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 X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0F7DC19F35 for ; Tue, 24 Aug 2021 20:31:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8603461139 for ; Tue, 24 Aug 2021 20:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235233AbhHXUcC (ORCPT ); Tue, 24 Aug 2021 16:32:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:37406 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234675AbhHXUcB (ORCPT ); Tue, 24 Aug 2021 16:32:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3738C610F7; Tue, 24 Aug 2021 20:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629837076; bh=u89RhbA1T4/YcegxqumOKFDZveULzg7IH3BXxWstXGA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=E7gmG9cu+2X8EpSv9jHNw194dQ/bFH+W8S5CviPC+WEzgK9x1GqwxeKDnQA93Ubc6 pIROpW9mCbmFawlLNt183dkzLJG92jUie48vdct5nMY9KMIpav4jCN5vVtcBqt99IN LlMRmUTD9hQbKroaOXlhVlrUixEOK798eHEQ6pmGyuqfJJo5J4wfidKynCvdtb3s37 PjcEO5DOcIPu3SLREF0Tt+IUZRL6NjCeGqQy3Vt+WmnxMDtnryxVfbjA5YVJAeYKm9 BpOJvSuNngQVXkAMINkK0ZwKmdIz+EDYyzVhKaDWPyJSTPhZYBRtaAf1VAW/wDK4NO xT3mGvV5LJ4bA== Date: Tue, 24 Aug 2021 15:31:15 -0500 From: Bjorn Helgaas To: Andi Kleen Cc: "Michael S. Tsirkin" , Dan Williams , "Kuppuswamy, Sathyanarayanan" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Peter Zijlstra , Andy Lutomirski , Bjorn Helgaas , Richard Henderson , Thomas Bogendoerfer , James E J Bottomley , Helge Deller , "David S . Miller" , Arnd Bergmann , Jonathan Corbet , Peter H Anvin , Dave Hansen , Tony Luck , Kirill Shutemov , Sean Christopherson , Kuppuswamy Sathyanarayanan , X86 ML , Linux Kernel Mailing List , Linux PCI , linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch , Linux Doc Mailing List , virtualization@lists.linux-foundation.org, Rajat Jain Subject: Re: [PATCH v4 11/15] pci: Add pci_iomap_shared{,_range} Message-ID: <20210824203115.GA3492097@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 24, 2021 at 01:14:02PM -0700, Andi Kleen wrote: > > On 8/24/2021 11:55 AM, Bjorn Helgaas wrote: > > [+cc Rajat; I still don't know what "shared memory with a hypervisor > > in a confidential guest" means, > > A confidential guest is a guest which uses memory encryption to isolate > itself from the host. It doesn't trust the host. But it still needs to > communicate with the host for IO, so it has some special memory areas that > are explicitly marked shared. These are used to do IO with the host. All > their usage needs to be carefully hardened to avoid any security attacks on > the guest, that's why we want to limit this interaction only to a small set > of hardened drivers. For MMIO, the set is currently only virtio and MSI-X. Good material for the commit log next time around. Thanks! Bjorn