[PATCH] nvme: reserve a keep-alive admin tag for all transports

[Keith Busch]

On Tue, Apr 28, 2026 at 09:15:10AM +0200, Maurizio Lombardi wrote:
> The spec 2.0a, at section 5.27.1.12 Keep Alive Timer (Feature Identifier
> 0Fh)
> 
> says:
> "Keep Alive Timeout (KATO):
>  
> This field specifies the timeout value for the Keep Alive feature in
> milliseconds.  [...]
> The default value for this field is 0h for NVMe transports that do not require use of the Keep Alive
> feature (e.g., NVMe over PCIe). For NVMe transports that require use of the Keep Alive feature
> (e.g., RDMA and TCP), the default value for this field is 1D4C0h "
> 
> To me, it sounds like for nvme-pci, keep alive isn't required, but could
> be activated.

The spec says the support is subject to the Transport binding
specification, which does not exist in the PCIe transport spec.