K 10 svn:author V 6 mhorne K 8 svn:date V 27 2021-08-11T17:26:30.917446Z K 7 svn:log V 1164 hwpmc: disable uncore class on Sandy Bridge and newer It was written for Nehalem and Westmere, with minor but incomplete updates for Sandy Bridge in 78d763a29b15. The uncore architecture changed significantly with this generation, bringing new layouts and locations for some MSRs. Misprogramming these MSRs in ucp_start_pmc() may panic the system, and this is trivially reproducible via pmcstat(8) on at least Broadwell and Haswell. Disable the class on these CPUs until it can be updated more completely and leave a TODO comment detailing some of the work required. Note that the nclasses value for Broadwell was already incorrect and doesn't need changing. The result is that any uncore events listed by pmcstat -L will no longer be allocatable, but this is already the case for newer generations of Intel CPUs. PR: 253687 Reported by: Zhenlei Huang Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D31389 (cherry picked from commit 4f35e8cba232d9256ab1399b8adfb761988e5eff) Git Hash: 88ef00584bc7f9f9e19546bc3ef8682d5c4d6cb6 Git Author: mhorne@FreeBSD.org END