On 26.08.24 16:24, Andrew Lunn wrote:

On Mon, Aug 26, 2024 at 11:06:09AM +0200, Dragos Tatulea wrote:

quoted

On 23.08.24 18:54, Carlos Bilbao wrote:

quoted

Hello,

I'm debugging my vDPA setup, and when using ioctl to retrieve the
configuration, I noticed that it's running in half duplex mode:

Configuration data (24 bytes):
  MAC address: (Mac address)
  Status: 0x0001
  Max virtqueue pairs: 8
  MTU: 1500
  Speed: 0 Mb
  Duplex: Half Duplex
  RSS max key size: 0
  RSS max indirection table length: 0
  Supported hash types: 0x00000000

I believe this might be contributing to the underperformance of vDPA.

mlx5_vdpa vDPA devicess currently do not support the VIRTIO_NET_F_SPEED_DUPLEX
feature which reports speed and duplex. You can check the state on the
PF.

Then it should probably report DUPLEX_UNKNOWN.

The speed of 0 also suggests SPEED_UNKNOWN is not being returned. So
this just looks buggy in general.

The virtio spec doesn't mention what those values should be when
VIRTIO_NET_F_SPEED_DUPLEX is not supported.

Jason, should vdpa_dev_net_config_fill() initialize the speed/duplex
fields to SPEED/DUPLEX_UNKNOWN instead of 0?

Thanks,
Dragos