arch/powerpc/kvm/book3s_hv_nested.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright IBM Corporation, 2018
   4  * Authors Suraj Jitindar Singh <[email protected]>
   5  *         Paul Mackerras <[email protected]>
   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         regs_ptr = kvmppc_get_gpr(vcpu, 5);
 237         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 238         err = kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv,
 239                                   sizeof(struct hv_guest_state)) ||
 240                 kvm_vcpu_read_guest(vcpu, regs_ptr, &l2_regs,
 241                                     sizeof(struct pt_regs));
 242         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 243         if (err)
 244                 return H_PARAMETER;
 245
 246         if (kvmppc_need_byteswap(vcpu))
 247                 byteswap_hv_regs(&l2_hv);
 248         if (l2_hv.version != HV_GUEST_STATE_VERSION)
 249                 return H_P2;
 250
 251         if (kvmppc_need_byteswap(vcpu))
 252                 byteswap_pt_regs(&l2_regs);
 253         if (l2_hv.vcpu_token >= NR_CPUS)
 254                 return H_PARAMETER;
 255
 256         /* translate lpid */
 257         l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true);
 258         if (!l2)
 259                 return H_PARAMETER;
 260         if (!l2->l1_gr_to_hr) {
 261                 mutex_lock(&l2->tlb_lock);
 262                 kvmhv_update_ptbl_cache(l2);
 263                 mutex_unlock(&l2->tlb_lock);
 264         }
 265
 266         /* save l1 values of things */
 267         vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
 268         saved_l1_regs = vcpu->arch.regs;
 269         kvmhv_save_hv_regs(vcpu, &saved_l1_hv);
 270
 271         /* convert TB values/offsets to host (L0) values */
 272         hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
 273         vc->tb_offset += l2_hv.tb_offset;
 274
 275         /* set L1 state to L2 state */
 276         vcpu->arch.nested = l2;
 277         vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
 278         vcpu->arch.regs = l2_regs;
 279         vcpu->arch.shregs.msr = vcpu->arch.regs.msr;
 280         mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD |
 281                 LPCR_LPES | LPCR_MER;
 282         lpcr = (vc->lpcr & ~mask) | (l2_hv.lpcr & mask);
 283         sanitise_hv_regs(vcpu, &l2_hv);
 284         restore_hv_regs(vcpu, &l2_hv);
 285
 286         vcpu->arch.ret = RESUME_GUEST;
 287         vcpu->arch.trap = 0;
 288         do {
 289                 if (mftb() >= hdec_exp) {
 290                         vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
 291                         r = RESUME_HOST;
 292                         break;
 293                 }
 294                 r = kvmhv_run_single_vcpu(vcpu, hdec_exp, 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         vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 328         err = kvm_vcpu_write_guest(vcpu, hv_ptr, &l2_hv,
 329                                    sizeof(struct hv_guest_state)) ||
 330                 kvm_vcpu_write_guest(vcpu, regs_ptr, &l2_regs,
 331                                    sizeof(struct pt_regs));
 332         srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 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                 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 513                 rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
 514                 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 515                 if (rc)
 516                         goto not_found;
 517         } else {
 518                 /* Load the data to be stored from the L1 guest into our buf */
 519                 vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
 520                 rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
 521                 srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 522                 if (rc)
 523                         goto not_found;
 524
 525                 /* Store from our buffer into the nested guest */
 526                 rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
 527                                                      eaddr, NULL, buf, n);
 528                 if (rc)
 529                         goto not_found;
 530         }
 531
 532 out_unlock:
 533         mutex_unlock(&gp->tlb_lock);
 534         kvmhv_put_nested(gp);
 535 out_free:
 536         kfree(buf);
 537         return rc;
 538 not_found:
 539         rc = H_NOT_FOUND;
 540         goto out_unlock;
 541 }
 542
 543 /*
 544  * Reload the partition table entry for a guest.
 545  * Caller must hold gp->tlb_lock.
