KVM: introduce id_to_memslot function

Introduce id_to_memslot to get memslot by slot id

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 13 insertions, 11 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index ba24022f4575..8f19d91ec3e7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2711,11 +2711,13 @@ static gva_t rmode_tss_base(struct kvm *kvm)
 {
 	if (!kvm->arch.tss_addr) {
 		struct kvm_memslots *slots;
+		struct kvm_memory_slot *slot;
 		gfn_t base_gfn;
 
 		slots = kvm_memslots(kvm);
-		base_gfn = slots->memslots[0].base_gfn +
-				 kvm->memslots->memslots[0].npages - 3;
+		slot = id_to_memslot(slots, 0);
+		base_gfn = slot->base_gfn + slot->npages - 3;
+
 		return base_gfn << PAGE_SHIFT;
 	}
 	return kvm->arch.tss_addr;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 917a287d21c8..b6776c613e6d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3520,7 +3520,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	if (log->slot >= KVM_MEMORY_SLOTS)
 		goto out;
 
-	memslot = &kvm->memslots->memslots[log->slot];
+	memslot = id_to_memslot(kvm->memslots, log->slot);
 	r = -ENOENT;
 	if (!memslot->dirty_bitmap)
 		goto out;
@@ -3531,27 +3531,27 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	/* If nothing is dirty, don't bother messing with page tables. */
 	if (nr_dirty_pages) {
 		struct kvm_memslots *slots, *old_slots;
-		unsigned long *dirty_bitmap;
+		unsigned long *dirty_bitmap, *dirty_bitmap_head;
 
-		dirty_bitmap = memslot->dirty_bitmap_head;
-		if (memslot->dirty_bitmap == dirty_bitmap)
-			dirty_bitmap += n / sizeof(long);
-		memset(dirty_bitmap, 0, n);
+		dirty_bitmap = memslot->dirty_bitmap;
+		dirty_bitmap_head = memslot->dirty_bitmap_head;
+		if (dirty_bitmap == dirty_bitmap_head)
+			dirty_bitmap_head += n / sizeof(long);
+		memset(dirty_bitmap_head, 0, n);
 
 		r = -ENOMEM;
 		slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
 		if (!slots)
 			goto out;
 		memcpy(slots, kvm->memslots, sizeof(struct kvm_memslots));
-		memslot = &slots->memslots[log->slot];
-		memslot->dirty_bitmap = dirty_bitmap;
+		memslot = id_to_memslot(slots, log->slot);
 		memslot->nr_dirty_pages = 0;
+		memslot->dirty_bitmap = dirty_bitmap_head;
 		update_memslots(slots, NULL);
 
 		old_slots = kvm->memslots;
 		rcu_assign_pointer(kvm->memslots, slots);
 		synchronize_srcu_expedited(&kvm->srcu);
-		dirty_bitmap = old_slots->memslots[log->slot].dirty_bitmap;
 		kfree(old_slots);
 
 		write_protect_slot(kvm, memslot, dirty_bitmap, nr_dirty_pages);