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=-11.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 EAF10C433E4 for ; Tue, 14 Jul 2020 11:44:23 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 9EA0A22201 for ; Tue, 14 Jul 2020 11:44:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BjOz0xAM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9EA0A22201 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+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=merlin.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=2mXjC59VTQPCEJ+3lJ7NdFiRrMPlO8KuJXm44qM8vqc=; b=BjOz0xAMg9iEE6seiSGjSJl8/ 1cntJyBrBaJbn7+V5Ihc5WuxoDMyNfq5JXaRP9TY6PEjz2ZzcDvYsDvTuSy8C6N2x+QOSkF1eKTt1 8yOA/stnwEZohz8yxwnH+OtFMGHIFQqfqFSvTw3jqI+x6wkZ2ghIdch0F6BBSU4+r58xwHCeWhuZS 5w0TKRSzxBWt6MFZkrc+O8lMEH9hI+Q4p0Oprwtf19t1NdVsF496/fkj8HjTFoNcFss0IbZ7fYAcK JVbRwa/IrzbyU0/Ow6ONH4R7knnTpeiG7f7KNJchuNTv8WkgnuJWzrKY+xLh6x12x1M3fNjzVnwfG /oxhQawQw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvJKe-00037l-HF; Tue, 14 Jul 2020 11:42:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvJKc-00036u-BV for linux-arm-kernel@lists.infradead.org; Tue, 14 Jul 2020 11:42:43 +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 C87D630E; Tue, 14 Jul 2020 04:42:37 -0700 (PDT) Received: from [10.57.32.45] (unknown [10.57.32.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 79D163F7BB; Tue, 14 Jul 2020 04:42:36 -0700 (PDT) Subject: Re: [PATCH 2/2] iommu/dma: Avoid SAC address trick for PCIe devices To: Joerg Roedel References: <20200713131426.GQ27672@8bytes.org> From: Robin Murphy Message-ID: Date: Tue, 14 Jul 2020 12:42:36 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200713131426.GQ27672@8bytes.org> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200714_074242_458446_DA3BC4C6 X-CRM114-Status: GOOD ( 21.95 ) 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: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jonathan.lemon@gmail.com, dwmw2@infradead.org, hch@lst.de, linux-arm-kernel@lists.infradead.org, baolu.lu@linux.intel.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-07-13 14:14, Joerg Roedel wrote: > On Wed, Jul 08, 2020 at 12:32:42PM +0100, Robin Murphy wrote: >> As for the intel-iommu implementation, relegate the opportunistic >> attempt to allocate a SAC address to the domain of conventional PCI >> devices only, to avoid it increasingly causing far more performance >> issues than possible benefits on modern PCI Express systems. >> >> Signed-off-by: Robin Murphy >> --- >> drivers/iommu/dma-iommu.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >> index 4959f5df21bd..0ff124f16ad4 100644 >> --- a/drivers/iommu/dma-iommu.c >> +++ b/drivers/iommu/dma-iommu.c >> @@ -426,7 +426,8 @@ static dma_addr_t iommu_dma_alloc_iova(struct iommu_domain *domain, >> dma_limit = min(dma_limit, (u64)domain->geometry.aperture_end); >> >> /* Try to get PCI devices a SAC address */ >> - if (dma_limit > DMA_BIT_MASK(32) && dev_is_pci(dev)) >> + if (dma_limit > DMA_BIT_MASK(32) && >> + dev_is_pci(dev) && !pci_is_pcie(to_pci_dev(dev))) >> iova = alloc_iova_fast(iovad, iova_len, >> DMA_BIT_MASK(32) >> shift, false); >> > > Unfortunatly this patch causes XHCI initialization failures on my AMD > Ryzen system. I will remove both from the IOMMU tree for now. > > I guess the XHCI chip in my system does not support full 64bit dma > addresses and needs a quirk or something like that. But until this is > resolved its better to not change the IOVA allocation behavior. Oh bother - yes, this could have been masking all manner of bugs. That system will presumably also break if you managed to exhaust the 32-bit IOVA space such that the allocator moved up to the higher range anyway, or if you passed the XHCI through to a VM with a sufficiently wacky GPA layout, but I guess those are cases that simply nobody's run into yet. Does the firmware actually report any upper address constraint such that Sebastian's IVRS aperture patches might help? Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel