[RFC,2/5] KVM: use a rapper function to calculate the sizes of dirty bitmaps

Commit Message

Takuya Yoshikawa April 9, 2010, 9:32 a.m. UTC

None

Patch

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index a7ab2ea..3ca857b 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -1136,7 +1136,7 @@  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 		kvm_for_each_vcpu(n, vcpu, kvm)
 			kvmppc_mmu_pte_pflush(vcpu, ga, ga_end);
 
-		n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+		n = kvm_dirty_bitmap_bytes(memslot);
 		memset(memslot->dirty_bitmap, 0, n);
 	}
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fd5c3d3..450ecfe 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2664,7 +2664,7 @@  int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	if (!memslot->dirty_bitmap)
 		goto out;
 
-	n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+	n = kvm_dirty_bitmap_bytes(memslot);
 
 	r = -ENOMEM;
 	dirty_bitmap = vmalloc(n);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8e91fa7..dd6bcf4 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -119,6 +119,11 @@  struct kvm_memory_slot {
 	int user_alloc;
 };
 
+static inline int kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
+{
+	return ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+}
+
 struct kvm_kernel_irq_routing_entry {
 	u32 gsi;
 	u32 type;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9379533..5ab581e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -645,7 +645,7 @@  skip_lpage:
 
 	/* Allocate page dirty bitmap if needed */
 	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
-		unsigned dirty_bytes = ALIGN(npages, BITS_PER_LONG) / 8;
+		int dirty_bytes = kvm_dirty_bitmap_bytes(&new);
 
 		new.dirty_bitmap = vmalloc(dirty_bytes);
 		if (!new.dirty_bitmap)
@@ -777,7 +777,7 @@  int kvm_get_dirty_log(struct kvm *kvm,
 	if (!memslot->dirty_bitmap)
 		goto out;
 
-	n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+	n = kvm_dirty_bitmap_bytes(memslot);
 
 	for (i = 0; !any && i < n/sizeof(long); ++i)
 		any = memslot->dirty_bitmap[i];