XDP Queue Limitation Issue

[pigri]

XDP Queue Limitation Issue

Problem

XDP program requests 3 queues but virtio_net driver only supports 1 queue, causing XDP_TX and XDP_REDIRECT operations to fall back to slower locked transmission mode.

Error Message

virtio_net virtio1 eth0: XDP request 3 queues but max is 1. XDP_TX and XDP_REDIRECT will operate in a slower locked tx mode.

Root Cause

• Hardware limitation: virtio_net interface only supports 1 queue (ethtool -l eth0 shows Combined: 1)
• XDP program expectation: Requests 3 queues for optimal performance
• Impact: Forces locked TX mode instead of lockless multi-queue operation

Environment

• Interface: eth0 (virtio_net)
• XDP Program: firewall (ID: 40)
• Driver: virtio_net
• Mode: XDP_DRV_MODE

Solutions

1. Accept limitation (recommended for virtualized environments)
2. Modify XDP program to request single queue
3. Use generic XDP mode (XDP_FLAGS_SKB_MODE)
4. Hardware upgrade to physical interface or multi-queue virtio_net

Status

Non-critical warning - XDP program functions correctly but with reduced performance.