[PATCH net-next 6/8] virtio: introduce packed ring defines

Jason Wang
Tue, 03 Jul 2018 05:38:02 -0000

include/uapi/linux/virtio_config.h |  2 ++
 include/uapi/linux/virtio_ring.h   | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/uapi/linux/virtio_config.h
b/include/uapi/linux/virtio_config.h
index 449132c..947f6a3 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -75,6 +75,8 @@
  */
 #define VIRTIO_F_IOMMU_PLATFORM		33

+#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 6d5d5fa..71c7a46 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -43,6 +43,8 @@
 #define VRING_DESC_F_WRITE	2
 /* This means the buffer contains a list of buffer descriptors. */
 #define VRING_DESC_F_INDIRECT	4
+#define VRING_DESC_F_AVAIL      7
+#define VRING_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
@@ -62,6 +64,36 @@
  * at the end of the used ring. Guest should ignore the used->flags field.
*/
 #define VIRTIO_RING_F_EVENT_IDX		29

+struct vring_desc_packed {
+	/* Buffer Address. */
+	__virtio64 addr;
+	/* Buffer Length. */
+	__virtio32 len;
+	/* Buffer ID. */
+	__virtio16 id;
+	/* The flags depending on descriptor type. */
+	__virtio16 flags;
+};
+
+/* Enable events */
+#define RING_EVENT_FLAGS_ENABLE 0x0
+/* Disable events */
+#define RING_EVENT_FLAGS_DISABLE 0x1
+/*
+ * Enable events for a specific descriptor
+ * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
+ * Only valid if VIRTIO_F_RING_EVENT_IDX has been negotiated.
+ */
+#define RING_EVENT_FLAGS_DESC 0x2
+/* The value 0x3 is reserved */
+
+struct vring_packed_desc_event {
+	/* Descriptor Ring Change Event Offset and Wrap Counter */
+	__virtio16 off_wrap;
+	/* Descriptor Ring Change Event Flags */
+	__virtio16 flags;
+};
+
 /* Virtio ring descriptors: 16 bytes.  These can chain together via
"next". */
 struct vring_desc {
 	/* Address (guest-physical). */
--
2.7.4