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 62D0EC636D6 for ; Wed, 22 Feb 2023 22:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232890AbjBVWdp (ORCPT ); Wed, 22 Feb 2023 17:33:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232083AbjBVWdm (ORCPT ); Wed, 22 Feb 2023 17:33:42 -0500 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D4F728D1B; Wed, 22 Feb 2023 14:33:40 -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 0ADBF1EC068E; Wed, 22 Feb 2023 23:33:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1677105219; 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:in-reply-to:in-reply-to: references:references; bh=KNxniYfnv/Wqlv/O7839+WaF1/8EwE+WSa7eOziAI2U=; b=rS3In1x0ygiA49jl10PLWw9kPeg6B8zKJ0gOPDWrBpNGLk/CN4dBn9mL1L5Y/8kpDbS4En N1bEIHB1P8XtFBrgJNQHZMvWdNoFLIZNq06heRMKIuQ5wECm6IEz6amGGz6g6YvsHfLFwc 2oCZcHzx9nAg72ejGoq2zFJ43e9O/RE= Date: Wed, 22 Feb 2023 23:33:38 +0100 From: Borislav Petkov To: Sean Christopherson Cc: "Michael Kelley (LINUX)" , Dave Hansen , "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" , "thomas.lendacky@amd.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: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 22, 2023 at 02:13:44PM -0800, Sean Christopherson wrote: > Because vTOM is a hardware feature, whereas the IO-APIC and vTPM being accessible > via private memory are software features. It's very possible to emulate the > IO-APIC in trusted code without vTOM. I know, but their use case is dictated by the fact that they're using a SNP guest *with* vTOM as a SEV feature. And so their guest does IO-APIC and vTPM *with* the vTOM SEV feature. That's what I'm trying to model. > > If the access method to the IO-APIC and vTPM are specific to the > > HyperV's vTOM implementation, then I don't mind if this were called > > > > cc_platform_has(CC_ATTR_GUEST_HYPERV_VTOM); > > I still think that's likely to caused problems in the future, e.g. if Hyper-V > moves more stuff into the paravisor or if Hyper-V ends up with similar functionality > for TDX. Yah, reportedly, TDX folks are not very interested in this case. > But it's not a sticking point, the only thing I'm fiercely resistant to > is conflating hardware features with software features. So you and I need to find a common ground... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette