From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A360C4321D for ; Fri, 17 Aug 2018 13:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F20121868 for ; Fri, 17 Aug 2018 13:40:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F20121868 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727530AbeHQQnr (ORCPT ); Fri, 17 Aug 2018 12:43:47 -0400 Received: from mx2.suse.de ([195.135.220.15]:48922 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726367AbeHQQnr (ORCPT ); Fri, 17 Aug 2018 12:43:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C7F19ADB5; Fri, 17 Aug 2018 13:40:20 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org Cc: boris.ostrovsky@oracle.com, hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, pasha.tatashin@oracle.com, Juergen Gross Subject: [PATCH] x86/xen: enable early use of set_fixmap in 32-bit Xen PV guest Date: Fri, 17 Aug 2018 15:40:16 +0200 Message-Id: <20180817134016.19957-1-jgross@suse.com> X-Mailer: git-send-email 2.13.7 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 7b25b9cb0dad83 ("x86/xen/time: Initialize pv xen time in init_hypervisor_platform()") moved the mapping of the shared info area before pagetable_init(). This breaks booting as 32-bit PV guest as the use of set_fixmap isn't possible at this time on 32-bit. This can be worked around by populating the needed PMD on 32-bit kernel earlier. In order not to reimplement populate_extra_pte() using extend_brk() for allocating new page tables extend alloc_low_pages() to do that in case the early page table pool is not yet available. Fixes: 7b25b9cb0dad83 Signed-off-by: Juergen Gross --- arch/x86/mm/init.c | 17 ++++++++++++----- arch/x86/xen/enlighten_pv.c | 2 ++ arch/x86/xen/mmu_pv.c | 2 ++ 3 files changed, 16 insertions(+), 5 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index acfab322fbe0..5c32a7665492 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -99,15 +99,22 @@ __ref void *alloc_low_pages(unsigned int num) } if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) { - unsigned long ret; - if (min_pfn_mapped >= max_pfn_mapped) - panic("alloc_low_pages: ran out of memory"); - ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT, + unsigned long ret = 0; + + if (min_pfn_mapped < max_pfn_mapped) { + ret = memblock_find_in_range( + min_pfn_mapped << PAGE_SHIFT, max_pfn_mapped << PAGE_SHIFT, PAGE_SIZE * num , PAGE_SIZE); + } + if (ret) + memblock_reserve(ret, PAGE_SIZE * num); + else if (can_use_brk_pgt) + ret = __pa(extend_brk(PAGE_SIZE * num, PAGE_SIZE)); + if (!ret) panic("alloc_low_pages: can not alloc memory"); - memblock_reserve(ret, PAGE_SIZE * num); + pfn = ret >> PAGE_SHIFT; } else { pfn = pgt_buf_end; diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index ee3b00c7acda..d7b2022ee301 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -122,6 +122,8 @@ static void __init xen_banner(void) static void __init xen_pv_init_platform(void) { + populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP)); + set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info); HYPERVISOR_shared_info = (void *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index 52206ad81e4b..9e7012858420 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -2171,6 +2171,8 @@ void __init xen_relocate_p2m(void) #else /* !CONFIG_X86_64 */ static RESERVE_BRK_ARRAY(pmd_t, initial_kernel_pmd, PTRS_PER_PMD); static RESERVE_BRK_ARRAY(pmd_t, swapper_kernel_pmd, PTRS_PER_PMD); +RESERVE_BRK(fixup_kernel_pmd, PAGE_SIZE); +RESERVE_BRK(fixup_kernel_pte, PAGE_SIZE); static void __init xen_write_cr3_init(unsigned long cr3) { -- 2.13.7