From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18734125A3 for ; Thu, 5 Oct 2023 13:16:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ZYCMtkZk" Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1696511808; x=1728047808; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=2WU7kKiOy1VKJ5VS01o46StvhoI+3fSkV4NdlGG5HN8=; b=ZYCMtkZk3aXGBWXUvkNgqBN+EDB0uyd13qOsU3/TA3p4HmKWJPnS33is /B8p6Xn9Ce2CbOb3LsFsTP/P+bJce1+EqHxDNRqkmK96mpbglpqAhTmuD ojWZ8FhYENTS3GEy+iJIcrjySsF3WvcYb5wDSkm+tTwawAZUUP2tEOV3S HOoiBsPE28D9MCC9Qwp20/EvLrnC+mwxPBpZ37RWjdz8uqM0mFlP5YHCn f/bNwoNjIH3TbnjI2ugRCDgegmdvQNPGBX4FX3HWNxSox08uSs3VjYxYc f4I0DL5N5zy/Mp+l08naXzgz7asmlf4I4AJtqLgqzu5c0qxMkR3q7Vhs8 A==; X-IronPort-AV: E=McAfee;i="6600,9927,10854"; a="380767174" X-IronPort-AV: E=Sophos;i="6.03,203,1694761200"; d="scan'208";a="380767174" 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> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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