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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 5513BC4360C for ; Fri, 4 Oct 2019 18:34:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 301372084D for ; Fri, 4 Oct 2019 18:34:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lhIe+/R5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 301372084D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KBciEtGC2n/GY3vlzgd4D3XsdCmAMhNAzb/2DR6w7bE=; b=lhIe+/R5n9MhCb3vsT4UgOQ39 A0geni/8wln0aNEMuYrq8o+D8T1/7JcOo3YriT7vlLBQypuu9rraV35R81teDZyyu+4q+53Vz4L1o gW38DG0ub4AP/yKBsWxt7sexvpjIRKVmoQ5Cn16kJzeclM3IrF959TTLCe/yOFywnYevZDpZ2QwYI a+uvhZr856CnAc2Dfm1un6rmmyQvBHrwqOrc4gG121As8g9HcV+lKIS9wS5rH0u3t0uSaJ/4Ey3mp VE2NQ1+MZywxr1ZkKP1O8KSKwIodxoHN9TF2qcV9ltSJQNm9/yGpiZe97t3VPOn4KlBPovV51GpeZ AWBtiLC1g==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGSPq-0003Mv-0Y; Fri, 04 Oct 2019 18:34:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iGSPm-0003M7-36 for linux-arm-kernel@lists.infradead.org; Fri, 04 Oct 2019 18:34:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3D5D215A1; Fri, 4 Oct 2019 11:34:52 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7C2143F534; Fri, 4 Oct 2019 11:34:50 -0700 (PDT) Subject: Re: [PATCH v2] iommu/arm-smmu: Break insecure users by disabling bypass by default To: Tim Harvey , Tirumalesh Chalamarla References: <20190301192017.39770-1-dianders@chromium.org> <5dce2964-8761-e7d0-8963-f0f5cb2feb02@arm.com> <1f6f7eb0-e1dc-d5a8-fb38-44c5bd839894@arm.com> <5cf9ec03-f6fb-8227-4ec5-62445038f283@arm.com> From: Robin Murphy Message-ID: Date: Fri, 4 Oct 2019 19:34:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191004_113454_220275_2CBA57ED X-CRM114-Status: GOOD ( 25.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: open list , linux-arm-msm@vger.kernel.org, Joerg Roedel , Will Deacon , Douglas Anderson , evgreen@chromium.org, tfiga@chromium.org, Rob Clark , iommu@lists.linux-foundation.org, Vivek Gautam , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 04/10/2019 18:13, Tim Harvey wrote: [...] >>> No difference... still need 'arm-smmu.disable_bypass=n' to boot. Are >>> all four iommu-map props above supposed to be the same? Seems to me >>> they all point to the same thing which looks wrong. >> >> Hmm... :/ >> >> Those mappings just set Stream ID == PCI RID (strictly each one should >> only need to cover the bus range assigned to that bridge, but it's not >> crucial) which is the same thing the driver assumes for the mmu-masters >> property, so either that's wrong and never could have worked anyway - >> have you tried VFIO on this platform? - or there are other devices also >> mastering through the SMMU that aren't described at all. Are you able to >> capture a boot log? The SMMU faults do encode information about the >> offending ID, and you can typically correlate their appearance >> reasonably well with endpoint drivers probing. >> > > Robin, > > VFIO is enabled in the kernel but I don't know anything about how to > test/use it: > $ grep VFIO .config > CONFIG_KVM_VFIO=y > CONFIG_VFIO_IOMMU_TYPE1=y > CONFIG_VFIO_VIRQFD=y > CONFIG_VFIO=y > # CONFIG_VFIO_NOIOMMU is not set > CONFIG_VFIO_PCI=y > CONFIG_VFIO_PCI_MMAP=y > CONFIG_VFIO_PCI_INTX=y > # CONFIG_VFIO_PLATFORM is not set > # CONFIG_VFIO_MDEV is not set No worries - since it's a networking-focused SoC I figured there was a chance you might be using DPDK or similar userspace drivers with the NIC VFs, but I was just casting around for a quick and easy baseline of whether the SMMU works at all (another way would be using Qemu to run a VM with one or more PCI devices assigned). > I do have a boot console yet I'm not seeing any smmu faults at all. > Perhaps I've mis-diagnosed the issue completely. To be clear when I > boot with arm-smmu.disable_bypass=y the serial console appears to not > accept input in userspace and with arm-smmu.disable_bypass=n I'm fine. > I'm using a buildroot initramfs rootfs for simplicity. The system > isn't hung as I originally expected as the LED heartbeat trigger > continues blinking... I just can't get console to accept input. Curiouser and curiouser... I'm inclined to suspect that the interrupt configuration might also be messed up, such that the SMMU is blocking traffic and jammed up due to pending faults, but you're not getting the IRQ delivered to find out. Does this patch help reveal anything? http://linux-arm.org/git?p=linux-rm.git;a=commitdiff;h=29ac3648b580920692c9b417b2fc606995826517 (untested, but it's a direct port of the one I've used for SMMUv3 to diagnose something similar) That said, it's also puzzling that no other drivers are reporting DMA errors or timeouts either - is there any chance that some device is set running by the firmware/bootloader and not taken over by a kernel driver? Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel