linux/arch/powerpc/kvm/book3s_hv_nested.c
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   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
  15#include <asm/kvm_ppc.h>
  16#include <asm/kvm_book3s.h>
  17#include <asm/mmu.h>
  18#include <asm/pgtable.h>
  19#include <asm/pgalloc.h>
  20#include <asm/pte-walk.h>
  21#include <asm/reg.h>
  22
  23static struct patb_entry *pseries_partition_tb;
  24
  25static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp);
  26static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free);
  27
  28void 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;
  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
  54static 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
  62static 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);
  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
  96static 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
 131static 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
 147static 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;
 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
 172void 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
 198static 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
 218long 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
 347long 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
 382void 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
 396static void kvmhv_flush_lpid(unsigned int lpid)
 397{
 398        long rc;
 399
 400        if (!kvmhv_on_pseries()) {
 401                radix__flush_tlb_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
 411void 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);
 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
 424static 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
 433void 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 */
 443long 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 */
 473long 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
 528out_unlock:
 529        mutex_unlock(&gp->tlb_lock);
 530        kvmhv_put_nested(gp);
 531out_free:
 532        kfree(buf);
 533        return rc;
 534not_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 */
 543static 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
 565struct 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 */
 599static 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
 618static 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 */
 646void 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 */
 679static 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
 692struct 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
 734void 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
 746static 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
 753static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
 754{
 755        return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
 756                                       RMAP_NESTED_GPA_MASK));
 757}
 758
 759void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
 760                            struct rmap_nested **n_rmap)
 761{
 762        struct llist_node *entry = ((struct llist_head *) rmapp)->first;
 763        struct rmap_nested *cursor;
 764        u64 rmap, new_rmap = (*n_rmap)->rmap;
 765
 766        /* Are there any existing entries? */
 767        if (!(*rmapp)) {
 768                /* No -> use the rmap as a single entry */
 769                *rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
 770                return;
 771        }
 772
 773        /* Do any entries match what we're trying to insert? */
 774        for_each_nest_rmap_safe(cursor, entry, &rmap) {
 775                if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
 776                        return;
 777        }
 778
 779        /* Do we need to create a list or just add the new entry? */
 780        rmap = *rmapp;
 781        if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
 782                *rmapp = 0UL;
 783        llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
 784        if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
 785                (*n_rmap)->list.next = (struct llist_node *) rmap;
 786
 787        /* Set NULL so not freed by caller */
 788        *n_rmap = NULL;
 789}
 790
 791static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
 792                                      unsigned long clr, unsigned long set,
 793                                      unsigned long hpa, unsigned long mask)
 794{
 795        struct kvm_nested_guest *gp;
 796        unsigned long gpa;
 797        unsigned int shift, lpid;
 798        pte_t *ptep;
 799
 800        gpa = n_rmap & RMAP_NESTED_GPA_MASK;
 801        lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
 802        gp = kvmhv_find_nested(kvm, lpid);
 803        if (!gp)
 804                return;
 805
 806        /* Find the pte */
 807        ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
 808        /*
 809         * If the pte is present and the pfn is still the same, update the pte.
 810         * If the pfn has changed then this is a stale rmap entry, the nested
 811         * gpa actually points somewhere else now, and there is nothing to do.
 812         * XXX A future optimisation would be to remove the rmap entry here.
 813         */
 814        if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
 815                __radix_pte_update(ptep, clr, set);
 816                kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
 817        }
 818}
 819
 820/*
 821 * For a given list of rmap entries, update the rc bits in all ptes in shadow
 822 * page tables for nested guests which are referenced by the rmap list.
 823 */
 824void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
 825                                    unsigned long clr, unsigned long set,
 826                                    unsigned long hpa, unsigned long nbytes)
 827{
 828        struct llist_node *entry = ((struct llist_head *) rmapp)->first;
 829        struct rmap_nested *cursor;
 830        unsigned long rmap, mask;
 831
 832        if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
 833                return;
 834
 835        mask = PTE_RPN_MASK & ~(nbytes - 1);
 836        hpa &= mask;
 837
 838        for_each_nest_rmap_safe(cursor, entry, &rmap)
 839                kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
 840}
 841
 842static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
 843                                   unsigned long hpa, unsigned long mask)
 844{
 845        struct kvm_nested_guest *gp;
 846        unsigned long gpa;
 847        unsigned int shift, lpid;
 848        pte_t *ptep;
 849
 850        gpa = n_rmap & RMAP_NESTED_GPA_MASK;
 851        lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
 852        gp = kvmhv_find_nested(kvm, lpid);
 853        if (!gp)
 854                return;
 855
 856        /* Find and invalidate the pte */
 857        ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
 858        /* Don't spuriously invalidate ptes if the pfn has changed */
 859        if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
 860                kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
 861}
 862
 863static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
 864                                        unsigned long hpa, unsigned long mask)
 865{
 866        struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
 867        struct rmap_nested *cursor;
 868        unsigned long rmap;
 869
 870        for_each_nest_rmap_safe(cursor, entry, &rmap) {
 871                kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
 872                kfree(cursor);
 873        }
 874}
 875
 876/* called with kvm->mmu_lock held */
 877void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
 878                                  const struct kvm_memory_slot *memslot,
 879                                  unsigned long gpa, unsigned long hpa,
 880                                  unsigned long nbytes)
 881{
 882        unsigned long gfn, end_gfn;
 883        unsigned long addr_mask;
 884
 885        if (!memslot)
 886                return;
 887        gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
 888        end_gfn = gfn + (nbytes >> PAGE_SHIFT);
 889
 890        addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
 891        hpa &= addr_mask;
 892
 893        for (; gfn < end_gfn; gfn++) {
 894                unsigned long *rmap = &memslot->arch.rmap[gfn];
 895                kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
 896        }
 897}
 898
 899static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
 900{
 901        unsigned long page;
 902
 903        for (page = 0; page < free->npages; page++) {
 904                unsigned long rmap, *rmapp = &free->arch.rmap[page];
 905                struct rmap_nested *cursor;
 906                struct llist_node *entry;
 907
 908                entry = llist_del_all((struct llist_head *) rmapp);
 909                for_each_nest_rmap_safe(cursor, entry, &rmap)
 910                        kfree(cursor);
 911        }
 912}
 913
 914static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
 915                                        struct kvm_nested_guest *gp,
 916                                        long gpa, int *shift_ret)
 917{
 918        struct kvm *kvm = vcpu->kvm;
 919        bool ret = false;
 920        pte_t *ptep;
 921        int shift;
 922
 923        spin_lock(&kvm->mmu_lock);
 924        ptep = __find_linux_pte(gp->shadow_pgtable, gpa, NULL, &shift);
 925        if (!shift)
 926                shift = PAGE_SHIFT;
 927        if (ptep && pte_present(*ptep)) {
 928                kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
 929                ret = true;
 930        }
 931        spin_unlock(&kvm->mmu_lock);
 932
 933        if (shift_ret)
 934                *shift_ret = shift;
 935        return ret;
 936}
 937
 938static inline int get_ric(unsigned int instr)
 939{
 940        return (instr >> 18) & 0x3;
 941}
 942
 943static inline int get_prs(unsigned int instr)
 944{
 945        return (instr >> 17) & 0x1;
 946}
 947
 948static inline int get_r(unsigned int instr)
 949{
 950        return (instr >> 16) & 0x1;
 951}
 952
 953static inline int get_lpid(unsigned long r_val)
 954{
 955        return r_val & 0xffffffff;
 956}
 957
 958static inline int get_is(unsigned long r_val)
 959{
 960        return (r_val >> 10) & 0x3;
 961}
 962
 963static inline int get_ap(unsigned long r_val)
 964{
 965        return (r_val >> 5) & 0x7;
 966}
 967
 968static inline long get_epn(unsigned long r_val)
 969{
 970        return r_val >> 12;
 971}
 972
 973static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
 974                                        int ap, long epn)
 975{
 976        struct kvm *kvm = vcpu->kvm;
 977        struct kvm_nested_guest *gp;
 978        long npages;
 979        int shift, shadow_shift;
 980        unsigned long addr;
 981
 982        shift = ap_to_shift(ap);
 983        addr = epn << 12;
 984        if (shift < 0)
 985                /* Invalid ap encoding */
 986                return -EINVAL;
 987
 988        addr &= ~((1UL << shift) - 1);
 989        npages = 1UL << (shift - PAGE_SHIFT);
 990
 991        gp = kvmhv_get_nested(kvm, lpid, false);
 992        if (!gp) /* No such guest -> nothing to do */
 993                return 0;
 994        mutex_lock(&gp->tlb_lock);
 995
 996        /* There may be more than one host page backing this single guest pte */
 997        do {
 998                kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
 999
1000                npages -= 1UL << (shadow_shift - PAGE_SHIFT);
1001                addr += 1UL << shadow_shift;
1002        } while (npages > 0);
1003
1004        mutex_unlock(&gp->tlb_lock);
1005        kvmhv_put_nested(gp);
1006        return 0;
1007}
1008
1009static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
1010                                     struct kvm_nested_guest *gp, int ric)
1011{
1012        struct kvm *kvm = vcpu->kvm;
1013
1014        mutex_lock(&gp->tlb_lock);
1015        switch (ric) {
1016        case 0:
1017                /* Invalidate TLB */
1018                spin_lock(&kvm->mmu_lock);
1019                kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
1020                                          gp->shadow_lpid);
1021                kvmhv_flush_lpid(gp->shadow_lpid);
1022                spin_unlock(&kvm->mmu_lock);
1023                break;
1024        case 1:
1025                /*
1026                 * Invalidate PWC
1027                 * We don't cache this -> nothing to do
1028                 */
1029                break;
1030        case 2:
1031                /* Invalidate TLB, PWC and caching of partition table entries */
1032                kvmhv_flush_nested(gp);
1033                break;
1034        default:
1035                break;
1036        }
1037        mutex_unlock(&gp->tlb_lock);
1038}
1039
1040static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
1041{
1042        struct kvm *kvm = vcpu->kvm;
1043        struct kvm_nested_guest *gp;
1044        int i;
1045
1046        spin_lock(&kvm->mmu_lock);
1047        for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
1048                gp = kvm->arch.nested_guests[i];
1049                if (gp) {
1050                        spin_unlock(&kvm->mmu_lock);
1051                        kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1052                        spin_lock(&kvm->mmu_lock);
1053                }
1054        }
1055        spin_unlock(&kvm->mmu_lock);
1056}
1057
1058static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
1059                                    unsigned long rsval, unsigned long rbval)
1060{
1061        struct kvm *kvm = vcpu->kvm;
1062        struct kvm_nested_guest *gp;
1063        int r, ric, prs, is, ap;
1064        int lpid;
1065        long epn;
1066        int ret = 0;
1067
1068        ric = get_ric(instr);
1069        prs = get_prs(instr);
1070        r = get_r(instr);
1071        lpid = get_lpid(rsval);
1072        is = get_is(rbval);
1073
1074        /*
1075         * These cases are invalid and are not handled:
1076         * r   != 1 -> Only radix supported
1077         * prs == 1 -> Not HV privileged
1078         * ric == 3 -> No cluster bombs for radix
1079         * is  == 1 -> Partition scoped translations not associated with pid
1080         * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
1081         */
1082        if ((!r) || (prs) || (ric == 3) || (is == 1) ||
1083            ((!is) && (ric == 1 || ric == 2)))
1084                return -EINVAL;
1085
1086        switch (is) {
1087        case 0:
1088                /*
1089                 * We know ric == 0
1090                 * Invalidate TLB for a given target address
1091                 */
1092                epn = get_epn(rbval);
1093                ap = get_ap(rbval);
1094                ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
1095                break;
1096        case 2:
1097                /* Invalidate matching LPID */
1098                gp = kvmhv_get_nested(kvm, lpid, false);
1099                if (gp) {
1100                        kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1101                        kvmhv_put_nested(gp);
1102                }
1103                break;
1104        case 3:
1105                /* Invalidate ALL LPIDs */
1106                kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
1107                break;
1108        default:
1109                ret = -EINVAL;
1110                break;
1111        }
1112
1113        return ret;
1114}
1115
1116/*
1117 * This handles the H_TLB_INVALIDATE hcall.
1118 * Parameters are (r4) tlbie instruction code, (r5) rS contents,
1119 * (r6) rB contents.
1120 */
1121long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
1122{
1123        int ret;
1124
1125        ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
1126                        kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
1127        if (ret)
1128                return H_PARAMETER;
1129        return H_SUCCESS;
1130}
1131
1132/* Used to convert a nested guest real address to a L1 guest real address */
1133static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
1134                                       struct kvm_nested_guest *gp,
1135                                       unsigned long n_gpa, unsigned long dsisr,
1136                                       struct kvmppc_pte *gpte_p)
1137{
1138        u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
1139        int ret;
1140
1141        ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
1142                                         &fault_addr);
1143
1144        if (ret) {
1145                /* We didn't find a pte */
1146                if (ret == -EINVAL) {
1147                        /* Unsupported mmu config */
1148                        flags |= DSISR_UNSUPP_MMU;
1149                } else if (ret == -ENOENT) {
1150                        /* No translation found */
1151                        flags |= DSISR_NOHPTE;
1152                } else if (ret == -EFAULT) {
1153                        /* Couldn't access L1 real address */
1154                        flags |= DSISR_PRTABLE_FAULT;
1155                        vcpu->arch.fault_gpa = fault_addr;
1156                } else {
1157                        /* Unknown error */
1158                        return ret;
1159                }
1160                goto forward_to_l1;
1161        } else {
1162                /* We found a pte -> check permissions */
1163                if (dsisr & DSISR_ISSTORE) {
1164                        /* Can we write? */
1165                        if (!gpte_p->may_write) {
1166                                flags |= DSISR_PROTFAULT;
1167                                goto forward_to_l1;
1168                        }
1169                } else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1170                        /* Can we execute? */
1171                        if (!gpte_p->may_execute) {
1172                                flags |= SRR1_ISI_N_OR_G;
1173                                goto forward_to_l1;
1174                        }
1175                } else {
1176                        /* Can we read? */
1177                        if (!gpte_p->may_read && !gpte_p->may_write) {
1178                                flags |= DSISR_PROTFAULT;
1179                                goto forward_to_l1;
1180                        }
1181                }
1182        }
1183
1184        return 0;
1185
1186forward_to_l1:
1187        vcpu->arch.fault_dsisr = flags;
1188        if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1189                vcpu->arch.shregs.msr &= ~0x783f0000ul;
1190                vcpu->arch.shregs.msr |= flags;
1191        }
1192        return RESUME_HOST;
1193}
1194
1195static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
1196                                       struct kvm_nested_guest *gp,
1197                                       unsigned long n_gpa,
1198                                       struct kvmppc_pte gpte,
1199                                       unsigned long dsisr)
1200{
1201        struct kvm *kvm = vcpu->kvm;
1202        bool writing = !!(dsisr & DSISR_ISSTORE);
1203        u64 pgflags;
1204        long ret;
1205
1206        /* Are the rc bits set in the L1 partition scoped pte? */
1207        pgflags = _PAGE_ACCESSED;
1208        if (writing)
1209                pgflags |= _PAGE_DIRTY;
1210        if (pgflags & ~gpte.rc)
1211                return RESUME_HOST;
1212
1213        spin_lock(&kvm->mmu_lock);
