3 files changed, 24 insertions, 17 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 729573b844e5..93ecafbfb1b6 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -333,26 +333,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
         if (mem->slot >= kvm->nmemslots)
                 kvm->nmemslots = mem->slot + 1;
 
+        *memslot = new;
+
         if (!kvm->n_requested_mmu_pages) {
-                unsigned int n_pages;
-
-                if (npages) {
-                        n_pages = npages * KVM_PERMILLE_MMU_PAGES / 1000;
-                        kvm_mmu_change_mmu_pages(kvm, kvm->n_alloc_mmu_pages +
-                                                 n_pages);
-                } else {
-                        unsigned int nr_mmu_pages;
-
-                        n_pages = old.npages * KVM_PERMILLE_MMU_PAGES / 1000;
-                        nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
-                        nr_mmu_pages = max(nr_mmu_pages,
-                                        (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
-                        kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
-                }
+                unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+                kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
         }
 
-        *memslot = new;
-
         kvm_mmu_slot_remove_write_access(kvm, mem->slot);
         kvm_flush_remote_tlbs(kvm);
 
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 4624f3789b9a..101cd5377a89 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -1535,6 +1535,25 @@ nomem:
         return -ENOMEM;
 }
 
+/*
+ * Caculate mmu pages needed for kvm.
+ */
+unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
+{
+        int i;
+        unsigned int nr_mmu_pages;
+        unsigned int  nr_pages = 0;
+
+        for (i = 0; i < kvm->nmemslots; i++)
+                nr_pages += kvm->memslots[i].npages;
+
+        nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
+        nr_mmu_pages = max(nr_mmu_pages,
+                        (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
+
+        return nr_mmu_pages;
+}
+
 #ifdef AUDIT
 
 static const char *audit_msg;
diff --git a/drivers/kvm/x86.h b/drivers/kvm/x86.h
index 90b791bf6287..71f2477d03fd 100644
--- a/drivers/kvm/x86.h
+++ b/drivers/kvm/x86.h
@@ -236,6 +236,7 @@ void kvm_mmu_set_nonpresent_ptes(u64 trap_pte, u64 notrap_pte);
 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
 void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
 void kvm_mmu_zap_all(struct kvm *kvm);
+unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm);
 void kvm_mmu_change_mmu_pages(struct kvm *kvm, unsigned int kvm_nr_mmu_pages);
 
 enum emulation_result {