From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com ([134.134.136.65]:39453 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726085AbeHXHIX (ORCPT ); Fri, 24 Aug 2018 03:08:23 -0400 Date: Thu, 23 Aug 2018 20:35:40 -0700 From: Andi Kleen To: Andre Tomt Cc: Vlastimil Babka , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Dave Hansen , Michal Hocko , stable@vger.kernel.org, Christopher Snowhill , George Anchev Subject: Re: [PATCH] x86/speculation/l1tf: fix off-by-one error when warning that system has too much RAM Message-ID: <20180824033540.GI12066@tassilo.jf.intel.com> References: <20180823134418.17008-1-vbabka@suse.cz> <20180823154437.GC12066@tassilo.jf.intel.com> <0fa72221-2272-4489-d9d3-0f68cb874087@tomt.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0fa72221-2272-4489-d9d3-0f68cb874087@tomt.net> Sender: stable-owner@vger.kernel.org List-ID: On Fri, Aug 24, 2018 at 04:22:57AM +0200, Andre Tomt wrote: > On 23. aug. 2018 17:44, Andi Kleen wrote: > > On Thu, Aug 23, 2018 at 03:44:18PM +0200, Vlastimil Babka wrote: > > > Two users have reported [1] that they have an "extremely unlikely" system > > > with more than MAX_PA/2 memory and L1TF mitigation is not effective. In fact > > > it's a CPU with 36bits phys limit (64GB) and 32GB memory, but due to holes > > > in the e820 map, the main region is almost 500MB over the 32GB limit: > > > > Ah I see it's a client part with very large DIMMs and someone being > > very brave and using that much memory without ECC. > > FYI; It is also happening on Xeon E3v2 (Ivy Bridge generation) w/ 32GB of > ECC RAM here, a low-end server part that officially supports up to 32GB. Good point. -andi