Re: [PATCH v7 30/46] vhost/net: force len for TX to host endian
On Sun, 30 Nov 2014 17:11:44 +0200
Michael S. Tsirkin m...@redhat.com 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.
I admit that I find this patch description hard to read :)
vhost/net keeps a copy of the used ring in host memory but (ab)uses
the length field for internal house-keeping. This works because the
length in the used ring for tx is always 0. In order to suppress sparse
errors, we need to force native endianness.
?
Signed-off-by: Michael S. Tsirkin m...@redhat.com
Reviewed-by: Jason Wang jasow...@redhat.com
---
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_PROGRESS1
+#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 |
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Re: [PATCH v7 30/46] vhost/net: force len for TX to host endian
On Mon, Dec 01, 2014 at 01:20:51PM +0100, Cornelia Huck wrote:
On Sun, 30 Nov 2014 17:11:44 +0200
Michael S. Tsirkin m...@redhat.com 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.
I admit that I find this patch description hard to read :)
vhost/net keeps a copy of the used ring in host memory but (ab)uses
the length field for internal house-keeping. This works because the
length in the used ring for tx is always 0. In order to suppress sparse
errors, we need to force native endianness.
?
Yes. Add to this These values are never exposed to guest.
Signed-off-by: Michael S. Tsirkin m...@redhat.com
Reviewed-by: Jason Wang jasow...@redhat.com
---
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_LEN0
+#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 |
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