Sort memslots base on its size and use line search to find it, so the larger memslots have better fit
The idea is from Avi Signed-off-by: Xiao Guangrong <[email protected]> --- include/linux/kvm_host.h | 22 +++++++++--- virt/kvm/kvm_main.c | 82 ++++++++++++++++++++++++++++++++------------- 2 files changed, 75 insertions(+), 29 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a0e4d63..83b396a 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -230,8 +230,12 @@ struct kvm_irq_routing_table {}; #define KVM_MEM_SLOTS_NUM (KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS) #endif +/* + * Note: + * memslots are not sorted by id anymore, please use id_to_memslot() + * to get the memslot by its id. + */ struct kvm_memslots { - int nmemslots; u64 generation; struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM]; }; @@ -307,9 +311,10 @@ static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i) (vcpup = kvm_get_vcpu(kvm, idx)) != NULL; \ idx++) -#define kvm_for_each_memslot(slots, memslot, i) \ - for (i = 0; i < (slots)->nmemslots && \ - ({ memslot = &(slots)->memslots[i]; 1; }); i++) +#define kvm_for_each_memslot(slots, memslot, i) \ + for (i = 0; i < KVM_MEM_SLOTS_NUM && \ + ({ memslot = &(slots)->memslots[i]; 1; }) && \ + memslot->npages != 0; i++) int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id); void kvm_vcpu_uninit(struct kvm_vcpu *vcpu); @@ -335,7 +340,14 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) static inline struct kvm_memory_slot * id_to_memslot(struct kvm_memslots *slots, int id) { - return &slots->memslots[id]; + int i; + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + if (slots->memslots[i].id == id) + return &slots->memslots[i]; + + WARN_ON(1); + return NULL; } #define HPA_MSB ((sizeof(hpa_t) * 8) - 1) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 09bb794..9425e3a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -440,6 +440,15 @@ static int kvm_init_mmu_notifier(struct kvm *kvm) #endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */ +static void kvm_init_memslots_id(struct kvm *kvm) +{ + int i; + struct kvm_memslots *slots = kvm->memslots; + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + slots->memslots[i].id = i; +} + static struct kvm *kvm_create_vm(void) { int r, i; @@ -465,6 +474,7 @@ static struct kvm *kvm_create_vm(void) kvm->memslots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!kvm->memslots) goto out_err_nosrcu; + kvm_init_memslots_id(kvm); if (init_srcu_struct(&kvm->srcu)) goto out_err_nosrcu; for (i = 0; i < KVM_NR_BUSES; i++) { @@ -630,15 +640,55 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot) } #endif /* !CONFIG_S390 */ +static struct kvm_memory_slot * +search_memslots(struct kvm_memslots *slots, gfn_t gfn) +{ + int i; + struct kvm_memory_slot *memslot; + + kvm_for_each_memslot(slots, memslot, i) + if (gfn >= memslot->base_gfn && + gfn < memslot->base_gfn + memslot->npages) + return memslot; + + return NULL; +} + +static int cmp_memslot(const void *slot1, const void *slot2) +{ + struct kvm_memory_slot *s1, *s2; + + s1 = (struct kvm_memory_slot *)slot1; + s2 = (struct kvm_memory_slot *)slot2; + + if (s1->npages < s2->npages) + return 1; + if (s1->npages > s2->npages) + return -1; + + return 0; +} + +/* + * Sort the memslots base on its size, so the larger slots + * will get better fit. + */ +static void sort_memslots(struct kvm_memslots *slots) +{ + sort(slots->memslots, KVM_MEM_SLOTS_NUM, + sizeof(struct kvm_memory_slot), cmp_memslot, NULL); +} + void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) { if (new) { int id = new->id; struct kvm_memory_slot *old = id_to_memslot(slots, id); + unsigned long npages = old->npages; *old = *new; - if (id >= slots->nmemslots) - slots->nmemslots = id + 1; + if (new->npages != npages) + sort_memslots(slots); } slots->generation++; @@ -979,16 +1029,7 @@ EXPORT_SYMBOL_GPL(kvm_is_error_hva); static struct kvm_memory_slot *__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn) { - int i; - - for (i = 0; i < slots->nmemslots; ++i) { - struct kvm_memory_slot *memslot = &slots->memslots[i]; - - if (gfn >= memslot->base_gfn - && gfn < memslot->base_gfn + memslot->npages) - return memslot; - } - return NULL; + return search_memslots(slots, gfn); } struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) @@ -999,20 +1040,13 @@ EXPORT_SYMBOL_GPL(gfn_to_memslot); int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { - int i; - struct kvm_memslots *slots = kvm_memslots(kvm); + struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); - for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *memslot = &slots->memslots[i]; - - if (memslot->flags & KVM_MEMSLOT_INVALID) - continue; + if (!memslot || memslot->id >= KVM_MEMORY_SLOTS || + memslot->flags & KVM_MEMSLOT_INVALID) + return 0; - if (gfn >= memslot->base_gfn - && gfn < memslot->base_gfn + memslot->npages) - return 1; - } - return 0; + return 1; } EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); -- 1.7.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