1214        /* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
1215        ret = kvmppc_hv_handle_set_rc(kvm, kvm->arch.pgtable, writing,
1216                                     gpte.raddr, kvm->arch.lpid);
1217        if (!ret) {
1218                ret = -EINVAL;
1219                goto out_unlock;
1220        }
1221
1222        /* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
1223        ret = kvmppc_hv_handle_set_rc(kvm, gp->shadow_pgtable, writing, n_gpa,
1224                                      gp->shadow_lpid);
1225        if (!ret)
1226                ret = -EINVAL;
1227        else
1228                ret = 0;
1229
1230out_unlock:
1231        spin_unlock(&kvm->mmu_lock);
1232        return ret;
1233}
1234
1235static inline int kvmppc_radix_level_to_shift(int level)
1236{
1237        switch (level) {
1238        case 2:
1239                return PUD_SHIFT;
1240        case 1:
1241                return PMD_SHIFT;
1242        default:
1243                return PAGE_SHIFT;
1244        }
1245}
1246
1247static inline int kvmppc_radix_shift_to_level(int shift)
1248{
1249        if (shift == PUD_SHIFT)
1250                return 2;
1251        if (shift == PMD_SHIFT)
1252                return 1;
1253        if (shift == PAGE_SHIFT)
1254                return 0;
1255        WARN_ON_ONCE(1);
1256        return 0;
1257}
1258
1259/* called with gp->tlb_lock held */
1260static long int __kvmhv_nested_page_fault(struct kvm_run *run,
1261                                          struct kvm_vcpu *vcpu,
1262                                          struct kvm_nested_guest *gp)
1263{
1264        struct kvm *kvm = vcpu->kvm;
1265        struct kvm_memory_slot *memslot;
1266        struct rmap_nested *n_rmap;
1267        struct kvmppc_pte gpte;
1268        pte_t pte, *pte_p;
1269        unsigned long mmu_seq;
1270        unsigned long dsisr = vcpu->arch.fault_dsisr;
1271        unsigned long ea = vcpu->arch.fault_dar;
1272        unsigned long *rmapp;
1273        unsigned long n_gpa, gpa, gfn, perm = 0UL;
1274        unsigned int shift, l1_shift, level;
1275        bool writing = !!(dsisr & DSISR_ISSTORE);
1276        bool kvm_ro = false;
1277        long int ret;
1278
1279        if (!gp->l1_gr_to_hr) {
1280                kvmhv_update_ptbl_cache(gp);
1281                if (!gp->l1_gr_to_hr)
1282                        return RESUME_HOST;
1283        }
1284
1285        /* Convert the nested guest real address into a L1 guest real address */
1286
1287        n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
1288        if (!(dsisr & DSISR_PRTABLE_FAULT))
1289                n_gpa |= ea & 0xFFF;
1290        ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
1291
1292        /*
1293         * If the hardware found a translation but we don't now have a usable
1294         * translation in the l1 partition-scoped tree, remove the shadow pte
1295         * and let the guest retry.
1296         */
1297        if (ret == RESUME_HOST &&
1298            (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
1299                      DSISR_BAD_COPYPASTE)))
1300                goto inval;
1301        if (ret)
1302                return ret;
1303
1304        /* Failed to set the reference/change bits */
1305        if (dsisr & DSISR_SET_RC) {
1306                ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
1307                if (ret == RESUME_HOST)
1308                        return ret;
1309                if (ret)
1310                        goto inval;
1311                dsisr &= ~DSISR_SET_RC;
1312                if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1313                               DSISR_PROTFAULT)))
1314                        return RESUME_GUEST;
1315        }
1316
1317        /*
1318         * We took an HISI or HDSI while we were running a nested guest which
1319         * means we have no partition scoped translation for that. This means
1320         * we need to insert a pte for the mapping into our shadow_pgtable.
1321         */
1322
1323        l1_shift = gpte.page_shift;
1324        if (l1_shift < PAGE_SHIFT) {
1325                /* We don't support l1 using a page size smaller than our own */
1326                pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
1327                        l1_shift, PAGE_SHIFT);
1328                return -EINVAL;
1329        }
1330        gpa = gpte.raddr;
1331        gfn = gpa >> PAGE_SHIFT;
1332
1333        /* 1. Get the corresponding host memslot */
1334
1335        memslot = gfn_to_memslot(kvm, gfn);
1336        if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
1337                if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
1338                        /* unusual error -> reflect to the guest as a DSI */
1339                        kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
1340                        return RESUME_GUEST;
1341                }
1342
1343                /* passthrough of emulated MMIO case */
1344                return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea, writing);
1345        }
1346        if (memslot->flags & KVM_MEM_READONLY) {
1347                if (writing) {
1348                        /* Give the guest a DSI */
1349                        kvmppc_core_queue_data_storage(vcpu, ea,
1350                                        DSISR_ISSTORE | DSISR_PROTFAULT);
1351                        return RESUME_GUEST;
1352                }
1353                kvm_ro = true;
1354        }
1355
1356        /* 2. Find the host pte for this L1 guest real address */
1357
1358        /* Used to check for invalidations in progress */
1359        mmu_seq = kvm->mmu_notifier_seq;
1360        smp_rmb();
1361
1362        /* See if can find translation in our partition scoped tables for L1 */
1363        pte = __pte(0);
1364        spin_lock(&kvm->mmu_lock);
1365        pte_p = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
1366        if (!shift)
1367                shift = PAGE_SHIFT;
1368        if (pte_p)
1369                pte = *pte_p;
1370        spin_unlock(&kvm->mmu_lock);
1371
1372        if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
1373                /* No suitable pte found -> try to insert a mapping */
1374                ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
1375                                        writing, kvm_ro, &pte, &level);
1376                if (ret == -EAGAIN)
1377                        return RESUME_GUEST;
1378                else if (ret)
1379                        return ret;
1380                shift = kvmppc_radix_level_to_shift(level);
1381        }
1382        /* Align gfn to the start of the page */
1383        gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
1384
1385        /* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
1386
1387        /* The permissions is the combination of the host and l1 guest ptes */
1388        perm |= gpte.may_read ? 0UL : _PAGE_READ;
1389        perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
1390        perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
1391        /* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
1392        perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
1393        perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
1394        pte = __pte(pte_val(pte) & ~perm);
1395
1396        /* What size pte can we insert? */
1397        if (shift > l1_shift) {
1398                u64 mask;
1399                unsigned int actual_shift = PAGE_SHIFT;
1400                if (PMD_SHIFT < l1_shift)
1401                        actual_shift = PMD_SHIFT;
1402                mask = (1UL << shift) - (1UL << actual_shift);
1403                pte = __pte(pte_val(pte) | (gpa & mask));
1404                shift = actual_shift;
1405        }
1406        level = kvmppc_radix_shift_to_level(shift);
1407        n_gpa &= ~((1UL << shift) - 1);
1408
1409        /* 4. Insert the pte into our shadow_pgtable */
1410
1411        n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
1412        if (!n_rmap)
1413                return RESUME_GUEST; /* Let the guest try again */
1414        n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
1415                (((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
1416        rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1417        ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
1418                                mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
1419        if (n_rmap)
1420                kfree(n_rmap);
1421        if (ret == -EAGAIN)
1422                ret = RESUME_GUEST;     /* Let the guest try again */
1423
1424        return ret;
1425
1426 inval:
1427        kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
1428        return RESUME_GUEST;
1429}
1430
1431long int kvmhv_nested_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu)
1432{
1433        struct kvm_nested_guest *gp = vcpu->arch.nested;
1434        long int ret;
1435
1436        mutex_lock(&gp->tlb_lock);
1437        ret = __kvmhv_nested_page_fault(run, vcpu, gp);
1438        mutex_unlock(&gp->tlb_lock);
1439        return ret;
1440}
1441
1442int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
1443{
1444        int ret = -1;
1445
1446        spin_lock(&kvm->mmu_lock);
1447        while (++lpid <= kvm->arch.max_nested_lpid) {
1448                if (kvm->arch.nested_guests[lpid]) {
1449                        ret = lpid;
1450                        break;
1451                }
1452        }
1453        spin_unlock(&kvm->mmu_lock);
1454        return ret;
1455}
1456