From 9811c78e968f26ca040c53f6180ff2018939ae24 Mon Sep 17 00:00:00 2001 From: Suraj Jitindar Singh Date: Mon, 8 Oct 2018 16:31:00 +1100 Subject: [PATCH] KVM: PPC: Book3S HV: Make kvmppc_mmu_radix_xlate process/partition table agnostic kvmppc_mmu_radix_xlate() is used to translate an effective address through the process tables. The process table and partition tables have identical layout. Exploit this fact to make the kvmppc_mmu_radix_xlate() function able to translate either an effective address through the process tables or a guest real address through the partition tables. [paulus@ozlabs.org - reduced diffs from previous code] Reviewed-by: David Gibson Signed-off-by: Suraj Jitindar Singh Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/kvm_book3s.h | 3 + arch/powerpc/kvm/book3s_64_mmu_radix.c | 109 +++++++++++++++++-------- 2 files changed, 78 insertions(+), 34 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index dd18d8174504..91c977948828 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -188,6 +188,9 @@ extern int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hc); extern int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long ea, unsigned long dsisr); +extern 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); extern int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, struct kvmppc_pte *gpte, bool data, bool iswrite); extern int kvmppc_init_vm_radix(struct kvm *kvm); diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index 71951b5a2c68..f2976f456fe0 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -29,83 +29,92 @@ */ static int p9_supported_radix_bits[4] = { 5, 9, 9, 13 }; -int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, - struct kvmppc_pte *gpte, bool data, bool iswrite) +/* + * 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; - u32 pid; int ret, level, ps; - __be64 prte, rpte; - unsigned long ptbl; - unsigned long root, pte, index; + unsigned long ptbl, root; unsigned long rts, bits, offset; - unsigned long gpa; - unsigned long proc_tbl_size; + unsigned long size, index; + struct prtb_entry entry; + u64 pte, base, gpa; + __be64 rpte; - /* Work out effective PID */ - switch (eaddr >> 62) { - case 0: - pid = vcpu->arch.pid; - break; - case 3: - pid = 0; - break; - default: + if ((table & PRTS_MASK) > 24) return -EINVAL; - } - proc_tbl_size = 1 << ((kvm->arch.process_table & PRTS_MASK) + 12); - if (pid * 16 >= proc_tbl_size) + size = 1ul << ((table & PRTS_MASK) + 12); + + /* Is the table big enough to contain this entry? */ + if ((table_index * sizeof(entry)) >= size) return -EINVAL; - /* Read partition table to find root of tree for effective PID */ - ptbl = (kvm->arch.process_table & PRTB_MASK) + (pid * 16); - ret = kvm_read_guest(kvm, ptbl, &prte, sizeof(prte)); + /* Read the table to find the root of the radix tree */ + ptbl = (table & PRTB_MASK) + (table_index * sizeof(entry)); + ret = kvm_read_guest(kvm, ptbl, &entry, sizeof(entry)); if (ret) return ret; - root = be64_to_cpu(prte); + /* Root is stored in the first double word */ + root = be64_to_cpu(entry.prtb0); rts = ((root & RTS1_MASK) >> (RTS1_SHIFT - 3)) | ((root & RTS2_MASK) >> RTS2_SHIFT); bits = root & RPDS_MASK; - root = root & RPDB_MASK; + base = root & RPDB_MASK; offset = rts + 31; - /* current implementations only support 52-bit space */ + /* 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) { + /* 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 (root & ((1UL << (bits + 3)) - 1)) + /* Check that low bits of page table base are zero */ + if (base & ((1UL << (bits + 3)) - 1)) return -EINVAL; - ret = kvm_read_guest(kvm, root + index * 8, + /* Read the entry from guest memory */ + ret = kvm_read_guest(kvm, base + (index * sizeof(rpte)), &rpte, sizeof(rpte)); if (ret) return ret; pte = __be64_to_cpu(rpte); if (!(pte & _PAGE_PRESENT)) return -ENOENT; + /* Check if a leaf entry */ if (pte & _PAGE_PTE) break; - bits = pte & 0x1f; - root = pte & 0x0fffffffffffff00ul; + /* 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 */ + + /* Need a leaf at lowest level; 512GB pages not supported */ if (level < 0 || level == 3) return -EINVAL; - /* offset is now log base 2 of the page size */ + /* 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); + gpa |= eaddr & ((1ul << offset) - 1); for (ps = MMU_PAGE_4K; ps < MMU_PAGE_COUNT; ++ps) if (offset == mmu_psize_defs[ps].shift) break; @@ -118,6 +127,38 @@ int kvmppc_mmu_radix_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, gpte->may_read = !!(pte & _PAGE_READ); gpte->may_write = !!(pte & _PAGE_WRITE); gpte->may_execute = !!(pte & _PAGE_EXEC); + + if (pte_ret_p) + *pte_ret_p = pte; + + return 0; +} + +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; -- 2.30.2