load = !!gp_to; 483 long rc; 484 485 if (gp_to && gp_from) /* One must be NULL to determine the direction */ 486 return H_PARAMETER; 487 488 if (eaddr & (0xFFFUL << 52)) 489 return H_PARAMETER; 490 491 buf = kzalloc(n, GFP_KERNEL); 492 if (!buf) 493 return H_NO_MEM; 494 495 gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false); 496 if (!gp) { 497 rc = H_PARAMETER; 498 goto out_free; 499 } 500 501 mutex_lock(&gp->tlb_lock); 502 503 if (is_load) { 504 /* Load from the nested guest into our buffer */ 505 rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, 506 eaddr, buf, NULL, n); 507 if (rc) 508 goto not_found; 509 510 /* Write what was loaded into our buffer back to the L1 guest */ 511 rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n); 512 if (rc) 513 goto not_found; 514 } else { 515 /* Load the data to be stored from the L1 guest into our buf */ 516 rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n); 517 if (rc) 518 goto not_found; 519 520 /* Store from our buffer into the nested guest */ 521 rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, 522 eaddr, NULL, buf, n); 523 if (rc) 524 goto not_found; 525 } 526 527 out_unlock: 528 mutex_unlock(&gp->tlb_lock); 529 kvmhv_put_nested(gp); 530 out_free: 531 kfree(buf); 532 return rc; 533 not_found: 534 rc = H_NOT_FOUND; 535 goto out_unlock; 536 } 537 538 /* 539 * Reload the partition table entry for a guest. 540 * Caller must hold gp->tlb_lock. 541 */ 542 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp) 543 { 544 int ret; 545 struct patb_entry ptbl_entry; 546 unsigned long ptbl_addr; 547 struct kvm *kvm = gp->l1_host; 548 549 ret = -EFAULT; 550 ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4); 551 if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) 552 ret = kvm_read_guest(kvm, ptbl_addr, 553 &ptbl_entry, sizeof(ptbl_entry)); 554 if (ret) { 555 gp->l1_gr_to_hr = 0; 556 gp->process_table = 0; 557 } else { 558 gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0); 559 gp->process_table = be64_to_cpu(ptbl_entry.patb1); 560 } 561 kvmhv_set_nested_ptbl(gp); 562 } 563 564 struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid) 565 { 566 struct kvm_nested_guest *gp; 567 long shadow_lpid; 568 569 gp = kzalloc(sizeof(*gp), GFP_KERNEL); 570 if (!gp) 571 return NULL; 572 gp->l1_host = kvm; 573 gp->l1_lpid = lpid; 574 mutex_init(&gp->tlb_lock); 575 gp->shadow_pgtable = pgd_alloc(kvm->mm); 576 if (!gp->shadow_pgtable) 577 goto out_free; 578 shadow_lpid = kvmppc_alloc_lpid(); 579 if (shadow_lpid < 0) 580 goto out_free2; 581 gp->shadow_lpid = shadow_lpid; 582 gp->radix = 1; 583 584 memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu)); 585 586 return gp; 587 588 out_free2: 589 pgd_free(kvm->mm, gp->shadow_pgtable); 590 out_free: 591 kfree(gp); 592 return NULL; 593 } 594 595 /* 596 * Free up any resources allocated for a nested guest. 597 */ 598 static void kvmhv_release_nested(struct kvm_nested_guest *gp) 599 { 600 struct kvm *kvm = gp->l1_host; 601 602 if (gp->shadow_pgtable) { 603 /* 604 * No vcpu is using this struct and no call to 605 * kvmhv_get_nested can find this struct, 606 * so we don't need to hold kvm->mmu_lock. 607 */ 608 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, 609 gp->shadow_lpid); 610 pgd_free(kvm->mm, gp->shadow_pgtable); 611 } 612 kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0); 613 kvmppc_free_lpid(gp->shadow_lpid); 614 kfree(gp); 615 } 616 617 static void kvmhv_remove_nested(struct kvm_nested_guest *gp) 618 { 619 struct kvm *kvm = gp->l1_host; 620 int lpid = gp->l1_lpid; 621 long ref; 622 623 spin_lock(&kvm->mmu_lock); 624 if (gp == kvm->arch.nested_guests[lpid]) { 625 kvm->arch.nested_guests[lpid] = NULL; 626 if (lpid == kvm->arch.max_nested_lpid) { 627 while (--lpid >= 0 && !kvm->arch.nested_guests[lpid]) 628 ; 629 kvm->arch.max_nested_lpid = lpid; 630 } 631 --gp->refcnt; 632 } 633 ref = gp->refcnt; 634 spin_unlock(&kvm->mmu_lock); 635 if (ref == 0) 636 kvmhv_release_nested(gp); 637 } 638 639 /* 640 * Free up all nested resources allocated for this guest. 641 * This is called with no vcpus of the guest running, when 642 * switching the guest to HPT mode or when destroying the 643 * guest. 644 */ 645 void kvmhv_release_all_nested(struct kvm *kvm) 646 { 647 int i; 648 struct kvm_nested_guest *gp; 649 struct kvm_nested_guest *freelist = NULL; 650 struct kvm_memory_slot *memslot; 651 int srcu_idx; 652 653 spin_lock(&kvm->mmu_lock); 654 for (i = 0; i <= kvm->arch.max_nested_lpid; i++) { 655 gp = kvm->arch.nested_guests[i]; 656 if (!gp) 657 continue; 658 kvm->arch.nested_guests[i] = NULL; 659 if (--gp->refcnt == 0) { 660 gp->next = freelist; 661 freelist = gp; 662 } 663 } 664 kvm->arch.max_nested_lpid = -1; 665 spin_unlock(&kvm->mmu_lock); 666 while ((gp = freelist) != NULL) { 667 freelist = gp->next; 668 kvmhv_release_nested(gp); 669 } 670 671 srcu_idx = srcu_read_lock(&kvm->srcu); 672 kvm_for_each_memslot(memslot, kvm_memslots(kvm)) 673 kvmhv_free_memslot_nest_rmap(memslot); 674 srcu_read_unlock(&kvm->srcu, srcu_idx); 675 } 676 677 /* caller must hold gp->tlb_lock */ 678 static void kvmhv_flush_nested(struct kvm_nested_guest *gp) 679 { 680 struct kvm *kvm = gp->l1_host; 681 682 spin_lock(&kvm->mmu_lock); 683 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid); 684 spin_unlock(&kvm->mmu_lock); 685 kvmhv_flush_lpid(gp->shadow_lpid); 686 kvmhv_update_ptbl_cache(gp); 687 if (gp->l1_gr_to_hr == 0) 688 kvmhv_remove_nested(gp); 689 } 690 691 struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid, 692 bool create) 693 { 694 struct kvm_nested_guest *gp, *newgp; 695 696 if (l1_lpid >= KVM_MAX_NESTED_GUESTS || 697 l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4))) 698 return NULL; 699 700 spin_lock(&kvm->mmu_lock); 701 gp = kvm->arch.nested_guests[l1_lpid]; 702 if (gp) 703 ++gp->refcnt; 704 spin_unlock(&kvm->mmu_lock); 705 706 if (gp || !create) 707 return gp; 708 709 newgp = kvmhv_alloc_nested(kvm, l1_lpid); 710 if (!newgp) 711 return NULL; 712 spin_lock(&kvm->mmu_lock); 713 if (kvm->arch.nested_guests[l1_lpid]) { 714 /* someone else beat us to it */ 715 gp = kvm->arch.nested_guests[l1_lpid]; 716 } else { 717 kvm->arch.nested_guests[l1_lpid] = newgp; 718 ++newgp->refcnt; 719 gp = newgp; 720 newgp = NULL; 721 if (l1_lpid > kvm->arch.max_nested_lpid) 722 kvm->arch.max_nested_lpid = l1_lpid; 723 } 724 ++gp->refcnt; 725 spin_unlock(&kvm->mmu_lock); 726 727 if (newgp) 728 kvmhv_release_nested(newgp); 729 730 return gp; 731 } 732 733 void kvmhv_put_nested(struct kvm_nested_guest *gp) 734 { 735 struct kvm *kvm = gp->l1_host; 736 long ref; 737 738 spin_lock(&kvm->mmu_lock); 739 ref = --gp->refcnt; 740 spin_unlock(&kvm->mmu_lock); 741 if (ref == 0) 742 kvmhv_release_nested(gp); 743 } 744 745 static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid) 746 { 747 if (lpid > kvm->arch.max_nested_lpid) 748 return NULL; 749 return kvm->arch.nested_guests[lpid]; 750 } 751 752 pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid, 753 unsigned long ea, unsigned *hshift) 754 { 755 struct kvm_nested_guest *gp; 756 pte_t *pte; 757 758 gp = kvmhv_find_nested(kvm, lpid); 759 if (!gp) 760 return NULL; 761 762 VM_WARN(!spin_is_locked(&kvm->mmu_lock), 763 "%s called with kvm mmu_lock not held \n", __func__); 764 pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift); 765 766 return pte; 767 } 768 769 static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2) 770 { 771 return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK | 772 RMAP_NESTED_GPA_MASK)); 773 } 774 775 void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp, 776 struct rmap_nested **n_rmap) 777 { 778 struct llist_node *entry = ((struct llist_head *) rmapp)->first; 779 struct rmap_nested *cursor; 780 u64 rmap, new_rmap = (*n_rmap)->rmap; 781 782 /* Are there any existing entries? */ 783 if (!(*rmapp)) { 784 /* No -> use the rmap as a single entry */ 785 *rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY; 786 return; 787 } 788 789 /* Do any entries match what we're trying to insert? */ 790 for_each_nest_rmap_safe(cursor, entry, &rmap) { 791 if (kvmhv_n_rmap_is_equal(rmap, new_rmap)) 792 return; 793 } 794 795 /* Do we need to create a list or just add the new entry? */ 796 rmap = *rmapp; 797 if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */ 798 *rmapp = 0UL; 799 llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp); 800 if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */ 801 (*n_rmap)->list.next = (struct llist_node *) rmap; 802 803 /* Set NULL so not freed by caller */ 804 *n_rmap = NULL; 805 } 806 807 static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap, 808 unsigned long clr, unsigned long set, 809 unsigned long hpa, unsigned long mask) 810 { 811 unsigned long gpa; 812 unsigned int shift, lpid; 813 pte_t *ptep; 814 815 gpa = n_rmap & RMAP_NESTED_GPA_MASK; 816 lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT; 817 818 /* Find the pte */ 819 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift); 820 /* 821 * If the pte is present and the pfn is still the same, update the pte. 822 * If the pfn has changed then this is a stale rmap entry, the nested 823 * gpa actually points somewhere else now, and there is nothing to do. 824 * XXX A future optimisation would be to remove the rmap entry here. 825 */ 826 if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) { 827 __radix_pte_update(ptep, clr, set); 828 kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid); 829 } 830 } 831 832 /* 833 * For a given list of rmap entries, update the rc bits in all ptes in shadow 834 * page tables for nested guests which are referenced by the rmap list. 835 */ 836 void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp, 837 unsigned long clr, unsigned long set, 838 unsigned long hpa, unsigned long nbytes) 839 { 840 struct llist_node *entry = ((struct llist_head *) rmapp)->first; 841 struct rmap_nested *cursor; 842 unsigned long rmap, mask; 843 844 if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED)) 845 return; 846 847 mask = PTE_RPN_MASK & ~(nbytes - 1); 848 hpa &= mask; 849 850 for_each_nest_rmap_safe(cursor, entry, &rmap) 851 kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask); 852 } 853 854 static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap, 855 unsigned long hpa, unsigned long mask) 856 { 857 struct kvm_nested_guest *gp; 858 unsigned long gpa; 859 unsigned int shift, lpid; 860 pte_t *ptep; 861 862 gpa = n_rmap & RMAP_NESTED_GPA_MASK; 863 lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT; 864 gp = kvmhv_find_nested(kvm, lpid); 865 if (!gp) 866 return; 867 868 /* Find and invalidate the pte */ 869 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift); 870 /* Don't spuriously invalidate ptes if the pfn has changed */ 871 if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) 872 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid); 873 } 874 875 static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp, 876 unsigned long hpa, unsigned long mask) 877 { 878 struct llist_node *entry = llist_del_all((struct llist_head *) rmapp); 879 struct rmap_nested *cursor; 880 unsigned long rmap; 881 882 for_each_nest_rmap_safe(cursor, entry, &rmap) { 883 kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask); 884 kfree(cursor); 885 } 886 } 887 888 /* called with kvm->mmu_lock held */ 889 void kvmhv_remove_nest_rmap_range(struct kvm *kvm, 890 const struct kvm_memory_slot *memslot, 891 unsigned long gpa, unsigned long hpa, 892 unsigned long nbytes) 893 { 894 unsigned long gfn, end_gfn; 895 unsigned long addr_mask; 896 897 if (!memslot) 898 return; 899 gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn; 900 end_gfn = gfn + (nbytes >> PAGE_SHIFT); 901 902 addr_mask = PTE_RPN_MASK & ~(nbytes - 1); 903 hpa &= addr_mask; 904 905 for (; gfn < end_gfn; gfn++) { 906 unsigned long *rmap = &memslot->arch.rmap[gfn]; 907 kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask); 908 } 909 } 910 911 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free) 912 { 913 unsigned long page; 914 915 for (page = 0; page < free->npages; page++) { 916 unsigned long rmap, *rmapp = &free->arch.rmap[page]; 917 struct rmap_nested *cursor; 918 struct llist_node *entry; 919 920 entry = llist_del_all((struct llist_head *) rmapp); 921 for_each_nest_rmap_safe(cursor, entry, &rmap) 922 kfree(cursor); 923 } 924 } 925 926 static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu, 927 struct kvm_nested_guest *gp, 928 long gpa, int *shift_ret) 929 { 930 struct kvm *kvm = vcpu->kvm; 931 bool ret = false; 932 pte_t *ptep; 933 int shift; 934 935 spin_lock(&kvm->mmu_lock); 936 ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift); 937 if (!shift) 938 shift = PAGE_SHIFT; 939 if (ptep && pte_present(*ptep)) { 940 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid); 941 ret = true; 942 } 943 spin_unlock(&kvm->mmu_lock); 944 945 if (shift_ret) 946 *shift_ret = shift; 947 return ret; 948 } 949 950 static inline int get_ric(unsigned int instr) 951 { 952 return (instr >> 18) & 0x3; 953 } 954 955 static inline int get_prs(unsigned int instr) 956 { 957 return (instr >> 17) & 0x1; 958 } 959 960 static inline int get_r(unsigned int instr) 961 { 962 return (instr >> 16) & 0x1; 963 } 964 965 static inline int get_lpid(unsigned long r_val) 966 { 967 return r_val & 0xffffffff; 968 } 969 970 static inline int get_is(unsigned long r_val) 971 { 972 return (r_val >> 10) & 0x3; 973 } 974 975 static inline int get_ap(unsigned long r_val) 976 { 977 return (r_val >> 5) & 0x7; 978 } 979 980 static inline long get_epn(unsigned long r_val) 981 { 982 return r_val >> 12; 983 } 984 985 static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid, 986 int ap, long epn) 987 { 988 struct kvm *kvm = vcpu->kvm; 989 struct kvm_nested_guest *gp; 990 long npages; 991 int shift, shadow_shift; 992 unsigned long addr; 993 994 shift = ap_to_shift(ap); 995 addr = epn << 12; 996 if (shift < 0) 997 /* Invalid ap encoding */ 998 return -EINVAL; 999 1000 addr &= ~((1UL << shift) - 1); 1001 npages = 1UL << (shift - PAGE_SHIFT); 1002 1003 gp = kvmhv_get_nested(kvm, lpid, false); 1004 if (!gp) /* No such guest -> nothing to do */ 1005 return 0; 1006 mutex_lock(&gp->tlb_lock); 1007 1008 /* There may be more than one host page backing this single guest pte */ 1009 do { 1010 kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift); 1011 1012 npages -= 1UL << (shadow_shift - PAGE_SHIFT); 1013 addr += 1UL << shadow_shift; 1014 } while (npages > 0); 1015 1016 mutex_unlock(&gp->tlb_lock); 1017 kvmhv_put_nested(gp); 1018 return 0; 1019 } 1020 1021 static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu, 1022 struct kvm_nested_guest *gp, int ric) 1023 { 1024 struct kvm *kvm = vcpu->kvm; 1025 1026 mutex_lock(&gp->tlb_lock); 1027 switch (ric) { 1028 case 0: 1029 /* Invalidate TLB */ 1030 spin_lock(&kvm->mmu_lock); 1031 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, 1032 gp->shadow_lpid); 1033 kvmhv_flush_lpid(gp->shadow_lpid); 1034 spin_unlock(&kvm->mmu_lock); 1035 break; 1036 case 1: 1037 /* 1038 * Invalidate PWC 1039 * We don't cache this -> nothing to do 1040 */ 1041 break; 1042 case 2: 1043 /* Invalidate TLB, PWC and caching of partition table entries */ 1044 kvmhv_flush_nested(gp); 1045 break; 1046 default: 1047 break; 1048 } 1049 mutex_unlock(&gp->tlb_lock); 1050 } 1051 1052 static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric) 1053 { 1054 struct kvm *kvm = vcpu->kvm; 1055 struct kvm_nested_guest *gp; 1056 int i; 1057 1058 spin_lock(&kvm->mmu_lock); 1059 for (i = 0; i <= kvm->arch.max_nested_lpid; i++) { 1060 gp = kvm->arch.nested_guests[i]; 1061 if (gp) { 1062 spin_unlock(&kvm->mmu_lock); 1063 kvmhv_emulate_tlbie_lpid(vcpu, gp, ric); 1064 spin_lock(&kvm->mmu_lock); 1065 } 1066 } 1067 spin_unlock(&kvm->mmu_lock); 1068 } 1069 1070 static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr, 1071 unsigned long rsval, unsigned long rbval) 1072 { 1073 struct kvm *kvm = vcpu->kvm; 1074 struct kvm_nested_guest *gp; 1075 int r, ric, prs, is, ap; 1076 int lpid; 1077 long epn; 1078 int ret = 0; 1079 1080 ric = get_ric(instr); 1081 prs = get_prs(instr); 1082 r = get_r(instr); 1083 lpid = get_lpid(rsval); 1084 is = get_is(rbval); 1085 1086 /* 1087 * These cases are invalid and are not handled: 1088 * r != 1 -> Only radix supported 1089 * prs == 1 -> Not HV privileged 1090 * ric == 3 -> No cluster bombs for radix 1091 * is == 1 -> Partition scoped translations not associated with pid 1092 * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA 1093 */ 1094 if ((!r) || (prs) || (ric == 3) || (is == 1) || 1095 ((!is) && (ric == 1 || ric == 2))) 1096 return -EINVAL; 1097 1098 switch (is) { 1099 case 0: 1100 /* 1101 * We know ric == 0 1102 * Invalidate TLB for a given target address 1103 */ 1104 epn = get_epn(rbval); 1105 ap = get_ap(rbval); 1106 ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn); 1107 break; 1108 case 2: 1109 /* Invalidate matching LPID */ 1110 gp = kvmhv_get_nested(kvm, lpid, false); 1111 if (gp) { 1112 kvmhv_emulate_tlbie_lpid(vcpu, gp, ric); 1113 kvmhv_put_nested(gp); 1114 } 1115 break; 1116 case 3: 1117 /* Invalidate ALL LPIDs */ 1118 kvmhv_emulate_tlbie_all_lpid(vcpu, ric); 1119 break; 1120 default: 1121 ret = -EINVAL; 1122 break; 1123 } 1124 1125 return ret; 1126 } 1127 1128 /* 1129 * This handles the H_TLB_INVALIDATE hcall. 