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->arch.kvm_run, vcpu, hdec_exp, 294 lpcr); 295 } while (is_kvmppc_resume_guest(r)); 296 297 /* save L2 state for return */ 298 l2_regs = vcpu->arch.regs; 299 l2_regs.msr = vcpu->arch.shregs.msr; 300 delta_purr = vcpu->arch.purr - l2_hv.purr; 301 delta_spurr = vcpu->arch.spurr - l2_hv.spurr; 302 delta_ic = vcpu->arch.ic - l2_hv.ic; 303 delta_vtb = vc->vtb - l2_hv.vtb; 304 save_hv_return_state(vcpu, vcpu->arch.trap, &l2_hv); 305 306 /* restore L1 state */ 307 vcpu->arch.nested = NULL; 308 vcpu->arch.regs = saved_l1_regs; 309 vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK; 310 /* set L1 MSR TS field according to L2 transaction state */ 311 if (l2_regs.msr & MSR_TS_MASK) 312 vcpu->arch.shregs.msr |= MSR_TS_S; 313 vc->tb_offset = saved_l1_hv.tb_offset; 314 restore_hv_regs(vcpu, &saved_l1_hv); 315 vcpu->arch.purr += delta_purr; 316 vcpu->arch.spurr += delta_spurr; 317 vcpu->arch.ic += delta_ic; 318 vc->vtb += delta_vtb; 319 320 kvmhv_put_nested(l2); 321 322 /* copy l2_hv_state and regs back to guest */ 323 if (kvmppc_need_byteswap(vcpu)) { 324 byteswap_hv_regs(&l2_hv); 325 byteswap_pt_regs(&l2_regs); 326 } 327 err = kvm_vcpu_write_guest(vcpu, hv_ptr, &l2_hv, 328 sizeof(struct hv_guest_state)); 329 if (err) 330 return H_AUTHORITY; 331 err = kvm_vcpu_write_guest(vcpu, regs_ptr, &l2_regs, 332 sizeof(struct pt_regs)); 333 if (err) 334 return H_AUTHORITY; 335 336 if (r == -EINTR) 337 return H_INTERRUPT; 338 339 if (vcpu->mmio_needed) { 340 kvmhv_nested_mmio_needed(vcpu, regs_ptr); 341 return H_TOO_HARD; 342 } 343 344 return vcpu->arch.trap; 345 } 346 347 long kvmhv_nested_init(void) 348 { 349 long int ptb_order; 350 unsigned long ptcr; 351 long rc; 352 353 if (!kvmhv_on_pseries()) 354 return 0; 355 if (!radix_enabled()) 356 return -ENODEV; 357 358 /* find log base 2 of KVMPPC_NR_LPIDS, rounding up */ 359 ptb_order = __ilog2(KVMPPC_NR_LPIDS - 1) + 1; 360 if (ptb_order < 8) 361 ptb_order = 8; 362 pseries_partition_tb = kmalloc(sizeof(struct patb_entry) << ptb_order, 363 GFP_KERNEL); 364 if (!pseries_partition_tb) { 365 pr_err("kvm-hv: failed to allocated nested partition table\n"); 366 return -ENOMEM; 367 } 368 369 ptcr = __pa(pseries_partition_tb) | (ptb_order - 8); 370 rc = plpar_hcall_norets(H_SET_PARTITION_TABLE, ptcr); 371 if (rc != H_SUCCESS) { 372 pr_err("kvm-hv: Parent hypervisor does not support nesting (rc=%ld)\n", 373 rc); 374 kfree(pseries_partition_tb); 375 pseries_partition_tb = NULL; 376 return -ENODEV; 377 } 378 379 return 0; 380 } 381 382 void kvmhv_nested_exit(void) 383 { 384 /* 385 * N.B. the kvmhv_on_pseries() test is there because it enables 386 * the compiler to remove the call to plpar_hcall_norets() 387 * when CONFIG_PPC_PSERIES=n. 388 */ 389 if (kvmhv_on_pseries() && pseries_partition_tb) { 390 plpar_hcall_norets(H_SET_PARTITION_TABLE, 0); 391 kfree(pseries_partition_tb); 392 pseries_partition_tb = NULL; 393 } 394 } 395 396 static void kvmhv_flush_lpid(unsigned int lpid) 397 { 398 long rc; 399 400 if (!kvmhv_on_pseries()) { 401 radix__flush_all_lpid(lpid); 402 return; 403 } 404 405 rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(2, 0, 1), 406 lpid, TLBIEL_INVAL_SET_LPID); 407 if (rc) 408 pr_err("KVM: TLB LPID invalidation hcall failed, rc=%ld\n", rc); 409 } 410 411 void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1) 412 { 413 if (!kvmhv_on_pseries()) { 414 mmu_partition_table_set_entry(lpid, dw0, dw1, true); 415 return; 416 } 417 418 pseries_partition_tb[lpid].patb0 = cpu_to_be64(dw0); 419 pseries_partition_tb[lpid].patb1 = cpu_to_be64(dw1); 420 /* L0 will do the necessary barriers */ 421 kvmhv_flush_lpid(lpid); 422 } 423 424 static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp) 425 { 426 unsigned long dw0; 427 428 dw0 = PATB_HR | radix__get_tree_size() | 429 __pa(gp->shadow_pgtable) | RADIX_PGD_INDEX_SIZE; 430 kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table); 431 } 432 433 void kvmhv_vm_nested_init(struct kvm *kvm) 434 { 435 kvm->arch.max_nested_lpid = -1; 436 } 437 438 /* 439 * Handle the H_SET_PARTITION_TABLE hcall. 440 * r4 = guest real address of partition table + log_2(size) - 12 441 * (formatted as for the PTCR). 442 */ 443 long kvmhv_set_partition_table(struct kvm_vcpu *vcpu) 444 { 445 struct kvm *kvm = vcpu->kvm; 446 unsigned long ptcr = kvmppc_get_gpr(vcpu, 4); 447 int srcu_idx; 448 long ret = H_SUCCESS; 449 450 srcu_idx = srcu_read_lock(&kvm->srcu); 451 /* 452 * Limit the partition table to 4096 entries (because that's what 453 * hardware supports), and check the base address. 454 */ 455 if ((ptcr & PRTS_MASK) > 12 - 8 || 456 !kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT)) 457 ret = H_PARAMETER; 458 srcu_read_unlock(&kvm->srcu, srcu_idx); 459 if (ret == H_SUCCESS) 460 kvm->arch.l1_ptcr = ptcr; 461 return ret; 462 } 463 464 /* 465 * Handle the H_COPY_TOFROM_GUEST hcall. 466 * r4 = L1 lpid of nested guest 467 * r5 = pid 468 * r6 = eaddr to access 469 * r7 = to buffer (L1 gpa) 470 * r8 = from buffer (L1 gpa) 471 * r9 = n bytes to copy 472 */ 473 long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu) 474 { 475 struct kvm_nested_guest *gp; 476 int l1_lpid = kvmppc_get_gpr(vcpu, 4); 477 int pid = kvmppc_get_gpr(vcpu, 5); 478 gva_t eaddr = kvmppc_get_gpr(vcpu, 6); 479 gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7); 480 gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8); 481 void *buf; 482 unsigned long n = kvmppc_get_gpr(vcpu, 9); 483 bool is_load = !!gp_to; 484 long rc; 485 486 if (gp_to && gp_from) /* One must be NULL to determine the direction */ 487 return H_PARAMETER; 488 489 if (eaddr & (0xFFFUL << 52)) 490 return H_PARAMETER; 491 492 buf = kzalloc(n, GFP_KERNEL); 493 if (!buf) 494 return H_NO_MEM; 495 496 gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false); 497 if (!gp) { 498 rc = H_PARAMETER; 499 goto out_free; 500 } 501 502 mutex_lock(&gp->tlb_lock); 503 504 if (is_load) { 505 /* Load from the nested guest into our buffer */ 506 rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, 507 eaddr, buf, NULL, n); 508 if (rc) 509 goto not_found; 510 511 /* Write what was loaded into our buffer back to the L1 guest */ 512 rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n); 513 if (rc) 514 goto not_found; 515 } else { 516 /* Load the data to be stored from the L1 guest into our buf */ 517 rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n); 518 if (rc) 519 goto not_found; 520 521 /* Store from our buffer into the nested guest */ 522 rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid, 523 eaddr, NULL, buf, n); 524 if (rc) 525 goto not_found; 526 } 527 528 out_unlock: 529 mutex_unlock(&gp->tlb_lock); 530 kvmhv_put_nested(gp); 531 out_free: 532 kfree(buf); 533 return rc; 534 not_found: 535 rc = H_NOT_FOUND; 536 goto out_unlock; 537 } 538 539 /* 540 * Reload the partition table entry for a guest. 541 * Caller must hold gp->tlb_lock. 542 */ 543 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp) 544 { 545 int ret; 546 struct patb_entry ptbl_entry; 547 unsigned long ptbl_addr; 548 struct kvm *kvm = gp->l1_host; 549 550 ret = -EFAULT; 551 ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4); 552 if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) 553 ret = kvm_read_guest(kvm, ptbl_addr, 554 &ptbl_entry, sizeof(ptbl_entry)); 555 if (ret) { 556 gp->l1_gr_to_hr = 0; 557 gp->process_table = 0; 558 } else { 559 gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0); 560 gp->process_table = be64_to_cpu(ptbl_entry.patb1); 561 } 562 kvmhv_set_nested_ptbl(gp); 563 } 564 565 struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid) 566 { 567 struct kvm_nested_guest *gp; 568 long shadow_lpid; 569 570 gp = kzalloc(sizeof(*gp), GFP_KERNEL); 571 if (!gp) 572 return NULL; 573 gp->l1_host = kvm; 574 gp->l1_lpid = lpid; 575 mutex_init(&gp->tlb_lock); 576 gp->shadow_pgtable = pgd_alloc(kvm->mm); 577 if (!gp->shadow_pgtable) 578 goto out_free; 579 shadow_lpid = kvmppc_alloc_lpid(); 580 if (shadow_lpid < 0) 581 goto out_free2; 582 gp->shadow_lpid = shadow_lpid; 583 gp->radix = 1; 584 585 memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu)); 586 587 return gp; 588 589 out_free2: 590 pgd_free(kvm->mm, gp->shadow_pgtable); 591 out_free: 592 kfree(gp); 593 return NULL; 594 } 595 596 /* 597 * Free up any resources allocated for a nested guest. 598 */ 599 static void kvmhv_release_nested(struct kvm_nested_guest *gp) 600 { 601 struct kvm *kvm = gp->l1_host; 602 603 if (gp->shadow_pgtable) { 604 /* 605 * No vcpu is using this struct and no call to 606 * kvmhv_get_nested can find this struct, 607 * so we don't need to hold kvm->mmu_lock. 608 */ 609 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, 610 gp->shadow_lpid); 611 pgd_free(kvm->mm, gp->shadow_pgtable); 612 } 613 kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0); 614 kvmppc_free_lpid(gp->shadow_lpid); 615 kfree(gp); 616 } 617 618 static void kvmhv_remove_nested(struct kvm_nested_guest *gp) 619 { 620 struct kvm *kvm = gp->l1_host; 621 int lpid = gp->l1_lpid; 622 long ref; 623 624 spin_lock(&kvm->mmu_lock); 625 if (gp == kvm->arch.nested_guests[lpid]) { 626 kvm->arch.nested_guests[lpid] = NULL; 627 if (lpid == kvm->arch.max_nested_lpid) { 628 while (--lpid >= 0 && !kvm->arch.nested_guests[lpid]) 629 ; 630 kvm->arch.max_nested_lpid = lpid; 631 } 632 --gp->refcnt; 633 } 634 ref = gp->refcnt; 635 spin_unlock(&kvm->mmu_lock); 636 if (ref == 0) 637 kvmhv_release_nested(gp); 638 } 639 640 /* 641 * Free up all nested resources allocated for this guest. 642 * This is called with no vcpus of the guest running, when 643 * switching the guest to HPT mode or when destroying the 644 * guest. 645 */ 646 void kvmhv_release_all_nested(struct kvm *kvm) 647 { 648 int i; 649 struct kvm_nested_guest *gp; 650 struct kvm_nested_guest *freelist = NULL; 651 struct kvm_memory_slot *memslot; 652 int srcu_idx; 653 654 spin_lock(&kvm->mmu_lock); 655 for (i = 0; i <= kvm->arch.max_nested_lpid; i++) { 656 gp = kvm->arch.nested_guests[i]; 657 if (!gp) 658 continue; 659 kvm->arch.nested_guests[i] = NULL; 660 if (--gp->refcnt == 0) { 661 gp->next = freelist; 662 freelist = gp; 663 } 664 } 665 kvm->arch.max_nested_lpid = -1; 666 spin_unlock(&kvm->mmu_lock); 667 while ((gp = freelist) != NULL) { 668 freelist = gp->next; 669 kvmhv_release_nested(gp); 670 } 671 672 srcu_idx = srcu_read_lock(&kvm->srcu); 673 kvm_for_each_memslot(memslot, kvm_memslots(kvm)) 674 kvmhv_free_memslot_nest_rmap(memslot); 675 srcu_read_unlock(&kvm->srcu, srcu_idx); 676 } 677 678 /* caller must hold gp->tlb_lock */ 679 static void kvmhv_flush_nested(struct kvm_nested_guest *gp) 680 { 681 struct kvm *kvm = gp->l1_host; 682 683 spin_lock(&kvm->mmu_lock); 684 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid); 685 spin_unlock(&kvm->mmu_lock); 686 kvmhv_flush_lpid(gp->shadow_lpid); 687 kvmhv_update_ptbl_cache(gp); 688 if (gp->l1_gr_to_hr == 0) 689 kvmhv_remove_nested(gp); 690 } 691 692 struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid, 693 bool create) 694 { 695 struct kvm_nested_guest *gp, *newgp; 696 697 if (l1_lpid >= KVM_MAX_NESTED_GUESTS || 698 l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4))) 699 return NULL; 700 701 spin_lock(&kvm->mmu_lock); 702 gp = kvm->arch.nested_guests[l1_lpid]; 703 if (gp) 704 ++gp->refcnt; 705 spin_unlock(&kvm->mmu_lock); 706 707 if (gp || !create) 708 return gp; 709 710 newgp = kvmhv_alloc_nested(kvm, l1_lpid); 711 if (!newgp) 712 return NULL; 713 spin_lock(&kvm->mmu_lock); 714 if (kvm->arch.nested_guests[l1_lpid]) { 715 /* someone else beat us to it */ 716 gp = kvm->arch.nested_guests[l1_lpid]; 717 } else { 718 kvm->arch.nested_guests[l1_lpid] = newgp; 719 ++newgp->refcnt; 720 gp = newgp; 721 newgp = NULL; 722 if (l1_lpid > kvm->arch.max_nested_lpid) 723 kvm->arch.max_nested_lpid = l1_lpid; 724 } 725 ++gp->refcnt; 726 spin_unlock(&kvm->mmu_lock); 727 728 if (newgp) 729 kvmhv_release_nested(newgp); 730 731 return gp; 732 } 733 734 void kvmhv_put_nested(struct kvm_nested_guest *gp) 735 { 736 struct kvm *kvm = gp->l1_host; 737 long ref; 738 739 spin_lock(&kvm->mmu_lock); 740 ref = --gp->refcnt; 741 spin_unlock(&kvm->mmu_lock); 742 if (ref == 0) 743 kvmhv_release_nested(gp); 744 } 745 746 static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid) 747 { 748 if (lpid > kvm->arch.max_nested_lpid) 749 return NULL; 750 return kvm->arch.nested_guests[lpid]; 751 } 752 753 pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid, 754 unsigned long ea, unsigned *hshift) 755 { 756 struct kvm_nested_guest *gp; 757 pte_t *pte; 758 759 gp = kvmhv_find_nested(kvm, lpid); 760 if (!gp) 761 return NULL; 762 763 VM_WARN(!spin_is_locked(&kvm->mmu_lock), 764 "%s called with kvm mmu_lock not held \n", __func__); 765 pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift); 766 767 return pte; 768 } 769 770 static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2) 771 { 772 return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK | 773 RMAP_NESTED_GPA_MASK)); 774 } 775 776 void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp, 777 struct rmap_nested **n_rmap) 778 { 779 struct llist_node *entry = ((struct llist_head *) rmapp)->first; 780 struct rmap_nested *cursor; 781 u64 rmap, new_rmap = (*n_rmap)->rmap; 782 783 /* Are there any existing entries? */ 784 if (!(*rmapp)) { 785 /* No -> use the rmap as a single entry */ 786 *rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY; 787 return; 788 } 789 790 /* Do any entries match what we're trying to insert? */ 791 for_each_nest_rmap_safe(cursor, entry, &rmap) { 792 if (kvmhv_n_rmap_is_equal(rmap, new_rmap)) 793 return; 794 } 795 796 /* Do we need to create a list or just add the new entry? */ 797 rmap = *rmapp; 798 if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */ 799 *rmapp = 0UL; 800 llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp); 801 if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */ 802 (*n_rmap)->list.next = (struct llist_node *) rmap; 803 804 /* Set NULL so not freed by caller */ 805 *n_rmap = NULL; 806 } 807 808 static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap, 809 unsigned long clr, unsigned long set, 810 unsigned long hpa, unsigned long mask) 811 { 812 unsigned long gpa; 813 unsigned int shift, lpid; 814 pte_t *ptep; 815 816 gpa = n_rmap & RMAP_NESTED_GPA_MASK; 817 lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT; 818 819 /* Find the pte */ 820 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift); 821 /* 822 * If the pte is present and the pfn is still the same, update the pte. 823 * If the pfn has changed then this is a stale rmap entry, the nested 824 * gpa actually points somewhere else now, and there is nothing to do. 825 * XXX A future optimisation would be to remove the rmap entry here. 826 */ 827 if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) { 828 __radix_pte_update(ptep, clr, set); 829 kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid); 830 } 831 } 832 833 /* 834 * For a given list of rmap entries, update the rc bits in all ptes in shadow 835 * page tables for nested guests which are referenced by the rmap list. 836 */ 837 void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp, 838 unsigned long clr, unsigned long set, 839 unsigned long hpa, unsigned long nbytes) 840 { 841 struct llist_node *entry = ((struct llist_head *) rmapp)->first; 842 struct rmap_nested *cursor; 843 unsigned long rmap, mask; 844 845 if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED)) 846 return; 847 848 mask = PTE_RPN_MASK & ~(nbytes - 1); 849 hpa &= mask; 850 851 for_each_nest_rmap_safe(cursor, entry, &rmap) 852 kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask); 853 } 854 855 static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap, 856 unsigned long hpa, unsigned long mask) 857 { 858 struct kvm_nested_guest *gp; 859 unsigned long gpa; 860 unsigned int shift, lpid; 861 pte_t *ptep; 862 863 gpa = n_rmap & RMAP_NESTED_GPA_MASK; 864 lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT; 865 gp = kvmhv_find_nested(kvm, lpid); 866 if (!gp) 867 return; 868 869 /* Find and invalidate the pte */ 870 ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift); 871 /* Don't spuriously invalidate ptes if the pfn has changed */ 872 if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) 873 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid); 874 } 875 876 static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp, 