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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 781E7C433DF for ; Tue, 2 Jun 2020 19:24:47 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 45EEE206E2 for ; Tue, 2 Jun 2020 19:24:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ytsu3/KD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 45EEE206E2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jgCWF-0006Jr-V6; Tue, 02 Jun 2020 19:24:15 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jgCWE-0006Jm-7D for xen-devel@lists.xenproject.org; Tue, 02 Jun 2020 19:24:14 +0000 X-Inumbo-ID: a439194e-a506-11ea-8993-bc764e2007e4 Received: from mail.kernel.org (unknown [198.145.29.99]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id a439194e-a506-11ea-8993-bc764e2007e4; Tue, 02 Jun 2020 19:24:13 +0000 (UTC) Received: from localhost (c-67-164-102-47.hsd1.ca.comcast.net [67.164.102.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 75312206E2; Tue, 2 Jun 2020 19:24:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591125852; bh=CStxKi7GNxsvMOGhzKrkhSxML7SEV2wR10QVNYr+zVQ=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=Ytsu3/KDvFSbmo4EBLSvzSQUqp49j6YwqLJF6HIJ0L3/EzovGzwYB4kBfS4zklWFw rOp4KdEOMBf/Xy4mOamRhjui9bq7qpePkiL6AyeqnikFIxOsUH8tELfE2ftVujQdPH XHHl54Svr0a4OukEQMXivIq0umgf5/xUQUPdZOrc= Date: Tue, 2 Jun 2020 12:24:05 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Corey Minyard Subject: Re: Troubles running Xen on Raspberry Pi 4 with 5.6.1 DomU In-Reply-To: <20200602183420.GE2880@minyard.net> Message-ID: References: <2187cd7c-4d48-986b-77d6-4428e8178404@oracle.com> <42253259-9663-67e8-117f-8ba631243585@xen.org> <20200602183420.GE2880@minyard.net> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; BOUNDARY="8323329-2140389372-1591125815=:6774" Content-ID: X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: jgross@suse.com, Peng Fan , Stefano Stabellini , Julien Grall , roman@zededa.com, "jeff.kubascik@dornerworks.com" , Julien Grall , Nataliya Korovkina , "xen-devel@lists.xenproject.org" , boris.ostrovsky@oracle.com, Stefano Stabellini Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-2140389372-1591125815=:6774 Content-Type: text/plain; CHARSET=UTF-8 Content-Transfer-Encoding: 8BIT Content-ID: On Tue, 2 Jun 2020, Corey Minyard wrote: > Snip > > > > > > > whether > > > > > > this was already done: > > > > > >      1) Does the kernel boot on baremetal (i.e without Xen)? This should > > > > > > help > > > > > > to confirm whether the bug is Xen is related. > > > > > > > > > > Yes it boots > > > > > > > > > > >      2) Swiotlb should not be necessary for basic dom0 boot on Arm. Did > > > > > > you try > > > > > > to disable it? This should help to confirm whether swiotlb is the > > > > > > problem or > > > > > > not. > > > > > > > > > > It boots disabling swiotlb-xen > > > > > > > > Thank you for the answer! swiotlb-xen should basically be a NOP for dom0. So > > > > this suggests swiotlb is doing some transformation on the DMA address. > > > > > > > > I have an idea what may have gone wrong. AFAICT, xen-swiotlb seems to assume > > > > the DMA address space and CPU address space is the same. Is RPI using the > > > > same address space? > > > > > > Another question, is the DMA request bounced? If so, are we sure the bounce > > > buffer is in the first GB? > > > > Yes, it is. This is actually where we spent the last few days, and I > > found another little related bug in the initialization of the > > swiotlb-xen but now I am sure the memory is under 1GB (0x34000000-0x38000000) > > Was anything ever resolved on this issue? It just kind of ended for me, > and I looked in the main kernel and didn't find anything that looked > related. Yes, we have a patch series on the list for the Linux kernel to fix this issue but it hasn't been merged yet: https://marc.info/?l=linux-kernel&m=159001831406263&w=2 --8323329-2140389372-1591125815=:6774--