From 8dc6cca556e4126f77b71cf8e0c45ccc78d1d213 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 11 Sep 2017 15:29:45 +1000 Subject: [PATCH] KVM: PPC: Book3S HV: Don't rely on host's page size information This removes the dependence of KVM on the mmu_psize_defs array (which stores information about hardware support for various page sizes) and the things derived from it, chiefly hpte_page_sizes[], hpte_page_size(), hpte_actual_page_size() and get_sllp_encoding(). We also no longer rely on the mmu_slb_size variable or the MMU_FTR_1T_SEGMENTS feature bit. The reason for doing this is so we can support a HPT guest on a radix host. In a radix host, the mmu_psize_defs array contains information about page sizes supported by the MMU in radix mode rather than the page sizes supported by the MMU in HPT mode. Similarly, mmu_slb_size and the MMU_FTR_1T_SEGMENTS bit are not set. Instead we hard-code knowledge of the behaviour of the HPT MMU in the POWER7, POWER8 and POWER9 processors (which are the only processors supported by HV KVM) - specifically the encoding of the LP fields in the HPT and SLB entries, and the fact that they have 32 SLB entries and support 1TB segments. Signed-off-by: Paul Mackerras --- arch/powerpc/include/asm/kvm_book3s_64.h | 116 +++++++++++++++++++++++++------ arch/powerpc/kvm/book3s_64_mmu_hv.c | 13 ++-- arch/powerpc/kvm/book3s_hv.c | 39 +++++------ arch/powerpc/kvm/book3s_hv_rm_mmu.c | 11 +-- 4 files changed, 126 insertions(+), 53 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h index d55c7f881ce7..b21936c7b190 100644 --- a/arch/powerpc/include/asm/kvm_book3s_64.h +++ b/arch/powerpc/include/asm/kvm_book3s_64.h @@ -107,18 +107,96 @@ static inline void __unlock_hpte(__be64 *hpte, unsigned long hpte_v) hpte[0] = cpu_to_be64(hpte_v); } +/* + * These functions encode knowledge of the POWER7/8/9 hardware + * interpretations of the HPTE LP (large page size) field. + */ +static inline int kvmppc_hpte_page_shifts(unsigned long h, unsigned long l) +{ + unsigned int lphi; + + if (!(h & HPTE_V_LARGE)) + return 12; /* 4kB */ + lphi = (l >> 16) & 0xf; + switch ((l >> 12) & 0xf) { + case 0: + return !lphi ? 24 : -1; /* 16MB */ + break; + case 1: + return 16; /* 64kB */ + break; + case 3: + return !lphi ? 34 : -1; /* 16GB */ + break; + case 7: + return (16 << 8) + 12; /* 64kB in 4kB */ + break; + case 8: + if (!lphi) + return (24 << 8) + 16; /* 16MB in 64kkB */ + if (lphi == 3) + return (24 << 8) + 12; /* 16MB in 4kB */ + break; + } + return -1; +} + +static inline int kvmppc_hpte_base_page_shift(unsigned long h, unsigned long l) +{ + return kvmppc_hpte_page_shifts(h, l) & 0xff; +} + +static inline int kvmppc_hpte_actual_page_shift(unsigned long h, unsigned long l) +{ + int tmp = kvmppc_hpte_page_shifts(h, l); + + if (tmp >= 0x100) + tmp >>= 8; + return tmp; +} + +static inline unsigned long kvmppc_actual_pgsz(unsigned long v, unsigned long r) +{ + return 1ul << kvmppc_hpte_actual_page_shift(v, r); +} + +static inline int kvmppc_pgsize_lp_encoding(int base_shift, int actual_shift) +{ + switch (base_shift) { + case 12: + switch (actual_shift) { + case 12: + return 0; + case 16: + return 7; + case 24: + return 0x38; + } + break; + case 16: + switch (actual_shift) { + case 16: + return 1; + case 24: + return 8; + } + break; + case 24: + return 0; + } + return -1; +} + static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r, unsigned long pte_index) { - int i, b_psize = MMU_PAGE_4K, a_psize = MMU_PAGE_4K; - unsigned int penc; + int a_pgshift, b_pgshift; unsigned long rb = 0, va_low, sllp; - unsigned int lp = (r >> LP_SHIFT) & ((1 << LP_BITS) - 1); - if (v & HPTE_V_LARGE) { - i = hpte_page_sizes[lp]; - b_psize = i & 0xf; - a_psize = i >> 4; + b_pgshift = a_pgshift = kvmppc_hpte_page_shifts(v, r); + if (a_pgshift >= 0x100) { + b_pgshift &= 0xff; + a_pgshift >>= 8; } /* @@ -152,37 +230,33 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r, va_low ^= v >> (SID_SHIFT_1T - 16); va_low &= 0x7ff; - switch (b_psize) { - case MMU_PAGE_4K: - sllp = get_sllp_encoding(a_psize); - rb |= sllp << 5; /* AP field */ + if (b_pgshift == 12) { + if (a_pgshift > 12) { + sllp = (a_pgshift == 16) ? 5 : 4; + rb |= sllp << 5; /* AP field */ + } rb |= (va_low & 0x7ff) << 12; /* remaining 11 bits of AVA */ - break; - default: - { + } else { int aval_shift; /* * remaining bits of AVA/LP fields * Also contain the rr bits of LP */ - rb |= (va_low << mmu_psize_defs[b_psize].shift) & 0x7ff000; + rb |= (va_low << b_pgshift) & 0x7ff000; /* * Now clear not needed LP bits based on actual psize */ - rb &= ~((1ul << mmu_psize_defs[a_psize].shift) - 1); + rb &= ~((1ul << a_pgshift) - 1); /* * AVAL field 58..77 - base_page_shift bits of va * we have space for 58..64 bits, Missing bits should * be zero filled. +1 is to take care of L bit shift */ - aval_shift = 64 - (77 - mmu_psize_defs[b_psize].shift) + 1; + aval_shift = 64 - (77 - b_pgshift) + 1; rb |= ((va_low << aval_shift) & 0xfe); rb |= 1; /* L field */ - penc = mmu_psize_defs[b_psize].penc[a_psize]; - rb |= penc << 12; /* LP field */ - break; - } + rb |= r & 0xff000 & ((1ul << a_pgshift) - 1); /* LP field */ } rb |= (v >> HPTE_V_SSIZE_SHIFT) << 8; /* B field */ return rb; diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 624b01175b79..cc21d3c71a8d 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -333,7 +333,7 @@ static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, { unsigned long ra_mask; - ra_mask = hpte_page_size(v, r) - 1; + ra_mask = kvmppc_actual_pgsz(v, r) - 1; return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); } @@ -504,7 +504,8 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, mmio_update = atomic64_read(&kvm->arch.mmio_update); if (mmio_update == vcpu->arch.pgfault_cache->mmio_update) { r = vcpu->arch.pgfault_cache->rpte; - psize = hpte_page_size(vcpu->arch.pgfault_hpte[0], r); + 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)); @@ -533,7 +534,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, return RESUME_GUEST; /* Translate the logical address and get the page */ - psize = hpte_page_size(hpte[0], r); + 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)); @@ -797,7 +798,7 @@ static void kvmppc_unmap_hpte(struct kvm *kvm, unsigned long i, /* Now check and modify the HPTE */ ptel = rev[i].guest_rpte; - psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel); + 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); @@ -1091,7 +1092,7 @@ static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp) rev[i].guest_rpte |= HPTE_R_C; note_hpte_modification(kvm, &rev[i]); } - n = hpte_page_size(v, r); + n = kvmppc_actual_pgsz(v, r); n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; if (n > npages_dirty) npages_dirty = n; @@ -1266,7 +1267,7 @@ static unsigned long resize_hpt_rehash_hpte(struct kvm_resize_hpt *resize, guest_rpte = rev->guest_rpte; ret = -EIO; - apsize = hpte_page_size(vpte, guest_rpte); + apsize = kvmppc_actual_pgsz(vpte, guest_rpte); if (!apsize) goto out; diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 9634425f0f39..b3817df58e0e 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3300,22 +3300,21 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu) } static void kvmppc_add_seg_page_size(struct kvm_ppc_one_seg_page_size **sps, - int linux_psize) + int shift, int sllp) { - struct