 546  */
 547 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
 548 {
 549         int ret;
 550         struct patb_entry ptbl_entry;
 551         unsigned long ptbl_addr;
 552         struct kvm *kvm = gp->l1_host;
 553
 554         ret = -EFAULT;
 555         ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
 556         if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) {
 557                 int srcu_idx = srcu_read_lock(&kvm->srcu);
 558                 ret = kvm_read_guest(kvm, ptbl_addr,
 559                                      &ptbl_entry, sizeof(ptbl_entry));
 560                 srcu_read_unlock(&kvm->srcu, srcu_idx);
 561         }
 562         if (ret) {
 563                 gp->l1_gr_to_hr = 0;
 564                 gp->process_table = 0;
 565         } else {
 566                 gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0);
 567                 gp->process_table = be64_to_cpu(ptbl_entry.patb1);
 568         }
 569         kvmhv_set_nested_ptbl(gp);
 570 }
 571
 572 struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
 573 {
 574         struct kvm_nested_guest *gp;
 575         long shadow_lpid;
 576
 577         gp = kzalloc(sizeof(*gp), GFP_KERNEL);
 578         if (!gp)
 579                 return NULL;
 580         gp->l1_host = kvm;
 581         gp->l1_lpid = lpid;
 582         mutex_init(&gp->tlb_lock);
 583         gp->shadow_pgtable = pgd_alloc(kvm->mm);
 584         if (!gp->shadow_pgtable)
 585                 goto out_free;
 586         shadow_lpid = kvmppc_alloc_lpid();
 587         if (shadow_lpid < 0)
 588                 goto out_free2;
 589         gp->shadow_lpid = shadow_lpid;
 590         gp->radix = 1;
 591
 592         memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu));
 593
 594         return gp;
 595
 596  out_free2:
 597         pgd_free(kvm->mm, gp->shadow_pgtable);
 598  out_free:
 599         kfree(gp);
 600         return NULL;
 601 }
 602
 603 /*
 604  * Free up any resources allocated for a nested guest.
 605  */
 606 static void kvmhv_release_nested(struct kvm_nested_guest *gp)
 607 {
 608         struct kvm *kvm = gp->l1_host;
 609
 610         if (gp->shadow_pgtable) {
 611                 /*
 612                  * No vcpu is using this struct and no call to
 613                  * kvmhv_get_nested can find this struct,
 614                  * so we don't need to hold kvm->mmu_lock.
 615                  */
 616                 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
 617                                           gp->shadow_lpid);
 618                 pgd_free(kvm->mm, gp->shadow_pgtable);
 619         }
 620         kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
 621         kvmppc_free_lpid(gp->shadow_lpid);
 622         kfree(gp);
 623 }
 624
 625 static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
 626 {
 627         struct kvm *kvm = gp->l1_host;
 628         int lpid = gp->l1_lpid;
 629         long ref;
 630
 631         spin_lock(&kvm->mmu_lock);
 632         if (gp == kvm->arch.nested_guests[lpid]) {
 633                 kvm->arch.nested_guests[lpid] = NULL;
 634                 if (lpid == kvm->arch.max_nested_lpid) {
 635                         while (--lpid >= 0 && !kvm->arch.nested_guests[lpid])
 636                                 ;
 637                         kvm->arch.max_nested_lpid = lpid;
 638                 }
 639                 --gp->refcnt;
 640         }
 641         ref = gp->refcnt;
 642         spin_unlock(&kvm->mmu_lock);
 643         if (ref == 0)
 644                 kvmhv_release_nested(gp);
 645 }
 646
 647 /*
 648  * Free up all nested resources allocated for this guest.
 649  * This is called with no vcpus of the guest running, when
 650  * switching the guest to HPT mode or when destroying the
 651  * guest.
