1 files changed, 30 insertions, 25 deletions

diff --git a/virt/kvm/iodev.h b/virt/kvm/iodev.h
index 55e8846ac3a6..12fd3caffd2b 100644
--- a/virt/kvm/iodev.h
+++ b/virt/kvm/iodev.h
@@ -17,49 +17,54 @@
 #define __KVM_IODEV_H__
 
 #include <linux/kvm_types.h>
+#include <asm/errno.h>
 
-struct kvm_io_device {
-	void (*read)(struct kvm_io_device *this,
+struct kvm_io_device;
+
+/**
+ * kvm_io_device_ops are called under kvm slots_lock.
+ * read and write handlers return 0 if the transaction has been handled,
+ * or non-zero to have it passed to the next device.
+ **/
+struct kvm_io_device_ops {
+	int (*read)(struct kvm_io_device *this,
+		    gpa_t addr,
+		    int len,
+		    void *val);
+	int (*write)(struct kvm_io_device *this,
 		     gpa_t addr,
 		     int len,
-		     void *val);
-	void (*write)(struct kvm_io_device *this,
-		      gpa_t addr,
-		      int len,
-		      const void *val);
-	int (*in_range)(struct kvm_io_device *this, gpa_t addr, int len,
-			int is_write);
+		     const void *val);
 	void (*destructor)(struct kvm_io_device *this);
+};
 
-	void             *private;
+
+struct kvm_io_device {
+	const struct kvm_io_device_ops *ops;
 };
 
-static inline void kvm_iodevice_read(struct kvm_io_device *dev,
-				     gpa_t addr,
-				     int len,
-				     void *val)
+static inline void kvm_iodevice_init(struct kvm_io_device *dev,
+				     const struct kvm_io_device_ops *ops)
 {
-	dev->read(dev, addr, len, val);
+	dev->ops = ops;
 }
 
-static inline void kvm_iodevice_write(struct kvm_io_device *dev,
-				      gpa_t addr,
-				      int len,
-				      const void *val)
+static inline int kvm_iodevice_read(struct kvm_io_device *dev,
+				    gpa_t addr, int l, void *v)
 {
-	dev->write(dev, addr, len, val);
+	return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
 }
 
-static inline int kvm_iodevice_inrange(struct kvm_io_device *dev,
-				       gpa_t addr, int len, int is_write)
+static inline int kvm_iodevice_write(struct kvm_io_device *dev,
+				     gpa_t addr, int l, const void *v)
 {
-	return dev->in_range(dev, addr, len, is_write);
+	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
 }
 
 static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
 {
-	if (dev->destructor)
-		dev->destructor(dev);
+	if (dev->ops->destructor)
+		dev->ops->destructor(dev);
 }
 
 #endif /* __KVM_IODEV_H__ */