877 unsigned long hpa, unsigned long mask) 878 { 879 struct llist_node *entry = llist_del_all((struct llist_head *) rmapp); 880 struct rmap_nested *cursor; 881 unsigned long rmap; 882 883 for_each_nest_rmap_safe(cursor, entry, &rmap) { 884 kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask); 885 kfree(cursor); 886 } 887 } 888 889 /* called with kvm->mmu_lock held */ 890 void kvmhv_remove_nest_rmap_range(struct kvm *kvm, 891 const struct kvm_memory_slot *memslot, 892 unsigned long gpa, unsigned long hpa, 893 unsigned long nbytes) 894 { 895 unsigned long gfn, end_gfn; 896 unsigned long addr_mask; 897 898 if (!memslot) 899 return; 900 gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn; 901 end_gfn = gfn + (nbytes >> PAGE_SHIFT); 902 903 addr_mask = PTE_RPN_MASK & ~(nbytes - 1); 904 hpa &= addr_mask; 905 906 for (; gfn < end_gfn; gfn++) { 907 unsigned long *rmap = &memslot->arch.rmap[gfn]; 908 kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask); 909 } 910 } 911 912 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free) 913 { 914 unsigned long page; 915 916 for (page = 0; page < free->npages; page++) { 917 unsigned long rmap, *rmapp = &free->arch.rmap[page]; 918 struct rmap_nested *cursor; 919 struct llist_node *entry; 920 921 entry = llist_del_all((struct llist_head *) rmapp); 922 for_each_nest_rmap_safe(cursor, entry, &rmap) 923 kfree(cursor); 924 } 925 } 926 927 static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu, 928 struct kvm_nested_guest *gp, 929 long gpa, int *shift_ret) 930 { 931 struct kvm *kvm = vcpu->kvm; 932 bool ret = false; 933 pte_t *ptep; 934 int shift; 935 936 spin_lock(&kvm->mmu_lock); 937 ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift); 938 if (!shift) 939 shift = PAGE_SHIFT; 940 if (ptep && pte_present(*ptep)) { 941 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid); 942 ret = true; 943 } 944 spin_unlock(&kvm->mmu_lock); 945 946 if (shift_ret) 947 *shift_ret = shift; 948 return ret; 949 } 950 951 static inline int get_ric(unsigned int instr) 952 { 953 return (instr >> 18) & 0x3; 954 } 955 956 static inline int get_prs(unsigned int instr) 957 { 958 return (instr >> 17) & 0x1; 959 } 960 961 static inline int get_r(unsigned int instr) 962 { 963 return (instr >> 16) & 0x1; 964 } 965 966 static inline int get_lpid(unsigned long r_val) 967 { 968 return r_val & 0xffffffff; 969 } 970 971 static inline int get_is(unsigned long r_val) 972 { 973 return (r_val >> 10) & 0x3; 974 } 975 976 static inline int get_ap(unsigned long r_val) 977 { 978 return (r_val >> 5) & 0x7; 979 } 980 981 static inline long get_epn(unsigned long r_val) 982 { 983 return r_val >> 12; 984 } 985 986 static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid, 987 int ap, long epn) 988 { 989 struct kvm *kvm = vcpu->kvm; 990 struct kvm_nested_guest *gp; 991 long npages; 992 int shift, shadow_shift; 993 unsigned long addr; 994 995 shift = ap_to_shift(ap); 996 addr = epn << 12; 997 if (shift < 0) 998 /* Invalid ap encoding */ 999 return -EINVAL; 1000 1001 addr &= ~((1UL << shift) - 1); 1002 npages = 1UL << (shift - PAGE_SHIFT); 1003 1004 gp = kvmhv_get_nested(kvm, lpid, false); 1005 if (!gp) /* No such guest -> nothing to do */ 1006 return 0; 1007 mutex_lock(&gp->tlb_lock); 1008 1009 /* There may be more than one host page backing this single guest pte */ 1010 do { 1011 kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift); 1012 1013 npages -= 1UL << (shadow_shift - PAGE_SHIFT); 1014 addr += 1UL << shadow_shift; 1015 } while (npages > 0); 1016 1017 mutex_unlock(&gp->tlb_lock); 1018 kvmhv_put_nested(gp); 1019 return 0; 1020 } 1021 1022 static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu, 1023 struct kvm_nested_guest *gp, int ric) 1024 { 1025 struct kvm *kvm = vcpu->kvm; 1026 1027 mutex_lock(&gp->tlb_lock); 1028 switch (ric) { 1029 case 0: 1030 /* Invalidate TLB */ 1031 spin_lock(&kvm->mmu_lock); 1032 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, 1033 gp->shadow_lpid); 1034 kvmhv_flush_lpid(gp->shadow_lpid); 1035 spin_unlock(&kvm->mmu_lock); 1036 break; 1037 case 1: 1038 /* 1039 * Invalidate PWC 