// SPDX-License-Identifier: GPL-2.0-only /* * * Copyright 2016 Paul Mackerras, IBM Corp. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Supported radix tree geometry. * Like p9, we support either 5 or 9 bits at the first (lowest) level, * for a page size of 64k or 4k. */ static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 }; unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, gva_t eaddr, void *to, void *from, unsigned long n) { int old_pid, old_lpid; unsigned long quadrant, ret = n; bool is_load = !!to; /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */ if (kvmhv_on_pseries()) return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr, (to != NULL) ? __pa(to): 0, (from != NULL) ? __pa(from): 0, n); if (eaddr & (0xFFFUL << 52)) return ret; quadrant = 1; if (!pid) quadrant = 2; if (is_load) from = (void *) (eaddr | (quadrant << 62)); else to = (void *) (eaddr | (quadrant << 62)); preempt_disable(); asm volatile("hwsync" ::: "memory"); isync(); /* switch the lpid first to avoid running host with unallocated pid */ old_lpid = mfspr(SPRN_LPID); if (old_lpid != lpid) mtspr(SPRN_LPID, lpid); if (quadrant == 1) { old_pid = mfspr(SPRN_PID); if (old_pid != pid) mtspr(SPRN_PID, pid); } isync(); pagefault_disable(); if (is_load) ret = __copy_from_user_inatomic(to, (const void __user *)from, n); else ret = __copy_to_user_inatomic((void __user *)to, from, n); pagefault_enable(); asm volatile("hwsync" ::: "memory"); isync(); /* switch the pid first to avoid running host with unallocated pid */ if (quadrant == 1 && pid != old_pid) mtspr(SPRN_PID, old_pid); if (lpid != old_lpid) mtspr(SPRN_LPID, old_lpid); isync(); preempt_enable(); return ret; } static long kvmhv_copy_tofrom_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to, void *from, unsigned long n) { int lpid = vcpu->kvm->arch.lpid; int pid = vcpu->arch.pid; /* This would cause a data segment intr so don't allow the access */ if (eaddr & (0x3FFUL << 52)) return -EINVAL; /* Should we be using the nested lpid */ if (vcpu->arch.nested) lpid = vcpu->arch.nested->shadow_lpid; /* If accessing quadrant 3 then pid is expected to be 0 */ if (((eaddr >> 62) & 0x3) == 0x3) pid = 0; eaddr &= ~(0xFFFUL << 52); return __kvmhv_copy_tofrom_guest_radix(lpid, pid, eaddr, to, from, n); } long kvmhv_copy_from_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *to, unsigned long n) { long ret; ret = kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, to, NULL, n); if (ret > 0) memset(to + (n - ret), 0, ret); return ret; } long kvmhv_copy_to_guest_radix(struct kvm_vcpu *vcpu, gva_t eaddr, void *from, unsigned long n) { return kvmhv_copy_tofrom_guest_radix(vcpu, eaddr, NULL, from, n); } int kvmppc_mmu_walk_radix_tree(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, u64 root, u64 *pte_ret_p) { struct kvm *kvm = vcpu->kvm; int ret, level, ps; unsigned long rts, bits, offset, index; u64 pte, base, gpa; __be64 rpte; rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) | ((root & RTS2_MASK) >> RTS2_SHIFT); bits = root & RPDS_MASK; base = root & RPDB_MASK; offset = rts + 31; /* Current implementations only support 52-bit space */ if (offset != 52) return -EINVAL; /* Walk each level of the radix tree */ for (level = 3; level >= 0; --level) { u64 addr; /* Check a valid size */ if (level && bits != p9_supported_radix_bits[level]) return -EINVAL; if (level == 0 && !(bits == 5 || bits == 9)) return -EINVAL; offset -= bits; index = (eaddr >> offset) & ((1UL << bits) - 1); /* Check that low bits of page table base are zero */ if (base & ((1UL << (bits + 3)) - 1)) return -EINVAL; /* Read the entry from guest memory */ addr = base + (index * sizeof(rpte)); kvm_vcpu_srcu_read_lock(vcpu); ret = kvm_read_guest(kvm, addr, &rpte, sizeof(rpte)); kvm_vcpu_srcu_read_unlock(vcpu); if (ret) { if (pte_ret_p) *pte_ret_p = addr; return ret; } pte = __be64_to_cpu(rpte); if (!(pte & _PAGE_PRESENT)) return -ENOENT; /* Check if a leaf entry */ if (pte & _PAGE_PTE) break; /* Get ready to walk the next level */ base = pte & RPDB_MASK; bits = pte & RPDS_MASK; } /* Need a leaf at lowest level; 512GB pages not supported */ if (level < 0 || level == 3) return -EINVAL; /* We found a valid leaf PTE */ /* Offset is now log base 2 of the page size */ gpa = pte & 0x01fffffffffff000ul; if (gpa & ((1ul << offset) - 1)) return -EINVAL; gpa |= eaddr & ((1ul << offset) - 1); for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps) if (offset == mmu_psize_defs[ps].shift) break; gpte->page_size = ps; gpte->page_shift = offset; gpte->eaddr = eaddr; gpte->raddr = gpa; /* Work out permissions */ gpte->may_read = !!(pte & _PAGE_READ); gpte->may_write = !!(pte & _PAGE_WRITE); gpte->may_execute = !!(pte & _PAGE_EXEC); gpte->rc = pte & (_PAGE_ACCESSED | _PAGE_DIRTY); if (pte_ret_p) *pte_ret_p = pte; return 0; } /* * Used to walk a partition or process table radix tree in guest memory * Note: We exploit the fact that a partition table and a process * table have the same layout, a partition-scoped page table and a * process-scoped page table have the same layout, and the 2nd * doubleword of a partition table entry has the same layout as * the PTCR register. */ int kvmppc_mmu_radix_translate_table(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, u64 table, int table_index, u64 *pte_ret_p) { struct kvm *kvm = vcpu->kvm; int ret; unsigned long size, ptbl, root; struct prtb_entry entry; if ((table & PRTS_MASK) > 24) return -EINVAL; size = 1ul << ((table & PRTS_MASK) + 12); /* Is the table big enough to contain this entry? */ if ((table_index * sizeof(entry)) >= size) return -EINVAL; /* Read the table to find the root of the radix tree */ ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry)); kvm_vcpu_srcu_read_lock(vcpu); ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry)); kvm_vcpu_srcu_read_unlock(vcpu); if (ret) return ret; /* Root is stored in the first double word */ root = be64_to_cpu(entry.prtb0); return kvmppc_mmu_walk_radix_tree(vcpu, eaddr, gpte, root, pte_ret_p); } int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, bool data, bool iswrite) { u32 pid; u64 pte; int ret; /* Work out effective PID */ switch (eaddr >> 62) { case 0: pid = vcpu->arch.pid; break; case 3: pid = 0; break; default: return -EINVAL; } ret = kvmppc_mmu_radix_translate_table(vcpu, eaddr, gpte, vcpu->kvm->arch.process_table, pid, &pte); if (ret) return ret; /* Check privilege (applies only to process scoped translations) */ if (kvmppc_get_msr(vcpu) & MSR_PR) { if (pte & _PAGE_PRIVILEGED) { gpte->may_read = 0; gpte->may_write = 0; gpte->may_execute = 0; } } else { if (!(pte & _PAGE_PRIVILEGED)) { /* Check AMR/IAMR to see if strict mode is in force */ if (vcpu->arch.amr & (1ul << 62)) gpte->may_read = 0; if (vcpu->arch.amr & (1ul << 63)) gpte->may_write = 0; if (vcpu->arch.iamr & (1ul << 62)) gpte->may_execute = 0; } } return 0; } void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr, unsigned int pshift, unsigned int lpid) { unsigned long psize = PAGE_SIZE; int psi; long rc; unsigned long rb; if (pshift) psize = 1UL << pshift; else pshift = PAGE_SHIFT; addr &= ~(psize - 1); if (!kvmhv_on_pseries()) { radix__flush_tlb_lpid_page(lpid, addr, psize); return; } psi = shift_to_mmu_psize(pshift); if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) { rb = addr | (mmu_get_ap(psi) << PPC_BITLSHIFT(58)); rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(0, 0, 1), lpid, rb); } else { rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU, H_RPTI_TYPE_NESTED | H_RPTI_TYPE_TLB, psize_to_rpti_pgsize(psi), addr, addr + psize); } if (rc) pr_err("KVM: TLB page invalidation hcall failed, rc=%ld\n", rc); } static void kvmppc_radix_flush_pwc(struct kvm *kvm, unsigned int lpid) { long rc; if (!kvmhv_on_pseries()) { radix__flush_pwc_lpid(lpid); return; } if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE)) rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(1, 0, 1), lpid, TLBIEL_INVAL_SET_LPID); else rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU, H_RPTI_TYPE_NESTED | H_RPTI_TYPE_PWC, H_RPTI_PAGE_ALL, 0, -1UL); if (rc) pr_err("KVM: TLB PWC invalidation hcall failed, rc=%ld\n", rc); } static unsigned long kvmppc_radix_update_pte(struct kvm *kvm, pte_t *ptep, unsigned long clr, unsigned long set, unsigned long addr, unsigned int shift) { return __radix_pte_update(ptep, clr, set); } static void kvmppc_radix_set_pte_at(struct kvm *kvm, unsigned long addr, pte_t *ptep, pte_t