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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1777BC3600E for ; Wed, 26 Mar 2025 06:49:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1txKZh-0003Ss-UF; Wed, 26 Mar 2025 02:49:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1txKZL-0003Mj-RA for qemu-devel@nongnu.org; Wed, 26 Mar 2025 02:48:56 -0400 Received: from mgamail.intel.com ([198.175.65.16]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1txKZI-00064V-6a for qemu-devel@nongnu.org; Wed, 26 Mar 2025 02:48:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1742971732; x=1774507732; h=message-id:date:mime-version:subject:from:to:cc: references:in-reply-to:content-transfer-encoding; bh=lGHap775uUsDXdJ0pqioIOwfjJYZBUBsKzdh01RnGGQ=; b=KG8MKxyfsFU1WqKIWX3ecT3tCKBigBu3hnyjt5sDQRuPiPRhRlwzw1XK aHttG2ih0AY7hx5A3asqh5pIRqe/8CWMsz5aEYI3lSTWGnpcJRYq3rv0a rKfosQFZ8qDMAVrGAxR6rNO9zMUhIf0N8puV4CECoj6RCIcweQXEFkId7 3vbboXtxMwxRuzw1o4YfRpwxcAmXvJkbfpcxlNBFh6WJczIwM+k6jOpGY y/8iBcfd/JvCLuCrfVOPFrfaLd5/cacKaHTJTrovlKNAksifCbfdlgL3N fIN4rxKA9DXaaF+xClfOvIbkug8NoI7tGihGf64FGDtfWf9tVtIWy/xBg w==; X-CSE-ConnectionGUID: kxwVZTRNQ1iM84F7hM31cA== X-CSE-MsgGUID: j4zVDmZhTP+SgME5+7PExg== X-IronPort-AV: E=McAfee;i="6700,10204,11384"; a="44345660" X-IronPort-AV: E=Sophos;i="6.14,277,1736841600"; d="scan'208";a="44345660" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2025 23:48:50 -0700 X-CSE-ConnectionGUID: 68MwVopJSLWzAXB4RNLlSw== X-CSE-MsgGUID: r+iBB8MXQ2eGfmOr8YxMVw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,277,1736841600"; d="scan'208";a="125182656" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.124.247.1]) ([10.124.247.1]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2025 23:48:46 -0700 Message-ID: <46f1d5cc-9ef0-4411-93e8-399d2c7e269b@intel.com> Date: Wed, 26 Mar 2025 14:48:42 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 52/52] docs: Add TDX documentation From: Xiaoyao Li To: =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= Cc: Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= , Igor Mammedov , Zhao Liu , "Michael S. Tsirkin" , Eric Blake , Markus Armbruster , Peter Maydell , Marcelo Tosatti , Huacai Chen , Rick Edgecombe , Francesco Lavra , qemu-devel@nongnu.org, kvm@vger.kernel.org References: <20250124132048.3229049-1-xiaoyao.li@intel.com> <20250124132048.3229049-53-xiaoyao.li@intel.com> <81e9d055-377c-4521-9588-a6bad60b3a6d@intel.com> Content-Language: en-US In-Reply-To: <81e9d055-377c-4521-9588-a6bad60b3a6d@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=198.175.65.16; envelope-from=xiaoyao.li@intel.com; helo=mgamail.intel.com X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.776, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 3/26/2025 11:36 AM, Xiaoyao Li wrote: > On 3/26/2025 2:46 AM, Daniel P. Berrangé wrote: >> On Fri, Jan 24, 2025 at 08:20:48AM -0500, Xiaoyao Li wrote: >>> Add docs/system/i386/tdx.rst for TDX support, and add tdx in >>> confidential-guest-support.rst >>> >>> Signed-off-by: Xiaoyao Li >>> --- >> >>> --- >>>   docs/system/confidential-guest-support.rst |   1 + >>>   docs/system/i386/tdx.rst                   | 156 +++++++++++++++++++++ >>>   docs/system/target-i386.rst                |   1 + >>>   3 files changed, 158 insertions(+) >>>   create mode 100644 docs/system/i386/tdx.rst >> >> >>> +Launching a TD (TDX VM) >>> +----------------------- >>> + >>> +To launch a TD, the necessary command line options are tdx-guest >>> object and >>> +split kernel-irqchip, as below: >>> + >>> +.. parsed-literal:: >>> + >>> +    |qemu_system_x86| \\ >>> +        -object tdx-guest,id=tdx0 \\ >>> +        -machine ...,kernel-irqchip=split,confidential-guest- >>> support=tdx0 \\ >>> +        -bios OVMF.fd \\ >>> + >>> +Restrictions >>> +------------ >>> + >>> + - kernel-irqchip must be split; >> >> Is there a reason why we don't make QEMU set kernel-irqchip=split >> automatically when tdx-guest is enabled ? >> >> It feels silly to default to a configuration that is known to be >> broken with TDX. I thought about making libvirt automatically >> set kernel-irqchip=split, or even above that making virt-install >> automatically set it. Addressing it in QEMU would seem the most >> appropriate place though. > > For x86, if not with machine older than machine-4.0, the default > kernel_irqchip is set to split when users don't set a value explicitly: > >  if (s->kernel_irqchip_split == ON_OFF_AUTO_AUTO) { >         s->kernel_irqchip_split = mc->default_kernel_irqchip_split ? > ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; >     } Ah! it happens later than tdx_kvm_init(). So we need something like... > > I think QEMU should only set it to split automatically for TDX guest > when users don't provide a explicit value. And current code just works > as expected. > > Further, I think we can at least add the check in tdx_kvm_init() like this > > if (kvm_state->kernel_irqchip_split != ON_OFF_AUTO_ON) { >     error_setg(errp, "TDX VM requires kernel_irqchip to be split"); >     return -EINVAL; > } ... @@ -693,6 +694,13 @@ static int tdx_kvm_init(ConfidentialGuestSupport *cgs, Error **errp) return -EINVAL; } + if (kvm_state->kernel_irqchip_split == ON_OFF_AUTO_AUTO ) { + kvm_state->kernel_irqchip_split = ON_OFF_AUTO_ON; + } else if(kvm_state->kernel_irqchip_split != ON_OFF_AUTO_ON) { + error_setg(errp, "TDX VM requires kernel_irqchip to be split"); + return -EINVAL; + } > Are you OK with it? > >> >> With regards, >> Daniel > >