[RFC v4 1/5] virtio: add packed ring definitions

[Tiwei Bie]

Signed-off-by: Tiwei Bie 
---
 include/uapi/linux/virtio_config.h | 12 +-
 include/uapi/linux/virtio_ring.h   | 36 ++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/virtio_config.h 
b/include/uapi/linux/virtio_config.h
index 308e2096291f..a6e392325e3a 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -49,7 +49,7 @@
  * transport being used (eg. virtio_ring), the rest are per-device feature
  * bits. */
 #define VIRTIO_TRANSPORT_F_START   28
-#define VIRTIO_TRANSPORT_F_END 34
+#define VIRTIO_TRANSPORT_F_END 36
 
 #ifndef VIRTIO_CONFIG_NO_LEGACY
 /* Do we get callbacks when the ring is completely used, even if we've
@@ -71,4 +71,14 @@
  * this is for compatibility with legacy systems.
  */
 #define VIRTIO_F_IOMMU_PLATFORM33
+
+/* This feature indicates support for the packed virtqueue layout. */
+#define VIRTIO_F_RING_PACKED   34
+
+/*
+ * This feature indicates that all buffers are used by the device
+ * in the same order in which they have been made available.
+ */
+#define VIRTIO_F_IN_ORDER  35
+
 #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 6d5d5faa989b..3932cb80c347 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -44,6 +44,9 @@
 /* This means the buffer contains a list of buffer descriptors. */
 #define VRING_DESC_F_INDIRECT  4
 
+#define VRING_DESC_F_AVAIL(b)  ((b) << 7)
+#define VRING_DESC_F_USED(b)   ((b) << 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 +56,10 @@
  * optimization.  */
 #define VRING_AVAIL_F_NO_INTERRUPT 1
 
+#define VRING_EVENT_F_ENABLE   0x0
+#define VRING_EVENT_F_DISABLE  0x1
+#define VRING_EVENT_F_DESC 0x2
+
 /* We support indirect buffer descriptors */
 #define VIRTIO_RING_F_INDIRECT_DESC28
 
@@ -171,4 +178,33 @@ 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 {
+   /* __virtio16 off  : 15; // Descriptor Event Offset
+* __virtio16 wrap : 1;  // Descriptor Event Wrap Counter */
+   __virtio16 off_wrap;
+   /* __virtio16 flags : 2; // Descriptor 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 /* _UAPI_LINUX_VIRTIO_RING_H */
-- 
2.17.0

[RFC v4 1/5] virtio: add packed ring definitions

[Tiwei Bie]

Signed-off-by: Tiwei Bie 
---
 include/uapi/linux/virtio_config.h | 12 +-
 include/uapi/linux/virtio_ring.h   | 36 ++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/virtio_config.h 
b/include/uapi/linux/virtio_config.h
index 308e2096291f..a6e392325e3a 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -49,7 +49,7 @@
  * transport being used (eg. virtio_ring), the rest are per-device feature
  * bits. */
 #define VIRTIO_TRANSPORT_F_START   28
-#define VIRTIO_TRANSPORT_F_END 34
+#define VIRTIO_TRANSPORT_F_END 36
 
 #ifndef VIRTIO_CONFIG_NO_LEGACY
 /* Do we get callbacks when the ring is completely used, even if we've
@@ -71,4 +71,14 @@
  * this is for compatibility with legacy systems.
  */
 #define VIRTIO_F_IOMMU_PLATFORM33
+
+/* This feature indicates support for the packed virtqueue layout. */
+#define VIRTIO_F_RING_PACKED   34
+
+/*
+ * This feature indicates that all buffers are used by the device
+ * in the same order in which they have been made available.
+ */
+#define VIRTIO_F_IN_ORDER  35
+
 #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */
diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h
index 6d5d5faa989b..3932cb80c347 100644
--- a/include/uapi/linux/virtio_ring.h
+++ b/include/uapi/linux/virtio_ring.h
@@ -44,6 +44,9 @@
 /* This means the buffer contains a list of buffer descriptors. */
 #define VRING_DESC_F_INDIRECT  4
 
+#define VRING_DESC_F_AVAIL(b)  ((b) << 7)
+#define VRING_DESC_F_USED(b)   ((b) << 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 +56,10 @@
  * optimization.  */
 #define VRING_AVAIL_F_NO_INTERRUPT 1
 
+#define VRING_EVENT_F_ENABLE   0x0
+#define VRING_EVENT_F_DISABLE  0x1
+#define VRING_EVENT_F_DESC 0x2
+
 /* We support indirect buffer descriptors */
 #define VIRTIO_RING_F_INDIRECT_DESC28
 
@@ -171,4 +178,33 @@ 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 {
+   /* __virtio16 off  : 15; // Descriptor Event Offset
+* __virtio16 wrap : 1;  // Descriptor Event Wrap Counter */
+   __virtio16 off_wrap;
+   /* __virtio16 flags : 2; // Descriptor 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 /* _UAPI_LINUX_VIRTIO_RING_H */
-- 
2.17.0