From patchwork Thu Jun 24 15:55:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claire Chang X-Patchwork-Id: 12342597 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 ADB04C49EA6 for ; Thu, 24 Jun 2021 16:02:18 +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 60D65611CE for ; Thu, 24 Jun 2021 16:02:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60D65611CE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.146947.270583 (Exim 4.92) (envelope-from ) id 1lwRnu-0007de-TX; Thu, 24 Jun 2021 16:02:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 146947.270583; Thu, 24 Jun 2021 16:02:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lwRnu-0007cb-OP; Thu, 24 Jun 2021 16:02:10 +0000 Received: by outflank-mailman (input) for mailman id 146947; Thu, 24 Jun 2021 16:02:09 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lwRjW-0002ED-5f for xen-devel@lists.xenproject.org; Thu, 24 Jun 2021 15:57:38 +0000 Received: from mail-pj1-x102c.google.com (unknown [2607:f8b0:4864:20::102c]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 2b9064ef-c70c-4fb8-9352-8c0a17f0ede4; Thu, 24 Jun 2021 15:57:10 +0000 (UTC) Received: by mail-pj1-x102c.google.com with SMTP id bb10-20020a17090b008ab029016eef083425so6176206pjb.5 for ; Thu, 24 Jun 2021 08:57:10 -0700 (PDT) Received: from localhost ([2401:fa00:95:205:165a:99ec:42d5:d8b]) by smtp.gmail.com with UTF8SMTPSA id x143sm3365707pfc.6.2021.06.24.08.57.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 24 Jun 2021 08:57:09 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 2b9064ef-c70c-4fb8-9352-8c0a17f0ede4 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=WbwCPwkWNsZyfDNcMOTWOtrRGSDB7ukqN5rFm3/fcqM=; b=ST6t0XkrMRO5f6HAim2SUwLoqEUtVKc7/G35fun8pnEgrYgmaoy7jqM/CzM5ROKScW CaGs/CYeApWd6boKyliYyHZkZ8m75hN3AsFBcdHAPE4h8DeZNWtiFC9jFlW6gHYxntTL /JewURtKdZPaJv0dBLRhrI68g5ieBdJUAcjT8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=WbwCPwkWNsZyfDNcMOTWOtrRGSDB7ukqN5rFm3/fcqM=; b=t9Swqbcv1zShPcHkU0ISi1lI0LohhQvyCxhqPIYBR2r/61RlgD43I4xvQNaf7L3evx uOEOxtGzbHzgdQznYhMLSShdQJSO24r2mCYdoLIfgeirHgb+hdU+pee1sRQiyUbaa4Vj OaE2Qv3iqopcVVo1OCLKOSVVm1sdtcmKEjITekTg3SJ2fNqDwktN3T2emJnJvukxgzPD jE5YbHEZTZAViU16KYd2yi7gJtsxNgyFq07QR3VyEaiXMfkP7QYf2k/Z1DdKOuaynD/p U2+IedveGVbr+vtMQt6oeuYqqkX0OsMLPs3+zBh98RSj/5taHjc2v4Xw86zj7ov1Z2a8 fTIg== X-Gm-Message-State: AOAM532txavLmeKVa9pLV40jO7fC6HUoTeeyqLOASIyuPYFCsCjarSPX ALBaUWRhJmw16u1SZF7D+qxhaA== X-Google-Smtp-Source: ABdhPJwI7EWsoc2ppnuqnW/9yjxiTzSeTHN60zP/WQgGph69JaVmO4yY57xwR4157oqtL7lcnhpfUA== X-Received: by 2002:a17:903:1043:b029:11e:7489:9bad with SMTP id f3-20020a1709031043b029011e74899badmr5076690plc.34.1624550229453; Thu, 24 Jun 2021 08:57:09 -0700 (PDT) From: Claire Chang To: Rob Herring , mpe@ellerman.id.au, Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski Cc: benh@kernel.crashing.org, paulus@samba.org, "list@263.net:IOMMU DRIVERS" , sstabellini@kernel.org, Robin Murphy , grant.likely@arm.com, xypron.glpk@gmx.de, Thierry Reding , mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org, Greg KH , Saravana Kannan , "Rafael J . Wysocki" , heikki.krogerus@linux.intel.com, Andy Shevchenko , Randy Dunlap , Dan Williams , Bartosz Golaszewski , linux-devicetree , lkml , linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org, Nicolas Boichat , Jim Quinlan , tfiga@chromium.org, bskeggs@redhat.com, bhelgaas@google.com, chris@chris-wilson.co.uk, tientzu@chromium.org, daniel@ffwll.ch, airlied@linux.ie, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com, jxgao@google.com, joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org, maarten.lankhorst@linux.intel.com, matthew.auld@intel.com, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com, thomas.lendacky@amd.com, quic_qiancai@quicinc.com Subject: [PATCH v15 10/12] swiotlb: Add restricted DMA pool initialization Date: Thu, 24 Jun 2021 23:55:24 +0800 Message-Id: <20210624155526.2775863-11-tientzu@chromium.org> X-Mailer: git-send-email 2.32.0.288.g62a8d224e6-goog In-Reply-To: <20210624155526.2775863-1-tientzu@chromium.org> References: <20210624155526.2775863-1-tientzu@chromium.org> MIME-Version: 1.0 Add the initialization function to create restricted DMA pools from matching reserved-memory nodes. Regardless of swiotlb setting, the restricted DMA pool is preferred if available. The restricted DMA pools provide a basic level of protection against the DMA overwriting buffer contents at unexpected times. However, to protect against general data leakage and system memory corruption, the system needs to provide a way to lock down the memory access, e.g., MPU. Signed-off-by: Claire Chang Reviewed-by: Christoph Hellwig Tested-by: Stefano Stabellini Tested-by: Will Deacon --- include/linux/swiotlb.h | 3 +- kernel/dma/Kconfig | 14 ++++++++ kernel/dma/swiotlb.c | 76 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 92 insertions(+), 1 deletion(-) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 3b9454d1e498..39284ff2a6cd 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -73,7 +73,8 @@ extern enum swiotlb_force swiotlb_force; * range check to see if the memory was in fact allocated by this * API. * @nslabs: The number of IO TLB blocks (in groups of 64) between @start and - * @end. This is command line adjustable via setup_io_tlb_npages. + * @end. For default swiotlb, this is command line adjustable via + * setup_io_tlb_npages. * @used: The number of used IO TLB block. * @list: The free list describing the number of free entries available * from each index. diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 77b405508743..3e961dc39634 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -80,6 +80,20 @@ config SWIOTLB bool select NEED_DMA_MAP_STATE +config DMA_RESTRICTED_POOL + bool "DMA Restricted Pool" + depends on OF && OF_RESERVED_MEM + select SWIOTLB + help + This enables support for restricted DMA pools which provide a level of + DMA memory protection on systems with limited hardware protection + capabilities, such as those lacking an IOMMU. + + For more information see + + and . + If unsure, say "n". + # # Should be selected if we can mmap non-coherent mappings to userspace. # The only thing that is really required is a way to set an uncached bit diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 6a7c6e30eb4b..3baf49c9b766 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -39,6 +39,13 @@ #ifdef CONFIG_DEBUG_FS #include #endif +#ifdef CONFIG_DMA_RESTRICTED_POOL +#include +#include +#include +#include +#include +#endif #include #include @@ -737,4 +744,73 @@ bool swiotlb_free(struct device *dev, struct page *page, size_t size) return true; } +static int rmem_swiotlb_device_init(struct reserved_mem *rmem, + struct device *dev) +{ + struct io_tlb_mem *mem = rmem->priv; + unsigned long nslabs = rmem->size >> IO_TLB_SHIFT; + + /* + * Since multiple devices can share the same pool, the private data, + * io_tlb_mem struct, will be initialized by the first device attached + * to it. + */ + if (!mem) { + mem = kzalloc(struct_size(mem, slots, nslabs), GFP_KERNEL); + if (!mem) + return -ENOMEM; + + set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), + rmem->size >> PAGE_SHIFT); + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); + mem->force_bounce = true; + mem->for_alloc = true; + + rmem->priv = mem; + + if (IS_ENABLED(CONFIG_DEBUG_FS)) { + mem->debugfs = + debugfs_create_dir(rmem->name, debugfs_dir); + swiotlb_create_debugfs_files(mem); + } + } + + dev->dma_io_tlb_mem = mem; + + return 0; +} + +static void rmem_swiotlb_device_release(struct reserved_mem *rmem, + struct device *dev) +{ + dev->dma_io_tlb_mem = io_tlb_default_mem; +} + +static const struct reserved_mem_ops rmem_swiotlb_ops = { + .device_init = rmem_swiotlb_device_init, + .device_release = rmem_swiotlb_device_release, +}; + +static int __init rmem_swiotlb_setup(struct reserved_mem *rmem) +{ + unsigned long node = rmem->fdt_node; + + if (of_get_flat_dt_prop(node, "reusable", NULL) || + of_get_flat_dt_prop(node, "linux,cma-default", NULL) || + of_get_flat_dt_prop(node, "linux,dma-default", NULL) || + of_get_flat_dt_prop(node, "no-map", NULL)) + return -EINVAL; + + if (PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { + pr_err("Restricted DMA pool must be accessible within the linear mapping."); + return -EINVAL; + } + + rmem->ops = &rmem_swiotlb_ops; + pr_info("Reserved memory: created restricted DMA pool at %pa, size %ld MiB\n", + &rmem->base, (unsigned long)rmem->size / SZ_1M); + return 0; +} + +RESERVEDMEM_OF_DECLARE(dma, "restricted-dma-pool", rmem_swiotlb_setup); #endif /* CONFIG_DMA_RESTRICTED_POOL */