From patchwork Tue Aug 1 08:32:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13335976 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C74EFC04E69 for ; Tue, 1 Aug 2023 09:05:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232556AbjHAJFU (ORCPT ); Tue, 1 Aug 2023 05:05:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232387AbjHAJEp (ORCPT ); Tue, 1 Aug 2023 05:04:45 -0400 Received: from mgamail.intel.com (unknown [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95B192D5B; Tue, 1 Aug 2023 02:03:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690880605; x=1722416605; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=YTgEgmA3f1uzY8PacyZ6XmpZcGIgDW5/dB0vDrivilc=; b=PO/74QaRNgZMmm/d126sLu+qzMi31gV2KHYwOavJBtselfWhz29z1Ej/ NHzmd1dMRNX57TbMoXuF6Plqd0+bV6h06LvR6Qht/u61GUVgEQK8+REW3 P4PvynmFKfng5j9kUf65jdru57T07GwxJT/ILfPdDPx8wd4Ap65g3ttJa kK+DpRXAG2yiVyGvVNz/q2l/o81jfgkANMkOP8KM6K8bzad3DNrFBkqiz ATWCU7UtiXHVm0yvtcohrZg5JLqx3x2NhE1uSq19cnh/sF7qgjvsT8Cu3 qSHMywRosVwN27ukaCKumRt/ORsmW1S3rF2+2SDLqiar9gHWxDRrRPeVz g==; X-IronPort-AV: E=McAfee;i="6600,9927,10788"; a="433082537" X-IronPort-AV: E=Sophos;i="6.01,246,1684825200"; d="scan'208";a="433082537" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Aug 2023 02:02:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10788"; a="975217048" X-IronPort-AV: E=Sophos;i="6.01,246,1684825200"; d="scan'208";a="975217048" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga006.fm.intel.com with ESMTP; 01 Aug 2023 02:02:04 -0700 From: Xin Li To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, kvm@vger.kernel.org, xen-devel@lists.xenproject.org Cc: Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Andy Lutomirski , Oleg Nesterov , Tony Luck , "K . Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Paolo Bonzini , Wanpeng Li , Vitaly Kuznetsov , Sean Christopherson , Peter Zijlstra , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Josh Poimboeuf , "Paul E . McKenney" , Catalin Marinas , Randy Dunlap , Steven Rostedt , Kim Phillips , Xin Li , Hyeonggon Yoo <42.hyeyoo@gmail.com>, "Liam R . Howlett" , Sebastian Reichel , "Kirill A . Shutemov" , Suren Baghdasaryan , Pawan Gupta , Babu Moger , Jim Mattson , Sandipan Das , Lai Jiangshan , Hans de Goede , Reinette Chatre , Daniel Sneddon , Breno Leitao , Nikunj A Dadhania , Brian Gerst , Sami Tolvanen , Alexander Potapenko , Andrew Morton , Arnd Bergmann , "Eric W . Biederman" , Kees Cook , Masami Hiramatsu , Masahiro Yamada , Ze Gao , Fei Li , Conghui , Ashok Raj , "Jason A . Donenfeld" , Mark Rutland , Jacob Pan , Jiapeng Chong , Jane Malalane , David Woodhouse , Boris Ostrovsky , Arnaldo Carvalho de Melo , Yantengsi , Christophe Leroy , Sathvika Vasireddy Subject: [PATCH RESEND v9 15/36] x86/fred: No ESPFIX needed when FRED is enabled Date: Tue, 1 Aug 2023 01:32:57 -0700 Message-Id: <20230801083318.8363-16-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230801083318.8363-1-xin3.li@intel.com> References: <20230801083318.8363-1-xin3.li@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: "H. Peter Anvin (Intel)" Because FRED always restores the full value of %rsp, ESPFIX is no longer needed when it's enabled. Signed-off-by: H. Peter Anvin (Intel) Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/kernel/espfix_64.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kernel/espfix_64.c b/arch/x86/kernel/espfix_64.c index 16f9814c9be0..48d133a54f45 100644 --- a/arch/x86/kernel/espfix_64.c +++ b/arch/x86/kernel/espfix_64.c @@ -106,6 +106,10 @@ void __init init_espfix_bsp(void) pgd_t *pgd; p4d_t *p4d; + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* Install the espfix pud into the kernel page directory */ pgd = &init_top_pgt[pgd_index(ESPFIX_BASE_ADDR)]; p4d = p4d_alloc(&init_mm, pgd, ESPFIX_BASE_ADDR); @@ -129,6 +133,10 @@ void init_espfix_ap(int cpu) void *stack_page; pteval_t ptemask; + /* FRED systems don't need ESPFIX */ + if (cpu_feature_enabled(X86_FEATURE_FRED)) + return; + /* We only have to do this once... */ if (likely(per_cpu(espfix_stack, cpu))) return; /* Already initialized */