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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 54251C0650F for ; Sun, 11 Aug 2019 08:55:43 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2DB6F21743 for ; Sun, 11 Aug 2019 08:55:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DB6F21743 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id C8DC5AF7; Sun, 11 Aug 2019 08:55:37 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id BE2B1AE0 for ; Sun, 11 Aug 2019 08:55:36 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-qt1-f196.google.com (mail-qt1-f196.google.com [209.85.160.196]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id EA2A1786 for ; Sun, 11 Aug 2019 08:55:34 +0000 (UTC) Received: by mail-qt1-f196.google.com with SMTP id b11so253098qtp.10 for ; Sun, 11 Aug 2019 01:55:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6/2qVAPvLy768Na8XqJHyfaQBOmu1VTQjHr1b0tqDos=; b=DYQRp8PTbmxFHl5c+jdAvcUrUIFqmhE1vSeEVNTo+45a/5YybV6PsOafMbOJM9Em0f rWwJp9PhCIqA/GOocy5l70B7/Obp8aMr9UAiN81jCcNrJGSMU64BOh5mDZrH3azGz+Ec kWUdQ7YV9O0vaRnQ3jhWg3vBeBNUHZZc1Yei/XiZnfWrleISdNo3V+9st60wdyeSarGF jnGhARh17qzSK+h1X9433MgKoMBMoqKPGpDo07QxbxgLpuRS4APM5ii4lBrDvGyhJhMq tk3RATAkKBLthKvk+4cJUwDjyci4WQUNsacksuYci7y7I6dj/0jt2UvebK4qCOE040Md 33QQ== X-Gm-Message-State: APjAAAX2YqyRsY0xMQK7mPX9QuHRhBiuaD5Ez4IDhXEZBtTPq5j63mB2 pxIeDZ9Ma5ws8Uliinpl8J3NjA== X-Google-Smtp-Source: APXvYqwQSHWl5DZCKxcv6b09e+m/U60yeBUP2tSK+Zxbso+cleqVM/RZ1b43sqdRDBiAuYOyKuC1mA== X-Received: by 2002:a0c:d91b:: with SMTP id p27mr25451190qvj.236.1565513734175; Sun, 11 Aug 2019 01:55:34 -0700 (PDT) Received: from redhat.com (bzq-79-181-91-42.red.bezeqint.net. [79.181.91.42]) by smtp.gmail.com with ESMTPSA id x26sm3314318qkn.116.2019.08.11.01.55.29 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Sun, 11 Aug 2019 01:55:33 -0700 (PDT) Date: Sun, 11 Aug 2019 04:55:27 -0400 From: "Michael S. Tsirkin" To: Christoph Hellwig Subject: Re: [RFC PATCH] virtio_ring: Use DMA API if guest memory is encrypted Message-ID: <20190811044431-mutt-send-email-mst@kernel.org> References: <87zhrj8kcp.fsf@morokweng.localdomain> <20190810143038-mutt-send-email-mst@kernel.org> <20190810220702.GA5964@ram.ibm.com> <20190811055607.GA12488@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190811055607.GA12488@lst.de> Cc: Benjamin Herrenschmidt , Jason Wang , Alexey Kardashevskiy , Ram Pai , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Paul Mackerras , iommu@lists.linux-foundation.org, David Gibson X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > So we need a flag on the virtio device, exposed by the > hypervisor (or hardware for hw virtio devices) that says: hey, I'm real, > don't take a shortcut. The point here is that it's actually still not real. So we would still use a physical address. However Linux decides that it wants extra security by moving all data through the bounce buffer. The distinction made is that one can actually give device a physical address of the bounce buffer. -- MST _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu