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 9A102EB64D7 for ; Fri, 30 Jun 2023 09:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232536AbjF3Jfc (ORCPT ); Fri, 30 Jun 2023 05:35:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232915AbjF3JfJ (ORCPT ); Fri, 30 Jun 2023 05:35:09 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73B9619C; Fri, 30 Jun 2023 02:35:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=gjvjkCCihEKSHCtNs55Vy6HK0fcX8LSjTlJEivouiKY=; b=q6KW/ltdiPKvvuRUgkhRpG5tiX xYPuaOz5D40BDLakmqRRweDB6CAbOHn5CbNRYUObwWPty+Rz7sxXyh62XDqPKlr/cq5bQYuU+k9h7 K/Z8H3HKvofJrY19uhf+RIta3h1hV8kLApOolc7NVHrSdb6RvUTaT7JwZwTxPX4LI9+9Xy72rG22a kF4L29JAf6v+j0l75hsaiKVdYYzy4PchGG9Q60FBOH9LaYWPbILZaeajIyiNXj6/KlV7DAJEmT9hP BYlCELyihyg0JOiaLMm4xWuaDdkxkPdRq+iPXtofR+QiyEtQp9l52W6yIUpwyqXXZdZGFCgArrW7A 1yKY3AjA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qFAWa-007wV9-29; Fri, 30 Jun 2023 09:34:44 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 21D78300118; Fri, 30 Jun 2023 11:34:44 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 07396245D3645; Fri, 30 Jun 2023 11:34:44 +0200 (CEST) Date: Fri, 30 Jun 2023 11:34:43 +0200 From: Peter Zijlstra To: "Huang, Kai" Cc: "kvm@vger.kernel.org" , "Raj, Ashok" , "Hansen, Dave" , "david@redhat.com" , "bagasdotme@gmail.com" , "Luck, Tony" , "ak@linux.intel.com" , "Wysocki, Rafael J" , "linux-kernel@vger.kernel.org" , "Christopherson,, Sean" , "mingo@redhat.com" , "pbonzini@redhat.com" , "linux-mm@kvack.org" , "tglx@linutronix.de" , "kirill.shutemov@linux.intel.com" , "Chatre, Reinette" , "Yamahata, Isaku" , "nik.borisov@suse.com" , "hpa@zytor.com" , "Shahar, Sagi" , "imammedo@redhat.com" , "bp@alien8.de" , "Gao, Chao" , "Brown, Len" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "Huang, Ying" , "Williams, Dan J" , "x86@kernel.org" Subject: Re: [PATCH v12 08/22] x86/virt/tdx: Get information about TDX module and TDX-capable memory Message-ID: <20230630093443.GE2533791@hirez.programming.kicks-ass.net> References: <20230628141011.GG2438817@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 29, 2023 at 09:15:39AM +0000, Huang, Kai wrote: > Sure. How about below? > > + /* > + * TDH.SYS.INFO writes the TDSYSINFO_STRUCT and the CMR array > + * to the buffers provided by the kernel (via RCX and R8 > + * respectively). The buffer size of the TDSYSINFO_STRUCT > + * (via RDX) and the maximum entries of the CMR array (via R9) > + * passed to this SEAMCALL must be at least the size of > + * TDSYSINFO_STRUCT and MAX_CMRS respectively. > + * > + * Upon a successful return, R9 contains the actual entries > + * written to the CMR array. > + */ > sysinfo_pa = __pa(sysinfo); > cmr_array_pa = __pa(cmr_array); > ret = seamcall(TDH_SYS_INFO, sysinfo_pa, TDSYSINFO_STRUCT_SIZE, > Or should I just repeat the spec like below? > + /* > + * TDH.SYS.INFO writes the TDSYSINFO_STRUCT and the CMR array > + * to the buffers provided by the kernel: > + * > + * Input: > + * - RCX: The buffer of TDSYSINFO_STRUCT > + * - RDX: The size of the TDSYSINFO_STRUCT buffer, must be at > + * at least the size of TDSYSINFO_STRUCT > + * - R8: The buffer of the CMR array > + * - R9: The entry number of the array, must be at least > + * MAX_CMRS. > + * > + * Output (successful): > + * - RDX: The actual bytes written to the TDSYSINFO_STRUCT > + * buffer > + * - R9: The actual entries written to the CMR array. > + */ > sysinfo_pa = __pa(sysinfo); > cmr_array_pa = __pa(cmr_array); > ret = seamcall(TDH_SYS_INFO, sysinfo_pa, TDSYSINFO_STRUCT_SIZE, Either of them work for me, thanks! > > SDM doesn't seem to be the place. That doesn't > > even list TDCALL/SEAMCALL in Volume 2 :-( Let alone describe the magic > > values. > > > > TDX has it's own specs at here: > > https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html > > For this one you can find it in here: > > https://cdrdv2.intel.com/v1/dl/getContent/733568 Yeah, eventually found it. I still think both TDCALL and SEAMCALL should be listed in SDM Vol.2 instruction listing -- every valid instruction should be found there IMO. I also feel strongly that a global ABI should be decided upon for them and the SDM would be a good place to mention that. leaving this to individual calls like now is a giant pain in the rear. As is, we have TDCALL leaf-0 with a giant regset but every other leaf has (c,d,8,9) for input and +(10,11) for output. Lets fix that in stone. Obviously I also very strongly feel any such ABI must not confict with pre-existing calling conventions -- IOW, using BP is out, must not happen.