pte) { radix__set_pte_at(kvm->mm, addr, ptep, pte, 0); } static struct kmem_cache *kvm_pte_cache; static struct kmem_cache *kvm_pmd_cache; static pte_t *kvmppc_pte_alloc(void) { pte_t *pte; pte = kmem_cache_alloc(kvm_pte_cache, GFP_KERNEL); /* pmd_populate() will only reference _pa(pte). */ kmemleak_ignore(pte); return pte; } static void kvmppc_pte_free(pte_t *ptep) { kmem_cache_free(kvm_pte_cache, ptep); } static pmd_t *kvmppc_pmd_alloc(void) { pmd_t *pmd; pmd = kmem_cache_alloc(kvm_pmd_cache, GFP_KERNEL); /* pud_populate() will only reference _pa(pmd). */ kmemleak_ignore(pmd); return pmd; } static void kvmppc_pmd_free(pmd_t *pmdp) { kmem_cache_free(kvm_pmd_cache, pmdp); } /* Called with kvm->mmu_lock held */ void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte, unsigned long gpa, unsigned int shift, const struct kvm_memory_slot *memslot, unsigned int lpid) { unsigned long old; unsigned long gfn = gpa >> PAGE_SHIFT; unsigned long page_size = PAGE_SIZE; unsigned long hpa; old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift); kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid); /* The following only applies to L1 entries */ if (lpid != kvm->arch.lpid) return; if (!memslot) { memslot = gfn_to_memslot(kvm, gfn); if (!memslot) return; } if (shift) { /* 1GB or 2MB page */ page_size = 1ul << shift; if (shift == PMD_SHIFT) kvm->stat.num_2M_pages--; else if (shift == PUD_SHIFT) kvm->stat.num_1G_pages--; } gpa &= ~(page_size - 1); hpa = old & PTE_RPN_MASK; kvmhv_remove_nest_rmap_range(kvm, memslot, gpa, hpa, page_size); if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) kvmppc_update_dirty_map(memslot, gfn, page_size); } /* * kvmppc_free_p?d are used to free existing page tables, and recursively * descend and clear and free children. * Callers are responsible for flushing the PWC. * * When page tables are being unmapped/freed as part of page fault path * (full == false), valid ptes are generally not expected; however, there * is one situation where they arise, which is when dirty page logging is * turned off for a memslot while the VM is running. The new memslot * becomes visible to page faults before the memslot commit function * gets to flush the memslot, which can lead to a 2MB page mapping being * installed for a guest physical address where there are already 64kB * (or 4kB) mappings (of sub-pages of the same 2MB page). */ static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full, unsigned int lpid) { if (full) { memset(pte, 0, sizeof(long) << RADIX_PTE_INDEX_SIZE); } else { pte_t *p = pte; unsigned long it; for (it = 0; it < PTRS_PER_PTE; ++it, ++p) { if (pte_val(*p) == 0) continue; kvmppc_unmap_pte(kvm, p, pte_pfn(*p) << PAGE_SHIFT, PAGE_SHIFT, NULL, lpid); } } kvmppc_pte_free(pte); } static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full, unsigned int lpid) { unsigned long im; pmd_t *p = pmd; for (im = 0; im < PTRS_PER_PMD; ++im, ++p) { if (!pmd_present(*p)) continue; if (pmd_is_leaf(*p)) { if (full) { pmd_clear(p); } else { WARN_ON_ONCE(1); kvmppc_unmap_pte(kvm, (pte_t *)p, pte_pfn(*(pte_t *)p) << PAGE_SHIFT, PMD_SHIFT, NULL, lpid); } } else { pte_t *pte; pte = pte_offset_map(p, 0); kvmppc_unmap_free_pte(kvm, pte, full, lpid); pmd_clear(p); } } kvmppc_pmd_free(pmd); } static void kvmppc_unmap_free_pud(struct kvm *kvm, pud_t *pud, unsigned int lpid) { unsigned long iu; pud_t *p = pud; for (iu = 0; iu < PTRS_PER_PUD; ++iu, ++p) { if (!pud_present(*p)) continue; if (pud_is_leaf(*p)) { pud_clear(p); } else { pmd_t *pmd; pmd = pmd_offset(p, 0); kvmppc_unmap_free_pmd(kvm, pmd, true, lpid); pud_clear(p); } } pud_free(kvm->mm, pud); } void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd, unsigned int lpid) { unsigned long ig; for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) { p4d_t *p4d = p4d_offset(pgd, 0); pud_t *pud; if (!p4d_present(*p4d)) continue; pud = pud_offset(p4d, 0); kvmppc_unmap_free_pud(kvm, pud, lpid); p4d_clear(p4d); } } void kvmppc_free_radix(struct kvm *kvm) { if (kvm->arch.pgtable) { kvmppc_free_pgtable_radix(kvm, kvm->arch.pgtable, kvm->arch.lpid); pgd_free(kvm->mm, kvm->arch.pgtable); kvm->arch.pgtable = NULL; } } static void kvmppc_unmap_free_pmd_entry_table(struct kvm *kvm, pmd_t *pmd, unsigned long gpa, unsigned int lpid) { pte_t *pte = pte_offset_kernel(pmd, 0); /* * Clearing the pmd entry then flushing the PWC ensures that the pte * page no longer be cached by the MMU, so can be freed without * flushing the PWC again. */ pmd_clear(pmd); kvmppc_radix_flush_pwc(kvm, lpid); kvmppc_unmap_free_pte(kvm, pte, false, lpid); } static void kvmppc_unmap_free_pud_entry_table(struct kvm *kvm, pud_t *pud, unsigned long gpa, unsigned int lpid) { pmd_t *pmd = pmd_offset(pud, 0); /* * Clearing the pud entry then flushing the PWC ensures that the pmd * page and any children pte pages will no longer be cached by the MMU, * so can be freed without flushing the PWC again. */ pud_clear(pud); kvmppc_radix_flush_pwc(kvm, lpid); kvmppc_unmap_free_pmd(kvm, pmd, false, lpid); } /* * There are a number of bits which may differ between different faults to * the same partition scope entry. RC bits, in the course of cleaning and * aging. And the write bit can change, either the access could have been * upgraded, or a read fault could happen concurrently with a write fault * that sets those bits first. */ #define PTE_BITS_MUST_MATCH (~(_PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)) int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte, unsigned long gpa, unsigned int level, unsigned long mmu_seq, unsigned int lpid, unsigned long *rmapp, struct rmap_nested **n_rmap) { pgd_t *pgd; p4d_t *p4d; pud_t *pud, *new_pud = NULL; pmd_t *pmd, *new_pmd = NULL; pte_t *ptep, *new_ptep = NULL; int ret; /* Traverse the guest's 2nd-level tree, allocate new levels needed */ pgd = pgtable + pgd_index(gpa); p4d = p4d_offset(pgd, gpa); pud = NULL; if (p4d_present(*p4d)) pud = pud_offset(p4d, gpa); else new_pud = pud_alloc_one(kvm->mm, gpa); pmd = NULL; if (pud && pud_present(*pud) && !pud_is_leaf(*pud)) pmd = pmd_offset(pud, gpa); else if (level <= 1) new_pmd = kvmppc_pmd_alloc(); if (level == 0 && !(pmd && pmd_present(*pmd) && !pmd_is_leaf(*pmd))) new_ptep = kvmppc_pte_alloc(); /* Check if we might have been invalidated; let the guest retry if so */ spin_lock(&kvm->mmu_lock); ret = -EAGAIN; if (mmu_invalidate_retry(kvm, mmu_seq)) goto out_unlock; /* Now traverse again under the lock and change the tree */ ret = -ENOMEM; if (p4d_none(*p4d)) { if (!new_pud) goto out_unlock; p4d_populate(kvm->mm, p4d, new_pud); new_pud = NULL; } pud = pud_offset(p4d, gpa); if (pud_is_leaf(*pud)) { unsigned long hgpa = gpa & PUD_MASK; /* Check if we raced and someone else has set the same thing */ if (level == 2) { if (pud_raw(*pud) == pte_raw(pte)) { ret = 0; goto out_unlock; } /* Valid 1GB page here already, add our extra bits */ WARN_ON_ONCE((pud_val(*pud) ^ pte_val(pte)) & PTE_BITS_MUST_MATCH); kvmppc_radix_update_pte(kvm, (pte_t *)pud, 0, pte_val(pte), hgpa, PUD_SHIFT); ret = 0; goto out_unlock; } /* * If we raced with another CPU which has just put * a 1GB pte in after we saw a pmd page, try again. */ if (!new_pmd) { ret = -EAGAIN; goto out_unlock; } /* Valid 1GB page here already, remove it */ kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL, lpid); } if (level == 2) { if (!pud_none(*pud)) { /* * There's a page table page here, but we wanted to * install a large page, so remove and free the page * table page. */ kvmppc_unmap_free_pud_entry_table(kvm, pud, gpa, lpid); } kvmppc_radix_set_pte_at(kvm, gpa, (pte_t *)pud, pte); if (rmapp && n_rmap) kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap); ret = 0; goto out_unlock; } if (pud_none(*pud)) { if (!new_pmd) goto out_unlock; pud_populate(kvm->mm, pud, new_pmd); new_pmd = NULL; } pmd = pmd_offset(pud, gpa); if (pmd_is_leaf(*pmd)) { unsigned long lgpa = gpa & PMD_MASK; /* Check if we raced and someone else has set the same thing */ if (level == 1) { if (pmd_raw(*pmd) == pte_raw(pte)) { ret = 0; goto out_unlock; } /* Valid 2MB page here already, add our extra bits */ WARN_ON_ONCE((pmd_val(*pmd) ^ pte_val(pte)) & PTE_BITS_MUST_MATCH); kvmppc_radix_update_pte(kvm, pmdp_ptep(pmd), 0, pte_val(pte), lgpa, PMD_SHIFT); ret = 0; goto out_unlock; } /* * If we raced with another CPU which has just put * a 2MB pte in after we saw a pte page, try again. */ if (!new_ptep) { ret = -EAGAIN; goto out_unlock; } /* Valid 2MB page here already, remove it */ kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL, lpid); } if (level == 1) { if (!pmd_none(*pmd)) { /* * There's a page table page here, but we wanted to * install a large page, so remove and free the page * table page. */ kvmppc_unmap_free_pmd_entry_table(kvm, pmd, gpa, lpid); } kvmppc_radix_set_pte_at(kvm, gpa, pmdp_ptep(pmd), pte); if (rmapp && n_rmap) kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap); ret = 0; goto out_unlock; } if (pmd_none(*pmd)) { if (!new_ptep) goto out_unlock; pmd_populate(kvm->mm, pmd, new_ptep); new_ptep = NULL; } ptep = pte_offset_kernel(pmd, gpa); if (pte_present(*ptep)) { /* Check if someone else set the same thing */ if (pte_raw(*ptep) == pte_raw(pte)) { ret = 0; goto out_unlock; } /* Valid page here already, add our extra bits */ WARN_ON_ONCE((pte_val(*ptep) ^ pte_val(pte)) & PTE_BITS_MUST_MATCH); kvmppc_radix_update_pte(kvm, ptep, 0, pte_val(pte), gpa, 0); ret = 0; goto out_unlock; } kvmppc_radix_set_pte_at(kvm, gpa, ptep, pte); if (rmapp && n_rmap) kvmhv_insert_nest_rmap(kvm, rmapp, n_rmap); ret = 0; out_unlock: spin_unlock(&kvm->mmu_lock); if (new_pud) pud_free(kvm->mm, new_pud); if (new_pmd) kvmppc_pmd_free(new_pmd); if (new_ptep) kvmppc_pte_free(new_ptep); return ret; } bool kvmppc_hv_handle_set_rc(struct kvm *kvm, bool nested, bool writing, unsigned long gpa, unsigned int lpid) { unsigned long pgflags; unsigned int shift; pte_t *ptep; /* * Need to set an R or C bit in the 2nd-level tables; * since we are just helping out the hardware here, * it is sufficient to do what the hardware does. */ pgflags = _PAGE_ACCESSED; if (writing) pgflags |= _PAGE_DIRTY; if (nested) ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift); else ptep = find_kvm_secondary_pte(kvm, gpa, &shift); if (ptep && pte_present(*ptep) && (!writing || pte_write(*ptep))) { kvmppc_radix_update_pte(kvm, ptep, 0, pgflags, gpa, shift); return true; } return false; } int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, unsigned long gpa, struct kvm_memory_slot *memslot, bool writing, bool kvm_ro, pte_t *inserted_pte, unsigned int *levelp) { struct kvm *kvm = vcpu->kvm; struct page *page = NULL; unsigned long mmu_seq; unsigned long hva, gfn = gpa >> PAGE_SHIFT; bool upgrade_write = false; bool *upgrade_p = &upgrade_write; pte_t pte, *ptep; unsigned int shift, level; int ret; bool large_enable; /* used to check for invalidations in progress */ mmu_seq = kvm->mmu_invalidate_seq; smp_rmb(); /* * Do a fast check first, since __gfn_to_pfn_memslot doesn't * do it with !atomic && !async, which is how we call it. * We always ask for write permission since the common case * is that the page is writable. */ hva = gfn_to_hva_memslot(memslot, gfn); if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) { upgrade_write = true; } else { unsigned long pfn; /* Call KVM generic code to do the slow-path check */ pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL, writing, upgrade_p, NULL); if (is_error_noslot_pfn(pfn)) return -EFAULT; page = NULL; if (pfn_valid(pfn)) { page = pfn_to_page(pfn); if (PageReserved(page)) page = NULL; } } /* * 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; } /* If we're logging dirty pages, always map single pages */ large_enable = !(memslot->flags & KVM_MEM_LOG_DIRTY_PAGES); /* Get pte level from shift/size */ if (large_enable && shift == PUD_SHIFT && (gpa & (PUD_SIZE - PAGE_SIZE)) == (hva & (PUD_SIZE - PAGE_SIZE))) { level = 2; } else if (large_enable && shift == PMD_SHIFT && (gpa & (PMD_SIZE - PAGE_SIZE)) == (hva & (PMD_SIZE - PAGE_SIZE))) { level = 1; } else { level = 0; if (shift > PAGE_SHIFT) { /* * If the pte maps more than one page, bring over * bits from the virtual address to get the real * address of the specific single page we want. */ unsigned long rpnmask = (1ul << shift) - PAGE_SIZE; pte = __pte(pte_val(pte) | (hva & rpnmask)); } } pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED); if (writing || upgrade_write) { if (pte_val(pte) & _PAGE_WRITE) pte = __pte(pte_val(pte) | _PAGE_DIRTY); } else { pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY)); } /* Allocate space in the tree and write the PTE */ ret = kvmppc_create_pte(kvm, kvm->arch.pgtable, pte, gpa, level, mmu_seq, kvm->arch.lpid, NULL, NULL); if (inserted_pte) *inserted_pte = pte; if (levelp) *levelp = level; if (page) { if (!ret && (pte_val(pte) & _PAGE_WRITE)) set_page_dirty_lock(page); put_page(page); } /* Increment number of large pages if we (successfully) inserted one */ if (!ret) { if (level == 1) kvm->stat.num_2M_pages++; else if (level == 2) kvm->stat.num_1G_pages++; } return ret; } int kvmppc_book3s_radix_page_fault(struct kvm_vcpu *vcpu, unsigned long ea, unsigned long dsisr) { struct kvm *kvm = vcpu->kvm; unsigned long gpa, gfn; struct kvm_memory_slot *memslot; long ret; bool writing = !!