This protocol provides boot-time service to do fault tolerant write capability for block devices in SMM environment.
Include/Protocol/SmmFaultTolerantWrite.h

PROTOCOL Information

PROTOCOL's Guid Name	PROTOCOL's Guid
gEfiSmmFaultTolerantWriteProtocolGuid	{ 0x3868fc3b, 0x7e45, 0x43a7, { 0x90, 0x6c, 0x4b, 0xa4, 0x7d, 0xe1, 0x75, 0x4d }}

Refer to Header File