KVM: cleanup io_device code

We modernize the io_device code so that we use container_of() instead of
dev->private, and move the vtable to a separate ops structure
(theoretically allows better caching for multiple instances of the same
ops structure)

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 15 insertions, 7 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 1150c6d5c7b..469b9faae66 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -220,10 +220,15 @@ void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 			__kvm_ioapic_update_eoi(ioapic, i, trigger_mode);
 }
 
+static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
+{
+	return container_of(dev, struct kvm_ioapic, dev);
+}
+
 static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr,
 			   int len, int is_write)
 {
-	struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+	struct kvm_ioapic *ioapic = to_ioapic(this);
 
 	return ((addr >= ioapic->base_address &&
 		 (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
@@ -232,7 +237,7 @@ static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr,
 static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 			     void *val)
 {
-	struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+	struct kvm_ioapic *ioapic = to_ioapic(this);
 	u32 result;
 
 	ioapic_debug("addr %lx\n", (unsigned long)addr);
@@ -269,7 +274,7 @@ static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 			      const void *val)
 {
-	struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
+	struct kvm_ioapic *ioapic = to_ioapic(this);
 	u32 data;
 
 	ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
@@ -314,6 +319,12 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 	ioapic->id = 0;
 }
 
+static const struct kvm_io_device_ops ioapic_mmio_ops = {
+	.read     = ioapic_mmio_read,
+	.write    = ioapic_mmio_write,
+	.in_range = ioapic_in_range,
+};
+
 int kvm_ioapic_init(struct kvm *kvm)
 {
 	struct kvm_ioapic *ioapic;
@@ -323,10 +334,7 @@ int kvm_ioapic_init(struct kvm *kvm)
 		return -ENOMEM;
 	kvm->arch.vioapic = ioapic;
 	kvm_ioapic_reset(ioapic);
-	ioapic->dev.read = ioapic_mmio_read;
-	ioapic->dev.write = ioapic_mmio_write;
-	ioapic->dev.in_range = ioapic_in_range;
-	ioapic->dev.private = ioapic;
+	kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 	ioapic->kvm = kvm;
 	kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
 	return 0;