// SPDX-License-Identifier: GPL-2.0-only /* * * Copyright 2010 Paul Mackerras, IBM Corp. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "book3s.h" #include "book3s_hv.h" #include "trace_hv.h" //#define DEBUG_RESIZE_HPT 1 #ifdef DEBUG_RESIZE_HPT #define resize_hpt_debug(resize, ...) \ do { \ printk(KERN_DEBUG "RESIZE HPT %p: ", resize); \ printk(__VA_ARGS__); \ } while (0) #else #define resize_hpt_debug(resize, ...) \ do { } while (0) #endif static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, long pte_index, unsigned long pteh, unsigned long ptel, unsigned long *pte_idx_ret); struct kvm_resize_hpt { /* These fields read-only after init */ struct kvm *kvm; struct work_struct work; u32 order; /* These fields protected by kvm->arch.mmu_setup_lock */ /* Possible values and their usage: * <0 an error occurred during allocation, * -EBUSY allocation is in the progress, * 0 allocation made successfully. */ int error; /* Private to the work thread, until error != -EBUSY, * then protected by kvm->arch.mmu_setup_lock. */ struct kvm_hpt_info hpt; }; int kvmppc_allocate_hpt(struct kvm_hpt_info *info, u32 order) { unsigned long hpt = 0; int cma = 0; struct page *page = NULL; struct revmap_entry *rev; unsigned long npte; if ((order < PPC_MIN_HPT_ORDER) || (order > PPC_MAX_HPT_ORDER)) return -EINVAL; page = kvm_alloc_hpt_cma(1ul << (order - PAGE_SHIFT)); if (page) { hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page)); memset((void *)hpt, 0, (1ul << order)); cma = 1; } if (!hpt) hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_RETRY_MAYFAIL |__GFP_NOWARN, order - PAGE_SHIFT); if (!hpt) return -ENOMEM; /* HPTEs are 2**4 bytes long */ npte = 1ul << (order - 4); /* Allocate reverse map array */ rev = vmalloc(array_size(npte, sizeof(struct revmap_entry))); if (!rev) { if (cma) kvm_free_hpt_cma(page, 1 << (order - PAGE_SHIFT)); else free_pages(hpt, order - PAGE_SHIFT); return -ENOMEM; } info->order = order; info->virt = hpt; info->cma = cma; info->rev = rev; return 0; } void kvmppc_set_hpt(struct kvm *kvm, struct kvm_hpt_info *info) { atomic64_set(&kvm->arch.mmio_update, 0); kvm->arch.hpt = *info; kvm->arch.sdr1 = __pa(info->virt) | (info->order - 18); pr_debug("KVM guest htab at %lx (order %ld), LPID %llx\n", info->virt, (long)info->order, kvm->arch.lpid); } int kvmppc_alloc_reset_hpt(struct kvm *kvm, int order) { int err = -EBUSY; struct kvm_hpt_info info; mutex_lock(&kvm->arch.mmu_setup_lock); if (kvm->arch.mmu_ready) { kvm->arch.mmu_ready = 0; /* order mmu_ready vs. vcpus_running */ smp_mb(); if (atomic_read(&kvm->arch.vcpus_running)) { kvm->arch.mmu_ready = 1; goto out; } } if (kvm_is_radix(kvm)) { err = kvmppc_switch_mmu_to_hpt(kvm); if (err) goto out; } if (kvm->arch.hpt.order == order) { /* We already have a suitable HPT */ /* Set the entire HPT to 0, i.e. invalid HPTEs */ memset((void *)kvm->arch.hpt.virt, 0, 1ul << order); /* * Reset all the reverse-mapping chains for all memslots */ kvmppc_rmap_reset(kvm); err = 0; goto out; } if (kvm->arch.hpt.virt) { kvmppc_free_hpt(&kvm->arch.hpt); kvmppc_rmap_reset(kvm); } err = kvmppc_allocate_hpt(&info, order); if (err < 0) goto out; kvmppc_set_hpt(kvm, &info); out: if (err == 0) /* Ensure that each vcpu will flush its TLB on next entry. */ cpumask_setall(&kvm->arch.need_tlb_flush); mutex_unlock(&kvm->arch.mmu_setup_lock); return err; } void kvmppc_free_hpt(struct kvm_hpt_info *info) { vfree(info->rev); info->rev = NULL; if (info->cma) kvm_free_hpt_cma(virt_to_page((void *)info->virt), 1 << (info->order - PAGE_SHIFT)); else if (info->virt) free_pages(info->virt, info->order - PAGE_SHIFT); info->virt = 0; info->order = 0; } /* Bits in first HPTE dword for pagesize 4k, 64k or 16M */ static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize) { return (pgsize > 0x1000) ? HPTE_V_LARGE : 0; } /* Bits in second HPTE dword for pagesize 4k, 64k or 16M */ static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize) { return (pgsize == 0x10000) ? 0x1000 : 0; } void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot, unsigned long porder) { unsigned long i; unsigned long npages; unsigned long hp_v, hp_r; unsigned long addr, hash; unsigned long psize; unsigned long hp0, hp1; unsigned long idx_ret; long ret; struct kvm *kvm = vcpu->kvm; psize = 1ul << porder; npages = memslot->npages >> (porder - PAGE_SHIFT); /* VRMA can't be > 1TB */ if (npages > 1ul << (40 - porder)) npages = 1ul << (40 - porder); /* Can't use more than 1 HPTE per HPTEG */ if (npages > kvmppc_hpt_mask(&kvm->arch.hpt) + 1) npages = kvmppc_hpt_mask(&kvm->arch.hpt) + 1; hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) | HPTE_V_BOLTED | hpte0_pgsize_encoding(psize); hp1 = hpte1_pgsize_encoding(psize) | HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX; for (i = 0; i < npages; ++i) { addr = i << porder; /* can't use hpt_hash since va > 64 bits */ hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvmppc_hpt_mask(&kvm->arch.hpt); /* * We assume that the hash table is empty and no * vcpus are using it at this stage. Since we create * at most one HPTE per HPTEG, we just assume entry 7 * is available and use it. */ hash = (hash << 3) + 7; hp_v = hp0 | ((addr >> 16) & ~0x7fUL); hp_r = hp1 | addr; ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r, &idx_ret); if (ret != H_SUCCESS) { pr_err("KVM: map_vrma at %lx failed, ret=%ld\n", addr, ret); break; } } } int kvmppc_mmu_hv_init(void) { unsigned long nr_lpids; if (!mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE)) return -EINVAL; if (cpu_has_feature(CPU_FTR_HVMODE)) { if (WARN_ON(mfspr(SPRN_LPID) != 0)) return -EINVAL; nr_lpids = 1UL << mmu_lpid_bits; } else { nr_lpids = 1UL << KVM_MAX_NESTED_GUESTS_SHIFT; } if (!cpu_has_feature(CPU_FTR_ARCH_300)) { /* POWER7 has 10-bit LPIDs, POWER8 has 12-bit LPIDs */ if (cpu_has_feature(CPU_FTR_ARCH_207S)) WARN_ON(nr_lpids != 1UL << 12); else WARN_ON(nr_lpids != 1UL << 10); /* * Reserve the last implemented LPID use in partition * switching for POWER7 and POWER8. */ nr_lpids -= 1; } kvmppc_init_lpid(nr_lpids); return 0; } static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags, long pte_index, unsigned long pteh, unsigned