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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 1F18AC31E40 for ; Tue, 6 Aug 2019 11:33:24 +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 F0A2820818 for ; Tue, 6 Aug 2019 11:33:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0A2820818 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 mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id B34E3D7F; Tue, 6 Aug 2019 11:33:23 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 882F2D7E for ; Tue, 6 Aug 2019 11:33:22 +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 smtp1.linuxfoundation.org (Postfix) with ESMTPS id 1467D8A8 for ; Tue, 6 Aug 2019 11:33:22 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id B6461227A81; Tue, 6 Aug 2019 13:33:18 +0200 (CEST) Date: Tue, 6 Aug 2019 13:33:18 +0200 From: Christoph Hellwig To: Lucas Stach Subject: Re: Regression due to d98849aff879 (dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code) Message-ID: <20190806113318.GA20215@lst.de> References: <1565082809.2323.24.camel@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1565082809.2323.24.camel@pengutronix.de> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: Tom Lendacky , iommu@lists.linux-foundation.org, Christoph Hellwig , linux-kernel@vger.kernel.org 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 Tue, Aug 06, 2019 at 11:13:29AM +0200, Lucas Stach wrote: > Hi Christoph, > > I just found a regression where my NVMe device is no longer able to set > up its HMB. > > After subject commit dma_direct_alloc_pages() is no longer initializing > dma_handle properly when DMA_ATTR_NO_KERNEL_MAPPING is set, as the > function is now returning too early. > > Now this could easily be fixed by adding the phy_to_dma translation to > the NO_KERNEL_MAPPING code path, but I'm not sure how this stuff > interacts with the memory encryption stuff set up later in the > function, so I guess this should be looked at by someone with more > experience with this code than me. There is not much we can do about the memory encryption case here, as that requires a kernel address to mark the memory as unencrypted. So the obvious trivial fix is probably the right one: diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 59bdceea3737..c49120193309 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -135,6 +135,7 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, if (!PageHighMem(page)) arch_dma_prep_coherent(page, size); /* return the page pointer as the opaque cookie */ + *dma_handle = phys_to_dma(dev, page_to_phys(page)); return page; } _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu