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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2011-11-24 17:41:54 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-12-27 11:17:42 +0200 |
| commit | f85e2cb5dbaf905e9470d3fe099b31619da431fc (patch) | |
| tree | eb4d486094e0f2c7503a9e28a8ac76ce84d2a09e | |
| parent | bf3e05bc1e2781d5d8d3ddb2d8bf2d6ec207e5cb (diff) | |
| download | linux-f85e2cb5dbaf905e9470d3fe099b31619da431fc.tar.gz linux-f85e2cb5dbaf905e9470d3fe099b31619da431fc.tar.bz2 linux-f85e2cb5dbaf905e9470d3fe099b31619da431fc.zip | |
KVM: introduce a table to map slot id to index in memslots array
The operation of getting dirty log is frequent when framebuffer-based
displays are used(for example, Xwindow), so, we introduce a mapping table
to speed up id_to_memslot()
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
| -rw-r--r-- | include/linux/kvm_host.h | 13 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 7 |
2 files changed, 13 insertions, 7 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9efdf5c703a5..8c5c30361b0d 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -239,6 +239,8 @@ struct kvm_irq_routing_table {}; struct kvm_memslots { u64 generation; struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM]; + /* The mapping table from slot id to the index in memslots[]. */ + int id_to_index[KVM_MEM_SLOTS_NUM]; }; struct kvm { @@ -341,14 +343,13 @@ 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) { - int i; + int index = slots->id_to_index[id]; + struct kvm_memory_slot *slot; - for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) - if (slots->memslots[i].id == id) - return &slots->memslots[i]; + slot = &slots->memslots[index]; - WARN_ON(1); - return NULL; + WARN_ON(slot->id != id); + return slot; } #define HPA_MSB ((sizeof(hpa_t) * 8) - 1) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6e8eb15dd30b..e289486edc6d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -446,7 +446,7 @@ static void kvm_init_memslots_id(struct kvm *kvm) struct kvm_memslots *slots = kvm->memslots; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) - slots->memslots[i].id = i; + slots->id_to_index[i] = slots->memslots[i].id = i; } static struct kvm *kvm_create_vm(void) @@ -674,8 +674,13 @@ static int cmp_memslot(const void *slot1, const void *slot2) */ static void sort_memslots(struct kvm_memslots *slots) { + int i; + sort(slots->memslots, KVM_MEM_SLOTS_NUM, sizeof(struct kvm_memory_slot), cmp_memslot, NULL); + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + slots->id_to_index[slots->memslots[i].id] = i; } void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) |