long ptel, unsigned long *pte_idx_ret) { long ret; preempt_disable(); ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel, kvm->mm->pgd, false, pte_idx_ret); preempt_enable(); if (ret == H_TOO_HARD) { /* this can't happen */ pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n"); ret = H_RESOURCE; /* or something */ } return ret; } static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, gva_t eaddr) { u64 mask; int i; for (i = 0; i < vcpu->arch.slb_nr; i++) { if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) continue; if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) mask = ESID_MASK_1T; else mask = ESID_MASK; if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) return &vcpu->arch.slb[i]; } return NULL; } static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, unsigned long ea) { unsigned long ra_mask; ra_mask = kvmppc_actual_pgsz(v, r) - 1; return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); } static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, bool data, bool iswrite) { struct kvm *kvm = vcpu->kvm; struct kvmppc_slb *slbe; unsigned long slb_v; unsigned long pp, key; unsigned long v, orig_v, gr; __be64 *hptep; long int index; int virtmode = __kvmppc_get_msr_hv(vcpu) & (data ? MSR_DR : MSR_IR); if (kvm_is_radix(vcpu->kvm)) return kvmppc_mmu_radix_xlate(vcpu, eaddr, gpte, data, iswrite); /* Get SLB entry */ if (virtmode) { slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); if (!slbe) return -EINVAL; slb_v = slbe->origv; } else { /* real mode access */ slb_v = vcpu->kvm->arch.vrma_slb_v; } preempt_disable(); /* Find the HPTE in the hash table */ index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, HPTE_V_VALID | HPTE_V_ABSENT); if (index < 0) { preempt_enable(); return -ENOENT; } hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4)); v = orig_v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; if (cpu_has_feature(CPU_FTR_ARCH_300)) v = hpte_new_to_old_v(v, be64_to_cpu(hptep[1])); gr = kvm->arch.hpt.rev[index].guest_rpte; unlock_hpte(hptep, orig_v); preempt_enable(); gpte->eaddr = eaddr; gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); /* Get PP bits and key for permission check */ pp = gr & (HPTE_R_PP0 | HPTE_R_PP); key = (__kvmppc_get_msr_hv(vcpu) & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; key &= slb_v; /* Calculate permissions */ gpte->may_read = hpte_read_permission(pp, key); gpte->may_write = hpte_write_permission(pp, key); gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); /* Storage key permission check for POWER7 */ if (data && virtmode) { int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); if (amrfield & 1) gpte->may_read = 0; if (amrfield & 2) gpte->may_write = 0; } /* Get the guest physical address */ gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); return 0; } /* * Quick test for whether an instruction is a load or a store. * If the instruction is a load or a store, then this will indicate * which it is, at least on server processors. (Embedded processors * have some external PID instructions that don't follow the rule * embodied here.) If the instruction isn't a load or store, then * this doesn't return anything useful. */ static int instruction_is_store(ppc_inst_t instr) { unsigned int mask; unsigned int suffix; mask = 0x10000000; suffix = ppc_inst_val(instr); if (ppc_inst_prefixed(instr)) suffix = ppc_inst_suffix(instr); else if ((suffix & 0xfc000000) == 0x7c000000) mask = 0x100; /* major opcode 31 */ return (suffix & mask) != 0; } int kvmppc_hv_emulate_mmio(struct kvm_vcpu *vcpu, unsigned long gpa, gva_t ea, int is_store) { ppc_inst_t last_inst; bool is_prefixed = !!(kvmppc_get_msr(vcpu) & SRR1_PREFIXED); /* * Fast path - check if the guest physical address corresponds to a * device on the FAST_MMIO_BUS, if so we can avoid loading the * instruction all together, then we can just handle it and return. */ if (is_store) { int idx, ret; idx = srcu_read_lock(&vcpu->kvm->srcu); ret = kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, (gpa_t) gpa, 0, NULL); srcu_read_unlock(&vcpu->kvm->srcu, idx); if (!ret) { kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + (is_prefixed ? 8 : 4)); return RESUME_GUEST; } } /* * If we fail, we just return to the guest and try executing it again. */ if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != EMULATE_DONE) return RESUME_GUEST; /* * WARNING: We do not know for sure whether the instruction we just * read from memory is the same that caused the fault in the first * place. * * If the fault is prefixed but the instruction is not or vice * versa, try again so that we don't advance pc the wrong amount. */ if (ppc_inst_prefixed(last_inst) != is_prefixed) return RESUME_GUEST; /* * If the instruction we read is neither an load or a store, * then it can't access memory, so we don't need to worry about * enforcing access permissions. So, assuming it is a load or * store, we just check that its direction (load or store) is * consistent with the original fault, since that's what we * checked the access permissions against. If there is a mismatch * we just return and retry the instruction. */ if (instruction_is_store(last_inst) != !!is_store) return RESUME_GUEST; /* * Emulated accesses are emulated by looking at the hash for * translation once, then performing the access later. The * translation could be invalidated in the meantime in which * point performing the subsequent memory access on the old * physical address could possibly be a security hole for the * guest (but not the host). * * This is less of an issue for MMIO stores since they aren't * globally visible. It could be an issue for MMIO loads to * a certain extent but we'll ignore it for now. */ vcpu->arch.paddr_accessed = gpa; vcpu->arch.vaddr_accessed = ea; return kvmppc_emulate_mmio(vcpu); } int kvmppc_book3s_hv_page_fault(struct kvm_vcpu *vcpu, unsigned long ea, unsigned long dsisr) { struct kvm *kvm = vcpu->kvm; unsigned long hpte[3], r; unsigned long hnow_v, hnow_r; __be64 *hptep; unsigned long mmu_seq, psize, pte_size; unsigned long gpa_base, gfn_base; unsigned long gpa, gfn, hva, pfn, hpa; struct kvm_memory_slot *memslot; unsigned long *rmap; struct revmap_entry *rev; struct page *page; long index, ret; bool is_ci; bool writing, write_ok; unsigned int shift; unsigned long rcbits; long mmio_update; pte_t pte, *ptep; if (kvm_is_radix(kvm)) return kvmppc_book3s_radix_page_fault(vcpu, ea, dsisr); /* * Real-mode code has already searched the HPT and found the * entry we're interested in. Lock the entry and check that * it hasn't changed. If it has, just return and re-execute the * instruction. */ if (ea != vcpu->arch.pgfault_addr) return RESUME_GUEST; if (vcpu->arch.pgfault_cache) { mmio_update = atomic64_read(&kvm->arch.mmio_update); if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) { r = vcpu->arch.pgfault_cache->rpte; psize = kvmppc_actual_pgsz(vcpu->arch.pgfault_hpte[0], r); gpa_base = r & HPTE_R_RPN & ~(psize - 1); gfn_base = gpa_base >> PAGE_SHIFT; gpa = gpa_base | (ea & (psize - 1)); return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, dsisr & DSISR_ISSTORE); } } index = vcpu->arch.pgfault_index; hptep = (__be64 *)(kvm->arch.hpt.virt + (index << 4)); rev = &kvm->arch.hpt.rev[index]; preempt_disable(); while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) cpu_relax(); hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK; hpte[1] = be64_to_cpu(hptep[1]); hpte[2] = r = rev->guest_rpte; unlock_hpte(hptep, hpte[0]); preempt_enable(); if (cpu_has_feature(CPU_FTR_ARCH_300)) { hpte[0] = hpte_new_to_old_v(hpte[0], hpte[1]); hpte[1] = hpte_new_to_old_r(hpte[1]); } if (hpte[0] != vcpu->arch.pgfault_hpte[0] || hpte[1] != vcpu->arch.pgfault_hpte[1]) return RESUME_GUEST; /* Translate the logical address and get the page */ psize = kvmppc_actual_pgsz(hpte[0], r); gpa_base = r & HPTE_R_RPN & ~(psize - 1); gfn_base = gpa_base >> PAGE_SHIFT; gpa = gpa_base | (ea & (psize - 1)); gfn = gpa >> PAGE_SHIFT; memslot = gfn_to_memslot(kvm, gfn); trace_kvm_page_fault_enter(vcpu, hpte, memslot, ea, dsisr); /* No memslot means it's an emulated MMIO region */ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, dsisr & DSISR_ISSTORE); /* * This should never happen, because of the slot_is_aligned() * check in kvmppc_do_h_enter(). */ if (gfn_base < memslot->base_gfn) return -EFAULT; /* used to check for invalidations in progress */ mmu_seq = kvm->mmu_invalidate_seq; smp_rmb(); ret = -EFAULT; page = NULL; writing = (dsisr & DSISR_ISSTORE) != 0; /* If writing != 0, then the HPTE must allow writing, if we get here */ write_ok = writing; hva = gfn_to_hva_memslot(memslot, gfn); pfn = __kvm_faultin_pfn(memslot, gfn, writing ? FOLL_WRITE : 0, &write_ok, &page); if (is_error_noslot_pfn(pfn)) return -EFAULT; /* * Read the PTE from the process' radix tree and use that * so we get the shift and attribute bits. */ spin_lock(&kvm->mmu_lock); ptep = find_kvm_host_pte(kvm, mmu_seq, hva, &shift); pte = __pte(0); if (ptep) pte = READ_ONCE(*ptep); spin_unlock(&kvm->mmu_lock); /* * If the PTE disappeared temporarily due to a THP * collapse, just return and let the guest try again. */ if (!pte_present(pte)) { if (page) put_page(page); return RESUME_GUEST; } hpa = pte_pfn(pte) << PAGE_SHIFT; pte_size = PAGE_SIZE; if (shift) pte_size = 1ul << shift; is_ci = pte_ci(pte); if (psize > pte_size) goto out_put; if (pte_size > psize) hpa |= hva & (pte_size - psize); /* Check WIMG vs. the actual page we're accessing */ if (!hpte_cache_flags_ok(r, is_ci)) { if (is_ci) goto out_put; /* * Allow guest to map emulated device memory as * uncacheable, but actually make it cacheable. */ r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M; } /* * Set the HPTE to point to hpa. * Since the hpa is at PAGE_SIZE granularity, make sure we * don't mask out lower-order bits if psize < PAGE_SIZE. */ if (psize < PAGE_SIZE) psize = PAGE_SIZE; r = (r & HPTE_R_KEY_HI) | (r & ~(HPTE_R_PP0 - psize)) | hpa; if (hpte_is_writable(r) && !write_ok) r = hpte_make_readonly(r); ret = RESUME_GUEST; preempt_disable(); while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) cpu_relax(); hnow_v = be64_to_cpu(hptep[0]); hnow_r = be64_to_cpu(hptep[1]); if (cpu_has_feature(CPU_FTR_ARCH_300)) { hnow_v = hpte_new_to_old_v(hnow_v, hnow_r); hnow_r = hpte_new_to_old_r(hnow_r); } /* * If the HPT is being resized, don't update the HPTE, * instead let the guest retry after the resize operation is complete. * The synchronization for mmu_ready test vs. set is provided * by the HPTE lock. */ if (!kvm->arch.mmu_ready) goto out_unlock; if ((hnow_v & ~HPTE_V_HVLOCK) != hpte[0] || hnow_r != hpte[1] || rev->guest_rpte != hpte[2]) /* HPTE has been changed under us; let the guest retry */ goto out_unlock; hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID; /* Always put the HPTE in the rmap chain for the page base address */ rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn]; lock_rmap(rmap); /* Check if we might have been invalidated; let the guest retry if so */ ret = RESUME_GUEST; if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) { unlock_rmap(rmap); goto out_unlock; } /* Only set R/C in real HPTE if set in both *rmap and guest_rpte */ rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT; r &= rcbits | ~(HPTE_R_R | HPTE_R_C); if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) { /* HPTE was previously valid, so we need to invalidate it */ unlock_rmap(rmap); hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); kvmppc_invalidate_hpte(kvm, hptep, index); /* don't lose previous R and C bits */ r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); } else { kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0); } if (cpu_has_feature(CPU_FTR_ARCH_300)) { r = hpte_old_to_new_r(hpte[0], r); hpte[0] = hpte_old_to_new_v(hpte[0]); } hptep[1] = cpu_to_be64(r); eieio(); __unlock_hpte(hptep, hpte[0]); asm volatile("ptesync" : : : "memory"); preempt_enable(); if (page && hpte_is_writable(r)) set_page_dirty_lock(page); out_put: trace_kvm_page_fault_exit(vcpu, hpte, ret); if (page) put_page(page); return ret; out_unlock: __unlock_hpte(hptep, be64_to_cpu(hptep[0])); preempt_enable(); goto out_put; } void kvmppc_rmap_reset(struct kvm *kvm) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int srcu_idx, bkt; srcu_idx = srcu_read_lock(&kvm->srcu); slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, bkt, slots) { /* Mutual exclusion with kvm_unmap_hva_range etc. */ spin_lock(&kvm->mmu_lock); /* * This assumes it is acceptable to lose reference and * change bits across a reset. */ memset(memslot->arch.rmap, 0, memslot->npages * sizeof(*memslot->arch.rmap)); spin_unlock(&kvm->mmu_lock); } srcu_read_unlock(&kvm->srcu, srcu_idx); } /* Must be called with both HPTE and rmap locked */ static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i, struct kvm_memory_slot *memslot, unsigned long *rmapp, unsigned long gfn) { __be64 *hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4)); struct revmap_entry *rev = kvm->arch.hpt.rev; unsigned long j, h; unsigned long ptel, psize, rcbits; j = rev[i].forw; if (j == i) { /* chain is now empty */ *rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX); } else { /* remove i from chain */ h = rev[i].back; rev[h].forw = j; rev[j].back = h; rev[i].forw = rev[i].back = i; *rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j; } /* Now check and modify the HPTE */ ptel = rev[i].guest_rpte; psize = kvmppc_actual_pgsz(be64_to_cpu(hptep[0]), ptel); if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && hpte_rpn(ptel, psize) == gfn) { hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); kvmppc_invalidate_hpte(kvm, hptep, i); hptep[1] &= ~cpu_to_be64(HPTE_R_KEY_HI | HPTE_R_KEY_LO); /* Harvest R and C */ rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C); *rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT; if ((rcbits & HPTE_R_C) && memslot->dirty_bitmap) kvmppc_update_dirty_map(memslot, gfn, psize); if (rcbits & ~rev[i].guest_rpte) { rev[i].guest_rpte = ptel | rcbits; note_hpte_modification(kvm, &rev[i]); } } } static void kvm_unmap_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { unsigned long i; __be64 *hptep; unsigned long *rmapp; rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; for (;;) { lock_rmap(rmapp); if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { unlock_rmap(rmapp); break; } /* * To avoid an ABBA deadlock with the HPTE lock bit, * we can't spin on the HPTE lock while holding the * rmap chain lock. */ i = *rmapp & KVMPPC_RMAP_INDEX; hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4)); if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { /* unlock rmap before spinning on the HPTE lock */ unlock_rmap(rmapp); while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) cpu_relax(); continue; } kvmppc_unmap_hpte(kvm, i, memslot, rmapp, gfn); unlock_rmap(rmapp); __unlock_hpte(hptep, be64_to_cpu(hptep[0])); } } bool kvm_unmap_gfn_range_hv(struct kvm *kvm, struct kvm_gfn_range *range) { gfn_t gfn; if (kvm_is_radix(kvm)) { for (gfn = range->start; gfn < range->end; gfn++) kvm_unmap_radix(kvm, range->slot, gfn); } else { for (gfn = range->start; gfn < range->end; gfn++) kvm_unmap_rmapp(kvm, range->slot, gfn); } return false; } void kvmppc_core_flush_memslot_hv(struct kvm *kvm, struct kvm_memory_slot *memslot) { unsigned long gfn; unsigned long n; unsigned long *rmapp; gfn = memslot->base_gfn; rmapp = memslot->arch.rmap; if (kvm_is_radix(kvm)) { kvmppc_radix_flush_memslot(kvm, memslot); return; } for (n = memslot->npages; n; --n, ++gfn) { /* * Testing the present bit without locking is OK because * the memslot has been marked invalid already, and hence * no new HPTEs referencing this page can be created, * thus the present bit can't go from 0 to 1. */ if (*rmapp & KVMPPC_RMAP_PRESENT) kvm_unmap_rmapp(kvm, memslot, gfn); ++rmapp; } } static bool kvm_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { struct revmap_entry *rev = kvm->arch.hpt.rev; unsigned long head, i, j; __be64 *hptep; bool ret = false; unsigned long *rmapp; rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; retry: lock_rmap(rmapp); if (*rmapp & KVMPPC_RMAP_REFERENCED) { *rmapp &= ~KVMPPC_RMAP_REFERENCED; ret = true; } if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { unlock_rmap(rmapp); return ret; } i = head = *rmapp & KVMPPC_RMAP_INDEX; do { hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4)); j = rev[i].forw; /* If this HPTE isn't referenced, ignore it */ if (!(be64_to_cpu(hptep[1]) & HPTE_R_R)) continue; if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { /* unlock rmap before spinning on the HPTE lock */ unlock_rmap(rmapp); while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK) cpu_relax(); goto retry; } /* Now check and modify the HPTE */ if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) && (be64_to_cpu(hptep[1]) & HPTE_R_R)) { kvmppc_clear_ref_hpte(kvm, hptep, i); if (!(rev[i].guest_rpte & HPTE_R_R)) { rev[i].guest_rpte |= HPTE_R_R; note_hpte_modification(kvm, &rev[i]); } ret = true; } __unlock_hpte(hptep, be64_to_cpu(hptep[0])); } while ((i = j) != head); unlock_rmap(rmapp); return ret; } bool kvm_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range) { gfn_t gfn; bool ret = false; if (kvm_is_radix(kvm)) { for (gfn = range->start; gfn < range->end; gfn++) ret |= kvm_age_radix(kvm, range->slot, gfn); } else { for (gfn = range->start; gfn < range->end; gfn++) ret |= kvm_age_rmapp(kvm, range->slot, gfn); } return ret; } static bool kvm_test_age_rmapp(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { struct revmap_entry *rev = kvm->arch.hpt.rev; unsigned long head, i, j; unsigned long *hp; bool ret = true; unsigned long *rmapp; rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; if (*rmapp & KVMPPC_RMAP_REFERENCED) return true; lock_rmap(rmapp); if (*rmapp & KVMPPC_RMAP_REFERENCED) goto out; if (*rmapp & KVMPPC_RMAP_PRESENT) { i = head = *rmapp & KVMPPC_RMAP_INDEX; do { hp = (unsigned long *)(kvm->arch.hpt.virt + (i << 4)); j = rev[i].forw; if (be64_to_cpu(hp[1]) & HPTE_R_R) goto out; } while ((i = j) != head); } ret = false; out: unlock_rmap(rmapp); return ret; } bool kvm_test_age_gfn_hv(struct kvm *kvm, struct kvm_gfn_range *range) { WARN_ON(range->start + 1 != range->end); if (kvm_is_radix(kvm)) return kvm_test_age_radix(kvm, range->slot, range->start); else return kvm_test_age_rmapp(kvm, range->slot, range->start); } static int vcpus_running(struct kvm *kvm) { return atomic_read(&kvm->arch.vcpus_running) != 0; } /* * Returns the number of system pages that are dirty. * This can be more than 1 if we find a huge-page HPTE. */ static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) { struct revmap_entry *rev = kvm->arch.hpt.rev; unsigned long head, i, j; unsigned long n; unsigned long v, r; __be64 *hptep; int npages_dirty = 0; retry: lock_rmap(rmapp); if (!