Linux Virtualization - Aug 2020 - [PATCH v3 38/38] virtio_net: use LE accessors for speed/duplex

Speed and duplex config fields depend on VIRTIO_NET_F_SPEED_DUPLEX
which being 63>31 depends on VIRTIO_F_VERSION_1.

Accordingly, use LE accessors for these fields.

Reported-by: Cornelia Huck <cohuck at redhat.com>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
---
 drivers/net/virtio_net.c        | 9 +++++----
 include/uapi/linux/virtio_net.h | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ba38765dc490..0934b1ec5320 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2264,12 +2264,13 @@ static void virtnet_update_settings(struct virtnet_info
*vi)
 	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
 		return;
 
-	speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
-						  speed));
+	virtio_cread_le(vi->vdev, struct virtio_net_config, speed, &speed);
+
 	if (ethtool_validate_speed(speed))
 		vi->speed = speed;
-	duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
-						  duplex));
+
+	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex, &duplex);
+
 	if (ethtool_validate_duplex(duplex))
 		vi->duplex = duplex;
 }
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index 27d996f29dd1..3f55a4215f11 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -99,7 +99,7 @@ struct virtio_net_config {
 	 * speed, in units of 1Mb. All values 0 to INT_MAX are legal.
 	 * Any other value stands for unknown.
 	 */
-	__virtio32 speed;
+	__le32 speed;
 	/*
 	 * 0x00 - half duplex
 	 * 0x01 - full duplex
-- 
MST

On Wed, 5 Aug 2020 09:45:00 -0400
"Michael S. Tsirkin" <mst at redhat.com> wrote:
> Speed and duplex config fields depend on VIRTIO_NET_F_SPEED_DUPLEX
> which being 63>31 depends on VIRTIO_F_VERSION_1.
> 
> Accordingly, use LE accessors for these fields.
> 
> Reported-by: Cornelia Huck <cohuck at redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
> ---
>  drivers/net/virtio_net.c        | 9 +++++----
>  include/uapi/linux/virtio_net.h | 2 +-
>  2 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index ba38765dc490..0934b1ec5320 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2264,12 +2264,13 @@ static void virtnet_update_settings(struct
virtnet_info *vi)
>  	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_SPEED_DUPLEX))
>  		return;
>  
> -	speed = virtio_cread32(vi->vdev, offsetof(struct virtio_net_config,
> -						  speed));
> +	virtio_cread_le(vi->vdev, struct virtio_net_config, speed,
&speed);
> +
>  	if (ethtool_validate_speed(speed))
>  		vi->speed = speed;
> -	duplex = virtio_cread8(vi->vdev, offsetof(struct virtio_net_config,
> -						  duplex));
> +
> +	virtio_cread_le(vi->vdev, struct virtio_net_config, duplex,
&duplex);
Looks a bit odd for an u8, but does not really hurt.
> +
>  	if (ethtool_validate_duplex(duplex))
>  		vi->duplex = duplex;
>  }
> diff --git a/include/uapi/linux/virtio_net.h
b/include/uapi/linux/virtio_net.h
> index 27d996f29dd1..3f55a4215f11 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -99,7 +99,7 @@ struct virtio_net_config {
>  	 * speed, in units of 1Mb. All values 0 to INT_MAX are legal.
>  	 * Any other value stands for unknown.
>  	 */
> -	__virtio32 speed;
> +	__le32 speed;
>  	/*
>  	 * 0x00 - half duplex
>  	 * 0x01 - full duplex
Reviewed-by: Cornelia Huck <cohuck at redhat.com>