diff mbox series

[net-next,v3] virtio-net: ethtool configurable RXCSUM

Message ID 20201012015820.62042-1-xiangxia.m.yue@gmail.com
State New
Headers show
Series [net-next,v3] virtio-net: ethtool configurable RXCSUM | expand

Commit Message

Tonghao Zhang Oct. 12, 2020, 1:58 a.m. UTC
From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Allow user configuring RXCSUM separately with ethtool -K,
reusing the existing virtnet_set_guest_offloads helper
that configures RXCSUM for XDP. This is conditional on
VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.

If Rx checksum is disabled, LRO should also be disabled.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/net/virtio_net.c | 48 ++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 12 deletions(-)

Comments

Jason Wang Oct. 12, 2020, 5:02 a.m. UTC | #1
On 2020/10/12 上午9:58, xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> Allow user configuring RXCSUM separately with ethtool -K,
> reusing the existing virtnet_set_guest_offloads helper
> that configures RXCSUM for XDP. This is conditional on
> VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.
>
> If Rx checksum is disabled, LRO should also be disabled.
>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>   drivers/net/virtio_net.c | 48 ++++++++++++++++++++++++++++++----------
>   1 file changed, 36 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 21b71148c532..d2d2c4a53cf2 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -68,6 +68,8 @@ static const unsigned long guest_offloads[] = {
>   				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
>   				(1ULL << VIRTIO_NET_F_GUEST_UFO))
>   
> +#define GUEST_OFFLOAD_CSUM_MASK (1ULL << VIRTIO_NET_F_GUEST_CSUM)
> +
>   struct virtnet_stat_desc {
>   	char desc[ETH_GSTRING_LEN];
>   	size_t offset;
> @@ -2522,29 +2524,48 @@ static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
>   	return 0;
>   }
>   
> +static netdev_features_t virtnet_fix_features(struct net_device *netdev,
> +					      netdev_features_t features)
> +{
> +	/* If Rx checksum is disabled, LRO should also be disabled. */
> +	if (!(features & NETIF_F_RXCSUM))
> +		features &= ~NETIF_F_LRO;
> +
> +	return features;
> +}
> +
>   static int virtnet_set_features(struct net_device *dev,
>   				netdev_features_t features)
>   {
>   	struct virtnet_info *vi = netdev_priv(dev);
> -	u64 offloads;
> +	u64 offloads = vi->guest_offloads;
>   	int err;
>   
> -	if ((dev->features ^ features) & NETIF_F_LRO) {
> -		if (vi->xdp_queue_pairs)
> -			return -EBUSY;
> +	/* Don't allow configuration while XDP is active. */
> +	if (vi->xdp_queue_pairs)
> +		return -EBUSY;
>   
> +	if ((dev->features ^ features) & NETIF_F_LRO) {
>   		if (features & NETIF_F_LRO)
> -			offloads = vi->guest_offloads_capable;
> +			offloads |= GUEST_OFFLOAD_LRO_MASK &
> +				    vi->guest_offloads_capable;
>   		else
> -			offloads = vi->guest_offloads_capable &
> -				   ~GUEST_OFFLOAD_LRO_MASK;
> +			offloads &= ~GUEST_OFFLOAD_LRO_MASK;
> +	}
>   
> -		err = virtnet_set_guest_offloads(vi, offloads);
> -		if (err)
> -			return err;
> -		vi->guest_offloads = offloads;
> +	if ((dev->features ^ features) & NETIF_F_RXCSUM) {
> +		if (features & NETIF_F_RXCSUM)
> +			offloads |= GUEST_OFFLOAD_CSUM_MASK &
> +				    vi->guest_offloads_capable;
> +		else
> +			offloads &= ~GUEST_OFFLOAD_CSUM_MASK;
>   	}
>   
> +	err = virtnet_set_guest_offloads(vi, offloads);
> +	if (err)
> +		return err;
> +
> +	vi->guest_offloads = offloads;
>   	return 0;
>   }
>   
> @@ -2563,6 +2584,7 @@ static const struct net_device_ops virtnet_netdev = {
>   	.ndo_features_check	= passthru_features_check,
>   	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
>   	.ndo_set_features	= virtnet_set_features,
> +	.ndo_fix_features	= virtnet_fix_features,
>   };
>   
>   static void virtnet_config_changed_work(struct work_struct *work)
> @@ -3013,8 +3035,10 @@ static int virtnet_probe(struct virtio_device *vdev)
>   	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
>   	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
>   		dev->features |= NETIF_F_LRO;
> -	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
> +	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
> +		dev->hw_features |= NETIF_F_RXCSUM;
>   		dev->hw_features |= NETIF_F_LRO;
> +	}
>   
>   	dev->vlan_features = dev->features;


Acked-by: Jason Wang <jasowang@redhat.com>


>
Willem de Bruijn Oct. 12, 2020, 1:33 p.m. UTC | #2
On Sun, Oct 11, 2020 at 10:03 PM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> Allow user configuring RXCSUM separately with ethtool -K,
> reusing the existing virtnet_set_guest_offloads helper
> that configures RXCSUM for XDP. This is conditional on
> VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.
>
> If Rx checksum is disabled, LRO should also be disabled.
>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Acked-by: Willem de Bruijn <willemb@google.com>

I had to recall why we cannot just rely on dev->features and
dev->hw_features to encode the set of feature capabilities, but need
guest_offloads_capable.

Flag NETIF_F_LRO encapsulates multiple VIRTIO_NET_F_GUEST_.. flags,
and a device may advertise a subset. We thus have to bound to the set
learned at probing time.
Jakub Kicinski Oct. 14, 2020, 12:28 a.m. UTC | #3
On Mon, 12 Oct 2020 09:58:20 +0800 xiangxia.m.yue@gmail.com wrote:
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> 
> Allow user configuring RXCSUM separately with ethtool -K,
> reusing the existing virtnet_set_guest_offloads helper
> that configures RXCSUM for XDP. This is conditional on
> VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.
> 
> If Rx checksum is disabled, LRO should also be disabled.
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Applied, thanks everyone!
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 21b71148c532..d2d2c4a53cf2 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -68,6 +68,8 @@  static const unsigned long guest_offloads[] = {
 				(1ULL << VIRTIO_NET_F_GUEST_ECN)  | \
 				(1ULL << VIRTIO_NET_F_GUEST_UFO))
 
+#define GUEST_OFFLOAD_CSUM_MASK (1ULL << VIRTIO_NET_F_GUEST_CSUM)
+
 struct virtnet_stat_desc {
 	char desc[ETH_GSTRING_LEN];
 	size_t offset;
@@ -2522,29 +2524,48 @@  static int virtnet_get_phys_port_name(struct net_device *dev, char *buf,
 	return 0;
 }
 
+static netdev_features_t virtnet_fix_features(struct net_device *netdev,
+					      netdev_features_t features)
+{
+	/* If Rx checksum is disabled, LRO should also be disabled. */
+	if (!(features & NETIF_F_RXCSUM))
+		features &= ~NETIF_F_LRO;
+
+	return features;
+}
+
 static int virtnet_set_features(struct net_device *dev,
 				netdev_features_t features)
 {
 	struct virtnet_info *vi = netdev_priv(dev);
-	u64 offloads;
+	u64 offloads = vi->guest_offloads;
 	int err;
 
-	if ((dev->features ^ features) & NETIF_F_LRO) {
-		if (vi->xdp_queue_pairs)
-			return -EBUSY;
+	/* Don't allow configuration while XDP is active. */
+	if (vi->xdp_queue_pairs)
+		return -EBUSY;
 
+	if ((dev->features ^ features) & NETIF_F_LRO) {
 		if (features & NETIF_F_LRO)
-			offloads = vi->guest_offloads_capable;
+			offloads |= GUEST_OFFLOAD_LRO_MASK &
+				    vi->guest_offloads_capable;
 		else
-			offloads = vi->guest_offloads_capable &
-				   ~GUEST_OFFLOAD_LRO_MASK;
+			offloads &= ~GUEST_OFFLOAD_LRO_MASK;
+	}
 
-		err = virtnet_set_guest_offloads(vi, offloads);
-		if (err)
-			return err;
-		vi->guest_offloads = offloads;
+	if ((dev->features ^ features) & NETIF_F_RXCSUM) {
+		if (features & NETIF_F_RXCSUM)
+			offloads |= GUEST_OFFLOAD_CSUM_MASK &
+				    vi->guest_offloads_capable;
+		else
+			offloads &= ~GUEST_OFFLOAD_CSUM_MASK;
 	}
 
+	err = virtnet_set_guest_offloads(vi, offloads);
+	if (err)
+		return err;
+
+	vi->guest_offloads = offloads;
 	return 0;
 }
 
@@ -2563,6 +2584,7 @@  static const struct net_device_ops virtnet_netdev = {
 	.ndo_features_check	= passthru_features_check,
 	.ndo_get_phys_port_name	= virtnet_get_phys_port_name,
 	.ndo_set_features	= virtnet_set_features,
+	.ndo_fix_features	= virtnet_fix_features,
 };
 
 static void virtnet_config_changed_work(struct work_struct *work)
@@ -3013,8 +3035,10 @@  static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO4) ||
 	    virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_TSO6))
 		dev->features |= NETIF_F_LRO;
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS))
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)) {
+		dev->hw_features |= NETIF_F_RXCSUM;
 		dev->hw_features |= NETIF_F_LRO;
+	}
 
 	dev->vlan_features = dev->features;