From nobody Tue Dec 16 13:28:05 2025 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) (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 2B2AF233158 for ; Wed, 12 Mar 2025 11:35:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.15 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741779305; cv=none; b=ONVfj/pJiTCAiIiwVt5aiQ1IqONQ5fCOJWVCnpTK3Tfjoc1sePmYCUNvoOozhKpAImBnaDD2y6/62AU1Zxj/WcSVEjFEuaknhap7Rb0xOAzIgiA23UvgFy9LSNjZOWrVWw2ojdjMoOjSl92x49Fl6Tb+nneZUb0Y3qvnvZ+Nrjw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741779305; c=relaxed/simple; bh=G0MmR5iRxBh07af046kGj0hf2GwsQOPoKtevieu66rQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eWldBKabr/3U22DY3kh3Y+vAG+HduvluGSctulTX0n14QwDJoLVaas8N98brjs9v5Y/Mpj1tJE3zvLZT0qI/S9Ro4Vfvp4xO1Fd0lhB7lpWCjTZ1hc5NnnP2u+WDlyq8vGl8bASnhOC64Ve6HAAGlIztR7CZj7Mn47PNh+MYfRM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=JuXGipWS; arc=none smtp.client-ip=192.198.163.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="JuXGipWS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1741779304; x=1773315304; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=G0MmR5iRxBh07af046kGj0hf2GwsQOPoKtevieu66rQ=; b=JuXGipWSBrSMRqTKfPigXac7XulQL3d2LN5r7DzIhc0N92e964TskbFf TsYfocWUy/QInWn7eP6yPSaqcbqhBCIiua2OyI9w0dwcBY4bivnjSyLsK gTJ/vNrWOM2PlkaYbVc9+T7udGCzSSYbNIJy7vM2v14xiWtWhl7gnxuOg umneOOfG9LBp8WMMC+EUKioAvlm4YQqTCBMX3GGSEwRtiH5vL4/oLuOpO q00wYpmNjGFiDWbRj7+lfOrzikMK4B4+/HS7dZKDVDmVUrz+K7eXCcIMd IDYljeHGxiMDNlvi4KL3tWcIeUxun4Xey73WR3KQ83d3q+uKMt2b8UiOj w==; X-CSE-ConnectionGUID: ioalGvEwTOGzVq7YhLT0Zg== X-CSE-MsgGUID: JdSq7KvSSFSdN6I5XYK4DQ== X-IronPort-AV: E=McAfee;i="6700,10204,11370"; a="42985198" X-IronPort-AV: E=Sophos;i="6.14,241,1736841600"; d="scan'208";a="42985198" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2025 04:35:04 -0700 X-CSE-ConnectionGUID: tYeeWgW8SNOS5zbhhCNt1Q== X-CSE-MsgGUID: 7n0YB7gcQmunXVsJtSyjRA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,241,1736841600"; d="scan'208";a="124776128" Received: from iweiny-desk3.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.124.221.164]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2025 04:34:59 -0700 From: Kai Huang To: dave.hansen@intel.com, bp@alien8.de, tglx@linutronix.de, peterz@infradead.org, mingo@redhat.com, kirill.shutemov@linux.intel.com Cc: hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com, rick.p.edgecombe@intel.com, reinette.chatre@intel.com, isaku.yamahata@intel.com, dan.j.williams@intel.com, thomas.lendacky@amd.com, ashish.kalra@amd.com, dwmw@amazon.co.uk, bhe@redhat.com, nik.borisov@suse.com, sagis@google.com Subject: [RFC PATCH 5/5] x86/virt/tdx: Update the kexec section in the TDX documentation Date: Thu, 13 Mar 2025 00:34:17 +1300 Message-ID: <2e88fd265c88cb42cef505e89c466c5625f4a5b6.1741778537.git.kai.huang@intel.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" TDX host kernel now supports kexec/kdump. Update the documentation to reflect that. Signed-off-by: Kai Huang --- Documentation/arch/x86/tdx.rst | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/Documentation/arch/x86/tdx.rst b/Documentation/arch/x86/tdx.rst index 719043cd8b46..8874c210e545 100644 --- a/Documentation/arch/x86/tdx.rst +++ b/Documentation/arch/x86/tdx.rst @@ -142,13 +142,6 @@ but depends on the BIOS to behave correctly. Note TDX works with CPU logical online/offline, thus the kernel still allows to offline logical CPU and online it again. =20 -Kexec() -~~~~~~~ - -TDX host support currently lacks the ability to handle kexec. For -simplicity only one of them can be enabled in the Kconfig. This will be -fixed in the future. - Erratum ~~~~~~~ =20 @@ -171,6 +164,16 @@ If the platform has such erratum, the kernel prints ad= ditional message in machine check handler to tell user the machine check may be caused by kernel bug on TDX private memory. =20 +Kexec +~~~~~~~ + +Kexec/kdump works normally when TDX is enabled in the kernel. One +limitation is if the old kernel has ever enabled TDX the new kernel won't +be able to use TDX anymore. + +One exception is kexec/kdump are disabled on the platform with the TDX +"tdx_pw_mce" erratum. This will be enhanced in the future. + Interaction vs S3 and deeper states ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ =20 --=20 2.48.1