(*rmapp & KVMPPC_RMAP_PRESENT)) { unlock_rmap(rmapp); return npages_dirty; } i = head = *rmapp & KVMPPC_RMAP_INDEX; do { unsigned long hptep1; hptep = (__be64 *) (kvm->arch.hpt.virt + (i << 4)); j = rev[i].forw; /* * Checking the C (changed) bit here is racy since there * is no guarantee about when the hardware writes it back. * If the HPTE is not writable then it is stable since the * page can't be written to, and we would have done a tlbie * (which forces the hardware to complete any writeback) * when making the HPTE read-only. * If vcpus are running then this call is racy anyway * since the page could get dirtied subsequently, so we * expect there to be a further call which would pick up * any delayed C bit writeback. * Otherwise we need to do the tlbie even if C==0 in * order to pick up any delayed writeback of C. */ hptep1 = be64_to_cpu(hptep[1]); if (!(hptep1 & HPTE_R_C) && (!hpte_is_writable(hptep1) || vcpus_running(kvm))) continue; if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) { /* unlock rmap before spinning on the HPTE lock */ unlock_rmap(rmapp); while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK)) cpu_relax(); goto retry; } /* Now check and modify the HPTE */ if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) { __unlock_hpte(hptep, be64_to_cpu(hptep[0])); continue; } /* need to make it temporarily absent so C is stable */ hptep[0] |= cpu_to_be64(HPTE_V_ABSENT); kvmppc_invalidate_hpte(kvm, hptep, i); v = be64_to_cpu(hptep[0]); r = be64_to_cpu(hptep[1]); if (r & HPTE_R_C) { hptep[1] = cpu_to_be64(r & ~HPTE_R_C); if (!(rev[i].guest_rpte & HPTE_R_C)) { rev[i].guest_rpte |= HPTE_R_C; note_hpte_modification(kvm, &rev[i]); } n = kvmppc_actual_pgsz(v, r); n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; if (n > npages_dirty) npages_dirty = n; eieio(); } v &= ~HPTE_V_ABSENT; v |= HPTE_V_VALID; __unlock_hpte(hptep, v); } while ((i = j) != head); unlock_rmap(rmapp); return npages_dirty; } void kvmppc_harvest_vpa_dirty(struct kvmppc_vpa *vpa, struct kvm_memory_slot *memslot, unsigned long *map) { unsigned long gfn; if (!vpa->dirty || !vpa->pinned_addr) return; gfn = vpa->gpa >> PAGE_SHIFT; if (gfn < memslot->base_gfn || gfn >= memslot->base_gfn + memslot->npages) return; vpa->dirty = false; if (map) __set_bit_le(gfn - memslot->base_gfn, map); } long kvmppc_hv_get_dirty_log_hpt(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long *map) { unsigned long i; unsigned long *rmapp; preempt_disable(); rmapp = memslot->arch.rmap; for (i = 0; i < memslot->npages; ++i) { int npages = kvm_test_clear_dirty_npages(kvm, rmapp); /* * Note that if npages > 0 then i must be a multiple of npages, * since we always put huge-page HPTEs in the rmap chain * corresponding to their page base address. */ if (npages) set_dirty_bits(map, i, npages); ++rmapp; } preempt_enable(); return 0; } void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, unsigned long *nb_ret) { struct kvm_memory_slot *memslot; unsigned long gfn = gpa >> PAGE_SHIFT; struct page *page, *pages[1]; int npages; unsigned long hva, offset; int srcu_idx; srcu_idx = srcu_read_lock(&kvm->srcu); memslot = gfn_to_memslot(kvm, gfn); if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) goto err; hva = gfn_to_hva_memslot(memslot, gfn); npages = get_user_pages_fast(hva, 1, FOLL_WRITE, pages); if (npages < 1) goto err; page = pages[0]; srcu_read_unlock(&kvm->srcu, srcu_idx); offset = gpa & (PAGE_SIZE - 1); if (nb_ret) *nb_ret = PAGE_SIZE - offset; return page_address(page) + offset; err: srcu_read_unlock(&kvm->srcu, srcu_idx); return NULL; } void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa, bool dirty) { struct page *page = virt_to_page(va); struct kvm_memory_slot *memslot; unsigned long gfn; int srcu_idx; put_page(page); if (!dirty) return; /* We need to mark this page dirty in the memslot dirty_bitmap, if any */ gfn = gpa >> PAGE_SHIFT; srcu_idx = srcu_read_lock(&kvm->srcu); memslot = gfn_to_memslot(kvm, gfn); if (memslot && memslot->dirty_bitmap) set_bit_le(gfn - memslot->base_gfn, memslot->dirty_bitmap); srcu_read_unlock(&kvm->srcu, srcu_idx); } /* * HPT resizing */ static int resize_hpt_allocate(struct kvm_resize_hpt *resize) { int rc; rc = kvmppc_allocate_hpt(&resize->hpt, resize->order); if (rc < 0) return rc; resize_hpt_debug(resize, "%s(): HPT @ 0x%lx\n", __func__, resize->hpt.virt); return 0; } static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, unsigned long idx) { struct kvm *kvm = resize->kvm; struct kvm_hpt_info *old = &kvm->arch.hpt; struct kvm_hpt_info *new = &resize->hpt; unsigned long old_hash_mask = (1ULL << (old->order - 7)) - 1; unsigned long new_hash_mask = (1ULL << (new->order - 7)) - 1; __be64 *hptep, *new_hptep; unsigned long vpte, rpte, guest_rpte; int ret; struct revmap_entry *rev; unsigned long apsize, avpn, pteg, hash; unsigned long new_idx, new_pteg, replace_vpte; int pshift; hptep = (__be64 *)(old->virt + (idx << 4)); /* Guest is stopped, so new HPTEs can't be added or faulted * in, only unmapped or altered by host actions. So, it's * safe to check this before we take the HPTE lock */ vpte = be64_to_cpu(hptep[0]); if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT)) return 0; /* nothing to do */ while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) cpu_relax(); vpte = be64_to_cpu(hptep[0]); ret = 0; if (!(vpte & HPTE_V_VALID) && !(vpte & HPTE_V_ABSENT)) /* Nothing to do */ goto out; if (cpu_has_feature(CPU_FTR_ARCH_300)) { rpte = be64_to_cpu(hptep[1]); vpte = hpte_new_to_old_v(vpte, rpte); } /* Unmap */ rev = &old->rev[idx]; guest_rpte = rev->guest_rpte; ret = -EIO; apsize = kvmppc_actual_pgsz(vpte, guest_rpte); if (!apsize) goto out; if (vpte & HPTE_V_VALID) { unsigned long gfn = hpte_rpn(guest_rpte, apsize); int srcu_idx = srcu_read_lock(&kvm->srcu); struct kvm_memory_slot *memslot = __gfn_to_memslot(kvm_memslots(kvm), gfn); if (memslot) { unsigned long *rmapp; rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; lock_rmap(rmapp); kvmppc_unmap_hpte(kvm, idx, memslot, rmapp, gfn); unlock_rmap(rmapp); } srcu_read_unlock(&kvm->srcu, srcu_idx); } /* Reload PTE after unmap */ vpte = be64_to_cpu(hptep[0]); BUG_ON(vpte & HPTE_V_VALID); BUG_ON(!