From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (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 21F0C1FC110; Fri, 10 Jul 2026 02:38:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783651129; cv=none; b=XYJ1iKFJzvywcnql64/I29QbqvKoFTkbUAye8N8FUe8lzI2vtGhtp3wsIK5ToVYyjjyGHr7SE+eSIZY/ZPJ0xHzXkSMwYuj0HaTA5yr3/jj4rmCHtWJhUaSaWqKVK4vOYdY1n9pqkUjnKVjkrOPtjUOcOgroJQMwe/r0yt7QbRo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783651129; c=relaxed/simple; bh=0x4C/1T5Fv93ZRCdQSTMXxEAbc6R3w5NCQmzNosc7lw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BG90INUdo2gSYO6GpTPOS9tRHIpRG2utXqZ4/TardAgWQrnJ/vIO1hAPwLgxcbiXJj0HWgZ8dvu59zd0CnZkD4CEaD3G86eTsiViYgSRzIrLCWwdeNLHdZresUrWlfU3mQNx2VjyymnMhVSR25w+N+Mh+TrQMdK6w33aAnUqYBk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XUk5gxZU; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XUk5gxZU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1783651128; x=1815187128; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=0x4C/1T5Fv93ZRCdQSTMXxEAbc6R3w5NCQmzNosc7lw=; b=XUk5gxZUzBIa3CSaBPO+W3tPRMMpIyo1JKYnj5YFcqJFiIxqsp+p79Wh dPk0w1qd1u5R7zJN0wo4K5XzjREk6ukp/X7mgikMTXrDDVOw6+cQ9tRe7 0gbL2rWQKI5e9aR/gyvd5+wtxQcLRUpaYLNSrBxpExMP3qPi93l2gmfUJ TNO2mA0P5nQoTCLP4pabdWgUuk1laPkNhgNwa10KzMJTAuj5DKNs6Ld/O SzlT+LYkhLnHN26e9+N+cKzV0f1rRZnTDHDrhT0csjjetaCCfV1apaP1C r0GL1keMNCSfoZ62gYTC7+mLumtPUXolxudNvrC0XmVLGQkGJi3/9GpPp A==; X-CSE-ConnectionGUID: 83s7oaxHSsSmzzRfmQbb8w== X-CSE-MsgGUID: HJO9jbWHRqqP+u88xu0wKQ== X-IronPort-AV: E=McAfee;i="6800,10657,11841"; a="86892644" X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="86892644" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jul 2026 19:38:47 -0700 X-CSE-ConnectionGUID: FcGnj3rGRLmz9m//DZZF2Q== X-CSE-MsgGUID: QWs2GEtpToOJleyf+4+PTQ== X-ExtLoop1: 1 Received: from binbinwu-mobl.ccr.corp.intel.com (HELO [10.124.241.120]) ([10.124.241.120]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jul 2026 19:38:44 -0700 Message-ID: Date: Fri, 10 Jul 2026 10:38:40 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] x86/tdx: Add helper to query maximum TD Quote size To: Kiryl Shutsemau , Peter Fang Cc: Dave Hansen , Rick Edgecombe , Kuppuswamy Sathyanarayanan , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org References: <20260612110853.3188196-1-peter.fang@intel.com> <20260612110853.3188196-2-peter.fang@intel.com> Content-Language: en-US From: Binbin Wu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/12/2026 8:36 PM, Kiryl Shutsemau wrote: >> >> +/** >> + * tdx_get_max_quote_size() - Get the maximum TD Quote size >> + * >> + * Read the maximum size of a TD Quote from a 4-byte TD metadata field. The TDX >> + * guest driver uses it to size the buffer for Quote retrieval. Older TDX >> + * modules do not support this field and return an error. >> + * >> + * Return: Maximum Quote size in bytes on success, or 0 on failure. >> + */ >> +u32 tdx_get_max_quote_size(void) >> +{ >> + u64 val, ret; >> + >> + ret = tdg_vm_rd(TDCS_QUOTE_MAX_SIZE, &val); >> + >> + return ret ? 0 : (u32)val; > > Cast is redundant. I thought in Linux kernel, the explicit cast is often preferred? E.g. as documentation of the metadata field’s width here? > >> +} >> +EXPORT_SYMBOL_GPL(tdx_get_max_quote_size); >> + >> static void __noreturn tdx_panic(const char *msg) >> { >> struct tdx_module_args args = { >