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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 33552C46470 for ; Tue, 7 Aug 2018 06:32:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5D5A21A0D for ; Tue, 7 Aug 2018 06:32:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="lyhqio/H" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5D5A21A0D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388620AbeHGIo4 (ORCPT ); Tue, 7 Aug 2018 04:44:56 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50132 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727725AbeHGIo4 (ORCPT ); Tue, 7 Aug 2018 04:44:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=OjdUrWSwu4kd4mbYjfRpPvSvS1GFlAjg9ccQhQRku2k=; b=lyhqio/Hl02oPna//bnrfFKBO ORFUiapWzw/puce1McvK3e8gMycTEa1j2jc4yT+LillNjbn89Ta98kmK9rWVeVlwvxcQpM+TZ+YMn 4mZsYfnPs9U7RmSBTIidMGTl7qe6gEeTq5sKmAMVACGSJemBY/BtvXv/K1cFKT8HYs3vNWByyzz1A 9Sir+C/SkJr+BjNK6C2GHSIjMJtUtH7w+QsAlMBIPD4B9QbF04vcrc43PmjleKd0XUHDKyEjgGy4O fqclGIf4e0GjFIpCnPPNSV+99Yreecoz7TU/tyMXgLgt1EmIMSDNx/Rm/oZzNS9l4EETeg5yBE92F VXLS1lJvA==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1fmvXF-0001kC-SQ; Tue, 07 Aug 2018 06:32:01 +0000 Date: Mon, 6 Aug 2018 23:32:01 -0700 From: Christoph Hellwig To: "Michael S. Tsirkin" Cc: Benjamin Herrenschmidt , Christoph Hellwig , Will Deacon , Anshuman Khandual , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, aik@ozlabs.ru, robh@kernel.org, joe@perches.com, elfring@users.sourceforge.net, david@gibson.dropbear.id.au, jasowang@redhat.com, mpe@ellerman.id.au, linuxram@us.ibm.com, haren@linux.vnet.ibm.com, paulus@samba.org, srikar@linux.vnet.ibm.com, robin.murphy@arm.com, jean-philippe.brucker@arm.com, marc.zyngier@arm.com Subject: Re: [RFC 0/4] Virtio uses DMA API for all devices Message-ID: <20180807063201.GB23159@infradead.org> References: <051fd78e15595b414839fa8f9d445b9f4d7576c6.camel@kernel.crashing.org> <20180805031046-mutt-send-email-mst@kernel.org> <20180806164106-mutt-send-email-mst@kernel.org> <20180806233024-mutt-send-email-mst@kernel.org> <0967fc30001323e6e38ed12c8dba8ee3d1aa13f5.camel@kernel.crashing.org> <20180807002857-mutt-send-email-mst@kernel.org> <93518075238a07e9f011774d89bdc652c083f1ba.camel@kernel.crashing.org> <20180807024503-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180807024503-mutt-send-email-mst@kernel.org> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 07, 2018 at 02:45:25AM +0300, Michael S. Tsirkin wrote: > > > I think that's where Christoph might have specific ideas about it. > > > > OK well, assuming Christoph can solve the direct case in a way that > > also work for the virtio !iommu case, we still want some bit of logic > > somewhere that will "switch" to swiotlb based ops if the DMA mask is > > limited. > > > > You mentioned an RFC for that ? Do you happen to have a link ? > > No but Christoph did I think. Do you mean the direct map retpoline mitigation? It is here: https://www.spinics.net/lists/netdev/msg495413.html https://www.spinics.net/lists/netdev/msg495785.html