From patchwork Mon May 11 19:17:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 11541457 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6889814B4 for ; Mon, 11 May 2020 19:17:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3EAEE20836 for ; Mon, 11 May 2020 19:17:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3EAEE20836 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6929990007C; Mon, 11 May 2020 15:17:41 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 61C48900036; Mon, 11 May 2020 15:17:41 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4E3E790007C; Mon, 11 May 2020 15:17:41 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 31B26900036 for ; Mon, 11 May 2020 15:17:41 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DE15A40D0 for ; Mon, 11 May 2020 19:17:40 +0000 (UTC) X-FDA: 76805397480.24.bear76_6016614ea3110 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,kirill.shutemov@linux.intel.com,,RULES_HIT:30003:30051:30054:30064:30070,0,RBL:192.55.52.151:@linux.intel.com:.lbl8.mailshell.net-62.18.0.100 64.95.201.95,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:22,LUA_SUMMARY:none X-HE-Tag: bear76_6016614ea3110 X-Filterd-Recvd-Size: 3798 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Mon, 11 May 2020 19:17:40 +0000 (UTC) IronPort-SDR: 3ZlzTMDyrzJZut9vPusdIPQvUdGy4Vj70gCqBz/iEurfVhJvz6PlOiSlzNIqAW6uUQVBh+cOqe /eLz4IB64iqQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2020 12:17:38 -0700 IronPort-SDR: 7rI5Y2URj4Z3ZVTn5xNuUPdfFIBRovGG6XDdw2LDRlLTSmih0uTEq4GyrUiFsSnLjPbUTZVGdP mJBavOIgkTEg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,381,1583222400"; d="scan'208";a="261865903" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga003.jf.intel.com with ESMTP; 11 May 2020 12:17:34 -0700 Received: by black.fi.intel.com (Postfix, from userid 1000) id CE171170; Mon, 11 May 2020 22:17:33 +0300 (EEST) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Cc: Dan Williams , Tony Luck , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" , Dave Hansen , stable@vger.kernel.org Subject: [PATCH] x86/mm: Fix boot with some memory above MAXMEM Date: Mon, 11 May 2020 22:17:21 +0300 Message-Id: <20200511191721.1416-1-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: A 5-level paging capable machine can have memory above 46-bit in the physical address space. This memory is only addressable in the 5-level paging mode: we don't have enough virtual address space to create direct mapping for such memory in the 4-level paging mode. Currently, we fail boot completely: NULL pointer dereference in subsection_map_init(). Skip creating a memblock for such memory instead and notify user that some memory is not addressable. Signed-off-by: Kirill A. Shutemov Reviewed-by: Dave Hansen Cc: stable@vger.kernel.org # v4.14 --- Tested with a hacked QEMU: https://gist.github.com/kiryl/d45eb54110944ff95e544972d8bdac1d --- arch/x86/kernel/e820.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index c5399e80c59c..d320d37d0f95 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1280,8 +1280,8 @@ void __init e820__memory_setup(void) void __init e820__memblock_setup(void) { + u64 size, end, not_addressable = 0; int i; - u64 end; /* * The bootstrap memblock region count maximum is 128 entries @@ -1307,7 +1307,22 @@ void __init e820__memblock_setup(void) if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN) continue; - memblock_add(entry->addr, entry->size); + if (entry->addr >= MAXMEM) { + not_addressable += entry->size; + continue; + } + + end = min_t(u64, end, MAXMEM - 1); + size = end - entry->addr; + not_addressable += entry->size - size; + memblock_add(entry->addr, size); + } + + if (not_addressable) { + pr_err("%lldGB of physical memory is not addressable in the paging mode\n", + not_addressable >> 30); + if (!pgtable_l5_enabled()) + pr_err("Consider enabling 5-level paging\n"); } /* Throw away partial pages: */