1130 * Parameters are (r4) tlbie instruction code, (r5) rS contents, 1131 * (r6) rB contents. 1132 */ 1133 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu) 1134 { 1135 int ret; 1136 1137 ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4), 1138 kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6)); 1139 if (ret) 1140 return H_PARAMETER; 1141 return H_SUCCESS; 1142 } 1143 1144 /* Used to convert a nested guest real address to a L1 guest real address */ 1145 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu, 1146 struct kvm_nested_guest *gp, 1147 unsigned long n_gpa, unsigned long dsisr, 1148 struct kvmppc_pte *gpte_p) 1149 { 1150 u64 fault_addr, flags = dsisr & DSISR_ISSTORE; 1151 int ret; 1152 1153 ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr, 1154 &fault_addr); 1155 1156 if (ret) { 1157 /* We didn't find a pte */ 1158 if (ret == -EINVAL) { 1159 /* Unsupported mmu config */ 1160 flags |= DSISR_UNSUPP_MMU; 1161 } else if (ret == -ENOENT) { 1162 /* No translation found */ 1163 flags |= DSISR_NOHPTE; 1164 } else if (ret == -EFAULT) { 1165 /* Couldn't access L1 real address */ 1166 flags |= DSISR_PRTABLE_FAULT; 1167 vcpu->arch.fault_gpa = fault_addr; 1168 } else { 1169 /* Unknown error */ 1170 return ret; 1171 } 1172 goto forward_to_l1; 1173 } else { 1174 /* We found a pte -> check permissions */ 1175 if (dsisr & DSISR_ISSTORE) { 1176 /* Can we write? */ 1177 if (!gpte_p->may_write) { 1178 flags |= DSISR_PROTFAULT; 1179 goto forward_to_l1; 1180 } 1181 } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { 1182 /* Can we execute? */ 1183 if (!gpte_p->may_execute) { 1184 flags |= SRR1_ISI_N_G_OR_CIP; 1185 goto forward_to_l1; 1186 } 1187 } else { 1188 /* Can we read? */ 1189 if (!gpte_p->may_read && !gpte_p->may_write) { 1190 flags |= DSISR_PROTFAULT; 1191 goto forward_to_l1; 1192 } 1193 } 1194 } 1195 1196 return 0; 1197 1198 forward_to_l1: 1199 vcpu->arch.fault_dsisr = flags; 1200 if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { 1201 vcpu->arch.shregs.msr &= SRR1_MSR_BITS; 1202 vcpu->arch.shregs.msr |= flags; 1203 } 1204 return RESUME_HOST; 1205 } 1206 1207 static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu, 1208 struct kvm_nested_guest *gp, 1209 unsigned long n_gpa, 1210 struct kvmppc_pte gpte, 1211 unsigned long dsisr) 1212 { 1213 struct kvm *kvm = vcpu->kvm; 1214 bool writing = !!(dsisr & DSISR_ISSTORE); 1215 u64 pgflags; 1216 long ret; 1217 1218 /* Are the rc bits set in the L1 partition scoped pte? */ 1219 pgflags = _PAGE_ACCESSED; 1220 if (writing) 1221 pgflags |= _PAGE_DIRTY; 1222 if (pgflags & ~gpte.rc) 1223 return RESUME_HOST; 1224 1225 spin_lock(&kvm->mmu_lock); 1226 /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */ 1227 ret = kvmppc_hv_handle_set_rc(kvm, false, writing, 1228 gpte.raddr, kvm->arch.lpid); 1229 if (!ret) { 1230 ret = -EINVAL; 1231 goto out_unlock; 1232 } 1233 1234 /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */ 1235 ret = kvmppc_hv_handle_set_rc(kvm, true, writing, 1236 n_gpa, gp->l1_lpid); 1237 if (!ret) 1238 ret = -EINVAL; 1239 else 1240 ret = 0; 1241 1242 out_unlock: 1243 spin_unlock(&kvm->mmu_lock); 1244 return ret; 1245 } 1246 1247 static inline int kvmppc_radix_level_to_shift(int level) 1248 { 1249 switch (level) { 1250 case 2: 1251 return PUD_SHIFT; 1252 case 1: 1253 return PMD_SHIFT; 1254 default: 1255 return PAGE_SHIFT; 1256 } 1257 } 1258 1259 static inline int kvmppc_radix_shift_to_level(int shift) 1260 { 1261 if (shift == PUD_SHIFT) 1262 return 2; 1263 if (shift == PMD_SHIFT) 1264 return 1; 1265 if (shift == PAGE_SHIFT) 1266 return 0; 1267 WARN_ON_ONCE(1); 1268 return 0; 1269 } 1270 1271 /* called with gp->tlb_lock held */ 1272 static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu, 1273 struct kvm_nested_guest *gp) 1274 { 1275 struct kvm *kvm = vcpu->kvm; 1276 struct kvm_memory_slot *memslot; 1277 struct rmap_nested *n_rmap; 1278 struct kvmppc_pte gpte; 1279 pte_t pte, *pte_p; 1280 unsigned long mmu_seq; 1281 unsigned long dsisr = vcpu->arch.fault_dsisr; 1282 unsigned long ea = vcpu->arch.fault_dar; 1283 unsigned long *rmapp; 1284 unsigned long n_gpa, gpa, gfn, perm = 0UL; 1285 unsigned int shift, l1_shift, level; 1286 bool writing = !!(dsisr & DSISR_ISSTORE); 1287 bool kvm_ro = false; 1288 long int ret; 1289 1290 if (!gp->l1_gr_to_hr) { 1291 kvmhv_update_ptbl_cache(gp); 1292 if (!gp->l1_gr_to_hr) 1293 return RESUME_HOST; 1294 } 1295 1296 /* Convert the nested guest real address into a L1 guest real address */ 1297 1298 n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL; 1299 if (!(dsisr & DSISR_PRTABLE_FAULT)) 1300 n_gpa |= ea & 0xFFF; 1301 ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte); 1302 1303 /* 1304 * If the hardware found a translation but we don't now have a usable 1305 * translation in the l1 partition-scoped tree, remove the shadow pte 1306 * and let the guest retry. 1307 */ 1308 if (ret == RESUME_HOST && 1309 (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G | 1310 DSISR_BAD_COPYPASTE))) 1311 goto inval; 1312 if (ret) 1313 return ret; 1314 1315 /* Failed to set the reference/change bits */ 1316 if (dsisr & DSISR_SET_RC) { 1317 ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr); 1318 if (ret == RESUME_HOST) 1319 return ret; 1320 if (ret) 1321 goto inval; 1322 dsisr &= ~DSISR_SET_RC; 1323 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE | 1324 DSISR_PROTFAULT))) 1325 return RESUME_GUEST; 1326 } 1327 1328 /* 1329 * We took an HISI or HDSI while we were running a nested guest which 1330 * means we have no partition scoped translation for that. This means 1331 * we need to insert a pte for the mapping into our shadow_pgtable. 1332 */ 1333 1334 l1_shift = gpte.page_shift; 1335 if (l1_shift < PAGE_SHIFT) { 1336 /* We don't support l1 using a page size smaller than our own */ 1337 pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n", 1338 l1_shift, PAGE_SHIFT); 1339 return -EINVAL; 1340 } 1341 gpa = gpte.raddr; 1342 gfn = gpa >> PAGE_SHIFT; 1343 1344 /* 1. Get the corresponding host memslot */ 1345 1346 memslot = gfn_to_memslot(kvm, gfn); 1347 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { 1348 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) { 1349 /* unusual error -> reflect to the guest as a DSI */ 1350 kvmppc_core_queue_data_storage(vcpu, ea, dsisr); 1351 return RESUME_GUEST; 1352 } 1353 1354 /* passthrough of emulated MMIO case */ 1355 return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing); 1356 } 1357 if (memslot->flags & KVM_MEM_READONLY) { 1358 if (writing) { 1359 /* Give the guest a DSI */ 1360 kvmppc_core_queue_data_storage(vcpu, ea, 1361 DSISR_ISSTORE | DSISR_PROTFAULT); 1362 return RESUME_GUEST; 1363 } 1364 kvm_ro = true; 1365 } 1366 1367 /* 2. Find the host pte for this L1 guest real address */ 1368 1369 /* Used to check for invalidations in progress */ 1370 mmu_seq = kvm->mmu_notifier_seq; 1371 smp_rmb(); 1372 1373 /* See if can find translation in our partition scoped tables for L1 */ 1374 pte = __pte(0); 1375 spin_lock(&kvm->mmu_lock); 1376 pte_p = find_kvm_secondary_pte(kvm, gpa, &shift); 1377 if (!shift) 1378 shift = PAGE_SHIFT; 1379 if (pte_p) 1380 pte = *pte_p; 1381 spin_unlock(&kvm->mmu_lock); 1382 1383 if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) { 1384 /* No suitable pte found -> try to insert a mapping */ 1385 ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, 1386 writing, kvm_ro, &pte, &level); 1387 if (ret == -EAGAIN) 1388 return RESUME_GUEST; 1389 else if (ret) 1390 return ret; 1391 shift = kvmppc_radix_level_to_shift(level); 1392 } 1393 /* Align gfn to the start of the page */ 1394 gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT; 1395 1396 /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */ 1397 1398 /* The permissions is the combination of the host and l1 guest ptes */ 1399 perm |= gpte.may_read ? 0UL : _PAGE_READ; 1400 perm |= gpte.may_write ? 0UL : _PAGE_WRITE; 1401 perm |= gpte.may_execute ? 0UL : _PAGE_EXEC; 1402 /* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */ 1403 perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED; 1404 perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY; 1405 pte = __pte(pte_val(pte) & ~perm); 1406 1407 /* What size pte can we insert? */ 1408 if (shift > l1_shift) { 1409 u64 mask; 1410 unsigned int actual_shift = PAGE_SHIFT; 1411 if (PMD_SHIFT < l1_shift) 1412 actual_shift = PMD_SHIFT; 1413 mask = (1UL << shift) - (1UL << actual_shift); 1414 pte = __pte(pte_val(pte) | (gpa & mask)); 1415 shift = actual_shift; 1416 } 1417 level = kvmppc_radix_shift_to_level(shift); 1418 n_gpa &= ~((1UL << shift) - 1); 1419 1420 /* 4. Insert the pte into our shadow_pgtable */ 1421 1422 n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL); 1423 if (!n_rmap) 1424 return RESUME_GUEST; /* Let the guest try again */ 1425 n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) | 1426 (((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT); 1427 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1428 ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level, 1429 mmu_seq, gp->shadow_lpid, rmapp, &n_rmap); 1430 kfree(n_rmap); 1431 if (ret == -EAGAIN) 1432 ret = RESUME_GUEST; /* Let the guest try again */ 1433 1434 return ret; 1435 1436 inval: 1437 kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL); 1438 return RESUME_GUEST; 1439 } 1440 1441 long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu) 1442 { 1443 struct kvm_nested_guest *gp = vcpu->arch.nested; 1444 long int ret; 1445 1446 mutex_lock(&gp->tlb_lock); 1447 ret = __kvmhv_nested_page_fault(vcpu, gp); 1448 mutex_unlock(&gp->tlb_lock); 1449 return ret; 1450 } 1451 1452 int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid) 1453 { 1454 int ret = -1; 1455 1456 spin_lock(&kvm->mmu_lock); 1457 while (++lpid <= kvm->arch.max_nested_lpid) { 1458 if (kvm->arch.nested_guests[lpid]) { 1459 ret = lpid; 1460 break; 1461 } 1462 } 1463 spin_unlock(&kvm->mmu_lock); 1464 return ret; 1465 } 1466