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 8B596C433FE for ; Mon, 28 Nov 2022 19:11:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231638AbiK1TLM (ORCPT ); Mon, 28 Nov 2022 14:11:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233130AbiK1TLL (ORCPT ); Mon, 28 Nov 2022 14:11:11 -0500 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BAC5D27937; Mon, 28 Nov 2022 11:11:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669662669; x=1701198669; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=zTgmYKgO75Lve7MV3Q2C6BWy8I6LIC0zD/4hqS76Z50=; b=BvTaxNPP+Vt7r/4CPUZvM3joaOlfuidHeJbFaC/RsF+wj1fmsv3+t67s DYQJKXEFKnUgWTzHJj2fsD2aLoj+xz36aLHbZwrgFZ/tpRfC2+ihCf+LX zC630ZmSCJa7S8NJv4p1JEqRFwTy/52s6sDYLI87bhEGX3AGwEx9NGJDk mdPppfqATaI8PmvWD+BaD4WUsCQ3ye8PhZ8kLi6AzAELyzEgGIvmN61mO lUt86jH3pVSuO+F6zLKKJOUCdVkO7j8nPlVeCeUX0aDcF5MyPTF1i+AJR i0MJRHLygJFPpIzsaizmDk/lhGXFK3IpFs9QJ/nQWD7byGSBSnGmTz4Qa g==; X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="313631536" X-IronPort-AV: E=Sophos;i="5.96,200,1665471600"; d="scan'208";a="313631536" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 11:11:09 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="712086678" X-IronPort-AV: E=Sophos;i="5.96,200,1665471600"; d="scan'208";a="712086678" Received: from nroy-mobl1.amr.corp.intel.com (HELO [10.212.209.4]) ([10.212.209.4]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 11:11:06 -0800 Message-ID: <54871aec-823b-1ff5-8362-688d10e97263@intel.com> Date: Mon, 28 Nov 2022 11:11:05 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH 5/6] x86/hyperv: Support hypercalls for TDX guests Content-Language: en-US To: Dexuan Cui , "Michael Kelley (LINUX)" , "ak@linux.intel.com" , "arnd@arndb.de" , "bp@alien8.de" , "brijesh.singh@amd.com" , "Williams, Dan J" , "dave.hansen@linux.intel.com" , Haiyang Zhang , "hpa@zytor.com" , "jane.chu@oracle.com" , "kirill.shutemov@linux.intel.com" , KY Srinivasan , "linux-arch@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "luto@kernel.org" , "mingo@redhat.com" , "peterz@infradead.org" , "rostedt@goodmis.org" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "seanjc@google.com" , "tglx@linutronix.de" , "tony.luck@intel.com" , "wei.liu@kernel.org" , "x86@kernel.org" Cc: "linux-kernel@vger.kernel.org" References: <20221121195151.21812-1-decui@microsoft.com> <20221121195151.21812-6-decui@microsoft.com> From: Dave Hansen In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On 11/28/22 11:03, Dexuan Cui wrote: ... > u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2) > { > struct tdx_hypercall_args args = { }; > > if (!(control & HV_HYPERCALL_FAST_BIT)) { > if (param1) > param1 = cc_mkdec(param1); > > if (param2) > param2 = cc_mkdec(param2); > } > > args.r10 = control; > args.rdx = param1; > args.r8 = param2; > > (void)__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT); > > return args.r11; > } I still think this is problematic. The cc_mkdec() should be done on the parameters when the code still *knows* that they are addresses. How do we know, for instance, that no hypercall using this interface will *ever* take the 0x0 physical address as an argument?