App Feature Requirements

The tables below indicate which features are required by the libfabric utility providers and select applications.

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Key

✓ = feature required for minimal use

* = feature required for general use or desired for performance

H = Supported mode bit, hidden from higher layers

S = Supported mode bit, passed through if higher layer handles, else hidden

P = Pass-through mode bit, higher layers must support

(no mark) = not applicable or not needed / in-case of mode bits: cannot pass-through or undefined behavior

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Endpoint Types	rxd	rxm
FI_EP_DGRAM	✓
FI_EP_MSG		✓
FI_EP_RDM

Primary Capabilities	rxd	rxm
FI_ATOMIC
FI_DIRECTED_RECV
FI_MSG	✓	✓
FI_MULTICAST
FI_NAMED_RX_CTX
FI_READ		✓
FI_RECV	✓	✓
FI_REMOTE_READ		✓
FI_REMOTE_WRITE		✓
FI_RMA		✓
FI_SEND	✓	✓
FI_TAGGED
FI_WRITE		✓
FI_VARIABLE_MSG

Secondary Capabilities	rxd	rxm
FI_FENCE
FI_LOCAL_COMM	*	*
FI_MULTI_RECV
FI_REMOTE_COMM	*	*
FI_RMA_EVENT
FI_RMA_PMEM
FI_SHARED_AV
FI_SOURCE
FI_SOURCE_ERR
FI_TRIGGER

Modes	rxd	rxm
FI_ASYNC_IOV
FI_BUFFERED_RECV
FI_CONTEXT	H
FI_CONTEXT2
FI_LOCAL_MR (compat)		S
FI_MSG_PREFIX	H
FI_NOTIFY_FLAGS_ONLY
FI_RESTRICTED_COMP
FI_RX_CQ_DATA		H

Memory Registration Modes	rxd	rxm
FI_MR_ALLOCATED		P
FI_MR_ENDPOINT
FI_MR_LOCAL	S	S
FI_MR_PROV_KEY		P
FI_MR_MMU_NOTIFY
FI_MR_RAW
FI_MR_RMA_EVENT
FI_MR_VIRT_ADDR		P
FI_MR_BASIC (compat)		✓
FI_MR_SCALABLE (compat)		✓

Additional Features	rxd	rxm
FABRIC_DIRECT
FI_RM_ENABLED		✓1
Scalable endpoints
Counters (local operations)
Counters (remote operations)

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¹ rxm requires RM enabled for every resource except CQ from underlying FI_EP_MSG provider.