From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 94C3A2C9C for ; Mon, 31 Jan 2022 17:23:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643649802; x=1675185802; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=xIYOgmHAUu2Fj3KeMiX4Tf2d+2ukgp180usOlMKTEGc=; b=UuRnukYix4gIqVyTI+seyv5YAW6BpIjuvj8lp82/z9alpUwb1KSV4sZA +UvBNfiouS7Bz4fLcvi5XgY2Ie1UQsDvikd0lMgeTFU1+w5p8mOF8wnk8 YIoDN+i04WQGIk8jYNdmISD8TV2lGKfoLhHDY2sbondxonNd25Ebm22Lj siSAdt0JcBh3+kIHVObQp8IGRCQM5cVqFqI7DnzVfSKLxv6VR5odxALNp qpDRg9ryAza7j6cZZG3UFg2Tws3w3S50iJVLWs/ku1GHj8krxxozshNWt Bpm2S0zi+ZhvlBWhY4FvwRzl291HGu7hs2IL/Kl1YMb/gbQ7Yfzt3MH7h A==; X-IronPort-AV: E=McAfee;i="6200,9189,10244"; a="228172482" X-IronPort-AV: E=Sophos;i="5.88,331,1635231600"; d="scan'208";a="228172482" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2022 09:23:21 -0800 X-IronPort-AV: E=Sophos;i="5.88,331,1635231600"; d="scan'208";a="582731220" Received: from agluck-desk2.sc.intel.com (HELO agluck-desk2.amr.corp.intel.com) ([10.3.52.146]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jan 2022 09:23:21 -0800 Date: Mon, 31 Jan 2022 09:23:20 -0800 From: "Luck, Tony" To: Borislav Petkov Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Smita Koralahalli Channabasappa , Wei Huang , Tom Lendacky , patches@lists.linux.dev Subject: Re: [PATCH v2 0/6] PPIN (Protected Processor Inventory Number) updates Message-ID: References: <20220107225442.1690165-1-tony.luck@intel.com> <20220121174743.1875294-1-tony.luck@intel.com> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Mon, Jan 31, 2022 at 01:31:49PM +0100, Borislav Petkov wrote: > On Fri, Jan 21, 2022 at 09:47:37AM -0800, Tony Luck wrote: > > ... > > They look good so far on my PPIN-enabled AMD box. > > > 5) Add "ppin" to /sys/devices/system/cpu/cpu*/topology/ppin > > > > The big question for this part is whether there is a better > > place to expose this value. I'm open to other suggestions. > > Yeah, I'm not sure about that either. I have > > $ grep -r . /sys/devices/system/cpu/cpu*/topology/ppin | cut -d: -f 2 | uniq -c > 32 0xxxxx > > 32 times the same number. > > Wouldn't > > /sys/devices/system/node/ > > be a better place? Maybe. > Even if those were logical nodes, it would still be less needless > replication and that would be one more way for root to figure out which > logical nodes belong to the same physical package... :-) That would work for existing products. There are some cases where a single package appears as mutiple nodes. But that's ok ... as you say, one more clue to the topology. I'm worried that some future thing might reverse that and have a "package" id for each die in a multi-die package which still appears as a single node. That would distort the meaning of "package", so it isn't supposed to happen. But if it did, Linux would be stuck just reporting one of the "package" ids. -Tony