 652  */
 653 void kvmhv_release_all_nested(struct kvm *kvm)
 654 {
 655         int i;
 656         struct kvm_nested_guest *gp;
 657         struct kvm_nested_guest *freelist = NULL;
 658         struct kvm_memory_slot *memslot;
 659         int srcu_idx;
 660
 661         spin_lock(&kvm->mmu_lock);
 662         for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
 663                 gp = kvm->arch.nested_guests[i];
 664                 if (!gp)
 665                         continue;
 666                 kvm->arch.nested_guests[i] = NULL;
 667                 if (--gp->refcnt == 0) {
 668                         gp->next = freelist;
 669                         freelist = gp;
 670                 }
 671         }
 672         kvm->arch.max_nested_lpid = -1;
 673         spin_unlock(&kvm->mmu_lock);
 674         while ((gp = freelist) != NULL) {
 675                 freelist = gp->next;
 676                 kvmhv_release_nested(gp);
 677         }
 678
 679         srcu_idx = srcu_read_lock(&kvm->srcu);
 680         kvm_for_each_memslot(memslot, kvm_memslots(kvm))
 681                 kvmhv_free_memslot_nest_rmap(memslot);
 682         srcu_read_unlock(&kvm->srcu, srcu_idx);
 683 }
 684
 685 /* caller must hold gp->tlb_lock */
 686 static void kvmhv_flush_nested(struct kvm_nested_guest *gp)
 687 {
 688         struct kvm *kvm = gp->l1_host;
 689
 690         spin_lock(&kvm->mmu_lock);
 691         kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
 692         spin_unlock(&kvm->mmu_lock);
 693         kvmhv_flush_lpid(gp->shadow_lpid);
 694         kvmhv_update_ptbl_cache(gp);
 695         if (gp->l1_gr_to_hr == 0)
 696                 kvmhv_remove_nested(gp);
 697 }
 698
 699 struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
 700                                           bool create)
 701 {
 702         struct kvm_nested_guest *gp, *newgp;
 703
 704         if (l1_lpid >= KVM_MAX_NESTED_GUESTS ||
 705             l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4)))
 706                 return NULL;
 707
 708         spin_lock(&kvm->mmu_lock);
 709         gp = kvm->arch.nested_guests[l1_lpid];
 710         if (gp)
 711                 ++gp->refcnt;
 712         spin_unlock(&kvm->mmu_lock);
 713
 714         if (gp || !create)
 715                 return gp;
 716
 717         newgp = kvmhv_alloc_nested(kvm, l1_lpid);
 718         if (!newgp)
 719                 return NULL;
 720         spin_lock(&kvm->mmu_lock);
 721         if (kvm->arch.nested_guests[l1_lpid]) {
 722                 /* someone else beat us to it */
 723                 gp = kvm->arch.nested_guests[l1_lpid];
 724         } else {
 725                 kvm->arch.nested_guests[l1_lpid] = newgp;
 726                 ++newgp->refcnt;
 727                 gp = newgp;
 728                 newgp = NULL;
 729                 if (l1_lpid > kvm->arch.max_nested_lpid)
 730                         kvm->arch.max_nested_lpid = l1_lpid;
 731         }
 732         ++gp->refcnt;
 733         spin_unlock(&kvm->mmu_lock);
 734
 735         if (newgp)
 736                 kvmhv_release_nested(newgp);
 737
 738         return gp;
 739 }
 740
 741 void kvmhv_put_nested(struct kvm_nested_guest *gp)
 742 {
 743         struct kvm *kvm = gp->l1_host;
 744         long ref;
 745
 746         spin_lock(&kvm->mmu_lock);
 747         ref = --gp->refcnt;
 748         spin_unlock(&kvm->mmu_lock);
 749         if (ref == 0)
 750                 kvmhv_release_nested(gp);
 751 }
 752
 753 static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
 754 {
 755         if (lpid > kvm->arch.max_nested_lpid)
 756                 return NULL;
 757         return kvm->arch.nested_guests[lpid];
 758 }
 759
 760 pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
 761                                  unsigned long ea, unsigned *hshift)
 762 {
 763         struct kvm_nested_guest *gp;
 764         pte_t *pte;
 765
 766         gp = kvmhv_find_nested(kvm, lpid);
 767         if (!gp)
 768                 return NULL;
 769
 770         VM_WARN(!spin_is_locked(&kvm->mmu_lock),
 771                 "%s called with kvm mmu_lock not held \n", __func__);
 772         pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
 773
 774         return pte;
 775 }
 776
 777 static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
 778 {
 779         return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
 780                                        RMAP_NESTED_GPA_MASK));
 781 }
 782
 783 void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
 784                             struct rmap_nested **n_rmap)
 785 {
 786         struct llist_node *entry = ((struct llist_head *) rmapp)->first;
 787         struct rmap_nested *cursor;
 788         u64 rmap, new_rmap = (*n_rmap)->rmap;
 789
 790         /* Are there any existing entries? */
 791         if (!(*rmapp)) {
 792                 /* No -> use the rmap as a single entry */
 793                 *rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
 794                 return;
 795         }
 796
 797         /* Do any entries match what we're trying to insert? */
 798         for_each_nest_rmap_safe(cursor, entry, &rmap) {
 799                 if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
 800                         return;
 801         }
 802
 803         /* Do we need to create a list or just add the new entry? */
 804         rmap = *rmapp;
 805         if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
 806                 *rmapp = 0UL;
 807         llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
 808         if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
 809                 (*n_rmap)->list.next = (struct llist_node *) rmap;
 810
 811         /* Set NULL so not freed by caller */
 812         *n_rmap = NULL;
 813 }
 814
 815 static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
 816                                       unsigned long clr, unsigned long set,
 817                                       unsigned long hpa, unsigned long mask)
 818 {
 819         unsigned long gpa;
 820         unsigned int shift, lpid;
 821         pte_t *ptep;
 822
 823         gpa = n_rmap & RMAP_NESTED_GPA_MASK;
 824         lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
 825
 826         /* Find the pte */
 827         ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
 828         /*
 829          * If the pte is present and the pfn is still the same, update the pte.
 830          * If the pfn has changed then this is a stale rmap entry, the nested
 831          * gpa actually points somewhere else now, and there is nothing to do.
 832          * XXX A future optimisation would be to remove the rmap entry here.
 833          */
 834         if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
 835                 __radix_pte_update(ptep, clr, set);
 836                 kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
 837         }
 838 }
 839
 840 /*
 841  * For a given list of rmap entries, update the rc bits in all ptes in shadow
 842  * page tables for nested guests which are referenced by the rmap list.
 843  */
 844 void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
 845                                     unsigned long clr, unsigned long set,
 846                                     unsigned long hpa, unsigned long nbytes)
 847 {
 848         struct llist_node *entry = ((struct llist_head *) rmapp)->first;
 849         struct rmap_nested *cursor;
 850         unsigned long rmap, mask;
 851
 852         if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
 853                 return;
 854
 855         mask = PTE_RPN_MASK & ~(nbytes - 1);
 856         hpa &= mask;
 857
 858         for_each_nest_rmap_safe(cursor, entry, &rmap)
 859                 kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
 860 }
 861
 862 static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
 863                                    unsigned long hpa, unsigned long mask)
 864 {
 865         struct kvm_nested_guest *gp;
 866         unsigned long gpa;
 867         unsigned int shift, lpid;
 868         pte_t *ptep;
 869
 870         gpa = n_rmap & RMAP_NESTED_GPA_MASK;
 871         lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
 872         gp = kvmhv_find_nested(kvm, lpid);
 873         if (!gp)
 874                 return;
 875
 876         /* Find and invalidate the pte */
 877         ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
 878         /* Don't spuriously invalidate ptes if the pfn has changed */
 879         if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
 880                 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
 881 }
 882
 883 static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
 884                                         unsigned long hpa, unsigned long mask)
 885 {
 886         struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
 887         struct rmap_nested *cursor;
 888         unsigned long rmap;
 889
 890         for_each_nest_rmap_safe(cursor, entry, &rmap) {
 891                 kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
 892                 kfree(cursor);
 893         }
 894 }
 895
 896 /* called with kvm->mmu_lock held */
 897 void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
 898                                   const struct kvm_memory_slot *memslot,
 899                                   unsigned long gpa, unsigned long hpa,
 900                                   unsigned long nbytes)
 901 {
 902         unsigned long gfn, end_gfn;
 903         unsigned long addr_mask;
 904
 905         if (!memslot)
 906                 return;
 907         gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
 908         end_gfn = gfn + (nbytes >> PAGE_SHIFT);
 909
 910         addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
 911         hpa &= addr_mask;
 912
 913         for (; gfn < end_gfn; gfn++) {
 914                 unsigned long *rmap = &memslot->arch.rmap[gfn];
 915                 kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
 916         }
 917 }
 918
 919 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
 920 {
 921         unsigned long page;
 922
 923         for (page = 0; page < free->npages; page++) {
 924                 unsigned long rmap, *rmapp = &free->arch.rmap[page];
 925                 struct rmap_nested *cursor;
 926                 struct llist_node *entry;
 927
 928                 entry = llist_del_all((struct llist_head *) rmapp);
 929                 for_each_nest_rmap_safe(cursor, entry, &rmap)
 930                         kfree(cursor);
 931         }
 932 }
 933
 934 static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
 935                                         struct kvm_nested_guest *gp,
 936                                         long gpa, int *shift_ret)
 937 {
 938         struct kvm *kvm = vcpu->kvm;
 939         bool ret = false;
 940         pte_t *ptep;
 941         int shift;
 942
 943         spin_lock(&kvm->mmu_lock);
 944         ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
 945         if (!shift)
 946                 shift = PAGE_SHIFT;
 947         if (ptep && pte_present(*ptep)) {
 948                 kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
 949                 ret = true;
 950         }
 951         spin_unlock(&kvm->mmu_lock);
 952
 953         if (shift_ret)
 954                 *shift_ret = shift;
 955         return ret;
 956 }
 957
 958 static inline int get_ric(unsigned int instr)
 959 {
 960         return (instr >> 18) & 0x3;
 961 }
 962
 963 static inline int get_prs(unsigned int instr)
 964 {
 965         return (instr >> 17) & 0x1;
 966 }
 967
 968 static inline int get_r(unsigned int instr)
 969 {
 970         return (instr >> 16) & 0x1;
 971 }
 972
 973 static inline int get_lpid(unsigned long r_val)
 974 {
 975         return r_val & 0xffffffff;
 976 }
 977
 978 static inline int get_is(unsigned long r_val)
 979 {
 980         return (r_val >> 10) & 0x3;
 981 }
 982
 983 static inline int get_ap(unsigned long r_val)
 984 {
 985         return (r_val >> 5) & 0x7;
 986 }
 987
 988 static inline long get_epn(unsigned long r_val)
 989 {
 990         return r_val >> 12;
 991 }
 992
 993 static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
 994                                         int ap, long epn)
 995 {
 996         struct kvm *kvm = vcpu->kvm;
 997         struct kvm_nested_guest *gp;
 998         long npages;
 999         int shift, shadow_shift;
1000         unsigned long addr;
1001
1002         shift = ap_to_shift(ap);
1003         addr = epn << 12;
1004         if (shift < 0)
1005                 /* Invalid ap encoding */
1006                 return -EINVAL;
1007
1008         addr &= ~((1UL << shift) - 1);
1009         npages = 1UL << (shift - PAGE_SHIFT);
1010
1011         gp = kvmhv_get_nested(kvm, lpid, false);
1012         if (!gp) /* No such guest -> nothing to do */
1013                 return 0;
1014         mutex_lock(&gp->tlb_lock);
1015
1016         /* There may be more than one host page backing this single guest pte */
1017         do {
1018                 kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
1019
1020                 npages -= 1UL << (shadow_shift - PAGE_SHIFT);
1021                 addr += 1UL << shadow_shift;
1022         } while (npages > 0);
1023
1024         mutex_unlock(&gp->tlb_lock);
1025         kvmhv_put_nested(gp);
1026         return 0;
1027 }
1028
1029 static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
1030                                      struct kvm_nested_guest *gp, int ric)
1031 {
1032         struct kvm *kvm = vcpu->kvm;
1033
1034         mutex_lock(&gp->tlb_lock);
1035         switch (ric) {
1036         case 0:
1037                 /* Invalidate TLB */
1038                 spin_lock(&kvm->mmu_lock);
1039                 kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
1040                                           gp->shadow_lpid);
1041                 kvmhv_flush_lpid(gp->shadow_lpid);
1042                 spin_unlock(&kvm->mmu_lock);
1043                 break;
1044         case 1:
1045                 /*
1046                  * Invalidate PWC
1047                  * We don't cache this -> nothing to do
1048                  */
1049                 break;
1050         case 2:
1051                 /* Invalidate TLB, PWC and caching of partition table entries */
1052                 kvmhv_flush_nested(gp);
1053                 break;
1054         default:
1055                 break;
1056         }
1057         mutex_unlock(&gp->tlb_lock);
1058 }
1059
1060 static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
1061 {
1062         struct kvm *kvm = vcpu->kvm;
1063         struct kvm_nested_guest *gp;
1064         int i;
1065
1066         spin_lock(&kvm->mmu_lock);
1067         for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
1068                 gp = kvm->arch.nested_guests[i];
1069                 if (gp) {
1070                         spin_unlock(&kvm->mmu_lock);
1071                         kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1072                         spin_lock(&kvm->mmu_lock);
1073                 }
1074         }
1075         spin_unlock(&kvm->mmu_lock);
1076 }
1077
1078 static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
1079                                     unsigned long rsval, unsigned long rbval)
1080 {
1081         struct kvm *kvm = vcpu->kvm;
1082         struct kvm_nested_guest *gp;
1083         int r, ric, prs, is, ap;
1084         int lpid;
1085         long epn;
1086         int ret = 0;
1087
1088         ric = get_ric(instr);
1089         prs = get_prs(instr);
1090         r = get_r(instr);
1091         lpid = get_lpid(rsval);
1092         is = get_is(rbval);
1093
1094         /*
1095          * These cases are invalid and are not handled:
1096          * r   != 1 -> Only radix supported
1097          * prs == 1 -> Not HV privileged
