[PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[xiangxia.m.yue]

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>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
v2:
* LRO depends the rx csum
* remove the unnecessary check
---
 drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
+	 * That is life. :)
+	 */
+	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 &
+		       vi->guest_offloads_capable;
 	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;
 		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;
+		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 +2585,7 @@ 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 +3036,10 @@ 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;
 
-- 
2.23.0

[PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[xiangxia.m.yue]

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>
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
v2:
* LRO depends the rx csum
* remove the unnecessary check
---
 drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
+	 * That is life. :)
+	 */
+	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 &
+		       vi->guest_offloads_capable;
 	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;
 		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;
+		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 +2585,7 @@ 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 +3036,10 @@ 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;
 
-- 
2.23.0

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Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Wed, Sep 30, 2020 at 4:05 AM <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>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

The first patch was merged into net.

Please wait until that is merged into net-next, as this depends on the
other patch.

> ---
> v2:
> * LRO depends the rx csum
> * remove the unnecessary check
> ---
>  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
>  1 file changed, 37 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> +        * That is life. :)

Please remove this second line.

> +        */
> +       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 &
> +                      vi->guest_offloads_capable;

When can vi->guest_offloads have bits set outside the mask of
vi->guest_offloads_capable?

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Wed, Sep 30, 2020 at 4:05 AM <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>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

The first patch was merged into net.

Please wait until that is merged into net-next, as this depends on the
other patch.

> ---
> v2:
> * LRO depends the rx csum
> * remove the unnecessary check
> ---
>  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
>  1 file changed, 37 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> +        * That is life. :)

Please remove this second line.

> +        */
> +       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 &
> +                      vi->guest_offloads_capable;

When can vi->guest_offloads have bits set outside the mask of
vi->guest_offloads_capable?
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Virtualization mailing list
Virtualization@lists.linux-foundation.org
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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Michael S. Tsirkin]

On Wed, Sep 30, 2020 at 10:03:00AM +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>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>


> ---
> v2:
> * LRO depends the rx csum
> * remove the unnecessary check
> ---
>  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
>  1 file changed, 37 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> +	 * That is life. :)
> +	 */
> +	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 &
> +		       vi->guest_offloads_capable;
>  	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;
>  		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;
> +		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 +2585,7 @@ 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 +3036,10 @@ 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;
>  
> -- 
> 2.23.0

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Michael S. Tsirkin]

On Wed, Sep 30, 2020 at 10:03:00AM +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>
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>


> ---
> v2:
> * LRO depends the rx csum
> * remove the unnecessary check
> ---
>  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
>  1 file changed, 37 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> +	 * That is life. :)
> +	 */
> +	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 &
> +		       vi->guest_offloads_capable;
>  	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;
>  		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;
> +		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 +2585,7 @@ 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 +3036,10 @@ 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;
>  
> -- 
> 2.23.0

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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Tonghao Zhang]

On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Wed, Sep 30, 2020 at 4:05 AM <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>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> The first patch was merged into net.
>
> Please wait until that is merged into net-next, as this depends on the
> other patch.
>
> > ---
> > v2:
> > * LRO depends the rx csum
> > * remove the unnecessary check
> > ---
> >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> >  1 file changed, 37 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > +        * That is life. :)
>
> Please remove this second line.
OK
> > +        */
> > +       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 &
> > +                      vi->guest_offloads_capable;
>
> When can vi->guest_offloads have bits set outside the mask of
> vi->guest_offloads_capable?
In this case, we can use only vi->guest_offloads. and
guest_offloads_capable will not be used any more.
so should we remove guest_offloads_capable ?


-- 
Best regards, Tonghao

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Tonghao Zhang]

On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Wed, Sep 30, 2020 at 4:05 AM <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>
> > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> The first patch was merged into net.
>
> Please wait until that is merged into net-next, as this depends on the
> other patch.
>
> > ---
> > v2:
> > * LRO depends the rx csum
> > * remove the unnecessary check
> > ---
> >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> >  1 file changed, 37 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > +        * That is life. :)
>
> Please remove this second line.
OK
> > +        */
> > +       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 &
> > +                      vi->guest_offloads_capable;
>
> When can vi->guest_offloads have bits set outside the mask of
> vi->guest_offloads_capable?
In this case, we can use only vi->guest_offloads. and
guest_offloads_capable will not be used any more.
so should we remove guest_offloads_capable ?


-- 
Best regards, Tonghao
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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> >
> > The first patch was merged into net.
> >
> > Please wait until that is merged into net-next, as this depends on the
> > other patch.
> >
> > > ---
> > > v2:
> > > * LRO depends the rx csum
> > > * remove the unnecessary check
> > > ---
> > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > +        * That is life. :)
> >
> > Please remove this second line.
> OK
> > > +        */
> > > +       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 &
> > > +                      vi->guest_offloads_capable;
> >
> > When can vi->guest_offloads have bits set outside the mask of
> > vi->guest_offloads_capable?
> In this case, we can use only vi->guest_offloads. and
> guest_offloads_capable will not be used any more.
> so should we remove guest_offloads_capable ?

That bitmap stores the capabilities of the device as learned at
initial device probe. I don't see how it can be removed.

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> >
> > The first patch was merged into net.
> >
> > Please wait until that is merged into net-next, as this depends on the
> > other patch.
> >
> > > ---
> > > v2:
> > > * LRO depends the rx csum
> > > * remove the unnecessary check
> > > ---
> > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > +        * That is life. :)
> >
> > Please remove this second line.
> OK
> > > +        */
> > > +       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 &
> > > +                      vi->guest_offloads_capable;
> >
> > When can vi->guest_offloads have bits set outside the mask of
> > vi->guest_offloads_capable?
> In this case, we can use only vi->guest_offloads. and
> guest_offloads_capable will not be used any more.
> so should we remove guest_offloads_capable ?

That bitmap stores the capabilities of the device as learned at
initial device probe. I don't see how it can be removed.
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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Tonghao Zhang]

On Fri, Oct 9, 2020 at 9:49 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
> >
> > On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> > <willemdebruijn.kernel@gmail.com> wrote:
> > >
> > > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> > >
> > > The first patch was merged into net.
> > >
> > > Please wait until that is merged into net-next, as this depends on the
> > > other patch.
> > >
> > > > ---
> > > > v2:
> > > > * LRO depends the rx csum
> > > > * remove the unnecessary check
> > > > ---
> > > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > > +        * That is life. :)
> > >
> > > Please remove this second line.
> > OK
> > > > +        */
> > > > +       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 &
> > > > +                      vi->guest_offloads_capable;
> > >
> > > When can vi->guest_offloads have bits set outside the mask of
> > > vi->guest_offloads_capable?
> > In this case, we can use only vi->guest_offloads. and
> > guest_offloads_capable will not be used any more.
> > so should we remove guest_offloads_capable ?
>
> That bitmap stores the capabilities of the device as learned at
> initial device probe. I don't see how it can be removed.
Hi Willem
guest_offloads_capable was introduced by
a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
and used only for LRO. Now we don't use it anymore, right ?
because this patch (virtio-net: ethtool configurable RXCSUM)
doesn't use it.


-- 
Best regards, Tonghao

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Tonghao Zhang]

On Fri, Oct 9, 2020 at 9:49 PM Willem de Bruijn
<willemdebruijn.kernel@gmail.com> wrote:
>
> On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
> >
> > On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> > <willemdebruijn.kernel@gmail.com> wrote:
> > >
> > > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> > >
> > > The first patch was merged into net.
> > >
> > > Please wait until that is merged into net-next, as this depends on the
> > > other patch.
> > >
> > > > ---
> > > > v2:
> > > > * LRO depends the rx csum
> > > > * remove the unnecessary check
> > > > ---
> > > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > > +        * That is life. :)
> > >
> > > Please remove this second line.
> > OK
> > > > +        */
> > > > +       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 &
> > > > +                      vi->guest_offloads_capable;
> > >
> > > When can vi->guest_offloads have bits set outside the mask of
> > > vi->guest_offloads_capable?
> > In this case, we can use only vi->guest_offloads. and
> > guest_offloads_capable will not be used any more.
> > so should we remove guest_offloads_capable ?
>
> That bitmap stores the capabilities of the device as learned at
> initial device probe. I don't see how it can be removed.
Hi Willem
guest_offloads_capable was introduced by
a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
and used only for LRO. Now we don't use it anymore, right ?
because this patch (virtio-net: ethtool configurable RXCSUM)
doesn't use it.


