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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 3BDF9C282C5 for ; Thu, 24 Jan 2019 08:41:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 160E7218A2 for ; Thu, 24 Jan 2019 08:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727455AbfAXIlJ (ORCPT ); Thu, 24 Jan 2019 03:41:09 -0500 Received: from verein.lst.de ([213.95.11.211]:47425 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725986AbfAXIlJ (ORCPT ); Thu, 24 Jan 2019 03:41:09 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id CD90268DD3; Thu, 24 Jan 2019 09:41:07 +0100 (CET) Date: Thu, 24 Jan 2019 09:41:07 +0100 From: Christoph Hellwig To: Joerg Roedel Cc: Christoph Hellwig , "Michael S . Tsirkin" , Jason Wang , Konrad Rzeszutek Wilk , Jens Axboe , virtualization@lists.linux-foundation.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jfehlig@suse.com, jon.grimm@amd.com, brijesh.singh@amd.com, jroedel@suse.de Subject: Re: [PATCH 2/5] swiotlb: Add is_swiotlb_active() function Message-ID: <20190124084107.GA19441@lst.de> References: <20190123163049.24863-1-joro@8bytes.org> <20190123163049.24863-3-joro@8bytes.org> <20190123212755.GA9032@lst.de> <20190124082923.GI32526@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190124082923.GI32526@8bytes.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 24, 2019 at 09:29:23AM +0100, Joerg Roedel wrote: > > As I've just introduced and fixed a bug in this area in the current > > cycle - I don't think no_iotlb_memory is what your want (and maybe > > not useful at all): if the arch valls swiotlb_exit after previously > > initializing a buffer it won't be set. You probably want to check > > for non-zero io_tlb_start and/or io_tlb_end. > > Okay, but that requires that I also set io_tlb_start and friends back to > zero in the failure path of swiotlb_init(). Otherwise it could be left > non-zero in case swiotlb_init_with_tbl() returns an error. Indeed, and we'll need to do that anyway as otherwise the dma mapping path might cause problems similar to the one when swiotlb_exit is called that I fixed.