Add types and macros for packed ring.

Signed-off-by: Tiwei Bie <redacted>
---
  include/uapi/linux/virtio_config.h |  3 +++
  include/uapi/linux/virtio_ring.h   | 52 ++++++++++++++++++++++++++++++++++++++
  2 files changed, 55 insertions(+)

diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index 449132c76b1c..1196e1c1d4f6 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h

@@ -75,6 +75,9 @@
   */
  #define VIRTIO_F_IOMMU_PLATFORM		33
  
+/* This feature indicates support for the packed virtqueue layout. */
+#define VIRTIO_F_RING_PACKED		34
+
  /*
   * Does the device support Single Root I/O Virtualization?
   */

diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 6d5d5faa989b..2414f8af26b3 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h

@@ -44,6 +44,13 @@
  /* This means the buffer contains a list of buffer descriptors. */
  #define VRING_DESC_F_INDIRECT	4
  
+/*
+ * Mark a descriptor as available or used in packed ring.
+ * Notice: they are defined as shifts instead of shifted values.

+ */
+#define VRING_PACKED_DESC_F_AVAIL	7
+#define VRING_PACKED_DESC_F_USED	15
+
  /* 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. */

@@ -53,6 +60,23 @@
   * optimization.  */
  #define VRING_AVAIL_F_NO_INTERRUPT	1
  
+/* Enable events in packed ring. */
+#define VRING_PACKED_EVENT_FLAG_ENABLE	0x0
+/* Disable events in packed ring. */
+#define VRING_PACKED_EVENT_FLAG_DISABLE	0x1
+/*
+ * Enable events for a specific descriptor in packed ring.
+ * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
+ * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated.
+ */
+#define VRING_PACKED_EVENT_FLAG_DESC	0x2

+
+/*
+ * Wrap counter bit shift in event suppression structure
+ * of packed ring.
+ */
+#define VRING_PACKED_EVENT_F_WRAP_CTR	15
+
  /* We support indirect buffer descriptors */
  #define VIRTIO_RING_F_INDIRECT_DESC	28
  

@@ -171,4 +195,32 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old)
  	return (__u16)(new_idx - event_idx - 1) < (__u16)(new_idx - old);
  }
  
+struct vring_packed_desc_event {
+	/* Descriptor Ring Change Event Offset/Wrap Counter. */
+	__le16 off_wrap;
+	/* Descriptor Ring Change Event Flags. */
+	__le16 flags;
+};
+
+struct vring_packed_desc {
+	/* Buffer Address. */
+	__le64 addr;
+	/* Buffer Length. */
+	__le32 len;
+	/* Buffer ID. */
+	__le16 id;
+	/* The flags depending on descriptor type. */
+	__le16 flags;
+};
+
+struct vring_packed {
+	unsigned int num;
+
+	struct vring_packed_desc *desc;
+
+	struct vring_packed_desc_event *driver;
+
+	struct vring_packed_desc_event *device;
+};
+
  #endif /* _UAPI_LINUX_VIRTIO_RING_H */