1040 * We don't cache this -> nothing to do 1041 */ 1042 break; 1043 case 2: 1044 /* Invalidate TLB, PWC and caching of partition table entries */ 1045 kvmhv_flush_nested(gp); 1046 break; 1047 default: 1048 break; 1049 } 1050 mutex_unlock(&gp->tlb_lock); 1051 } 1052 1053 static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric) 1054 { 1055 struct kvm *kvm = vcpu->kvm; 1056 struct kvm_nested_guest *gp; 1057 int i; 1058 1059 spin_lock(&kvm->mmu_lock); 1060 for (i = 0; i <= kvm->arch.max_nested_lpid; i++) { 1061 gp = kvm->arch.nested_guests[i]; 1062 if (gp) { 1063 spin_unlock(&kvm->mmu_lock); 1064 kvmhv_emulate_tlbie_lpid(vcpu, gp, ric); 1065 spin_lock(&kvm->mmu_lock); 1066 } 1067 } 1068 spin_unlock(&kvm->mmu_lock); 1069 } 1070 1071 static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr, 1072 unsigned long rsval, unsigned long rbval) 1073 { 1074 struct kvm *kvm = vcpu->kvm; 1075 struct kvm_nested_guest *gp; 1076 int r, ric, prs, is, ap; 1077 int lpid; 1078 long epn; 1079 int ret = 0; 1080 1081 ric = get_ric(instr); 1082 prs = get_prs(instr); 1083 r = get_r(instr); 1084 lpid = get_lpid(rsval); 1085 is = get_is(rbval); 1086 1087 /* 1088 * These cases are invalid and are not handled: 1089 * r != 1 -> Only radix supported 1090 * prs == 1 -> Not HV privileged 1091 * ric == 3 -> No cluster bombs for radix 1092 * is == 1 -> Partition scoped translations not associated with pid 1093 * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA 1094 */ 1095 if ((!r) || (prs) || (ric == 3) || (is == 1) || 1096 ((!is) && (ric == 1 || ric == 2))) 1097 return -EINVAL; 1098 1099 switch (is) { 1100 case 0: 1101 /* 1102 * We know ric == 0 1103 * Invalidate TLB for a given target address 1104 */ 1105 epn = get_epn(rbval); 1106 ap = get_ap(rbval); 1107 ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn); 1108 break; 1109 case 2: 1110 /* Invalidate matching LPID */ 1111 gp = kvmhv_get_nested(kvm, lpid, false); 1112 if (gp) { 1113 kvmhv_emulate_tlbie_lpid(vcpu, gp, ric); 1114 kvmhv_put_nested(gp); 1115 } 1116 break; 1117 case 3: 1118 /* Invalidate ALL LPIDs */ 1119 kvmhv_emulate_tlbie_all_lpid(vcpu, ric); 1120 break; 1121 default: 1122 ret = -EINVAL; 1123 break; 1124 } 1125 1126 return ret; 1127 } 1128 1129 /* 1130 * This handles the H_TLB_INVALIDATE hcall. 1131 * Parameters are (r4) tlbie instruction code, (r5) rS contents, 1132 * (r6) rB contents. 1133 */ 1134 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu) 1135 { 1136 int ret; 1137 1138 ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4), 1139 kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6)); 1140 if (ret) 1141 return H_PARAMETER; 1142 return H_SUCCESS; 1143 } 1144 1145 /* Used to convert a nested guest real address to a L1 guest real address */ 1146 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu, 1147 struct kvm_nested_guest *gp, 1148 unsigned long n_gpa, unsigned long dsisr, 1149 struct kvmppc_pte *gpte_p) 1150 { 1151 u64 fault_addr, flags = dsisr & DSISR_ISSTORE; 1152 int ret; 1153 1154 ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr, 1155 &fault_addr); 1156 1157 if (ret) { 1158 /* We didn't find a pte */ 1159 if (ret == -EINVAL) { 1160 /* Unsupported mmu config */ 1161 flags |= DSISR_UNSUPP_MMU; 1162 } else if (ret == -ENOENT) { 1163 /* No translation found */ 1164 flags |= DSISR_NOHPTE; 1165 } else if (ret == -EFAULT) { 1166 /* Couldn't access L1 real address */ 1167 flags |= DSISR_PRTABLE_FAULT; 1168 vcpu->arch.fault_gpa = fault_addr; 1169 } else { 1170 /* Unknown error */ 1171 return ret; 1172 } 1173 goto forward_to_l1; 1174 } else { 1175 /* We found a pte -> check permissions */ 1176 if (dsisr & DSISR_ISSTORE) { 1177 /* Can we write? */ 1178 if (!gpte_p->may_write) { 1179 flags |= DSISR_PROTFAULT; 1180 goto forward_to_l1; 1181 } 1182 } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { 1183 /* Can we execute? */ 1184 if (!gpte_p->may_execute) { 1185 flags |= SRR1_ISI_N_G_OR_CIP; 1186 goto forward_to_l1; 1187 } 1188 } else { 1189 /* Can we read? */ 1190 if (!gpte_p->may_read && !gpte_p->may_write) { 1191 flags |= DSISR_PROTFAULT; 1192 goto forward_to_l1; 1193 } 1194 } 1195 } 1196 1197 return 0; 1198 1199 forward_to_l1: 1200 vcpu->arch.fault_dsisr = flags; 1201 if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) { 1202 vcpu->arch.shregs.msr &= SRR1_MSR_BITS; 1203 vcpu->arch.shregs.msr |= flags; 1204 } 1205 return RESUME_HOST; 1206 } 1207 1208 static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu, 1209 struct kvm_nested_guest *gp, 1210 unsigned long n_gpa, 1211 struct kvmppc_pte gpte, 1212 unsigned long dsisr) 1213 { 1214 struct kvm *kvm = vcpu->kvm; 1215 bool writing = !!