(dsisr & DSISR_ISSTORE); bool kvm_ro = false; /* Check for unusual errors */ if (dsisr & DSISR_UNSUPP_MMU) { pr_err("KVM: Got unsupported MMU fault\n"); return -EFAULT; } if (dsisr & DSISR_BADACCESS) { /* Reflect to the guest as DSI */ pr_err("KVM: Got radix HV page fault with DSISR=%lx\n", dsisr); kvmppc_core_queue_data_storage(vcpu, ea, dsisr); return RESUME_GUEST; } /* Translate the logical address */ gpa = vcpu->arch.fault_gpa & ~0xfffUL; gpa &= ~0xF000000000000000ul; gfn = gpa >> PAGE_SHIFT; if (!(dsisr & DSISR_PRTABLE_FAULT)) gpa |= ea & 0xfff; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) return kvmppc_send_page_to_uv(kvm, gfn); /* Get the corresponding memslot */ memslot = gfn_to_memslot(kvm, gfn); /* No memslot means it's an emulated MMIO region */ if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS | DSISR_SET_RC)) { /* * Bad address in guest page table tree, or other * unusual error - reflect it to the guest as DSI. */ kvmppc_core_queue_data_storage(vcpu, ea, dsisr); return RESUME_GUEST; } return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing); } if (memslot->flags & KVM_MEM_READONLY) { if (writing) { /* give the guest a DSI */ kvmppc_core_queue_data_storage(vcpu, ea, DSISR_ISSTORE | DSISR_PROTFAULT); return RESUME_GUEST; } kvm_ro = true; } /* Failed to set the reference/change bits */ if (dsisr & DSISR_SET_RC) { spin_lock(&kvm->mmu_lock); if (kvmppc_hv_handle_set_rc(kvm, false, writing, gpa, kvm->arch.lpid)) dsisr &= ~DSISR_SET_RC; spin_unlock(&kvm->mmu_lock); if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE | DSISR_PROTFAULT | DSISR_SET_RC))) return RESUME_GUEST; } /* Try to insert a pte */ ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot, writing, kvm_ro, NULL, NULL); if (ret == 0 || ret == -EAGAIN) ret = RESUME_GUEST; return ret; } /* Called with kvm->mmu_lock held */ void kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { pte_t *ptep; unsigned long gpa = gfn << PAGE_SHIFT; unsigned int shift; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) { uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT); return; } ptep = find_kvm_secondary_pte(kvm, gpa, &shift); if (ptep && pte_present(*ptep)) kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot, kvm->arch.lpid); } /* Called with kvm->mmu_lock held */ bool kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { pte_t *ptep; unsigned long gpa = gfn << PAGE_SHIFT; unsigned int shift; bool ref = false; unsigned long old, *rmapp; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) return ref; ptep = find_kvm_secondary_pte(kvm, gpa, &shift); if (ptep && pte_present(*ptep) && pte_young(*ptep)) { old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0, gpa, shift); /* XXX need to flush tlb here? */ /* Also clear bit in ptes in shadow pgtable for nested guests */ rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_ACCESSED, 0, old & PTE_RPN_MASK, 1UL << shift); ref = true; } return ref; } /* Called with kvm->mmu_lock held */ bool kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long gfn) { pte_t *ptep; unsigned long gpa = gfn << PAGE_SHIFT; unsigned int shift; bool ref = false; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) return ref; ptep = find_kvm_secondary_pte(kvm, gpa, &shift); if (ptep && pte_present(*ptep) && pte_young(*ptep)) ref = true; return ref; } bool kvm_test_clear_young_hv(struct kvm *kvm, struct kvm_gfn_range *range) { bool err; gfn_t gfn = range->start; rcu_read_lock(); err = !kvm_is_radix(kvm); if (err) goto unlock; /* * Case 1: This function kvmppc_switch_mmu_to_hpt() * * rcu_read_lock() * Test kvm_is_radix() kvm->arch.radix = 0 * Use