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=-8.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 EF5FBC433DF for ; Wed, 19 Aug 2020 04:44:01 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 A98E220888 for ; Wed, 19 Aug 2020 04:44:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A98E220888 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 silver.osuosl.org (Postfix) with ESMTP id 53AA72094B; Wed, 19 Aug 2020 04:44:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id CJi7SW2FST9n; Wed, 19 Aug 2020 04:43:59 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id 5C952204AF; Wed, 19 Aug 2020 04:43:59 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3E7CBC0889; Wed, 19 Aug 2020 04:43:59 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 398EAC0051 for ; Wed, 19 Aug 2020 04:43:58 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 288C486866 for ; Wed, 19 Aug 2020 04:43:58 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sS5kRiquRjXG for ; Wed, 19 Aug 2020 04:43:56 +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 whitealder.osuosl.org (Postfix) with ESMTPS id A9CBA86856 for ; Wed, 19 Aug 2020 04:43:56 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id D70DE68AFE; Wed, 19 Aug 2020 06:43:51 +0200 (CEST) Date: Wed, 19 Aug 2020 06:43:51 +0200 From: Christoph Hellwig To: Thiago Jung Bauermann Subject: Re: [PATCH v3] powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory Message-ID: <20200819044351.GA19391@lst.de> References: <20200818221126.391073-1-bauerman@linux.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200818221126.391073-1-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 Tue, Aug 18, 2020 at 07:11:26PM -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(). > > Signed-off-by: Thiago Jung Bauermann Looks fine to me (except for the pointlessly long comment lines, but I've been told that's the powerpc way). _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu