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 08C0BEB64DA for ; Wed, 12 Jul 2023 19:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231784AbjGLT1Y (ORCPT ); Wed, 12 Jul 2023 15:27:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232295AbjGLT1V (ORCPT ); Wed, 12 Jul 2023 15:27:21 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86EC21FD8; Wed, 12 Jul 2023 12:27:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689190039; x=1720726039; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=rmWix9xmBsf4l8C7qj1+gB0nzdzmGQbV/inpq2dCZcc=; b=Aid4RyFCzfUZvqXnzgV3ltK01viKtdg8kHF8QlH3s0WeyqTI5wIrJ/8o nJRrvjw0sUF9lgDadt3J69HRzFgevsBoxlvfEmV7yh45FrMIFtwyjlOze QlRXGmXF42eDciV2aiwVZVjxvuIFJ6/jhH+h0oqOlbeo9a5py383m7VG8 s01nN2KxHbpOui4bTapG3E2uSS/XUb7oaxBgFS0pUoyfGMUAA1mYb3ofK dehdI1jUxLdAM1zKdFMOPgcia+7KNheYOiU8N2Kbbbua0Rem/D4ynhpn1 CGB6DcL82qlpfHP1eUN37wAyErQ+tj5A3glkr9S6N/MZnMtWqiUHwo4lc w==; X-IronPort-AV: E=McAfee;i="6600,9927,10769"; a="368517455" X-IronPort-AV: E=Sophos;i="6.01,200,1684825200"; d="scan'208";a="368517455" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2023 12:27:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10769"; a="845755269" X-IronPort-AV: E=Sophos;i="6.01,200,1684825200"; d="scan'208";a="845755269" Received: from averypay-mobl1.amr.corp.intel.com (HELO [10.212.212.40]) ([10.212.212.40]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jul 2023 12:27:18 -0700 Message-ID: <400c0d11-fa14-cb1c-f6ed-02f850753e46@linux.intel.com> Date: Wed, 12 Jul 2023 12:27:18 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.13.0 Subject: Re: [PATCH 02/10] x86/tdx: Use cmovc to save a label in TDX_MODULE_CALL asm Content-Language: en-US To: Kai Huang , peterz@infradead.org, kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org Cc: dave.hansen@intel.com, tglx@linutronix.de, bp@alien8.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, seanjc@google.com, pbonzini@redhat.com, kvm@vger.kernel.org, isaku.yamahata@intel.com References: <70784afc0a42d4dc1b1e743f90d89f7728496add.1689151537.git.kai.huang@intel.com> From: Sathyanarayanan Kuppuswamy In-Reply-To: <70784afc0a42d4dc1b1e743f90d89f7728496add.1689151537.git.kai.huang@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/12/23 1:55 AM, Kai Huang wrote: > Change 'jnc .Lno_vmfailinvalid' to 'cmovc %rdi, %rax' to save the > .Lno_vmfailinvalid label in the TDX_MODULE_CALL asm macro. You are removing the label, right? What use "save"? > > Note %rdi, which is used as the first argument, has been saved to %rax > as TDCALL leaf ID thus is free to hold the error code for cmovc. > > This is basically based on Peter's code. > > Cc: Kirill A. Shutemov > Cc: Dave Hansen > Cc: Peter Zijlstra > Suggested-by: Peter Zijlstra > Signed-off-by: Kai Huang > --- > arch/x86/virt/vmx/tdx/tdxcall.S | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/virt/vmx/tdx/tdxcall.S b/arch/x86/virt/vmx/tdx/tdxcall.S > index 49a54356ae99..3524915d8bd9 100644 > --- a/arch/x86/virt/vmx/tdx/tdxcall.S > +++ b/arch/x86/virt/vmx/tdx/tdxcall.S > @@ -57,10 +57,8 @@ > * This value will never be used as actual SEAMCALL error code as > * it is from the Reserved status code class. > */ > - jnc .Lno_vmfailinvalid > - mov $TDX_SEAMCALL_VMFAILINVALID, %rax > -.Lno_vmfailinvalid: > - > + mov $TDX_SEAMCALL_VMFAILINVALID, %rdi > + cmovc %rdi, %rax > .else > tdcall > .endif -- Sathyanarayanan Kuppuswamy Linux Kernel Developer