kvm->arch.pgtable synchronize_rcu() * rcu_read_unlock() * kvmppc_free_radix() * * * Case 2: This function kvmppc_switch_mmu_to_radix() * * kvmppc_init_vm_radix() * smp_wmb() * Test kvm_is_radix() kvm->arch.radix = 1 * smp_rmb() * Use kvm->arch.pgtable */ smp_rmb(); while (gfn < range->end) { pte_t *ptep; pte_t old, new; unsigned int shift; ptep = find_kvm_secondary_pte_unlocked(kvm, gfn * PAGE_SIZE, &shift); if (!ptep) goto next; VM_WARN_ON_ONCE(!page_count(virt_to_page(ptep))); old = READ_ONCE(*ptep); if (!pte_present(old) || !pte_young(old)) goto next; new = pte_mkold(old); if (kvm_should_clear_young(range, gfn)) pte_xchg(ptep, old, new); next: gfn += shift ? BIT(shift - PAGE_SHIFT) : 1; } unlock: rcu_read_unlock(); return err; } /* Returns the number of PAGE_SIZE pages that are dirty */ static int kvm_radix_test_clear_dirty(struct kvm *kvm, struct kvm_memory_slot *memslot, int pagenum) { unsigned long gfn = memslot->base_gfn + pagenum; unsigned long gpa = gfn << PAGE_SHIFT; pte_t *ptep, pte; unsigned int shift; int ret = 0; unsigned long old, *rmapp; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) return ret; /* * For performance reasons we don't hold kvm->mmu_lock while walking the * partition scoped table. */ ptep = find_kvm_secondary_pte_unlocked(kvm, gpa, &shift); if (!ptep) return 0; pte = READ_ONCE(*ptep); if (pte_present(pte) && pte_dirty(pte)) { spin_lock(&kvm->mmu_lock); /* * Recheck the pte again */ if (pte_val(pte) != pte_val(*ptep)) { /* * We have KVM_MEM_LOG_DIRTY_PAGES enabled. Hence we can * only find PAGE_SIZE pte entries here. We can continue * to use the pte addr returned by above page table * walk. */ if (!pte_present(*ptep) || !pte_dirty(*ptep)) { spin_unlock(&kvm->mmu_lock); return 0; } } ret = 1; VM_BUG_ON(shift); old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_DIRTY, 0, gpa, shift); kvmppc_radix_tlbie_page(kvm, gpa, shift, kvm->arch.lpid); /* Also clear bit in ptes in shadow pgtable for nested guests */ rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; kvmhv_update_nest_rmap_rc_list(kvm, rmapp, _PAGE_DIRTY, 0, old & PTE_RPN_MASK, 1UL << shift); spin_unlock(&kvm->mmu_lock); } return ret; } long kvmppc_hv_get_dirty_log_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long *map) { unsigned long i, j; int npages; for (i = 0; i < memslot->npages; i = j) { npages = kvm_radix_test_clear_dirty(kvm, memslot, i); /* * Note that if npages > 0 then i must be a multiple of npages, * since huge pages are only used to back the guest at guest * real addresses that are a multiple of their size. * Since we have at most one PTE covering any given guest * real address, if npages > 1 we can skip to i + npages. */ j = i + 1; if (npages) { set_dirty_bits(map, i, npages); j = i + npages; } } return 0; } void kvmppc_radix_flush_memslot(struct kvm *kvm, const struct kvm_memory_slot *memslot) { unsigned long n; pte_t *ptep; unsigned long gpa; unsigned int shift; if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START) kvmppc_uvmem_drop_pages(memslot, kvm, true); if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) return; gpa = memslot->base_gfn << PAGE_SHIFT; spin_lock(&kvm->mmu_lock); for (n = memslot->npages; n; --n) { ptep = find_kvm_secondary_pte(kvm, gpa, &shift); if (ptep && pte_present(*ptep)) kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot, kvm->arch.lpid); gpa += PAGE_SIZE; } /* * Increase the mmu notifier sequence number to prevent any page * fault that read the memslot earlier from writing a PTE. */ kvm->mmu_invalidate_seq++; spin_unlock(&kvm->mmu_lock); } static void add_rmmu_ap_encoding(struct kvm_ppc_rmmu_info *info, int psize, int *indexp) { if (!mmu_psize_defs[psize].shift) return; info->ap_encodings[*indexp] = mmu_psize_defs[psize].shift | (mmu_psize_defs[psize].ap << 29); ++(*indexp); } int kvmhv_get_rmmu_info(struct kvm *kvm, struct kvm_ppc_rmmu_info *info) { int i; if (!radix_enabled()) return -EINVAL; memset(info, 0, sizeof(*info)); /* 4k page size */ info->geometries[0].page_shift = 12; info->geometries[0].level_bits[0] = 9; for (i = 1; i < 4; ++i) info->geometries[0].level_bits[i] = p9_supported_radix_bits[i]; /* 64k page size */ info->geometries[1].page_shift = 16; for (i = 0; i < 4; ++i) info->geometries[1].level_bits[i] = p9_supported_radix_bits[i]; i = 0; add_rmmu_ap_encoding(info, MMU_PAGE_4K, &i); add_rmmu_ap_encoding(info, MMU_PAGE_64K, &i); add_rmmu_ap_encoding(info, MMU_PAGE_2M, &i); add_rmmu_ap_encoding(info, MMU_PAGE_1G, &i); return 0; } int kvmppc_init_vm_radix(struct kvm *kvm) { kvm->arch.pgtable = pgd_alloc(kvm->mm); if (!kvm->arch.pgtable) return -ENOMEM; return 0; } static void pte_ctor(void *addr) { memset(addr, 0, RADIX_PTE_TABLE_SIZE); } static void pmd_ctor(void *addr) { memset(addr, 0, RADIX_PMD_TABLE_SIZE); } struct debugfs_radix_state { struct kvm *kvm; struct mutex mutex; unsigned long gpa; int lpid; int chars_left; int buf_index; char buf[128]; u8 hdr; }; static int debugfs_radix_open(struct inode *inode, struct file *file) { struct kvm *kvm = inode->i_private; struct debugfs_radix_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_radix_release(struct inode *inode, struct file *file) { struct debugfs_radix_state *p = file->private_data; kvm_put_kvm(p->kvm); kfree(p); return 0; } static ssize_t debugfs_radix_read(struct file *file, char __user *buf, size_t len, loff_t *ppos) { struct debugfs_radix_state *p = file->private_data; ssize_t ret, r; unsigned long n; struct kvm *kvm; unsigned long gpa; pgd_t *pgt; struct kvm_nested_guest *nested; pgd_t *pgdp; p4d_t p4d, *p4dp; pud_t pud, *pudp; pmd_t pmd, *pmdp; pte_t *ptep; int shift; unsigned long pte; 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; } } gpa = p->gpa; nested = NULL; pgt = NULL; while (len != 0 && p->lpid >= 0) { if (gpa >= RADIX_PGTABLE_RANGE) { gpa = 0; pgt = NULL; if (nested) { kvmhv_put_nested(nested); nested = NULL; } p->lpid = kvmhv_nested_next_lpid(kvm, p->lpid); p->hdr = 0; if (p->lpid < 0) break; } if (!pgt) { if (p->lpid == 0) { pgt = kvm->arch.pgtable; } else { nested = kvmhv_get_nested(kvm, p->lpid, false); if (!nested) { gpa = RADIX_PGTABLE_RANGE; continue; } pgt = nested->shadow_pgtable; } } n = 0; if (!p->hdr) { if (p->lpid > 0) n = scnprintf(p->buf, sizeof(p->buf), "\nNested LPID %d: ", p->lpid); n += scnprintf(p->buf + n, sizeof(p->buf) - n, "pgdir: %lx\n", (unsigned long)pgt); p->hdr = 1; goto copy; } pgdp = pgt + pgd_index(gpa); p4dp = p4d_offset(pgdp, gpa); p4d = READ_ONCE(*p4dp); if (!(p4d_val(p4d) & _PAGE_PRESENT)) { gpa = (gpa & P4D_MASK) + P4D_SIZE; continue; } pudp = pud_offset(&p4d, gpa); pud = READ_ONCE(*pudp); if (!(pud_val(pud) & _PAGE_PRESENT)) { gpa = (gpa & PUD_MASK) + PUD_SIZE; continue; } if (pud_val(pud) & _PAGE_PTE) { pte = pud_val(pud); shift = PUD_SHIFT; goto leaf; } pmdp = pmd_offset(&pud, gpa); pmd = READ_ONCE(*pmdp); if (!(pmd_val(pmd) & _PAGE_PRESENT)) { gpa = (gpa & PMD_MASK) + PMD_SIZE; continue; } if (pmd_val(pmd) & _PAGE_PTE) { pte = pmd_val(pmd); shift = PMD_SHIFT; goto leaf; } ptep = pte_offset_kernel(&pmd, gpa); pte = pte_val(READ_ONCE(*ptep)); if (!(pte & _PAGE_PRESENT)) { gpa += PAGE_SIZE; continue; } shift = PAGE_SHIFT; leaf: n = scnprintf(p->buf, sizeof(p->buf), " %lx: %lx %d\n", gpa, pte, shift); gpa += 1ul << shift; copy: 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; break; } } p->gpa = gpa; if (nested) kvmhv_put_nested(nested); out: mutex_unlock(&p->mutex); return ret; } static ssize_t debugfs_radix_write(struct file *file, const char __user *buf, size_t len, loff_t *ppos) { return -EACCES; } static const struct file_operations debugfs_radix_fops = { .owner = THIS_MODULE, .open = debugfs_radix_open, .release = debugfs_radix_release, .read = debugfs_radix_read, .write = debugfs_radix_write, .llseek = generic_file_llseek, }; void kvmhv_radix_debugfs_init(struct kvm *kvm) { debugfs_create_file("radix", 0400, kvm->debugfs_dentry, kvm, &debugfs_radix_fops); } int kvmppc_radix_init(void) { unsigned long size = sizeof(void *) << RADIX_PTE_INDEX_SIZE; kvm_pte_cache = kmem_cache_create("kvm-pte", size, size, SLAB_TYPESAFE_BY_RCU, pte_ctor); if (!kvm_pte_cache) return -ENOMEM; size = sizeof(void *) << RADIX_PMD_INDEX_SIZE; kvm_pmd_cache = kmem_cache_create("kvm-pmd", size, size, SLAB_TYPESAFE_BY_RCU, pmd_ctor); if (!kvm_pmd_cache) { kmem_cache_destroy(kvm_pte_cache); return -ENOMEM; } return 0; } void kvmppc_radix_exit(void) { kmem_cache_destroy(kvm_pte_cache); kmem_cache_destroy(kvm_pmd_cache); }