Re: [PATCH] vdpa: Set speed and duplex of mlx5_vnet to UNKNOWN

[Carlos Bilbao <cbilbao@digitalocean.com>]

Hello,

On 8/29/24 5:20 AM, Dragos Tatulea wrote:
>
> On 28.08.24 20:16, Carlos Bilbao wrote:
>> From: Carlos Bilbao <cbilbao@digitalocean.com>
>>
>> mlx5_vdpa vDPA devices currently don't support reporting or setting the
>> speed and duplex and hence should be UNKNOWN instead of zero.
>>
>> Signed-off-by: Carlos Bilbao <cbilbao@digitalocean.com>
>> ---
>>  drivers/vdpa/mlx5/net/mlx5_vnet.c |  7 +++++++
>>  drivers/vdpa/vdpa.c               | 23 +++++++++++++++++++++++
>>  include/uapi/linux/vdpa.h         |  2 ++
>>  3 files changed, 32 insertions(+)
>>
>> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> index fa78e8288ebb..319f5c6121de 100644
>> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
>> @@ -3795,6 +3795,13 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
>>  	init_rwsem(&ndev->reslock);
>>  	config = &ndev->config;
>>  
>> +	/*
>> +	 * mlx5_vdpa vDPA devices currently don't support reporting or
>> +	 * setting the speed or duplex.
>> +	 */
>> +	config->speed  = SPEED_UNKNOWN;
>> +	config->duplex = DUPLEX_UNKNOWN;
>> +
> The values in virtio_net_config are little endian so you'll need to explicitly
> convert them. As speed is a u32, you'll need to add a cpu_to_mlx5vdpa32() helper.
>
> Thanks,
> Dragos
>
>>  	if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) {
>>  		err = config_func_mtu(mdev, add_config->net.mtu);
>>  		if (err)
>> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
>> index 4dbd2e55a288..abde23e0041d 100644
>> --- a/drivers/vdpa/vdpa.c
>> +++ b/drivers/vdpa/vdpa.c
>> @@ -15,6 +15,7 @@
>>  #include <net/genetlink.h>
>>  #include <linux/mod_devicetable.h>
>>  #include <linux/virtio_ids.h>
>> +#include <uapi/linux/ethtool.h>
>>  
>>  static LIST_HEAD(mdev_head);
>>  /* A global mutex that protects vdpa management device and device level operations. */
>> @@ -919,6 +920,22 @@ static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 features,
>>  	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16);
>>  }
>>  
>> +static int vdpa_dev_net_speed_config_fill(struct sk_buff *msg, u64 features,
>> +					struct virtio_net_config *config)
>> +{
>> +	__le32 speed = cpu_to_le32(SPEED_UNKNOWN);
>> +
>> +	return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_SPEED, sizeof(speed), &speed);
>> +}
>> +
>> +static int vdpa_dev_net_duplex_config_fill(struct sk_buff *msg, u64 features,
>> +					struct virtio_net_config *config)
>> +{
>> +	u8 duplex = DUPLEX_UNKNOWN;
>> +
>> +	return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_DUPLEX, sizeof(duplex), &duplex);
>> +}
>> +
>>  static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
>>  {
>>  	struct virtio_net_config config = {};
>> @@ -941,6 +958,12 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
>>  	if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
>>  		return -EMSGSIZE;
>>  
>> +	if (vdpa_dev_net_speed_config_fill(msg, features_device, &config))
>> +		return -EMSGSIZE;
>> +
>> +	if (vdpa_dev_net_duplex_config_fill(msg, features_device, &config))
>> +		return -EMSGSIZE;
>> +
>>  	return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
>>  }
>>  
>> diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
>> index 842bf1201ac4..1c64ee0dd7b1 100644
>> --- a/include/uapi/linux/vdpa.h
>> +++ b/include/uapi/linux/vdpa.h
>> @@ -43,6 +43,8 @@ enum vdpa_attr {
>>  	VDPA_ATTR_DEV_NET_STATUS,		/* u8 */
>>  	VDPA_ATTR_DEV_NET_CFG_MAX_VQP,		/* u16 */
>>  	VDPA_ATTR_DEV_NET_CFG_MTU,		/* u16 */
>> +	VDPA_ATTR_DEV_NET_CFG_SPEED,		/* u32 */
>> +	VDPA_ATTR_DEV_NET_CFG_DUPLEX,		/* u8 */
>>  
>>  	VDPA_ATTR_DEV_NEGOTIATED_FEATURES,	/* u64 */
>>  	VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,		/* u32 */


Thank you all for the feedback, everyone. I will prepare a patch set with
two commits:

 - One to set speed and duplex to UNKNOWN (in little-endian format, thank
   you, Dragos).

 - Another to update the vDPA tool to allow setting the values for speed
   and duplex, including support in set_config(). I'll add a comment
   clarifying that this support isn't fully implemented at the hardware
   level yet.

Regards,
Carlos