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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 21026C433E1 for ; Tue, 18 Aug 2020 06:59:21 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 E716420639 for ; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E716420639 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id ADA4584D56; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RILFLmuN5hnV; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 3922384D0A; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 1BA31C07FF; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2FB2CC0051 for ; Tue, 18 Aug 2020 06:59:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 1826184D41 for ; Tue, 18 Aug 2020 06:59:18 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SaByuoK-1XvK for ; Tue, 18 Aug 2020 06:59:16 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by fraxinus.osuosl.org (Postfix) with ESMTPS id B762F84D0A for ; Tue, 18 Aug 2020 06:59:16 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 1DC1A68AFE; Tue, 18 Aug 2020 08:59:12 +0200 (CEST) Date: Tue, 18 Aug 2020 08:59:11 +0200 From: Christoph Hellwig To: Thiago Jung Bauermann Subject: Re: [PATCH v2] powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory Message-ID: <20200818065911.GA2324@lst.de> References: <20200817214658.103093-1-bauerman@linux.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200817214658.103093-1-bauerman@linux.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Konrad Rzeszutek Wilk , Robin Murphy , Ram Pai , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Satheesh Rajendran , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 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 Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Mon, Aug 17, 2020 at 06:46:58PM -0300, Thiago Jung Bauermann wrote: > POWER secure guests (i.e., guests which use the Protection Execution > Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but > they don't need the SWIOTLB memory to be in low addresses since the > hypervisor doesn't have any addressing limitation. > > This solves a SWIOTLB initialization problem we are seeing in secure guests > with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved > memory, which leaves no space for SWIOTLB in low addresses. > > To do this, we use mostly the same code as swiotlb_init(), but allocate the > buffer using memblock_alloc() instead of memblock_alloc_low(). > > We also need to add swiotlb_set_no_iotlb_memory() in order to set the > no_iotlb_memory flag if initialization fails. Do you really need the helper? As far as I can tell the secure guests very much rely on swiotlb for all I/O, so you might as well panic if you fail to allocate it. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 F1185C433E1 for ; Tue, 18 Aug 2020 07:01:14 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 A9D0D20658 for ; Tue, 18 Aug 2020 07:01:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9D0D20658 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BW1zD0vPPzDqXB for ; Tue, 18 Aug 2020 17:01:12 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BW1x22v2SzDqC8 for ; Tue, 18 Aug 2020 16:59:17 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id 1DC1A68AFE; Tue, 18 Aug 2020 08:59:12 +0200 (CEST) Date: Tue, 18 Aug 2020 08:59:11 +0200 From: Christoph Hellwig To: Thiago Jung Bauermann Subject: Re: [PATCH v2] powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory Message-ID: <20200818065911.GA2324@lst.de> References: <20200817214658.103093-1-bauerman@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200817214658.103093-1-bauerman@linux.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Konrad Rzeszutek Wilk , Robin Murphy , Ram Pai , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Satheesh Rajendran , linuxppc-dev@lists.ozlabs.org, Christoph Hellwig , Marek Szyprowski Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Aug 17, 2020 at 06:46:58PM -0300, Thiago Jung Bauermann wrote: > POWER secure guests (i.e., guests which use the Protection Execution > Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but > they don't need the SWIOTLB memory to be in low addresses since the > hypervisor doesn't have any addressing limitation. > > This solves a SWIOTLB initialization problem we are seeing in secure guests > with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved > memory, which leaves no space for SWIOTLB in low addresses. > > To do this, we use mostly the same code as swiotlb_init(), but allocate the > buffer using memblock_alloc() instead of memblock_alloc_low(). > > We also need to add swiotlb_set_no_iotlb_memory() in order to set the > no_iotlb_memory flag if initialization fails. Do you really need the helper? As far as I can tell the secure guests very much rely on swiotlb for all I/O, so you might as well panic if you fail to allocate it. 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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 D7A1FC433DF for ; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB2BB20639 for ; Tue, 18 Aug 2020 06:59:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726451AbgHRG7T (ORCPT ); Tue, 18 Aug 2020 02:59:19 -0400 Received: from verein.lst.de ([213.95.11.211]:60408 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726165AbgHRG7P (ORCPT ); Tue, 18 Aug 2020 02:59:15 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 1DC1A68AFE; Tue, 18 Aug 2020 08:59:12 +0200 (CEST) Date: Tue, 18 Aug 2020 08:59:11 +0200 From: Christoph Hellwig To: Thiago Jung Bauermann Cc: iommu@lists.linux-foundation.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Konrad Rzeszutek Wilk , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Michael Ellerman , Ram Pai , Satheesh Rajendran Subject: Re: [PATCH v2] powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory Message-ID: <20200818065911.GA2324@lst.de> References: <20200817214658.103093-1-bauerman@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200817214658.103093-1-bauerman@linux.ibm.com> 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 Mon, Aug 17, 2020 at 06:46:58PM -0300, Thiago Jung Bauermann wrote: > POWER secure guests (i.e., guests which use the Protection Execution > Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but > they don't need the SWIOTLB memory to be in low addresses since the > hypervisor doesn't have any addressing limitation. > > This solves a SWIOTLB initialization problem we are seeing in secure guests > with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved > memory, which leaves no space for SWIOTLB in low addresses. > > To do this, we use mostly the same code as swiotlb_init(), but allocate the > buffer using memblock_alloc() instead of memblock_alloc_low(). > > We also need to add swiotlb_set_no_iotlb_memory() in order to set the > no_iotlb_memory flag if initialization fails. Do you really need the helper? As far as I can tell the secure guests very much rely on swiotlb for all I/O, so you might as well panic if you fail to allocate it.