Re: [PATCH v6 30/46] vhost/net: force len for TX to host endian

From: Jason Wang
Date: Fri Nov 28 2014 - 03:37:14 EST




On Fri, Nov 28, 2014 at 4:10 AM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
vhost/net keeps a copy of some used ring but (ab)uses length
field for internal house-keeping. This works because
for tx used length is always 0.
Suppress sparse errors: we use native endian-ness internally but never
expose it to guest.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/vhost/net.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8dae2f7..dce5c58 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -48,15 +48,15 @@ MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;"
* status internally; used for zerocopy tx only.
*/
/* Lower device DMA failed */
-#define VHOST_DMA_FAILED_LEN 3
+#define VHOST_DMA_FAILED_LEN ((__force __virtio32)3)
/* Lower device DMA done */
-#define VHOST_DMA_DONE_LEN 2
+#define VHOST_DMA_DONE_LEN ((__force __virtio32)2)
/* Lower device DMA in progress */
-#define VHOST_DMA_IN_PROGRESS 1
+#define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1)
/* Buffer unused */
-#define VHOST_DMA_CLEAR_LEN 0
+#define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0)
-#define VHOST_DMA_IS_DONE(len) ((len) >= VHOST_DMA_DONE_LEN)
+#define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN)
enum {
VHOST_NET_FEATURES = VHOST_FEATURES |
--
MST

Reviewed-by: Jason Wang <jasowang@xxxxxxxxxx>

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