-- 
Best regards, Tonghao
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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Fri, Oct 9, 2020 at 10:10 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Fri, Oct 9, 2020 at 9:49 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
> > >
> > > On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> > > <willemdebruijn.kernel@gmail.com> wrote:
> > > >
> > > > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> > > >
> > > > The first patch was merged into net.
> > > >
> > > > Please wait until that is merged into net-next, as this depends on the
> > > > other patch.
> > > >
> > > > > ---
> > > > > v2:
> > > > > * LRO depends the rx csum
> > > > > * remove the unnecessary check
> > > > > ---
> > > > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > > > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > > > +        * That is life. :)
> > > >
> > > > Please remove this second line.
> > > OK
> > > > > +        */
> > > > > +       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 &
> > > > > +                      vi->guest_offloads_capable;
> > > >
> > > > When can vi->guest_offloads have bits set outside the mask of
> > > > vi->guest_offloads_capable?
> > > In this case, we can use only vi->guest_offloads. and
> > > guest_offloads_capable will not be used any more.
> > > so should we remove guest_offloads_capable ?
> >
> > That bitmap stores the capabilities of the device as learned at
> > initial device probe. I don't see how it can be removed.
> Hi Willem
> guest_offloads_capable was introduced by
> a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> and used only for LRO. Now we don't use it anymore, right ?
> because this patch (virtio-net: ethtool configurable RXCSUM)
> doesn't use it.

It is needed, because it serves as an upper bound on configurable options.

virtnet_set_features cannot enable LRO unless the LRO flags are
captured by the feature negotiation at probe time.

I think on enable you need something like

-                       offloads = vi->guest_offloads_capable;
+                       offloads |= vi->guest_offloads_capable &
GUEST_OFFLOAD_LRO_MASK;

instead of unconditional

+                       offloads |= GUEST_OFFLOAD_LRO_MASK;

Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Willem de Bruijn]

On Fri, Oct 9, 2020 at 10:10 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
>
> On Fri, Oct 9, 2020 at 9:49 PM Willem de Bruijn
> <willemdebruijn.kernel@gmail.com> wrote:
> >
> > On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com> wrote:
> > >
> > > On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> > > <willemdebruijn.kernel@gmail.com> wrote:
> > > >
> > > > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> > > >
> > > > The first patch was merged into net.
> > > >
> > > > Please wait until that is merged into net-next, as this depends on the
> > > > other patch.
> > > >
> > > > > ---
> > > > > v2:
> > > > > * LRO depends the rx csum
> > > > > * remove the unnecessary check
> > > > > ---
> > > > >  drivers/net/virtio_net.c | 49 ++++++++++++++++++++++++++++++----------
> > > > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > > > >
> > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > > > +        * That is life. :)
> > > >
> > > > Please remove this second line.
> > > OK
> > > > > +        */
> > > > > +       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 &
> > > > > +                      vi->guest_offloads_capable;
> > > >
> > > > When can vi->guest_offloads have bits set outside the mask of
> > > > vi->guest_offloads_capable?
> > > In this case, we can use only vi->guest_offloads. and
> > > guest_offloads_capable will not be used any more.
> > > so should we remove guest_offloads_capable ?
> >
> > That bitmap stores the capabilities of the device as learned at
> > initial device probe. I don't see how it can be removed.
> Hi Willem
> guest_offloads_capable was introduced by
> a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> and used only for LRO. Now we don't use it anymore, right ?
> because this patch (virtio-net: ethtool configurable RXCSUM)
> doesn't use it.

It is needed, because it serves as an upper bound on configurable options.

virtnet_set_features cannot enable LRO unless the LRO flags are
captured by the feature negotiation at probe time.

I think on enable you need something like

-                       offloads = vi->guest_offloads_capable;
+                       offloads |= vi->guest_offloads_capable &
GUEST_OFFLOAD_LRO_MASK;

instead of unconditional

+                       offloads |= GUEST_OFFLOAD_LRO_MASK;
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Re: [PATCH net-next v2] virtio-net: ethtool configurable RXCSUM

[Tonghao Zhang]

[-- Attachment #1.1: Type: text/plain, Size: 4837 bytes --]

On Sun, Oct 11, 2020 at 2:58 AM Willem de Bruijn <
willemdebruijn.kernel@gmail.com> wrote:
>
> On Fri, Oct 9, 2020 at 10:10 PM Tonghao Zhang <xiangxia.m.yue@gmail.com>
wrote:
> >
> > On Fri, Oct 9, 2020 at 9:49 PM Willem de Bruijn
> > <willemdebruijn.kernel@gmail.com> wrote:
> > >
> > > On Thu, Oct 8, 2020 at 9:19 PM Tonghao Zhang <xiangxia.m.yue@gmail.com>
wrote:
> > > >
> > > > On Wed, Sep 30, 2020 at 6:05 PM Willem de Bruijn
> > > > <willemdebruijn.kernel@gmail.com> wrote:
> > > > >
> > > > > On Wed, Sep 30, 2020 at 4:05 AM <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>
> > > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> > > > >
> > > > > The first patch was merged into net.
> > > > >
> > > > > Please wait until that is merged into net-next, as this depends
on the
> > > > > other patch.
> > > > >
> > > > > > ---
> > > > > > v2:
> > > > > > * LRO depends the rx csum
> > > > > > * remove the unnecessary check
> > > > > > ---
> > > > > >  drivers/net/virtio_net.c | 49
++++++++++++++++++++++++++++++----------
> > > > > >  1 file changed, 37 insertions(+), 12 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> > > > > > index 21b71148c532..5407a0106771 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 +2524,49 @@ 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.
> > > > > > +        * That is life. :)
> > > > >
> > > > > Please remove this second line.
> > > > OK
> > > > > > +        */
> > > > > > +       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 &
> > > > > > +                      vi->guest_offloads_capable;
> > > > >
> > > > > When can vi->guest_offloads have bits set outside the mask of
> > > > > vi->guest_offloads_capable?
> > > > In this case, we can use only vi->guest_offloads. and
> > > > guest_offloads_capable will not be used any more.
> > > > so should we remove guest_offloads_capable ?
> > >
> > > That bitmap stores the capabilities of the device as learned at
> > > initial device probe. I don't see how it can be removed.
> > Hi Willem
> > guest_offloads_capable was introduced by
> > a02e8964eaf9 ("virtio-net: ethtool configurable LRO")
> > and used only for LRO. Now we don't use it anymore, right ?
> > because this patch (virtio-net: ethtool configurable RXCSUM)
> > doesn't use it.
>
> It is needed, because it serves as an upper bound on configurable options.
>
> virtnet_set_features cannot enable LRO unless the LRO flags are
> captured by the feature negotiation at probe time.
>
> I think on enable you need something like
>
> -                       offloads = vi->guest_offloads_capable;
> +                       offloads |= vi->guest_offloads_capable &
> GUEST_OFFLOAD_LRO_MASK;
>
> instead of unconditional
>
> +                       offloads |= GUEST_OFFLOAD_LRO_MASK;
Thanks, I send v3 with your suggestion. please review.
http://patchwork.ozlabs.org/project/netdev/patch/20201012015820.62042-1-xiangxia.m.yue@gmail.com/



--
Best regards, Tonghao
-- 
Best regards, Tonghao

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