KVM: MMU: introduce slot_handle_level_range() and its helpers

There are several places walking all rmaps for the memslot so that
introduce common functions to cleanup the code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 316c432..d1d072d 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4454,6 +4454,75 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
        init_kvm_mmu(vcpu);
 }
 
+/* The return value indicates if tlb flush on all vcpus is needed. */
+typedef bool (*slot_level_handler) (struct kvm *kvm, unsigned long *rmap);
+
+/* The caller should hold mmu-lock before calling this function. */
+static bool
+slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                       slot_level_handler fn, int start_level, int end_level,
+                       gfn_t start_gfn, gfn_t end_gfn, bool lock_flush_tlb)
+{
+       struct slot_rmap_walk_iterator iterator;
+       bool flush = false;
+
+       for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn,
+                       end_gfn, &iterator) {
+               if (iterator.rmap)
+                       flush |= fn(kvm, iterator.rmap);
+
+               if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
+                       if (flush && lock_flush_tlb) {
+                               kvm_flush_remote_tlbs(kvm);
+                               flush = false;
+                       }
+                       cond_resched_lock(&kvm->mmu_lock);
+               }
+       }
+
+       if (flush && lock_flush_tlb) {
+               kvm_flush_remote_tlbs(kvm);
+               flush = false;
+       }
+
+       return flush;
+}
+
+static bool
+slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                 slot_level_handler fn, int start_level, int end_level,
+                 bool lock_flush_tlb)
+{
+       return slot_handle_level_range(kvm, memslot, fn, start_level,
+                       end_level, memslot->base_gfn,
+                       memslot->base_gfn + memslot->npages - 1,
+                       lock_flush_tlb);
+}
+
+static bool
+slot_handle_all_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                     slot_level_handler fn, bool lock_flush_tlb)
+{
+       return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL,
+                                PT_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);
+}
+
+static bool
+slot_handle_large_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                       slot_level_handler fn, bool lock_flush_tlb)
+{
+       return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL + 1,
+                                PT_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);
+}
+
+static bool
+slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
+                slot_level_handler fn, bool lock_flush_tlb)
+{
+       return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL,
+                                PT_PAGE_TABLE_LEVEL, lock_flush_tlb);
+}
+
 void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
                                      struct kvm_memory_slot *memslot)
 {