[RFC PATCH V2 4/8] vhost_net: do not explicitly manipulate vhost_used_elem

[Jason Wang]

Two helpers of setting/getting used len were introduced to avoid
explicitly manipulating vhost_used_elem in zerocopy code. This will be
used to hide used_elem internals and simplify packed ring
implementation.

Signed-off-by: Jason Wang 
---
 drivers/vhost/net.c   | 11 +--
 drivers/vhost/vhost.c | 12 ++--
 drivers/vhost/vhost.h |  5 +
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7ea2aee..7be8b55 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -337,9 +337,10 @@ static void vhost_zerocopy_signal_used(struct vhost_net 
*net,
int j = 0;
 
for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
-   if (vq->heads[i].elem.len == VHOST_DMA_FAILED_LEN)
+   if (vhost_get_used_len(vq, >heads[i]) ==
+   VHOST_DMA_FAILED_LEN)
vhost_net_tx_err(net);
-   if (VHOST_DMA_IS_DONE(vq->heads[i].elem.len)) {
+   if (VHOST_DMA_IS_DONE(vhost_get_used_len(vq, >heads[i]))) {
vq->heads[i].elem.len = VHOST_DMA_CLEAR_LEN;
++j;
} else
@@ -537,10 +538,8 @@ static void handle_tx(struct vhost_net *net)
struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
 
-   vq->heads[nvq->upend_idx].elem.id =
-   cpu_to_vhost32(vq, used.elem.id);
-   vq->heads[nvq->upend_idx].elem.len =
-   VHOST_DMA_IN_PROGRESS;
+   vhost_set_used_len(vq, , VHOST_DMA_IN_PROGRESS);
+   vq->heads[nvq->upend_idx] = used;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = nvq->ubufs;
ubuf->desc = nvq->upend_idx;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 8744dae..65954d6 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2100,11 +2100,19 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 }
 EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
 
-static void vhost_set_used_len(struct vhost_virtqueue *vq,
-  struct vhost_used_elem *used, int len)
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+   struct vhost_used_elem *used, int len)
 {
used->elem.len = cpu_to_vhost32(vq, len);
 }
+EXPORT_SYMBOL_GPL(vhost_set_used_len);
+
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+  struct vhost_used_elem *used)
+{
+   return vhost32_to_cpu(vq, used->elem.len);
+}
+EXPORT_SYMBOL_GPL(vhost_get_used_len);
 
 /* This is a multi-buffer version of vhost_get_desc, that works if
  * vq has read descriptors only.
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8399887..d57c875 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -198,6 +198,11 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
   unsigned *log_num,
   unsigned int quota,
   s16 *count);
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+   struct vhost_used_elem *used,
+   int len);
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+  struct vhost_used_elem *used);
 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
 
 int vhost_vq_init_access(struct vhost_virtqueue *);
-- 
2.7.4

[RFC PATCH V2 4/8] vhost_net: do not explicitly manipulate vhost_used_elem

[Jason Wang]

Two helpers of setting/getting used len were introduced to avoid
explicitly manipulating vhost_used_elem in zerocopy code. This will be
used to hide used_elem internals and simplify packed ring
implementation.

Signed-off-by: Jason Wang 
---
 drivers/vhost/net.c   | 11 +--
 drivers/vhost/vhost.c | 12 ++--
 drivers/vhost/vhost.h |  5 +
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7ea2aee..7be8b55 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -337,9 +337,10 @@ static void vhost_zerocopy_signal_used(struct vhost_net 
*net,
int j = 0;
 
for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) {
-   if (vq->heads[i].elem.len == VHOST_DMA_FAILED_LEN)
+   if (vhost_get_used_len(vq, >heads[i]) ==
+   VHOST_DMA_FAILED_LEN)
vhost_net_tx_err(net);
-   if (VHOST_DMA_IS_DONE(vq->heads[i].elem.len)) {
+   if (VHOST_DMA_IS_DONE(vhost_get_used_len(vq, >heads[i]))) {
vq->heads[i].elem.len = VHOST_DMA_CLEAR_LEN;
++j;
} else
@@ -537,10 +538,8 @@ static void handle_tx(struct vhost_net *net)
struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
 
-   vq->heads[nvq->upend_idx].elem.id =
-   cpu_to_vhost32(vq, used.elem.id);
-   vq->heads[nvq->upend_idx].elem.len =
-   VHOST_DMA_IN_PROGRESS;
+   vhost_set_used_len(vq, , VHOST_DMA_IN_PROGRESS);
+   vq->heads[nvq->upend_idx] = used;
ubuf->callback = vhost_zerocopy_callback;
ubuf->ctx = nvq->ubufs;
ubuf->desc = nvq->upend_idx;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 8744dae..65954d6 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2100,11 +2100,19 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 }
 EXPORT_SYMBOL_GPL(vhost_get_vq_desc);
 
-static void vhost_set_used_len(struct vhost_virtqueue *vq,
-  struct vhost_used_elem *used, int len)
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+   struct vhost_used_elem *used, int len)
 {
used->elem.len = cpu_to_vhost32(vq, len);
 }
+EXPORT_SYMBOL_GPL(vhost_set_used_len);
+
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+  struct vhost_used_elem *used)
+{
+   return vhost32_to_cpu(vq, used->elem.len);
+}
+EXPORT_SYMBOL_GPL(vhost_get_used_len);
 
 /* This is a multi-buffer version of vhost_get_desc, that works if
  * vq has read descriptors only.
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8399887..d57c875 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -198,6 +198,11 @@ int vhost_get_bufs(struct vhost_virtqueue *vq,
   unsigned *log_num,
   unsigned int quota,
   s16 *count);
+void vhost_set_used_len(struct vhost_virtqueue *vq,
+   struct vhost_used_elem *used,
+   int len);
+int vhost_get_used_len(struct vhost_virtqueue *vq,
+  struct vhost_used_elem *used);
 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
 
 int vhost_vq_init_access(struct vhost_virtqueue *);
-- 
2.7.4