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 5299AC54EBD for ; Fri, 13 Jan 2023 16:08:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbjAMQIH (ORCPT ); Fri, 13 Jan 2023 11:08:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230077AbjAMQHo (ORCPT ); Fri, 13 Jan 2023 11:07:44 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76F0381D4F; Fri, 13 Jan 2023 08:00:29 -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 E46401EC0657; Fri, 13 Jan 2023 17:00:27 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1673625627; 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=27o6Yp9lIyQ9qbRTNp3Mdd/CmshSTWD6HQz/gXlOA3o=; b=e25h2q38vIHUR9CNYNMf4tXTOlOHI4G8rk4VVrsSmSLtK5pcWLoKu4BpzQjB4kuEIq3lg+ IsXSlOSBZ8LddYkmLkfbbsvYWLBHAbCUKnqKZnif4mdcYkpHnf//cFvKItev7lixW7KDtI BAYLJEDGsUX250/UeZjiceJ21LbTllE= Date: Fri, 13 Jan 2023 17:00:24 +0100 From: Borislav Petkov To: Michael Roth Cc: kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, dovmurik@linux.ibm.com, tobin@ibm.com, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, dgilbert@redhat.com, jarkko@kernel.org, ashish.kalra@amd.com, harald@profian.com, Nikunj A Dadhania Subject: Re: [PATCH RFC v7 07/64] KVM: SEV: Handle KVM_HC_MAP_GPA_RANGE hypercall Message-ID: References: <20221214194056.161492-1-michael.roth@amd.com> <20221214194056.161492-8-michael.roth@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221214194056.161492-8-michael.roth@amd.com> Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Wed, Dec 14, 2022 at 01:39:59PM -0600, Michael Roth wrote: > From: Nikunj A Dadhania > > KVM_HC_MAP_GPA_RANGE hypercall is used by the SEV guest to notify a > change in the page encryption status to the hypervisor. > > The hypercall exits to userspace with KVM_EXIT_HYPERCALL exit code, > currently this is used for explicit memory conversion between > shared/private for memfd based private memory. So Tom and I spent a while to figure out what this is doing... Please explain in more detail what that is. Like the hypercall gets ignored for memslots which cannot be private...? And what's the story with supporting UPM with SEV{,-ES} guests? In general, this text needs more background and why this is being done. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette