From f571c0973e4b8c888e049b6842e4b4f93b5c609c Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 15 Jun 2015 16:55:33 +0800 Subject: [PATCH] KVM: MTRR: introduce mtrr_for_each_mem_type It walks all MTRRs and gets all the memory cache type setting for the specified range also it checks if the range is fully covered by MTRRs Signed-off-by: Xiao Guangrong [Adjust for range_size->range_shift change. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mtrr.c | 188 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 188 insertions(+) diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c index b5346d20f458..4c6ac464063e 100644 --- a/arch/x86/kvm/mtrr.c +++ b/arch/x86/kvm/mtrr.c @@ -220,6 +220,15 @@ static int fixed_mtrr_seg_unit_range_index(int seg, int unit) 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; @@ -266,6 +275,14 @@ static int fixed_mtrr_addr_seg_to_range_index(u64 addr, int seg) 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; @@ -409,6 +426,177 @@ 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; + /* [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->partial_map = 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->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;