mmu_psize_def *def = &mmu_psize_defs[linux_psize]; - - if (!def->shift) - return; - (*sps)->page_shift = def->shift; - (*sps)->slb_enc = def->sllp; - (*sps)->enc[0].page_shift = def->shift; - (*sps)->enc[0].pte_enc = def->penc[linux_psize]; + (*sps)->page_shift = shift; + (*sps)->slb_enc = sllp; + (*sps)->enc[0].page_shift = shift; + (*sps)->enc[0].pte_enc = kvmppc_pgsize_lp_encoding(shift, shift); /* - * Add 16MB MPSS support if host supports it + * Add 16MB MPSS support (may get filtered out by userspace) */ - if (linux_psize != MMU_PAGE_16M && def->penc[MMU_PAGE_16M] != -1) { - (*sps)->enc[1].page_shift = 24; - (*sps)->enc[1].pte_enc = def->penc[MMU_PAGE_16M]; + if (shift != 24) { + int penc = kvmppc_pgsize_lp_encoding(shift, 24); + if (penc != -1) { + (*sps)->enc[1].page_shift = 24; + (*sps)->enc[1].pte_enc = penc; + } } (*sps)++; } @@ -3340,16 +3339,15 @@ static int kvm_vm_ioctl_get_smmu_info_hv(struct kvm *kvm, info->data_keys = 32; info->instr_keys = cpu_has_feature(CPU_FTR_ARCH_207S) ? 32 : 0; - info->flags = KVM_PPC_PAGE_SIZES_REAL; - if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) - info->flags |= KVM_PPC_1T_SEGMENTS; - info->slb_size = mmu_slb_size; + /* POWER7, 8 and 9 all have 1T segments and 32-entry SLB */ + info->flags = KVM_PPC_PAGE_SIZES_REAL | KVM_PPC_1T_SEGMENTS; + info->slb_size = 32; /* We only support these sizes for now, and no muti-size segments */ sps = &info->sps[0]; - kvmppc_add_seg_page_size(&sps, MMU_PAGE_4K); - kvmppc_add_seg_page_size(&sps, MMU_PAGE_64K); - kvmppc_add_seg_page_size(&sps, MMU_PAGE_16M); + kvmppc_add_seg_page_size(&sps, 12, 0); + kvmppc_add_seg_page_size(&sps, 16, SLB_VSID_L | SLB_VSID_LP_01); + kvmppc_add_seg_page_size(&sps, 24, SLB_VSID_L); return 0; } @@ -4352,4 +4350,3 @@ module_exit(kvmppc_book3s_exit_hv); MODULE_LICENSE("GPL"); MODULE_ALIAS_MISCDEV(KVM_MINOR); MODULE_ALIAS("devname:kvm"); - diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 4efe364f1188..cf98f17c1aa6 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -129,7 +129,7 @@ static unsigned long *revmap_for_hpte(struct kvm *kvm, unsigned long hpte_v, unsigned long *rmap; unsigned long gfn; - gfn = hpte_rpn(hpte_gr, hpte_page_size(hpte_v, hpte_gr)); + gfn = hpte_rpn(hpte_gr, kvmppc_actual_pgsz(hpte_v, hpte_gr)); memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn); if (!memslot) return NULL; @@ -169,7 +169,8 @@ static void remove_revmap_chain(struct kvm *kvm, long pte_index, } *rmap |= rcbits << KVMPPC_RMAP_RC_SHIFT; if (rcbits & HPTE_R_C) - kvmppc_update_rmap_change(rmap, hpte_page_size(hpte_v, hpte_r)); + kvmppc_update_rmap_change(rmap, + kvmppc_actual_pgsz(hpte_v, hpte_r)); unlock_rmap(rmap); } @@ -193,7 +194,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags, if (kvm_is_radix(kvm)) return H_FUNCTION; - psize = hpte_page_size(pteh, ptel); + psize = kvmppc_actual_pgsz(pteh, ptel); if (!psize) return H_PARAMETER; writing = hpte_is_writable(ptel); @@ -848,7 +849,7 @@ long kvmppc_h_clear_mod(struct kvm_vcpu *vcpu, unsigned long flags, r = be64_to_cpu(hpte[1]); gr |= r & (HPTE_R_R | HPTE_R_C); if (r & HPTE_R_C) { - unsigned long psize = hpte_page_size(v, r); + unsigned long psize = kvmppc_actual_pgsz(v, r); hpte[1] = cpu_to_be64(r & ~HPTE_R_C); eieio(); rmap = revmap_for_hpte(kvm, v, gr); @@ -1014,7 +1015,7 @@ long kvmppc_hv_find_lock_hpte(struct kvm *kvm, gva_t eaddr, unsigned long slb_v, * Check the HPTE again, including base page size */ if ((v & valid) && (v & mask) == val && - hpte_base_page_size(v, r) == (1ul << pshift)) + kvmppc_hpte_base_page_shift(v, r) == pshift) /* Return with the HPTE still locked */ return (hash << 3) + (i >> 1); -- 2.11.4.GIT