1 files changed, 76 insertions, 0 deletions

diff --git a/include/kvm/iodev.h b/include/kvm/iodev.h
new file mode 100644
index 000000000000..a6d208b916f5
--- /dev/null
+++ b/include/kvm/iodev.h
@@ -0,0 +1,76 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __KVM_IODEV_H__
+#define __KVM_IODEV_H__
+
+#include <linux/kvm_types.h>
+#include <linux/errno.h>
+
+struct kvm_io_device;
+struct kvm_vcpu;
+
+/**
+ * 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_vcpu *vcpu,
+                    struct kvm_io_device *this,
+                    gpa_t addr,
+                    int len,
+                    void *val);
+        int (*write)(struct kvm_vcpu *vcpu,
+                     struct kvm_io_device *this,
+                     gpa_t addr,
+                     int len,
+                     const void *val);
+        void (*destructor)(struct kvm_io_device *this);
+};
+
+
+struct kvm_io_device {
+        const struct kvm_io_device_ops *ops;
+};
+
+static inline void kvm_iodevice_init(struct kvm_io_device *dev,
+                                     const struct kvm_io_device_ops *ops)
+{
+        dev->ops = ops;
+}
+
+static inline int kvm_iodevice_read(struct kvm_vcpu *vcpu,
+                                    struct kvm_io_device *dev, gpa_t addr,
+                                    int l, void *v)
+{
+        return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v)
+                                : -EOPNOTSUPP;
+}
+
+static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
+                                     struct kvm_io_device *dev, gpa_t addr,
+                                     int l, const void *v)
+{
+        return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v)
+                                 : -EOPNOTSUPP;
+}
+
+static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
+{
+        if (dev->ops->destructor)
+                dev->ops->destructor(dev);
+}
+
+#endif /* __KVM_IODEV_H__ */