(dsisr & DSISR_ISSTORE); 1216 u64 pgflags; 1217 long ret; 1218 1219 /* Are the rc bits set in the L1 partition scoped pte? */ 1220 pgflags = _PAGE_ACCESSED; 1221 if (writing) 1222 pgflags |= _PAGE_DIRTY; 1223 if (pgflags & ~gpte.rc) 1224 return RESUME_HOST; 1225 1226 spin_lock(&kvm->mmu_lock); 1227 /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */ 1228 ret = kvmppc_hv_handle_set_rc(kvm, false, writing, 1229 gpte.raddr, kvm->arch.lpid); 1230 if (!ret) { 1231 ret = -EINVAL; 1232 goto out_unlock; 1233 } 1234 1235 /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */ 1236 ret = kvmppc_hv_handle_set_rc(kvm, true, writing, 1237 n_gpa, gp->shadow_lpid); 1238 if (!ret) 1239 ret = -EINVAL; 1240 else 1241 ret = 0; 1242 1243 out_unlock: 1244 spin_unlock(&kvm->mmu_lock); 1245 return ret; 1246 } 1247 1248 static inline int kvmppc_radix_level_to_shift(int level) 1249 { 1250 switch (level) { 1251 case 2: 1252 return PUD_SHIFT; 1253 case 1: 1254 return PMD_SHIFT; 1255 default: 1256 return PAGE_SHIFT; 1257 } 1258 } 1259 1260 static inline int kvmppc_radix_shift_to_level(int shift) 1261 { 1262 if (shift == PUD_SHIFT) 1263 return 2; 1264 if (shift == PMD_SHIFT) 1265 return 1; 1266 if (shift == PAGE_SHIFT) 1267 return 0; 1268 WARN_ON_ONCE(1); 1269 return 0; 1270 } 1271 1272 /* called with gp->tlb_lock held */ 1273 static long int __kvmhv_nested_page_fault(struct kvm_run *run, 1274 struct kvm_vcpu *vcpu, 1275 struct kvm_nested_guest *gp) 1276 { 1277 struct kvm *kvm = vcpu->kvm; 1278 struct kvm_memory_slot *memslot; 1279 struct rmap_nested *n_rmap; 1280 struct kvmppc_pte gpte; 1281 pte_t pte, *pte_p; 1282 unsigned long mmu_seq; 1283 unsigned long dsisr = vcpu->arch.fault_dsisr; 1284 unsigned long ea = vcpu->arch.fault_dar; 1285 unsigned long *rmapp; 1286 unsigned long n_gpa, gpa, gfn, perm = 0UL; 1287 unsigned int shift, l1_shift, level; 1288 bool writing = !!(dsisr & DSISR_ISSTORE); 1289 bool kvm_ro = false; 1290 long int ret; 1291 1292 if (!gp->l1_gr_to_hr) { 1293 kvmhv_update_ptbl_cache(gp); 1294 if (!gp->l1_gr_to_hr) 1295 return RESUME_HOST; 1296 } 1297 1298 /* Convert the nested guest real address into a L1 guest real address */ 1299 1300 n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL; 1301 if (!(dsisr & DSISR_PRTABLE_FAULT)) 1302 n_gpa |= ea & 0xFFF; 1303 ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte); 1304 1305 /* 1306 * If the hardware found a translation but we don't now have a usable 1307 * translation in the l1 partition-scoped tree, remove the shadow pte 1308 * and let the guest retry. 1309 */ 1310 if (ret == RESUME_HOST && 1311 (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G | 1312 DSISR_BAD_COPYPASTE))) 1313 goto inval; 1314 if (ret) 1315 return ret; 1316 1317 /* Failed to set the reference/change bits */ 1318 if (dsisr & DSISR_SET_RC) { 1319 ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr); 1320 if (ret == RESUME_HOST) 1321 return ret; 1322 if (ret) 1323 goto inval; 1324 dsisr &= ~DSISR_SET_RC; 1325 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE | 1326 DSISR_PROTFAULT))) 1327 return RESUME_GUEST; 1328 } 1329 1330 /* 1331 * We took an HISI or HDSI while we were running a nested guest which 1332 * means we have no partition scoped translation for that. This means 1333 * we need to insert a pte for the mapping into our shadow_pgtable. 