From e5fd91f1ef340da553f7a79da9540c3db711c937 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 8 Sep 2015 01:01:14 -0300 Subject: Linux-libre 4.2-gnu --- arch/x86/kvm/mtrr.c | 719 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 719 insertions(+) create mode 100644 arch/x86/kvm/mtrr.c (limited to 'arch/x86/kvm/mtrr.c') diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c new file mode 100644 index 000000000..9e8bf1357 --- /dev/null +++ b/arch/x86/kvm/mtrr.c @@ -0,0 +1,719 @@ +/* + * vMTRR implementation + * + * Copyright (C) 2006 Qumranet, Inc. + * Copyright 2010 Red Hat, Inc. and/or its affiliates. + * Copyright(C) 2015 Intel Corporation. + * + * Authors: + * Yaniv Kamay + * Avi Kivity + * Marcelo Tosatti + * Paolo Bonzini + * Xiao Guangrong + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ + +#include +#include + +#include "cpuid.h" +#include "mmu.h" + +#define IA32_MTRR_DEF_TYPE_E (1ULL << 11) +#define IA32_MTRR_DEF_TYPE_FE (1ULL << 10) +#define IA32_MTRR_DEF_TYPE_TYPE_MASK (0xff) + +static bool msr_mtrr_valid(unsigned msr) +{ + switch (msr) { + case 0x200 ... 0x200 + 2 * KVM_NR_VAR_MTRR - 1: + case MSR_MTRRfix64K_00000: + case MSR_MTRRfix16K_80000: + case MSR_MTRRfix16K_A0000: + case MSR_MTRRfix4K_C0000: + case MSR_MTRRfix4K_C8000: + case MSR_MTRRfix4K_D0000: + case MSR_MTRRfix4K_D8000: + case MSR_MTRRfix4K_E0000: + case MSR_MTRRfix4K_E8000: + case MSR_MTRRfix4K_F0000: + case MSR_MTRRfix4K_F8000: + case MSR_MTRRdefType: + case MSR_IA32_CR_PAT: + return true; + case 0x2f8: + return true; + } + return false; +} + +static bool valid_pat_type(unsigned t) +{ + return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */ +} + +static bool valid_mtrr_type(unsigned t) +{ + return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */ +} + +bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) +{ + int i; + u64 mask; + + if (!msr_mtrr_valid(msr)) + return false; + + if (msr == MSR_IA32_CR_PAT) { + for (i = 0; i < 8; i++) + if (!valid_pat_type((data >> (i * 8)) & 0xff)) + return false; + return true; + } else if (msr == MSR_MTRRdefType) { + if (data & ~0xcff) + return false; + return valid_mtrr_type(data & 0xff); + } else if (msr >= MSR_MTRRfix64K_00000 && msr <= MSR_MTRRfix4K_F8000) { + for (i = 0; i < 8 ; i++) + if (!valid_mtrr_type((data >> (i * 8)) & 0xff)) + return false; + return true; + } + + /* variable MTRRs */ + WARN_ON(!(msr >= 0x200 && msr < 0x200 + 2 * KVM_NR_VAR_MTRR)); + + mask = (~0ULL) << cpuid_maxphyaddr(vcpu); + if ((msr & 1) == 0) { + /* MTRR base */ + if (!valid_mtrr_type(data & 0xff)) + return false; + mask |= 0xf00; + } else + /* MTRR mask */ + mask |= 0x7ff; + if (data & mask) { + kvm_inject_gp(vcpu, 0); + return false; + } + + return true; +} +EXPORT_SYMBOL_GPL(kvm_mtrr_valid); + +static bool mtrr_is_enabled(struct kvm_mtrr *mtrr_state) +{ + return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_E); +} + +static bool fixed_mtrr_is_enabled(struct kvm_mtrr *mtrr_state) +{ + return !!(mtrr_state->deftype & IA32_MTRR_DEF_TYPE_FE); +} + +static u8 mtrr_default_type(struct kvm_mtrr *mtrr_state) +{ + return mtrr_state->deftype & IA32_MTRR_DEF_TYPE_TYPE_MASK; +} + +static u8 mtrr_disabled_type(void) +{ + /* + * Intel SDM 11.11.2.2: all MTRRs are disabled when + * IA32_MTRR_DEF_TYPE.E bit is cleared, and the UC + * memory type is applied to all of physical memory. + */ + return MTRR_TYPE_UNCACHABLE; +} + +/* +* Three terms are used in the following code: +* - segment, it indicates the address segments covered by fixed MTRRs. +* - unit, it corresponds to the MSR entry in the segment. +* - range, a range is covered in one memory cache type. +*/ +struct fixed_mtrr_segment { + u64 start; + u64 end; + + int range_shift; + + /* the start position in kvm_mtrr.fixed_ranges[]. */ + int range_start; +}; + +static struct fixed_mtrr_segment fixed_seg_table[] = { + /* MSR_MTRRfix64K_00000, 1 unit. 64K fixed mtrr. */ + { + .start = 0x0, + .end = 0x80000, + .range_shift = 16, /* 64K */ + .range_start = 0, + }, + + /* + * MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000, 2 units, + * 16K fixed mtrr. + */ + { + .start = 0x80000, + .end = 0xc0000, + .range_shift = 14, /* 16K */ + .range_start = 8, + }, + + /* + * MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000, 8 units, + * 4K fixed mtrr. + */ + { + .start = 0xc0000, + .end = 0x100000, + .range_shift = 12, /* 12K */ + .range_start = 24, + } +}; + +/* + * The size of unit is covered in one MSR, one MSR entry contains + * 8 ranges so that unit size is always 8 * 2^range_shift. + */ +static u64 fixed_mtrr_seg_unit_size(int seg) +{ + return 8 << fixed_seg_table[seg].range_shift; +} + +static bool fixed_msr_to_seg_unit(u32 msr, int *seg, int *unit) +{ + switch (msr) { + case MSR_MTRRfix64K_00000: + *seg = 0; + *unit = 0; + break; + case MSR_MTRRfix16K_80000 ... MSR_MTRRfix16K_A0000: + *seg = 1; + *unit = msr - MSR_MTRRfix16K_80000; + break; + case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000: + *seg = 2; + *unit = msr - MSR_MTRRfix4K_C0000; + break; + default: + return false; + } + + return true; +} + +static void fixed_mtrr_seg_unit_range(int seg, int unit, u64 *start, u64 *end) +{ + struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg]; + u64 unit_size = fixed_mtrr_seg_unit_size(seg); + + *start = mtrr_seg->start + unit * unit_size; + *end = *start + unit_size; + WARN_ON(*end > mtrr_seg->end); +} + +static int fixed_mtrr_seg_unit_range_index(int seg, int unit) +{ + struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg]; + + WARN_ON(mtrr_seg->start + unit * fixed_mtrr_seg_unit_size(seg) + > mtrr_seg->end); + + /* each unit has 8 ranges. */ + return mtrr_seg->range_start + 8 * unit; +} + +static int fixed_mtrr_seg_end_range_index(int seg) +{ + struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg]; + int n; + + n = (mtrr_seg->end - mtrr_seg->start) >> mtrr_seg->range_shift; + return mtrr_seg->range_start + n - 1; +} + +static bool fixed_msr_to_range(u32 msr, u64 *start, u64 *end) +{ + int seg, unit; + + if (!fixed_msr_to_seg_unit(msr, &seg, &unit)) + return false; + + fixed_mtrr_seg_unit_range(seg, unit, start, end); + return true; +} + +static int fixed_msr_to_range_index(u32 msr) +{ + int seg, unit; + + if (!fixed_msr_to_seg_unit(msr, &seg, &unit)) + return -1; + + return fixed_mtrr_seg_unit_range_index(seg, unit); +} + +static int fixed_mtrr_addr_to_seg(u64 addr) +{ + struct fixed_mtrr_segment *mtrr_seg; + int seg, seg_num = ARRAY_SIZE(fixed_seg_table); + + for (seg = 0; seg < seg_num; seg++) { + mtrr_seg = &fixed_seg_table[seg]; + if (mtrr_seg->start >= addr && addr < mtrr_seg->end) + return seg; + } + + return -1; +} + +static int fixed_mtrr_addr_seg_to_range_index(u64 addr, int seg) +{ + struct fixed_mtrr_segment *mtrr_seg; + int index; + + mtrr_seg = &fixed_seg_table[seg]; + index = mtrr_seg->range_start; + index += (addr - mtrr_seg->start) >> mtrr_seg->range_shift; + return index; +} + +static u64 fixed_mtrr_range_end_addr(int seg, int index) +{ + struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg]; + int pos = index - mtrr_seg->range_start; + + return mtrr_seg->start + ((pos + 1) << mtrr_seg->range_shift); +} + +static void var_mtrr_range(struct kvm_mtrr_range *range, u64 *start, u64 *end) +{ + u64 mask; + + *start = range->base & PAGE_MASK; + + mask = range->mask & PAGE_MASK; + mask |= ~0ULL << boot_cpu_data.x86_phys_bits; + + /* This cannot overflow because writing to the reserved bits of + * variable MTRRs causes a #GP. + */ + *end = (*start | ~mask) + 1; +} + +static void update_mtrr(struct kvm_vcpu *vcpu, u32 msr) +{ + struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state; + gfn_t start, end; + int index; + + if (msr == MSR_IA32_CR_PAT || !tdp_enabled || + !kvm_arch_has_noncoherent_dma(vcpu->kvm)) + return; + + if (!mtrr_is_enabled(mtrr_state) && msr != MSR_MTRRdefType) + return; + + /* fixed MTRRs. */ + if (fixed_msr_to_range(msr, &start, &end)) { + if (!fixed_mtrr_is_enabled(mtrr_state)) + return; + } else if (msr == MSR_MTRRdefType) { + start = 0x0; + end = ~0ULL; + } else { + /* variable range MTRRs. */ + index = (msr - 0x200) / 2; + var_mtrr_range(&mtrr_state->var_ranges[index], &start, &end); + } + + kvm_zap_gfn_range(vcpu->kvm, gpa_to_gfn(start), gpa_to_gfn(end)); +} + +static bool var_mtrr_range_is_valid(struct kvm_mtrr_range *range) +{ + return (range->mask & (1 << 11)) != 0; +} + +static void set_var_mtrr_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) +{ + struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state; + struct kvm_mtrr_range *tmp, *cur; + int index, is_mtrr_mask; + + index = (msr - 0x200) / 2; + is_mtrr_mask = msr - 0x200 - 2 * index; + cur = &mtrr_state->var_ranges[index]; + + /* remove the entry if it's in the list. */ + if (var_mtrr_range_is_valid(cur)) + list_del(&mtrr_state->var_ranges[index].node); + + if (!is_mtrr_mask) + cur->base = data; + else + cur->mask = data; + + /* add it to the list if it's enabled. */ + if (var_mtrr_range_is_valid(cur)) { + list_for_each_entry(tmp, &mtrr_state->head, node) + if (cur->base >= tmp->base) + break; + list_add_tail(&cur->node, &tmp->node); + } +} + +int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data) +{ + int index; + + if (!kvm_mtrr_valid(vcpu, msr, data)) + return 1; + + index = fixed_msr_to_range_index(msr); + if (index >= 0) + *(u64 *)&vcpu->arch.mtrr_state.fixed_ranges[index] = data; + else if (msr == MSR_MTRRdefType) + vcpu->arch.mtrr_state.deftype = data; + else if (msr == MSR_IA32_CR_PAT) + vcpu->arch.pat = data; + else + set_var_mtrr_msr(vcpu, msr, data); + + update_mtrr(vcpu, msr); + return 0; +} + +int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata) +{ + int index; + + /* MSR_MTRRcap is a readonly MSR. */ + if (msr == MSR_MTRRcap) { + /* + * SMRR = 0 + * WC = 1 + * FIX = 1 + * VCNT = KVM_NR_VAR_MTRR + */ + *pdata = 0x500 | KVM_NR_VAR_MTRR; + return 0; + } + + if (!msr_mtrr_valid(msr)) + return 1; + + index = fixed_msr_to_range_index(msr); + if (index >= 0) + *pdata = *(u64 *)&vcpu->arch.mtrr_state.fixed_ranges[index]; + else if (msr == MSR_MTRRdefType) + *pdata = vcpu->arch.mtrr_state.deftype; + else if (msr == MSR_IA32_CR_PAT) + *pdata = vcpu->arch.pat; + else { /* Variable MTRRs */ + int is_mtrr_mask; + + index = (msr - 0x200) / 2; + is_mtrr_mask = msr - 0x200 - 2 * index; + if (!is_mtrr_mask) + *pdata = vcpu->arch.mtrr_state.var_ranges[index].base; + else + *pdata = vcpu->arch.mtrr_state.var_ranges[index].mask; + } + + return 0; +} + +void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu) +{ + INIT_LIST_HEAD(&vcpu->arch.mtrr_state.head); +} + +struct mtrr_iter { + /* input fields. */ + struct kvm_mtrr *mtrr_state; + u64 start; + u64 end; + + /* output fields. */ + int mem_type; + /* mtrr is completely disabled? */ + bool mtrr_disabled; + /* [start, end) is not fully covered in MTRRs? */ + bool partial_map; + + /* private fields. */ + union { + /* used for fixed MTRRs. */ + struct { + int index; + int seg; + }; + + /* used for var MTRRs. */ + struct { + struct kvm_mtrr_range *range; + /* max address has been covered in var MTRRs. */ + u64 start_max; + }; + }; + + bool fixed; +}; + +static bool mtrr_lookup_fixed_start(struct mtrr_iter *iter) +{ + int seg, index; + + if (!fixed_mtrr_is_enabled(iter->mtrr_state)) + return false; + + seg = fixed_mtrr_addr_to_seg(iter->start); + if (seg < 0) + return false; + + iter->fixed = true; + index = fixed_mtrr_addr_seg_to_range_index(iter->start, seg); + iter->index = index; + iter->seg = seg; + return true; +} + +static bool match_var_range(struct mtrr_iter *iter, + struct kvm_mtrr_range *range) +{ + u64 start, end; + + var_mtrr_range(range, &start, &end); + if (!(start >= iter->end || end <= iter->start)) { + iter->range = range; + + /* + * the function is called when we do kvm_mtrr.head walking. + * Range has the minimum base address which interleaves + * [looker->start_max, looker->end). + */ + iter->partial_map |= iter->start_max < start; + + /* update the max address has been covered. */ + iter->start_max = max(iter->start_max, end); + return true; + } + + return false; +} + +static void __mtrr_lookup_var_next(struct mtrr_iter *iter) +{ + struct kvm_mtrr *mtrr_state = iter->mtrr_state; + + list_for_each_entry_continue(iter->range, &mtrr_state->head, node) + if (match_var_range(iter, iter->range)) + return; + + iter->range = NULL; + iter->partial_map |= iter->start_max < iter->end; +} + +static void mtrr_lookup_var_start(struct mtrr_iter *iter) +{ + struct kvm_mtrr *mtrr_state = iter->mtrr_state; + + iter->fixed = false; + iter->start_max = iter->start; + iter->range = list_prepare_entry(iter->range, &mtrr_state->head, node); + + __mtrr_lookup_var_next(iter); +} + +static void mtrr_lookup_fixed_next(struct mtrr_iter *iter) +{ + /* terminate the lookup. */ + if (fixed_mtrr_range_end_addr(iter->seg, iter->index) >= iter->end) { + iter->fixed = false; + iter->range = NULL; + return; + } + + iter->index++; + + /* have looked up for all fixed MTRRs. */ + if (iter->index >= ARRAY_SIZE(iter->mtrr_state->fixed_ranges)) + return mtrr_lookup_var_start(iter); + + /* switch to next segment. */ + if (iter->index > fixed_mtrr_seg_end_range_index(iter->seg)) + iter->seg++; +} + +static void mtrr_lookup_var_next(struct mtrr_iter *iter) +{ + __mtrr_lookup_var_next(iter); +} + +static void mtrr_lookup_start(struct mtrr_iter *iter) +{ + if (!mtrr_is_enabled(iter->mtrr_state)) { + iter->mtrr_disabled = true; + return; + } + + if (!mtrr_lookup_fixed_start(iter)) + mtrr_lookup_var_start(iter); +} + +static void mtrr_lookup_init(struct mtrr_iter *iter, + struct kvm_mtrr *mtrr_state, u64 start, u64 end) +{ + iter->mtrr_state = mtrr_state; + iter->start = start; + iter->end = end; + iter->mtrr_disabled = false; + iter->partial_map = false; + iter->fixed = false; + iter->range = NULL; + + mtrr_lookup_start(iter); +} + +static bool mtrr_lookup_okay(struct mtrr_iter *iter) +{ + if (iter->fixed) { + iter->mem_type = iter->mtrr_state->fixed_ranges[iter->index]; + return true; + } + + if (iter->range) { + iter->mem_type = iter->range->base & 0xff; + return true; + } + + return false; +} + +static void mtrr_lookup_next(struct mtrr_iter *iter) +{ + if (iter->fixed) + mtrr_lookup_fixed_next(iter); + else + mtrr_lookup_var_next(iter); +} + +#define mtrr_for_each_mem_type(_iter_, _mtrr_, _gpa_start_, _gpa_end_) \ + for (mtrr_lookup_init(_iter_, _mtrr_, _gpa_start_, _gpa_end_); \ + mtrr_lookup_okay(_iter_); mtrr_lookup_next(_iter_)) + +u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn) +{ + struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state; + struct mtrr_iter iter; + u64 start, end; + int type = -1; + const int wt_wb_mask = (1 << MTRR_TYPE_WRBACK) + | (1 << MTRR_TYPE_WRTHROUGH); + + start = gfn_to_gpa(gfn); + end = start + PAGE_SIZE; + + mtrr_for_each_mem_type(&iter, mtrr_state, start, end) { + int curr_type = iter.mem_type; + + /* + * Please refer to Intel SDM Volume 3: 11.11.4.1 MTRR + * Precedences. + */ + + if (type == -1) { + type = curr_type; + continue; + } + + /* + * If two or more variable memory ranges match and the + * memory types are identical, then that memory type is + * used. + */ + if (type == curr_type) + continue; + + /* + * If two or more variable memory ranges match and one of + * the memory types is UC, the UC memory type used. + */ + if (curr_type == MTRR_TYPE_UNCACHABLE) + return MTRR_TYPE_UNCACHABLE; + + /* + * If two or more variable memory ranges match and the + * memory types are WT and WB, the WT memory type is used. + */ + if (((1 << type) & wt_wb_mask) && + ((1 << curr_type) & wt_wb_mask)) { + type = MTRR_TYPE_WRTHROUGH; + continue; + } + + /* + * For overlaps not defined by the above rules, processor + * behavior is undefined. + */ + + /* We use WB for this undefined behavior. :( */ + return MTRR_TYPE_WRBACK; + } + + if (iter.mtrr_disabled) + return mtrr_disabled_type(); + + /* not contained in any MTRRs. */ + if (type == -1) + return mtrr_default_type(mtrr_state); + + /* + * We just check one page, partially covered by MTRRs is + * impossible. + */ + WARN_ON(iter.partial_map); + + return type; +} +EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type); + +bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, + int page_num) +{ + struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state; + struct mtrr_iter iter; + u64 start, end; + int type = -1; + + start = gfn_to_gpa(gfn); + end = gfn_to_gpa(gfn + page_num); + mtrr_for_each_mem_type(&iter, mtrr_state, start, end) { + if (type == -1) { + type = iter.mem_type; + continue; + } + + if (type != iter.mem_type) + return false; + } + + if (iter.mtrr_disabled) + return true; + + if (!iter.partial_map) + return true; + + if (type == -1) + return true; + + return type == mtrr_default_type(mtrr_state); +} -- cgit v1.2.3-54-g00ecf