1098          * ric == 3 -> No cluster bombs for radix
1099          * is  == 1 -> Partition scoped translations not associated with pid
1100          * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
1101          */
1102         if ((!r) || (prs) || (ric == 3) || (is == 1) ||
1103             ((!is) && (ric == 1 || ric == 2)))
1104                 return -EINVAL;
1105
1106         switch (is) {
1107         case 0:
1108                 /*
1109                  * We know ric == 0
1110                  * Invalidate TLB for a given target address
1111                  */
1112                 epn = get_epn(rbval);
1113                 ap = get_ap(rbval);
1114                 ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
1115                 break;
1116         case 2:
1117                 /* Invalidate matching LPID */
1118                 gp = kvmhv_get_nested(kvm, lpid, false);
1119                 if (gp) {
1120                         kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1121                         kvmhv_put_nested(gp);
1122                 }
1123                 break;
1124         case 3:
1125                 /* Invalidate ALL LPIDs */
1126                 kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
1127                 break;
1128         default:
1129                 ret = -EINVAL;
1130                 break;
1131         }
1132
1133         return ret;
1134 }
1135
1136 /*
1137  * This handles the H_TLB_INVALIDATE hcall.
1138  * Parameters are (r4) tlbie instruction code, (r5) rS contents,
1139  * (r6) rB contents.
1140  */
1141 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
1142 {
1143         int ret;
1144
1145         ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
1146                         kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
1147         if (ret)
1148                 return H_PARAMETER;
1149         return H_SUCCESS;
1150 }
1151
1152 /* Used to convert a nested guest real address to a L1 guest real address */
1153 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
1154                                        struct kvm_nested_guest *gp,
1155                                        unsigned long n_gpa, unsigned long dsisr,
1156                                        struct kvmppc_pte *gpte_p)
1157 {
1158         u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
1159         int ret;
1160
1161         ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
1162                                          &fault_addr);
1163
1164         if (ret) {
1165                 /* We didn't find a pte */
1166                 if (ret == -EINVAL) {
1167                         /* Unsupported mmu config */
1168                         flags |= DSISR_UNSUPP_MMU;
1169                 } else if (ret == -ENOENT) {
1170                         /* No translation found */
1171                         flags |= DSISR_NOHPTE;
1172                 } else if (ret == -EFAULT) {
1173                         /* Couldn't access L1 real address */
1174                         flags |= DSISR_PRTABLE_FAULT;
1175                         vcpu->arch.fault_gpa = fault_addr;
1176                 } else {
1177                         /* Unknown error */
1178                         return ret;
1179                 }
1180                 goto forward_to_l1;
1181         } else {
1182                 /* We found a pte -> check permissions */
1183                 if (dsisr & DSISR_ISSTORE) {
1184                         /* Can we write? */
1185                         if (!gpte_p->may_write) {
1186                                 flags |= DSISR_PROTFAULT;
1187                                 goto forward_to_l1;
1188                         }
1189                 } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1190                         /* Can we execute? */
1191                         if (!gpte_p->may_execute) {
1192                                 flags |= SRR1_ISI_N_G_OR_CIP;
1193                                 goto forward_to_l1;
1194                         }
1195                 } else {
1196                         /* Can we read? */
1197                         if (!gpte_p->may_read && !gpte_p->may_write) {
1198                                 flags |= DSISR_PROTFAULT;
1199                                 goto forward_to_l1;
1200                         }
1201                 }
1202         }
1203
1204         return 0;
1205
1206 forward_to_l1:
1207         vcpu->arch.fault_dsisr = flags;
1208         if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1209                 vcpu->arch.shregs.msr &= SRR1_MSR_BITS;
1210                 vcpu->arch.shregs.msr |= flags;
1211         }
1212         return RESUME_HOST;
1213 }
1214