1334 */ 1335 1336 l1_shift = gpte.page_shift; 1337 if (l1_shift < PAGE_SHIFT) { 1338 /* We don't support l1 using a page size smaller than our own */ 1339 pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n", 1340 l1_shift, PAGE_SHIFT); 1341 return -EINVAL; 1342 } 1343 gpa = gpte.raddr; 1344 gfn = gpa >> PAGE_SHIFT; 1345 1346 /* 1. Get the corresponding host memslot */ 1347 1348 memslot = gfn_to_memslot(kvm, gfn); 1349 if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { 1350 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) { 1351 /* unusual error -> reflect to the guest as a DSI */ 1352 kvmppc_core_queue_data_storage(vcpu, ea, dsisr); 1353 return RESUME_GUEST; 1354 } 1355 1356 /* passthrough of emulated MMIO case */ 1357 return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing); 1358 } 1359 if (memslot->flags & KVM_MEM_READONLY) { 1360 if (writing) { 1361 /* Give the guest a DSI */ 1362 kvmppc_core_queue_data_storage(vcpu, ea, 1363 DSISR_ISSTORE | DSISR_PROTFAULT); 1364 return RESUME_GUEST; 1365 } 1366 kvm_ro = true; 1367 } 1368 1369 /* 2. Find the host pte for this L1 guest real address */ 1370 1371 /* Used to check for invalidations in progress */ 1372 mmu_seq = kvm->mmu_notifier_seq; 1373 smp_rmb(); 1374 1375 /* See if can find translation in our partition scoped tables for L1 */ 1376 pte = __pte(0); 1377 spin_lock(&kvm->mmu_lock); 1378 pte_p = find_kvm_secondary_pte(kvm, gpa, &shift); 1379 if (!shift) 1380 shift = PAGE_SHIFT; 1381 if (pte_p) 1382 pte = *pte_p; 1383 spin_unlock(&kvm->mmu_lock); 1384 1385 if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) { 1386 /* No suitable pte found -> try to insert a mapping */ 1387 ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, 1388 writing, kvm_ro, &pte, &level); 1389 if (ret == -EAGAIN) 1390 return RESUME_GUEST; 1391 else if (ret) 1392 return ret; 1393 shift = kvmppc_radix_level_to_shift(level); 1394 } 1395 /* Align gfn to the start of the page */ 1396 gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT; 1397 1398 /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */ 1399 1400 /* The permissions is the combination of the host and l1 guest ptes */ 1401 perm |= gpte.may_read ? 0UL : _PAGE_READ; 1402 perm |= gpte.may_write ? 0UL : _PAGE_WRITE; 1403 perm |= gpte.may_execute ? 0UL : _PAGE_EXEC; 1404 /* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */ 1405 perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED; 1406 perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY; 1407 pte = __pte(pte_val(pte) & ~perm); 1408 1409 /* What size pte can we insert? */ 1410 if (shift > l1_shift) { 1411 u64 mask; 1412 unsigned int actual_shift = PAGE_SHIFT; 1413 if (PMD_SHIFT < l1_shift) 1414 actual_shift = PMD_SHIFT; 1415 mask = (1UL << shift) - (1UL << actual_shift); 1416 pte = __pte(pte_val(pte) | (gpa & mask)); 1417 shift = actual_shift; 1418 } 1419 level = kvmppc_radix_shift_to_level(shift); 1420 n_gpa &= ~((1UL << shift) - 1); 1421 1422 /* 4. Insert the pte into our shadow_pgtable */ 1423 1424 n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL); 1425 if (!n_rmap) 1426 return RESUME_GUEST; /* Let the guest try again */ 1427 n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) | 1428 (((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT); 1429 rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; 1430 ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level, 1431 mmu_seq, gp->shadow_lpid, rmapp, &n_rmap); 1432 if (n_rmap) 1433 kfree(n_rmap); 1434 if (ret == -EAGAIN) 1435 ret = RESUME_GUEST; /* Let the guest try again */ 1436 1437 return ret; 1438 1439 inval: 1440 kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL); 1441 return RESUME_GUEST; 1442 } 1443 1444 long int kvmhv_nested_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu) 1445 { 1446 struct kvm_nested_guest *gp = vcpu->arch.nested; 1447 long int ret; 1448 1449 mutex_lock(&gp->tlb_lock); 1450 ret = __kvmhv_nested_page_fault(run, vcpu, gp); 1451 mutex_unlock(&gp->tlb_lock); 1452 return ret; 1453 } 1454 1455 int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid) 1456 { 1457 int ret = -1; 1458 1459 spin_lock(&kvm->mmu_lock); 1460 while (++lpid <= kvm->arch.max_nested_lpid) { 1461 if (kvm->arch.nested_guests[lpid]) { 1462 ret = lpid; 1463 break; 1464 } 1465 } 1466 spin_unlock(&kvm->mmu_lock); 1467 return ret; 1468 } 1469