From patchwork Tue Aug 1 08:33:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Xin3" X-Patchwork-Id: 13335983 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 D7E27C04FE2 for ; Tue, 1 Aug 2023 09:06:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232674AbjHAJGc (ORCPT ); Tue, 1 Aug 2023 05:06:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232565AbjHAJF7 (ORCPT ); Tue, 1 Aug 2023 05:05:59 -0400 Received: from mgamail.intel.com (unknown [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2E9B3C3D; Tue, 1 Aug 2023 02:04:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690880658; x=1722416658; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=QeZUtDgMAPwFIrdo9TmaG72+ignP6GGIZpxe8B2aw6k=; b=Ywoci1Nx767Qty2t1CqBpNGNVjPof5Bi8up/OSJlMMO8yy2nT9hpW/1D NwvWsUC4s03u01/O7/CWLr1Q5vo5PyrjZ+lc7KMTyjyCZNGgiAggFjGpJ Xp28tf4lpso00bEqh08+ZptdsqcHWaFKIMcOEovyuovWJDgsOZqeI3qaW ZZlg0+D6GpCDvX8EeJuzYiI6Afc76xKrihKyo37g7tw+rMifAhDZRYy5f ++7jQ+0t9C2VcZ54LsNZqi2+hBqYahdaWu1DuTvWGjRBRpZM4bywlc/u5 JOdZGKrm7qNF2M7kUwge+gItcwJ9xcZqMisC+di0XZyjcgH3EJwsq2tav g==; X-IronPort-AV: E=McAfee;i="6600,9927,10788"; a="433082781" X-IronPort-AV: E=Sophos;i="6.01,246,1684825200"; d="scan'208";a="433082781" 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 02:02:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10788"; a="975217078" X-IronPort-AV: E=Sophos;i="6.01,246,1684825200"; d="scan'208";a="975217078" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga006.fm.intel.com with ESMTP; 01 Aug 2023 02:02:10 -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 22/36] x86/fred: Add a double fault entry stub for FRED Date: Tue, 1 Aug 2023 01:33:04 -0700 Message-Id: <20230801083318.8363-23-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 The IDT event delivery of a double fault pushes an error code into the orig_ax member of the pt_regs structure, and the error code is passed as the second argument of its C-handler exc_double_fault(), although the pt_regs structure is already passed as the first argument. The existing IDT double fault asm entry code does the following movq ORIG_RAX(%rsp), %rsi /* get error code into 2nd argument*/ movq $-1, ORIG_RAX(%rsp) /* no syscall to restart */ to set the orig_ax member to -1 just before calling the C-handler. X86_TRAP_TS, X86_TRAP_NP, X86_TRAP_SS, X86_TRAP_GP, X86_TRAP_AC and X86_TRAP_CP are all handled in the same way because the IDT event delivery pushes an error code into their stack frame for them. The commit d99015b1abbad ("x86: move entry_64.S register saving out of the macros") introduced the changes to set orig_ax to -1, but I can't see why. Our tests with FRED seem fine if orig_ax is left unchanged instead of set to -1. It's probably cleaner and simpler to remove the second argument from exc_double_fault() while leave orig_ax unchanged to pass the error code inside the first argument, at least on native x86_64. That would be a separate, pre-FRED, patch. For now just add a double fault entry stub for FRED, which simply calls the existing exc_double_fault(). Tested-by: Shan Kang Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 1 + arch/x86/kernel/traps.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index f559dd9dc4f2..bd701ac87528 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -116,6 +116,7 @@ DECLARE_FRED_HANDLER(fred_exc_nmi); DECLARE_FRED_HANDLER(fred_exc_debug); DECLARE_FRED_HANDLER(fred_exc_page_fault); DECLARE_FRED_HANDLER(fred_exc_machine_check); +DECLARE_FRED_HANDLER(fred_exc_double_fault); #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index b10464966a81..49dd92458eb0 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -555,6 +555,13 @@ DEFINE_IDTENTRY_DF(exc_double_fault) instrumentation_end(); } +#ifdef CONFIG_X86_FRED +DEFINE_FRED_HANDLER(fred_exc_double_fault) +{ + exc_double_fault(regs, regs->orig_ax); +} +#endif + DEFINE_IDTENTRY(exc_bounds) { if (notify_die(DIE_TRAP, "bounds", regs, 0,