1215 static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
1216                                        struct kvm_nested_guest *gp,
1217                                        unsigned long n_gpa,
1218                                        struct kvmppc_pte gpte,
1219                                        unsigned long dsisr)
1220 {
1221         struct kvm *kvm = vcpu->kvm;
1222         bool writing = !!(dsisr & DSISR_ISSTORE);
1223         u64 pgflags;
1224         long ret;
1225
1226         /* Are the rc bits set in the L1 partition scoped pte? */
1227         pgflags = _PAGE_ACCESSED;
1228         if (writing)
1229                 pgflags |= _PAGE_DIRTY;
1230         if (pgflags & ~gpte.rc)
1231                 return RESUME_HOST;
1232
1233         spin_lock(&kvm->mmu_lock);
1234         /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
1235         ret = kvmppc_hv_handle_set_rc(kvm, false, writing,
1236                                       gpte.raddr, kvm->arch.lpid);
1237         if (!ret) {
1238                 ret = -EINVAL;
1239                 goto out_unlock;
1240         }
1241
1242         /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
1243         ret = kvmppc_hv_handle_set_rc(kvm, true, writing,
1244                                       n_gpa, gp->l1_lpid);
1245         if (!ret)
1246                 ret = -EINVAL;
1247         else
1248                 ret = 0;
1249
1250 out_unlock:
1251         spin_unlock(&kvm->mmu_lock);
1252         return ret;
1253 }
1254
1255 static inline int kvmppc_radix_level_to_shift(int level)
1256 {
1257         switch (level) {
1258         case 2:
1259                 return PUD_SHIFT;
1260         case 1:
1261                 return PMD_SHIFT;
1262         default:
1263                 return PAGE_SHIFT;
1264         }
1265 }
1266
1267 static inline int kvmppc_radix_shift_to_level(int shift)
1268 {
1269         if (shift == PUD_SHIFT)
1270                 return 2;
1271         if (shift == PMD_SHIFT)
1272                 return 1;
1273         if (shift == PAGE_SHIFT)
1274                 return 0;
1275         WARN_ON_ONCE(1);
1276         return 0;
1277 }
1278
1279 /* called with gp->tlb_lock held */
1280 static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
1281                                           struct kvm_nested_guest *gp)
1282 {
1283         struct kvm *kvm = vcpu->kvm;
1284         struct kvm_memory_slot *memslot;
1285         struct rmap_nested *n_rmap;
1286         struct kvmppc_pte gpte;
1287         pte_t pte, *pte_p;
1288         unsigned long mmu_seq;
1289         unsigned long dsisr = vcpu->arch.fault_dsisr;
1290         unsigned long ea = vcpu->arch.fault_dar;
1291         unsigned long *rmapp;
1292         unsigned long n_gpa, gpa, gfn, perm = 0UL;
1293         unsigned int shift, l1_shift, level;
1294         bool writing = !!(dsisr & DSISR_ISSTORE);
1295         bool kvm_ro = false;
1296         long int ret;
1297
1298         if (!gp->l1_gr_to_hr) {
1299                 kvmhv_update_ptbl_cache(gp);
1300                 if (!gp->l1_gr_to_hr)
1301                         return RESUME_HOST;
1302         }
1303
1304         /* Convert the nested guest real address into a L1 guest real address */
1305
1306         n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
1307         if (!(dsisr & DSISR_PRTABLE_FAULT))
1308                 n_gpa |= ea & 0xFFF;
1309         ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
1310
1311         /*
1312          * If the hardware found a translation but we don't now have a usable
1313          * translation in the l1 partition-scoped tree, remove the shadow pte
1314          * and let the guest retry.
1315          */
1316         if (ret == RESUME_HOST &&
1317             (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
1318                       DSISR_BAD_COPYPASTE)))
1319                 goto inval;
1320         if (ret)
1321                 return ret;
1322
1323         /* Failed to set the reference/change bits */
1324         if (dsisr & DSISR_SET_RC) {
1325                 ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
1326                 if (ret == RESUME_HOST)
1327                         return ret;
1328                 if (ret)
1329                         goto inval;
1330                 dsisr &= ~DSISR_SET_RC;
1331                 if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1332                                DSISR_PROTFAULT)))
1333                         return RESUME_GUEST;
1334         }
1335
1336         /*
1337          * We took an HISI or HDSI while we were running a nested guest which
1338          * means we have no partition scoped translation for that. This means
1339          * we need to insert a pte for the mapping into our shadow_pgtable.
1340          */
1341
1342         l1_shift = gpte.page_shift;
1343         if (l1_shift < PAGE_SHIFT) {
1344                 /* We don't support l1 using a page size smaller than our own */
1345                 pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
1346                         l1_shift, PAGE_SHIFT);
1347                 return -EINVAL;
1348         }
1349         gpa = gpte.raddr;
1350         gfn = gpa >> PAGE_SHIFT;
1351
1352         /* 1. Get the corresponding host memslot */
1353
1354         memslot = gfn_to_memslot(kvm, gfn);
1355         if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
1356                 if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
1357                         /* unusual error -> reflect to the guest as a DSI */
1358                         kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
1359                         return RESUME_GUEST;
1360                 }
1361
1362                 /* passthrough of emulated MMIO case */
1363                 return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
1364         }
1365         if (memslot->flags & KVM_MEM_READONLY) {
1366                 if (writing) {
1367                         /* Give the guest a DSI */
1368                         kvmppc_core_queue_data_storage(vcpu, ea,
1369                                         DSISR_ISSTORE | DSISR_PROTFAULT);
1370                         return RESUME_GUEST;
1371                 }
1372                 kvm_ro = true;
1373         }
1374
1375         /* 2. Find the host pte for this L1 guest real address */
1376
1377         /* Used to check for invalidations in progress */
1378         mmu_seq = kvm->mmu_notifier_seq;
1379         smp_rmb();
1380
1381         /* See if can find translation in our partition scoped tables for L1 */
1382         pte = __pte(0);
1383         spin_lock(&kvm->mmu_lock);
1384         pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
1385         if (!shift)
1386                 shift = PAGE_SHIFT;
1387         if (pte_p)
1388                 pte = *pte_p;
1389         spin_unlock(&kvm->mmu_lock);
1390
1391         if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
1392                 /* No suitable pte found -> try to insert a mapping */
1393                 ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
1394                                         writing, kvm_ro, &pte, &level);
1395                 if (ret == -EAGAIN)
1396                         return RESUME_GUEST;
1397                 else if (ret)
1398                         return ret;
1399                 shift = kvmppc_radix_level_to_shift(level);
1400         }
1401         /* Align gfn to the start of the page */
1402         gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
1403
1404         /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
1405
1406         /* The permissions is the combination of the host and l1 guest ptes */
1407         perm |= gpte.may_read ? 0UL : _PAGE_READ;
1408         perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
1409         perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
1410         /* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
1411         perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
1412         perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
1413         pte = __pte(pte_val(pte) & ~perm);
1414
1415         /* What size pte can we insert? */
1416         if (shift > l1_shift) {
1417                 u64 mask;
1418                 unsigned int actual_shift = PAGE_SHIFT;
1419                 if (PMD_SHIFT < l1_shift)
1420                         actual_shift = PMD_SHIFT;
1421                 mask = (1UL << shift) - (1UL << actual_shift);
1422                 pte = __pte(pte_val(pte) | (gpa & mask));
1423                 shift = actual_shift;
1424         }
1425         level = kvmppc_radix_shift_to_level(shift);
1426         n_gpa &= ~((1UL << shift) - 1);
1427
1428         /* 4. Insert the pte into our shadow_pgtable */
1429
1430         n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
1431         if (!n_rmap)
1432                 return RESUME_GUEST; /* Let the guest try again */
1433         n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
1434                 (((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
1435         rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1436         ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
1437                                 mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
1438         kfree(n_rmap);
1439         if (ret == -EAGAIN)
1440                 ret = RESUME_GUEST;     /* Let the guest try again */
1441
1442         return ret;
1443
1444  inval:
1445         kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
1446         return RESUME_GUEST;
1447 }
1448
1449 long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
1450 {
1451         struct kvm_nested_guest *gp = vcpu->arch.nested;
1452         long int ret;
1453
1454         mutex_lock(&gp->tlb_lock);
1455         ret = __kvmhv_nested_page_fault(vcpu, gp);
1456         mutex_unlock(&gp->tlb_lock);
1457         return ret;
1458 }
1459
1460 int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
1461 {
1462         int ret = -1;
1463
1464         spin_lock(&kvm->mmu_lock);
1465         while (++lpid <= kvm->arch.max_nested_lpid) {
1466                 if (kvm->arch.nested_guests[lpid]) {
1467                         ret = lpid;
1468                         break;
1469                 }
1470         }
1471         spin_unlock(&kvm->mmu_lock);
1472         return ret;
1473 }