Add Linux virtio interface definitions

The Linux virtio/vhost headers are too polluted to be included from C++
code, so create a local copy.

virtio-interface.hh

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2014 Cloudius Systems, Ltd.
+ *
+ */
+
+#ifndef VIRTIO_INTERFACE_HH_
+#define VIRTIO_INTERFACE_HH_
+
+#ifndef _LINUX_VIRTIO_RING_H
+#define _LINUX_VIRTIO_RING_H
+
+/* An interface for efficient virtio implementation, currently for use by KVM
+ * and lguest, but hopefully others soon.  Do NOT change this since it will
+ * break existing servers and clients.
+ *
+ * This header is BSD licensed so anyone can use the definitions to implement
+ * compatible drivers/servers.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of IBM nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Copyright Rusty Russell IBM Corporation 2007. */
+
+/* This marks a buffer as continuing via the next field. */
+#define VRING_DESC_F_NEXT       1
+/* This marks a buffer as write-only (otherwise read-only). */
+#define VRING_DESC_F_WRITE      2
+/* This means the buffer contains a list of buffer descriptors. */
+#define VRING_DESC_F_INDIRECT   4
+
+/* The Host uses this in used->flags to advise the Guest: don't kick me when
+ * you add a buffer.  It's unreliable, so it's simply an optimization.  Guest
+ * will still kick if it's out of buffers. */
+#define VRING_USED_F_NO_NOTIFY  1
+/* The Guest uses this in avail->flags to advise the Host: don't interrupt me
+ * when you consume a buffer.  It's unreliable, so it's simply an
+ * optimization.  */
+#define VRING_AVAIL_F_NO_INTERRUPT      1
+
+/* We support indirect buffer descriptors */
+#define VIRTIO_RING_F_INDIRECT_DESC     (1 << 28)
+
+/* The Guest publishes the used index for which it expects an interrupt
+ * at the end of the avail ring. Host should ignore the avail->flags field. */
+/* The Host publishes the avail index for which it expects a kick
+ * at the end of the used ring. Guest should ignore the used->flags field. */
+#define VIRTIO_RING_F_EVENT_IDX         (1 << 29)
+
+/* The standard layout for the ring is a continuous chunk of memory which looks
+ * like this.  We assume num is a power of 2.
+ *
+ * struct vring
+ * {
+ *      // The actual descriptors (16 bytes each)
+ *      struct vring_desc desc[num];
+ *
+ *      // A ring of available descriptor heads with free-running index.
+ *      uint16_t avail_flags;
+ *      uint16_t avail_idx;
+ *      uint16_t available[num];
+ *      uint16_t used_event_idx;
+ *
+ *      // Padding to the next align boundary.
+ *      char pad[];
+ *
+ *      // A ring of used descriptor heads with free-running index.
+ *      uint16_t used_flags;
+ *      uint16_t used_idx;
+ *      struct vring_used_elem used[num];
+ *      uint16_t avail_event_idx;
+ * };
+ */
+
+#endif
+
+#define VIRTIO_NET_F_CSUM (1 << 0)
+#define VIRTIO_NET_F_GUEST_CSUM (1 << 1)
+#define VIRTIO_NET_F_CTRL_GUEST_OFFLOADS (1 << 2)
+#define VIRTIO_NET_F_MAC (1 << 5)
+#define VIRTIO_NET_F_GUEST_TSO4 (1 << 7)
+#define VIRTIO_NET_F_GUEST_TSO6 (1 << 8)
+#define VIRTIO_NET_F_GUEST_ECN (1 << 9)
+#define VIRTIO_NET_F_GUEST_UFO (1 << 10)
+#define VIRTIO_NET_F_HOST_TSO4 (1 << 11)
+#define VIRTIO_NET_F_HOST_TSO6 (1 << 12)
+#define VIRTIO_NET_F_HOST_ECN (1 << 13)
+#define VIRTIO_NET_F_HOST_UFO (1 << 14)
+#define VIRTIO_NET_F_MRG_RXBUF (1 << 15)
+#define VIRTIO_NET_F_STATUS (1 << 16)
+#define VIRTIO_NET_F_CTRL_VQ (1 << 17)
+#define VIRTIO_NET_F_CTRL_RX (1 << 18)
+#define VIRTIO_NET_F_CTRL_VLAN (1 << 19)
+#define VIRTIO_NET_F_GUEST_ANNOUNCE (1 << 21)
+#define VIRTIO_NET_F_MQ (1 << 22)
+#define VIRTIO_NET_F_CTRL_MAC_ADDR (1 << 23)
+
+#endif /* VIRTIO_INTERFACE_HH_ */