linux-kernel - Re: AMD EPYC Topology problems

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20181209125648.GA15262@zn.tnic>
Date:   Sun, 9 Dec 2018 13:56:48 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Andrew Cooper <andrew.cooper3@...rix.com>
Cc:     Xen-devel List <xen-devel@...ts.xen.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Jan Beulich <JBeulich@...e.com>,
        Brian Woods <brian.woods@....com>,
        SuraveeSuthikulpanit <suravee.suthikulpanit@....com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Brijesh Singh <brijeshkumar.singh@....com>
Subject: Re: AMD EPYC Topology problems

On Mon, Dec 03, 2018 at 11:23:49AM +0000, Andrew Cooper wrote:
> Right, but the documentation also states that where it says package, it
> means "Node" in AMD's terminology, and the information in CPUID is per
> socket, not per node.
> 
> My point is that the numbers ending up in cpuinfo_x86 don't match the
> semantics described by the documentation.

Ok, I think I know where the issue stems from:

	definition of "package" in the AMD docs != definition of "package" in Documentation/x86/topology.txt

AMD's is "Processor: A package containing one or more Nodes." whereas
ours is:

  "Packages contain a number of cores plus shared resources, e.g. DRAM
   controller, shared caches etc."

and physical sockets we don't care about because they're not relevant to
sw.

Yeah, lemme discuss this with tglx to refresh what we were thinking then. :)

Stay tuned.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.