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 94724C64ED6 for ; Thu, 16 Feb 2023 13:33:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229714AbjBPNdH (ORCPT ); Thu, 16 Feb 2023 08:33:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229521AbjBPNdF (ORCPT ); Thu, 16 Feb 2023 08:33:05 -0500 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2690028239; Thu, 16 Feb 2023 05:33:04 -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 B43F21EC0758; Thu, 16 Feb 2023 14:33:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1676554382; 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=4It5WNTzj3y34rvlS749Hz/wiDmES420yCM4l9P4P7U=; b=gf0e1sXnrMK9yS752n1XbBJTfBklzKLy7wB4qpiBtyaSiWE4u5Ms3bcAVOBWSRzBs7ZCi7 ETAO1fzNXRcZQ1jN2Sp0UDeGfWP3jiEh9EHGoEZdEJUy8MSZz1Hg3TttFzAuZAE1KbSkAw nbmwnCc/eKTOd9FQYcQRUonTAtj6tZ8= Date: Thu, 16 Feb 2023 14:32:59 +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 Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 10, 2023 at 11:47:27PM +0000, Sean Christopherson wrote: > I agree with Boris' comment that a one-off "other encrypted range" is a hack, but > that's just an API problem. The kernel already has hypervisor specific hooks (and > for SEV-ES even), why not expand that? That way figuring out which devices are > private is wholly contained in Hyper-V code, at least until there's a generic > solution for enumerating private devices, though that seems unlikely to happen > and will be a happy problem to solve if it does come about. I feel ya and this all makes sense and your proposals look clean enough to me but we still need some way of determining whether this is a vTOM on hyperv because there's the next crapola with https://lore.kernel.org/r/20230209072220.6836-4-jgross@suse.com because apparently hyperv does PAT but disables MTRRs for such vTOM SEV-SNP guests and ... madness. But that's not the only example - Xen has been doing this thing too. And Jürgen has been trying to address this in a clean way but it is a pain. What I don't want to have is a gazillion ways to check what needs to happen for which guest type. Because people who change the kernel to run on baremetal, will break them. And I can't blame them. We try to support all kinds of guests in the x86 code but this support should be plain and simple. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette