[Qemu-devel] [PATCH v1 02/16] virtio: introduce packed ring definitions

[wexu@redhat.com]

From: Wei Xu <wexu@redhat.com>

>From 1.1 spec.

Signed-off-by: Wei Xu <wexu@redhat.com>
---
 include/standard-headers/linux/virtio_config.h | 15 +++++++++
 include/standard-headers/linux/virtio_ring.h   | 43 ++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/include/standard-headers/linux/virtio_config.h b/include/standard-headers/linux/virtio_config.h
index 0b19436..9f450fd 100644
--- a/include/standard-headers/linux/virtio_config.h
+++ b/include/standard-headers/linux/virtio_config.h
@@ -75,6 +75,21 @@
  */
 #define VIRTIO_F_IOMMU_PLATFORM		33
 
+/* This feature indicates support for the packed virtqueue layout. */
+#define VIRTIO_F_RING_PACKED		34
+
+/* 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 */
+
 /*
  * Does the device support Single Root I/O Virtualization?
  */
diff --git a/include/standard-headers/linux/virtio_ring.h b/include/standard-headers/linux/virtio_ring.h
index d26e72b..1719c6f 100644
--- a/include/standard-headers/linux/virtio_ring.h
+++ b/include/standard-headers/linux/virtio_ring.h
@@ -42,6 +42,10 @@
 /* This means the buffer contains a list of buffer descriptors. */
 #define VRING_DESC_F_INDIRECT	4
 
+/* Mark a descriptor as available or used. */
+#define VRING_DESC_F_AVAIL	(1ul << 7)
+#define VRING_DESC_F_USED	(1ul << 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. */
@@ -51,6 +55,17 @@
  * optimization.  */
 #define VRING_AVAIL_F_NO_INTERRUPT	1
 
+/* Enable events. */
+#define VRING_EVENT_F_ENABLE	0x0
+/* Disable events. */
+#define VRING_EVENT_F_DISABLE	0x1
+/*
+ * Enable events for a specific descriptor
+ * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
+ * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated.
+ */
+#define VRING_EVENT_F_DESC	0x2
+
 /* We support indirect buffer descriptors */
 #define VIRTIO_RING_F_INDIRECT_DESC	28
 
@@ -169,4 +184,32 @@ static inline int vring_need_event(uint16_t event_idx, uint16_t new_idx, uint16_
 	return (uint16_t)(new_idx - event_idx - 1) < (uint16_t)(new_idx - old);
 }
 
+struct vring_packed_desc_event {
+	/* Descriptor Ring Change Event Offset/Wrap Counter. */
+	__virtio16 off_wrap;
+	/* Descriptor Ring Change Event Flags. */
+	__virtio16 flags;
+};
+
+struct vring_packed_desc {
+	/* Buffer Address. */
+	__virtio64 addr;
+	/* Buffer Length. */
+	__virtio32 len;
+	/* Buffer ID. */
+	__virtio16 id;
+	/* The flags depending on descriptor type. */
+	__virtio16 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 /* _LINUX_VIRTIO_RING_H */
-- 
1.8.3.1