(vpte & HPTE_V_ABSENT)); ret = 0; if (!(vpte & HPTE_V_BOLTED)) goto out; rpte = be64_to_cpu(hptep[1]); if (cpu_has_feature(CPU_FTR_ARCH_300)) { vpte = hpte_new_to_old_v(vpte, rpte); rpte = hpte_new_to_old_r(rpte); } pshift = kvmppc_hpte_base_page_shift(vpte, rpte); avpn = HPTE_V_AVPN_VAL(vpte) & ~(((1ul << pshift) - 1) >> 23); pteg = idx / HPTES_PER_GROUP; if (vpte & HPTE_V_SECONDARY) pteg = ~pteg; if (!(vpte & HPTE_V_1TB_SEG)) { unsigned long offset, vsid; /* We only have 28 - 23 bits of offset in avpn */ offset = (avpn & 0x1f) << 23; vsid = avpn >> 5; /* We can find more bits from the pteg value */ if (pshift < 23) offset |= ((vsid ^ pteg) & old_hash_mask) << pshift; hash = vsid ^ (offset >> pshift); } else { unsigned long offset, vsid; /* We only have 40 - 23 bits of seg_off in avpn */ offset = (avpn & 0x1ffff) << 23; vsid = avpn >> 17; if (pshift < 23) offset |= ((vsid ^ (vsid << 25) ^ pteg) & old_hash_mask) << pshift; hash = vsid ^ (vsid << 25) ^ (offset >> pshift); } new_pteg = hash & new_hash_mask; if (vpte & HPTE_V_SECONDARY) new_pteg = ~hash & new_hash_mask; new_idx = new_pteg * HPTES_PER_GROUP + (idx % HPTES_PER_GROUP); new_hptep = (__be64 *)(new->virt + (new_idx << 4)); replace_vpte = be64_to_cpu(new_hptep[0]); if (cpu_has_feature(CPU_FTR_ARCH_300)) { unsigned long replace_rpte = be64_to_cpu(new_hptep[1]); replace_vpte = hpte_new_to_old_v(replace_vpte, replace_rpte); } if (replace_vpte & (HPTE_V_VALID | HPTE_V_ABSENT)) { BUG_ON(new->order >= old->order); if (replace_vpte & HPTE_V_BOLTED) { if (vpte & HPTE_V_BOLTED) /* Bolted collision, nothing we can do */ ret = -ENOSPC; /* Discard the new HPTE */ goto out; } /* Discard the previous HPTE */ } if (cpu_has_feature(CPU_FTR_ARCH_300)) { rpte = hpte_old_to_new_r(vpte, rpte); vpte = hpte_old_to_new_v(vpte); } new_hptep[1] = cpu_to_be64(rpte); new->rev[new_idx].guest_rpte = guest_rpte; /* No need for a barrier, since new HPT isn't active */ new_hptep[0] = cpu_to_be64(vpte); unlock_hpte(new_hptep, vpte); out: unlock_hpte(hptep, vpte); return ret; } static int resize_hpt_rehash(struct kvm_resize_hpt *resize) { struct kvm *kvm = resize->kvm; unsigned long i; int rc; for (i = 0; i < kvmppc_hpt_npte(&kvm->arch.hpt); i++) { rc = resize_hpt_rehash_hpte(resize, i); if (rc != 0) return rc; } return 0; } static void resize_hpt_pivot(struct kvm_resize_hpt *resize) { struct kvm *kvm = resize->kvm; struct kvm_hpt_info hpt_tmp; /* Exchange the pending tables in the resize structure with * the active tables */ resize_hpt_debug(resize, "resize_hpt_pivot()\n"); spin_lock(&kvm->mmu_lock); asm volatile("ptesync" : : : "memory"); hpt_tmp = kvm->arch.hpt; kvmppc_set_hpt(kvm, &resize->hpt); resize->hpt = hpt_tmp; spin_unlock(&kvm->mmu_lock); synchronize_srcu_expedited(&kvm->srcu); if (cpu_has_feature(CPU_FTR_ARCH_300)) kvmppc_setup_partition_table(kvm); resize_hpt_debug(resize, "resize_hpt_pivot() done\n"); } static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize) { if (WARN_ON(!mutex_is_locked(&kvm->arch.mmu_setup_lock))) return; if (!resize) return; if (resize->error != -EBUSY) { if (resize->hpt.virt) kvmppc_free_hpt(&resize->hpt); kfree(resize); } if (kvm->arch.resize_hpt == resize) kvm->arch.resize_hpt = NULL; } static void resize_hpt_prepare_work(struct work_struct *work) { struct kvm_resize_hpt *resize = container_of(work, struct kvm_resize_hpt, work); struct kvm *kvm = resize->kvm; int err = 0; if (WARN_ON(resize->error != -EBUSY)) return; mutex_lock(&kvm->arch.mmu_setup_lock); /* Request is still current? */ if (kvm->arch.resize_hpt == resize) { /* We may request large allocations here: * do not sleep with kvm->arch.mmu_setup_lock held for a while. */ mutex_unlock(&kvm->arch.mmu_setup_lock); resize_hpt_debug(resize, "%s(): order = %d\n", __func__, resize->order); err = resize_hpt_allocate(resize); /* We have strict assumption about -EBUSY * when preparing for HPT resize. */ if (WARN_ON(err == -EBUSY)) err = -EINPROGRESS; mutex_lock(&kvm->arch.mmu_setup_lock); /* It is possible that kvm->arch.resize_hpt != resize * after we grab kvm->arch.mmu_setup_lock again. */ } resize->error = err; if (kvm->arch.resize_hpt != resize) resize_hpt_release(kvm, resize); mutex_unlock(&kvm->arch.mmu_setup_lock); } int kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm, struct kvm_ppc_resize_hpt *rhpt) { unsigned long flags = rhpt->flags; unsigned long shift = rhpt->shift; struct kvm_resize_hpt *resize; int ret; if (flags != 0 || kvm_is_radix(kvm)) return -EINVAL; if (shift && ((shift < 18) || (shift > 46))) return -EINVAL; mutex_lock(&kvm->arch.mmu_setup_lock); resize = kvm->arch.resize_hpt; if (resize) { if (resize->order == shift) { /* Suitable resize in progress? */ ret = resize->error; if (ret == -EBUSY) ret = 100; /* estimated time in ms */ else if (ret) resize_hpt_release(kvm, resize); goto out; } /* not suitable, cancel it */ resize_hpt_release(kvm, resize); } ret = 0; if (!shift) goto out; /* nothing to do */ /* start new resize */ resize = kzalloc(sizeof(*resize), GFP_KERNEL); if (!resize) { ret = -ENOMEM; goto out; } resize->error = -EBUSY; resize->order = shift; resize->kvm = kvm; INIT_WORK(&resize->work, resize_hpt_prepare_work); kvm->arch.resize_hpt = resize; schedule_work(&resize->work); ret = 100; /* estimated time in ms */ out: mutex_unlock(&kvm->arch.mmu_setup_lock); return ret; } static void resize_hpt_boot_vcpu(void *opaque) { /* Nothing to do, just force a KVM exit */ } int kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm, struct kvm_ppc_resize_hpt *rhpt) { unsigned long flags = rhpt->flags; unsigned long shift = rhpt->shift; struct kvm_resize_hpt *resize; int ret; if (flags != 0 || kvm_is_radix(kvm)) return -EINVAL; if (shift && ((shift < 18) || (shift > 46))) return -EINVAL; mutex_lock(&kvm->arch.mmu_setup_lock); resize = kvm->arch.resize_hpt; /* This shouldn't be possible */ ret = -EIO; if (WARN_ON(!kvm->arch.mmu_ready)) goto out_no_hpt; /* Stop VCPUs from running while we mess with the HPT */ kvm->arch.mmu_ready = 0; smp_mb(); /* Boot all CPUs out of the guest so they re-read * mmu_ready */ on_each_cpu(resize_hpt_boot_vcpu, NULL, 1); ret = -ENXIO; if (!resize || (resize->order != shift)) goto out; ret = resize->error; if (ret) goto out; ret = resize_hpt_rehash(resize); if (ret) goto out; resize_hpt_pivot(resize); out: /* Let VCPUs run again */ kvm->arch.mmu_ready = 1; smp_mb(); out_no_hpt: resize_hpt_release(kvm, resize); mutex_unlock(&kvm->arch.mmu_setup_lock); return ret; } /* * Functions for reading and writing the hash table via reads and * writes on a file descriptor. * * Reads return the guest view of the hash table, which has to be * pieced together from the real hash table and the guest_rpte * values in the revmap array. * * On writes, each HPTE written is considered in turn, and if it * is valid, it is written to the HPT as if an H_ENTER with the * exact flag set was done. When the invalid count is non-zero * in the header written to the stream, the kernel will make * sure that that many HPTEs are invalid, and invalidate them * if not. */ struct kvm_htab_ctx { unsigned long index; unsigned long flags; struct kvm *kvm; int first_pass; }; #define HPTE_SIZE (2 * sizeof(unsigned long)) /* * Returns 1 if this HPT entry has been modified or has pending * R/C bit changes. */ static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp) { unsigned long rcbits_unset; if (revp->guest_rpte & HPTE_GR_MODIFIED) return 1; /* Also need to consider changes in reference and changed bits */ rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) && (be64_to_cpu(hptp[1]) & rcbits_unset)) return 1; return 0; } static long record_hpte(unsigned long flags, __be64 *hptp, unsigned long *hpte, struct revmap_entry *revp, int want_valid, int first_pass) { unsigned long v, r, hr; unsigned long rcbits_unset; int ok = 1; int valid, dirty; /* Unmodified entries are uninteresting except on the first pass */ dirty = hpte_dirty(revp, hptp); if (!first_pass && !dirty) return 0; valid = 0; if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) { valid = 1; if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED)) valid = 0; } if (valid != want_valid) return 0; v = r = 0; if (valid || dirty) { /* lock the HPTE so it's stable and read it */ preempt_disable(); while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) cpu_relax(); v = be64_to_cpu(hptp[0]); hr = be64_to_cpu(hptp[1]); if (cpu_has_feature(CPU_FTR_ARCH_300)) { v = hpte_new_to_old_v(v, hr); hr = hpte_new_to_old_r(hr); } /* re-evaluate valid and dirty from synchronized HPTE value */ valid = !!(v & HPTE_V_VALID); dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED); /* Harvest R and C into guest view if necessary */ rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C); if (valid && (rcbits_unset & hr)) { revp->guest_rpte |= (hr & (HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED; dirty = 1; } if (v & HPTE_V_ABSENT) { v &= ~HPTE_V_ABSENT; v |= HPTE_V_VALID; valid = 1; } if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED)) valid = 0; r = revp->guest_rpte; /* only clear modified if this is the right sort of entry */ if (valid == want_valid && dirty) { r &= ~HPTE_GR_MODIFIED; revp->guest_rpte = r; } unlock_hpte(hptp, be64_to_cpu(hptp[0])); preempt_enable(); if (!(valid == want_valid && (first_pass || dirty))) ok = 0; } hpte[0] = cpu_to_be64(v); hpte[1] = cpu_to_be64(r); return ok; } static ssize_t kvm_htab_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct kvm_htab_ctx *ctx = file->private_data; struct kvm *kvm = ctx->kvm; struct kvm_get_htab_header hdr; __be64 *hptp; struct revmap_entry *revp; unsigned long i, nb, nw; unsigned long __user *lbuf; struct kvm_get_htab_header __user *hptr; unsigned long flags; int first_pass; unsigned long hpte[2]; if (!access_ok(buf, count)) return -EFAULT; if (kvm_is_radix(kvm)) return 0; first_pass = ctx->first_pass; flags = ctx->flags; i = ctx->index; hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE)); revp = kvm->arch.hpt.rev + i; lbuf = (unsigned long __user *)buf; nb = 0; while (nb + sizeof(hdr) + HPTE_SIZE < count) { /* Initialize header */ hptr = (struct kvm_get_htab_header __user *)buf; hdr.n_valid = 0; hdr.n_invalid = 0; nw = nb; nb += sizeof(hdr); lbuf = (unsigned long __user *)(buf + sizeof(hdr)); /* Skip uninteresting entries, i.e. clean on not-first pass */ if (!first_pass) { while (i < kvmppc_hpt_npte(&kvm->arch.hpt) && !hpte_dirty(revp, hptp)) { ++i; hptp += 2; ++revp; } } hdr.index = i; /* Grab a series of valid entries */ while (i < kvmppc_hpt_npte(&kvm->arch.hpt) && hdr.n_valid < 0xffff && nb + HPTE_SIZE < count && record_hpte(flags, hptp, hpte, revp, 1, first_pass)) { /* valid entry, write it out */ ++hdr.n_valid; if (__put_user(hpte[0], lbuf) || __put_user(hpte[1], lbuf + 1)) return -EFAULT; nb += HPTE_SIZE; lbuf += 2; ++i; hptp += 2; ++revp; } /* Now skip invalid entries while we can */ while (i < kvmppc_hpt_npte(&kvm->arch.hpt) && hdr.n_invalid < 0xffff && record_hpte(flags, hptp, hpte, revp, 0, first_pass)) { /* found an invalid entry */ ++hdr.n_invalid; ++i; hptp += 2; ++revp; } if (hdr.n_valid || hdr.n_invalid) { /* write back the header */ if (__copy_to_user(hptr, &hdr, sizeof(hdr))) return -EFAULT; nw = nb; buf = (char __user *)lbuf; } else { nb = nw; } /* Check if we've wrapped around the hash table */ if (i >= kvmppc_hpt_npte(&kvm->arch.hpt)) { i = 0; ctx->first_pass = 0; break; } } ctx->index = i; return nb; } static ssize_t kvm_htab_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct kvm_htab_ctx *ctx = file->private_data; struct kvm *kvm = ctx->kvm; struct kvm_get_htab_header hdr; unsigned long i, j; unsigned long v, r; unsigned long __user *lbuf; __be64 *hptp; unsigned long tmp[2]; ssize_t nb; long int err, ret; int mmu_ready; int pshift; if (!access_ok(buf, count)) return -EFAULT; if (kvm_is_radix(kvm)) return -EINVAL; /* lock out vcpus from running while we're doing this */ mutex_lock(&kvm->arch.mmu_setup_lock); mmu_ready = kvm->arch.mmu_ready; if (mmu_ready) { kvm->arch.mmu_ready = 0; /* temporarily */ /* order mmu_ready vs. vcpus_running */ smp_mb(); if (atomic_read(&kvm->arch.vcpus_running)) { kvm->arch.mmu_ready = 1; mutex_unlock(&kvm->arch.mmu_setup_lock); return -EBUSY; } } err = 0; for (nb = 0; nb + sizeof(hdr) <= count; ) { err = -EFAULT; if (__copy_from_user(&hdr, buf, sizeof(hdr))) break; err = 0; if (nb + hdr.n_valid * HPTE_SIZE > count) break; nb += sizeof(hdr); buf += sizeof(hdr); err = -EINVAL; i = hdr.index; if (i >= kvmppc_hpt_npte(&kvm->arch.hpt) || i + hdr.n_valid + hdr.n_invalid > kvmppc_hpt_npte(&kvm->arch.hpt)) break; hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE)); lbuf = (unsigned long __user *)buf; for (j = 0; j < hdr.n_valid; ++j) { __be64 hpte_v; __be64 hpte_r; err = -EFAULT; if (__get_user(hpte_v, lbuf) || __get_user(hpte_r, lbuf + 1)) goto out; v = be64_to_cpu(hpte_v); r = be64_to_cpu(hpte_r); err = -EINVAL; if (!(v & HPTE_V_VALID)) goto out; pshift = kvmppc_hpte_base_page_shift(v, r); if (pshift <= 0) goto out; lbuf += 2; nb += HPTE_SIZE; if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) kvmppc_do_h_remove(kvm, 0, i, 0, tmp); err = -EIO; ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r, tmp); if (ret != H_SUCCESS) { pr_err("%s ret %ld i=%ld v=%lx r=%lx\n", __func__, ret, i, v, r); goto out; } if (!mmu_ready && is_vrma_hpte(v)) { unsigned long senc, lpcr; senc = slb_pgsize_encoding(1ul << pshift); kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T | (VRMA_VSID << SLB_VSID_SHIFT_1T); if (!cpu_has_feature(CPU_FTR_ARCH_300)) { lpcr = senc << (LPCR_VRMASD_SH - 4); kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD); } else { kvmppc_setup_partition_table(kvm); } mmu_ready = 1; } ++i; hptp += 2; } for (j = 0; j < hdr.n_invalid; ++j) { if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) kvmppc_do_h_remove(kvm, 0, i, 0, tmp); ++i; hptp += 2; } err = 0; } out: /* Order HPTE updates vs. mmu_ready */ smp_wmb(); kvm->arch.mmu_ready = mmu_ready; mutex_unlock(&kvm->arch.mmu_setup_lock); if (err) return err; return nb; } static int kvm_htab_release(struct inode *inode, struct file *filp) { struct kvm_htab_ctx *ctx = filp->private_data; filp->private_data = NULL; if (!(ctx->flags & KVM_GET_HTAB_WRITE)) atomic_dec(&ctx->kvm->arch.hpte_mod_interest); kvm_put_kvm(ctx->kvm); kfree(ctx); return 0; } static const struct file_operations kvm_htab_fops = { .read = kvm_htab_read, .write = kvm_htab_write, .llseek = default_llseek, .release = kvm_htab_release, }; int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf) { int ret; struct kvm_htab_ctx *ctx; int rwflag; /* reject flags we don't recognize */ if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE)) return -EINVAL; ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; kvm_get_kvm(kvm); ctx->kvm = kvm; ctx->index = ghf->start_index; ctx->flags = ghf->flags; ctx->first_pass = 1; rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY; ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC); if (ret < 0) { kfree(ctx); kvm_put_kvm_no_destroy(kvm); return ret; } if (rwflag == O_RDONLY) { mutex_lock(&kvm->slots_lock); atomic_inc(&kvm->arch.hpte_mod_interest); /* make sure kvmppc_do_h_enter etc. see the increment */ synchronize_srcu_expedited(&kvm->srcu); mutex_unlock(&kvm->slots_lock); } return ret; } struct debugfs_htab_state { struct kvm *kvm; struct mutex mutex; unsigned long hpt_index; int chars_left; int buf_index; char buf[64]; }; static int debugfs_htab_open(struct inode *inode, struct file *file) { struct kvm *kvm = inode->i_private; struct debugfs_htab_state *p; p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return -ENOMEM; kvm_get_kvm(kvm); p->kvm = kvm; mutex_init(&p->mutex); file->private_data = p; return nonseekable_open(inode, file); } static int debugfs_htab_release(struct inode *inode, struct file *file) { struct debugfs_htab_state *p = file->private_data; kvm_put_kvm(p->kvm); kfree(p); return 0; } static ssize_t debugfs_htab_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { struct debugfs_htab_state *p = file->private_data; ssize_t ret, r; unsigned long i, n; unsigned long v, hr, gr; struct kvm *kvm; __be64 *hptp; kvm = p->kvm; if (kvm_is_radix(kvm)) return 0; ret = mutex_lock_interruptible(&p->mutex); if (ret) return ret; if (p->chars_left) { n = p->chars_left; if (n > len) n = len; r = copy_to_user(buf, p->buf + p->buf_index, n); n -= r; p->chars_left -= n; p->buf_index += n; buf += n; len -= n; ret = n; if (r) { if (!n) ret = -EFAULT; goto out; } } i = p->hpt_index; hptp = (__be64 *)(kvm->arch.hpt.virt + (i * HPTE_SIZE)); for (; len != 0 && i < kvmppc_hpt_npte(&kvm->arch.hpt); ++i, hptp += 2) { if (!(be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))) continue; /* lock the HPTE so it's stable and read it */ preempt_disable(); while (!try_lock_hpte(hptp, HPTE_V_HVLOCK)) cpu_relax(); v = be64_to_cpu(hptp[0]) & ~HPTE_V_HVLOCK; hr = be64_to_cpu(hptp[1]); gr = kvm->arch.hpt.rev[i].guest_rpte; unlock_hpte(hptp, v); preempt_enable(); if (!(v & (HPTE_V_VALID | HPTE_V_ABSENT))) continue; n = scnprintf(p->buf, sizeof(p->buf), "%6lx %.16lx %.16lx %.16lx\n", i, v, hr, gr); p->chars_left = n; if (n > len) n = len; r = copy_to_user(buf, p->buf, n); n -= r; p->chars_left -= n; p->buf_index = n; buf += n; len -= n; ret += n; if (r) { if (!ret) ret = -EFAULT; goto out; } } p->hpt_index = i; out: mutex_unlock(&p->mutex); return ret; } static ssize_t debugfs_htab_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { return -EACCES; } static const struct file_operations debugfs_htab_fops = { .owner = THIS_MODULE, .open = debugfs_htab_open, .release = debugfs_htab_release, .read = debugfs_htab_read, .write = debugfs_htab_write, .llseek = generic_file_llseek, }; void kvmppc_mmu_debugfs_init(struct kvm *kvm) { debugfs_create_file("htab", 0400, kvm->debugfs_dentry, kvm, &debugfs_htab_fops); } void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu) { struct kvmppc_mmu *mmu = &vcpu->arch.mmu; vcpu->arch.slb_nr = 32; /* POWER7/POWER8 */ mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate; vcpu->arch.hflags |= BOOK3S_HFLAG_SLB; }