ENA (NIC) with support for tcp-data-split

Based on the available information, there is no specific mention of support for tcp-data-split capability in the Elastic Network Adapter (ENA) drivers for EC2 instances, including bare-metal instances.

The ENA driver documentation outlines various features and capabilities across different versions, but tcp-data-split is not explicitly mentioned as a supported feature. The ENA drivers have been updated over time with improvements to stability, performance, and additional capabilities like support for IPv6 Tx checksum calculation, wide Low Latency Queuing (LLQ), and network performance metrics, but there's no indication of tcp-data-split support.

For enhanced networking capabilities, AWS provides the Elastic Network Adapter (ENA) which offers various networking features depending on the Nitro version implemented by the instance type. Different instance families (compute optimized, memory optimized, etc.) have different network specifications, but none are specifically mentioned as supporting tcp-data-split for io_uring's zero-copy recv capability.

There is no information available about planned implementation dates for tcp-data-split support in ENA drivers. If you require this specific feature, you might want to contact AWS Support directly for more detailed information about current or future support for this capability.
Sources
Enable enhanced networking with ENA on your EC2 instances - Amazon Elastic Compute Cloud
Track ENA Windows driver version releases - Amazon Elastic Compute Cloud

Hi Tim,

TCP Data Split support on AWS ENA NICs is limited and depends on the instance type, ENA driver version, and kernel version. Check the ENA driver version, kernel version, and AWS documentation for specific instance types. Bare-metal instances might have better support, but it's not guaranteed. Manual driver upgrades are risky. Monitor AWS release notes or contact AWS Support for updates. As an alternative, consider using splice() system call for zero-copy

Step 1: Determine ENA Driver and Kernel Version Use the following commands to check the ENA driver and kernel versions:

modinfo ena (to check ENA driver version) uname -r (to check kernel version) Step 2: Consult AWS Documentation Refer to AWS documentation for the specific EC2 instance type to determine if TCP Data Split is supported with the installed ENA driver and kernel version. Look for ENA-specific documentation related to advanced networking features or io_uring optimization.

Step 3: Evaluate Bare-Metal Instances If TCP Data Split is critical, investigate specific bare-metal instance types, checking their specifications and installed ENA driver versions. Note that support is not guaranteed and experimentation may be necessary.

Step 4: Assess Driver Upgrade Risks Avoid manual ENA driver upgrades unless you possess significant Linux system administration and driver management expertise. Incompatible drivers can lead to network instability or instance failure.

Step 5: Monitor AWS Updates Stay informed about new features and updates by monitoring AWS release notes and announcements related to EC2 and ENA.

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