[dpdk-dev] [PATCH] net/virtio-user: fix not working on 32-bit system

[Jianfeng Tan <jianfeng.tan@intel.com>]

virtio-user cannot work on 32-bit system as higher 32-bit of the
addr field (64-bit) in the desc is filled with non-zero value
which should not happen for a 32-bit system.

This is a regression bug. For 32-bit system, the first 4 bytes
is the virtual address, with following 8 bytes pointing to
physical addr. With below wrong definition, both virtual address
and lower 4 bytes of physical addr are obtained.
  #define VIRTIO_MBUF_ADDR(mb, vq) \
	(*(uint64_t *)((uintptr_t)(mb) + (vq)->offset))

Fixes: 25f80d108780 ("net/virtio: fix packet corruption")
Cc: stable@dpdk.org

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
---
 drivers/net/virtio/virtqueue.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index f9e3736..f43ea70 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -72,7 +72,8 @@ struct rte_mbuf;
  * Return the physical address (or virtual address in case of
  * virtio-user) of mbuf data buffer.
  */
-#define VIRTIO_MBUF_ADDR(mb, vq) (*(uint64_t *)((uintptr_t)(mb) + (vq)->offset))
+#define VIRTIO_MBUF_ADDR(mb, vq) \
+	((uint64_t)((uintptr_t)(*(void **)((uintptr_t)(mb) + (vq)->offset))))
 #else
 #define VIRTIO_MBUF_ADDR(mb, vq) ((mb)->buf_physaddr)
 #endif
-- 
2.7.4