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 7D8DEC64EC4 for ; Thu, 9 Mar 2023 14:52:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231995AbjCIOwJ (ORCPT ); Thu, 9 Mar 2023 09:52:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231976AbjCIOvh (ORCPT ); Thu, 9 Mar 2023 09:51:37 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06738F4039; Thu, 9 Mar 2023 06:50:11 -0800 (PST) Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 0AC781EC06C0; Thu, 9 Mar 2023 15:45:09 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1678373109; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=If/RB/hr/c7VUMqd+cgR77ldxUk5sLws7vhF9to8FDQ=; b=jus71OLR74X/1ogUazggcBxXv8CUTmUJ1nEFSUoX3c2qdRny1LQLWh9C1o6fblZiFQqeMB aZ1BaeLhfeAOgz3a0/k6Rz9q2rDEQvgImmdDPFWDJaDR93eM4YldkMU+jxzTn4PyNgGxpp Pgtvm//JDTh8xON5nJ7CO7crxDtsGkY= Date: Thu, 9 Mar 2023 15:45:05 +0100 From: Borislav Petkov To: =?utf-8?B?SsO2cmcgUsO2ZGVs?= Cc: Tom Lendacky , David Woodhouse , Dave Hansen , "Michael Kelley (LINUX)" , Sean Christopherson , "hpa@zytor.com" , KY Srinivasan , Haiyang Zhang , "wei.liu@kernel.org" , Dexuan Cui , "luto@kernel.org" , "peterz@infradead.org" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "lpieralisi@kernel.org" , "robh@kernel.org" , "kw@linux.com" , "bhelgaas@google.com" , "arnd@arndb.de" , "hch@lst.de" , "m.szyprowski@samsung.com" , "robin.murphy@arm.com" , "brijesh.singh@amd.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "dave.hansen@linux.intel.com" , Tianyu Lan , "kirill.shutemov@linux.intel.com" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "ak@linux.intel.com" , "isaku.yamahata@intel.com" , "dan.j.williams@intel.com" , "jane.chu@oracle.com" , "tony.luck@intel.com" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "linux-hyperv@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-arch@vger.kernel.org" , "iommu@lists.linux.dev" Subject: Re: [PATCH v5 06/14] x86/ioremap: Support hypervisor specified range to map as encrypted Message-ID: <20230309144505.GEZAnw8QpyOyMpCD4r@fat_crate.local> References: <255249f2-47af-07b7-d9d9-9edfdd108348@intel.com> <20230306215104.GEZAZgSPa4qBBu9lRd@fat_crate.local> <20230309115937.GAZAnKKRef99EwOu/S@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 09, 2023 at 03:36:45PM +0100, Jörg Rödel wrote: > Yes, that is right. The key is mainly for the NMI entry path which can > be performance relevant in some situations. For SEV-ES some special > handling is needed there to re-enable NMIs and adjust the #VC stack in > case it was raised on the VC-handlers entry path. So the performance argument is meh. That key will be replaced by if (cc_vendor == CC_VENDOR_AMD && cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT) which is something like 4 insns or so. Tops. Haven't looked yet but it should be cheap. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette