port-amd64/54489: panic: assertion "rcr4() & CR4_SMAP" failed on HP DL380 Gen10

[tnn%nygren.pp.se@localhost]

>Number:         54489
>Category:       port-amd64
>Synopsis:       panic: assertion "rcr4() & CR4_SMAP" failed on HP DL380 Gen10
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 26 15:15:00 +0000 2019
>Originator:     Tobias Nygren
>Release:        9.99.10
>Organization:
>Environment:
N/A
>Description:
Tried to boot a -current GENERIC kernel on a dual socket HP DL380 Gen10.

It failed with assertion "rcr4() & CR4_SMAP" at arch/x86/x86/patch.c line 299 during multiprocessor hatch.

The machine has:
Slot 0: 16 core "Intel(R) Xeon(R) Gold 6130 CPU 2 2.10GHz"  
Slot 1: 16 core "Intel(R) Xeon(R) Gold 6130 CPU 2 2.10GHz"  
Memory: 384 GB RAM.

I tried to #if 0 the SMAP code but then the kernel asserted later with "ci->ci_tlbstate != TLBSTATE_VALID" in x86/pmap.c line 2792.
>How-To-Repeat:

>Fix: