Re: [libvirt] [PATCH] "pclmuldq" was introduced with Westmere, not Sandy Bridge. This feature is important to get proper performance for aes-128-gcm in openssl, an important cipher for https communication.

[Jan-Frode Myklebust]

Just some documentation for the fact that this was introduced with
Westmere:

        
https://software.intel.com/sites/default/files/managed/72/cc/clmul-wp-rev-2.02-2014-04-20.pdf

        "Intel® PCLMULQDQ instruction is a new instruction available
         beginning with the all new 2010 Intel® Core™ processor family based on
         the 32nm Intel® microarchitecture codename Westmere"

        https://en.wikipedia.org/wiki/CLMUL_instruction_set

        "Carry-less Multiplication (CLMUL) is an extension to the x86
         instruction set used by microprocessors from Intel and AMD which was
         proposed by Intel in March 2008[1] and made available in the Intel
         Westmere processors announced in early 2010."

        https://en.wikipedia.org/wiki/Westmere_%28microarchitecture%29

        "Delivers seven new instructions (AES instruction set or AES-NI)
        that will be used by the AES algorithm. Also an instruction called
        PCLMULQDQ (see CLMUL instruction set) that will perform carry-less
        multiplication for use in cryptography."



  -jf

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