virtio: add packed ring types and macros

Add types and macros for packed ring.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/virtio_config.h b/include/uapi/linux/virtio_config.h
index 449132c76b1cc809fc0c9d4cd90e3f56ed44442b..1196e1c1d4f6c494ee95b8d679e90a7def6d66b4 100644 (file)
--- 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 6d5d5faa989b9247cba12e1e27ac26683dc2efca..2414f8af26b3ee882be9acc96fa273b33befa317 100644 (file)
--- 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 */