| /* |
| * vMTRR implementation |
| * |
| * Copyright (C) 2006 Qumranet, Inc. |
| * Copyright 2010 Red Hat, Inc. and/or its affiliates. |
| * Copyright(C) 2015 Intel Corporation. |
| * |
| * Authors: |
| * Yaniv Kamay <yaniv@qumranet.com> |
| * Avi Kivity <avi@qumranet.com> |
| * Marcelo Tosatti <mtosatti@redhat.com> |
| * Paolo Bonzini <pbonzini@redhat.com> |
| * Xiao Guangrong <guangrong.xiao@linux.intel.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| */ |
| |
| #include <linux/kvm_host.h> |
| #include <linux/nospec.h> |
| #include <asm/mtrr.h> |
| |
| #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; |
| } |
| 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(struct kvm_vcpu *vcpu) |
| { |
| /* |
| * 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. |
| * |
| * However, virtual machines can be run with CPUID such that |
| * there are no MTRRs. In that case, the firmware will never |
| * enable MTRRs and it is obviously undesirable to run the |
| * guest entirely with UC memory and we use WB. |
| */ |
| if (guest_cpuid_has_mtrr(vcpu)) |
| return MTRR_TYPE_UNCACHABLE; |
| else |
| return MTRR_TYPE_WRBACK; |
| } |
| |
| /* |
| * 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 = array_index_nospec( |
| msr - MSR_MTRRfix16K_80000, |
| MSR_MTRRfix16K_A0000 - MSR_MTRRfix16K_80000 + 1); |
| break; |
| case MSR_MTRRfix4K_C0000 ... MSR_MTRRfix4K_F8000: |
| *seg = 2; |
| *unit = array_index_nospec( |
| msr - MSR_MTRRfix4K_C0000, |
| MSR_MTRRfix4K_F8000 - MSR_MTRRfix4K_C0000 + 1); |
| 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; |
| |
| /* 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); |
| |
| /* Extend the mask with all 1 bits to the left, since those |
| * bits must implicitly be 0. The bits are then cleared |
| * when reading them. |
| */ |
| if (!is_mtrr_mask) |
| cur->base = data; |
| else |
| cur->mask = data | (-1LL << cpuid_maxphyaddr(vcpu)); |
| |
| /* 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; |
| |
| *pdata &= (1ULL << cpuid_maxphyaddr(vcpu)) - 1; |
| } |
| |
| 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 = NULL; |
| 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(vcpu); |
| |
| /* 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); |
| } |