diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_radix.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_radix.c | 1492 |
1 files changed, 1492 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c new file mode 100644 index 000000000..10aacbf92 --- /dev/null +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -0,0 +1,1492 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright 2016 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/anon_inodes.h> +#include <linux/file.h> +#include <linux/debugfs.h> +#include <linux/pgtable.h> + +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> +#include "book3s_hv.h" +#include <asm/page.h> +#include <asm/mmu.h> +#include <asm/pgalloc.h> +#include <asm/pte-walk.h> +#include <asm/ultravisor.h> +#include <asm/kvm_book3s_uvmem.h> +#include <asm/plpar_wrappers.h> +#include <asm/firmware.h> + +/* + * 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 (kvmppc_get_amr_hv(vcpu) & (1ul << 62)) + gpte->may_read = 0; + if (kvmppc_get_amr_hv(vcpu) & (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_kernel(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, + kvmppc_get_msr(vcpu) & SRR1_PREFIXED, + 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, + kvmppc_get_msr(vcpu) & SRR1_PREFIXED, + 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, + kvmppc_get_msr(vcpu) & SRR1_PREFIXED, + 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; +} + +/* 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, 0, 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, 0, 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); +} |