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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 17448E9271A for ; Thu, 5 Oct 2023 15:58:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235241AbjJEP6A (ORCPT ); Thu, 5 Oct 2023 11:58:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233396AbjJEP4n (ORCPT ); Thu, 5 Oct 2023 11:56:43 -0400 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A2B66620 for ; Thu, 5 Oct 2023 07:04:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696514684; x=1728050684; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2WU7kKiOy1VKJ5VS01o46StvhoI+3fSkV4NdlGG5HN8=; b=ILf+ujyDGQFTZ/JWQGF/IuxJRj9c2B3cRVH/yThZTCIvai3jd0BnON98 WpvuwH33ehUeNYnLpnOlTaXJ6+zbtnNWtW7O50Hvh4dn01uZMvOO90DUb NhuPkD2bBa6KM1dUGCsou8fxDlEYAFhiryQz0Fbs03R9xUYRdRFobOTGj Kcck4+YunlRspwl5ysV93KBaq0rbXcFNjihdAtwlK4ukOK5k7yAYYNi7H WEVYCnxeh5ByDK3YidMcfO/tWgN3OzHiAnuw9nTUAnZibhd4Kla+RhemE 9p5mGKHBtFpVCeZ5FcA7hEhUi9MPqE2cKMIb5v5dVkYAd094UNqN0vd2f g==; X-IronPort-AV: E=McAfee;i="6600,9927,10854"; a="380767178" X-IronPort-AV: E=Sophos;i="6.03,203,1694761200"; d="scan'208";a="380767178" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2023 06:14:28 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10854"; a="728449267" X-IronPort-AV: E=Sophos;i="6.03,203,1694761200"; d="scan'208";a="728449267" Received: from skwasnia-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.251.222.71]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2023 06:14:23 -0700 Received: by box.shutemov.name (Postfix, from userid 1000) id 3D69E10A14E; Thu, 5 Oct 2023 16:14:14 +0300 (+03) From: "Kirill A. Shutemov" To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "Rafael J. Wysocki" , Peter Zijlstra , Adrian Hunter , Kuppuswamy Sathyanarayanan , Elena Reshetova , Jun Nakajima , Rick Edgecombe , Tom Lendacky , kexec@lists.infradead.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 05/13] x86/kexec: Keep CR4.MCE set during kexec for TDX guest Date: Thu, 5 Oct 2023 16:13:54 +0300 Message-ID: <20231005131402.14611-6-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231005131402.14611-1-kirill.shutemov@linux.intel.com> References: <20231005131402.14611-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org TDX guests are not allowed to clear CR4.MCE. Attempt to clear it leads to #VE. Use alternatives to keep the flag during kexec for TDX guests. The change doesn't affect non-TDX environments. Signed-off-by: Kirill A. Shutemov --- arch/x86/kernel/relocate_kernel_64.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 56cab1bb25f5..bea89814b48e 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -145,11 +145,16 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) * Set cr4 to a known state: * - physical address extension enabled * - 5-level paging, if it was enabled before + * - Machine check exception on TDX guest. Clearing MCE is not allowed + * in TDX guests. */ movl $X86_CR4_PAE, %eax testq $X86_CR4_LA57, %r13 jz 1f orl $X86_CR4_LA57, %eax +1: + ALTERNATIVE "jmp 1f", "", X86_FEATURE_TDX_GUEST + orl $X86_CR4_MCE, %eax 1: movq %rax, %cr4 -- 2.41.0