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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 A1BCCC43460 for ; Fri, 23 Apr 2021 11:34:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CAA861422 for ; Fri, 23 Apr 2021 11:34:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234057AbhDWLfR (ORCPT ); Fri, 23 Apr 2021 07:35:17 -0400 Received: from foss.arm.com ([217.140.110.172]:33678 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229957AbhDWLfP (ORCPT ); Fri, 23 Apr 2021 07:35:15 -0400 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) Subject: Re: [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization To: Claire Chang , 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, 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, nouveau@lists.freedesktop.org, rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 B5F82C433ED for ; Fri, 23 Apr 2021 11:35:09 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 23C1B613B0 for ; Fri, 23 Apr 2021 11:35:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23C1B613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FRXJq0wlbz30HC for ; Fri, 23 Apr 2021 21:35:07 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=steven.price@arm.com; receiver=) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4FRXJN1svKz2yRT for ; Fri, 23 Apr 2021 21:34:42 +1000 (AEST) 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) Subject: Re: [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com, Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , Robin Murphy , bauerman@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 ECA00C43461 for ; Fri, 23 Apr 2021 15:20:32 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AD0BD613B0 for ; Fri, 23 Apr 2021 15:20:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AD0BD613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=nouveau-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1BEB96EC09; Fri, 23 Apr 2021 15:20:28 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 35AA26EB82; Fri, 23 Apr 2021 11:34:40 +0000 (UTC) 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Language: en-GB X-Mailman-Approved-At: Fri, 23 Apr 2021 15:20:26 +0000 Subject: Re: [Nouveau] [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization X-BeenThere: nouveau@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Nouveau development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, benh@kernel.crashing.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, Robin Murphy , jani.nikula@linux.intel.com, Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: nouveau-bounces@lists.freedesktop.org Sender: "Nouveau" On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture _______________________________________________ Nouveau mailing list Nouveau@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/nouveau 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 97D94C433ED for ; Fri, 23 Apr 2021 11:34:48 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 08CFC613B0 for ; Fri, 23 Apr 2021 11:34:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08CFC613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id AC4D660DD8; Fri, 23 Apr 2021 11:34:47 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EJwbLVNuvpaU; Fri, 23 Apr 2021 11:34:45 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTP id 152E1605F5; Fri, 23 Apr 2021 11:34:45 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id ED0FEC000F; Fri, 23 Apr 2021 11:34:44 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7323DC000B for ; Fri, 23 Apr 2021 11:34:43 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 585084061E for ; Fri, 23 Apr 2021 11:34:43 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id F08-0KZjIb6r for ; Fri, 23 Apr 2021 11:34:40 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp2.osuosl.org (Postfix) with ESMTP id 7F2C54060B for ; Fri, 23 Apr 2021 11:34:40 +0000 (UTC) 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) Subject: Re: [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Language: en-GB Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, benh@kernel.crashing.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , daniel@ffwll.ch, airlied@linux.ie, maarten.lankhorst@linux.intel.com, linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com, Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , "list@263.net:IOMMU DRIVERS" , Jim Quinlan , Robin Murphy , bauerman@linux.ibm.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 EA6A4C43462 for ; Fri, 23 Apr 2021 11:34:42 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 809C66145A for ; Fri, 23 Apr 2021 11:34:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 809C66145A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9566E6EB7D; Fri, 23 Apr 2021 11:34:41 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 35AA26EB82; Fri, 23 Apr 2021 11:34:40 +0000 (UTC) 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) Subject: Re: [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Language: en-GB X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , airlied@linux.ie, Robin Murphy , Nicolas Boichat , rodrigo.vivi@intel.com, bhelgaas@google.com, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel 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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 3A5C3C433B4 for ; Fri, 23 Apr 2021 11:34:46 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 C2224613B0 for ; Fri, 23 Apr 2021 11:34:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2224613B0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CC90C6EB7E; Fri, 23 Apr 2021 11:34:41 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id 35AA26EB82; Fri, 23 Apr 2021 11:34:40 +0000 (UTC) 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 204A413A1; Fri, 23 Apr 2021 04:34:39 -0700 (PDT) Received: from [192.168.1.179] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D48233F694; Fri, 23 Apr 2021 04:34:32 -0700 (PDT) To: Claire Chang , Joerg Roedel , Will Deacon , Frank Rowand , Konrad Rzeszutek Wilk , boris.ostrovsky@oracle.com, jgross@suse.com, Christoph Hellwig , Marek Szyprowski References: <20210422081508.3942748-1-tientzu@chromium.org> <20210422081508.3942748-6-tientzu@chromium.org> From: Steven Price Message-ID: Date: Fri, 23 Apr 2021 12:34:31 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210422081508.3942748-6-tientzu@chromium.org> Content-Language: en-GB Subject: Re: [Intel-gfx] [PATCH v5 05/16] swiotlb: Add restricted DMA pool initialization X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, benh@kernel.crashing.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, mingo@kernel.org, jxgao@google.com, sstabellini@kernel.org, Saravana Kannan , xypron.glpk@gmx.de, "Rafael J . Wysocki" , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , airlied@linux.ie, Robin Murphy , Nicolas Boichat , bhelgaas@google.com, Dan Williams , Andy Shevchenko , nouveau@lists.freedesktop.org, Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 22/04/2021 09:14, Claire Chang wrote: > Add the initialization function to create restricted DMA pools from > matching reserved-memory nodes. > > Signed-off-by: Claire Chang > --- > include/linux/device.h | 4 +++ > include/linux/swiotlb.h | 3 +- > kernel/dma/swiotlb.c | 80 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 86 insertions(+), 1 deletion(-) > > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..4987608ea4ff 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -416,6 +416,7 @@ struct dev_links_info { > * @dma_pools: Dma pools (if dma'ble device). > * @dma_mem: Internal for coherent mem override. > * @cma_area: Contiguous memory area for dma allocations > + * @dma_io_tlb_mem: Internal for swiotlb io_tlb_mem override. > * @archdata: For arch-specific additions. > * @of_node: Associated device tree node. > * @fwnode: Associated device node supplied by platform firmware. > @@ -521,6 +522,9 @@ struct device { > #ifdef CONFIG_DMA_CMA > struct cma *cma_area; /* contiguous memory area for dma > allocations */ > +#endif > +#ifdef CONFIG_DMA_RESTRICTED_POOL > + struct io_tlb_mem *dma_io_tlb_mem; > #endif > /* arch specific additions */ > struct dev_archdata archdata; > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index 216854a5e513..03ad6e3b4056 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -72,7 +72,8 @@ 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/swiotlb.c b/kernel/dma/swiotlb.c > index 57a9adb920bf..ffbb8724e06c 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 > @@ -681,3 +688,76 @@ static int __init swiotlb_create_default_debugfs(void) > late_initcall(swiotlb_create_default_debugfs); > > #endif > + > +#ifdef CONFIG_DMA_RESTRICTED_POOL > +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; > + > + if (dev->dma_io_tlb_mem) > + return 0; > + > + /* 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; > +#ifdef CONFIG_ARM > + if (!PageHighMem(pfn_to_page(PHYS_PFN(rmem->base)))) { > + kfree(mem); > + return -EINVAL; > + } > +#endif /* CONFIG_ARM */ > + swiotlb_init_io_tlb_mem(mem, rmem->base, nslabs, false); > + > + rmem->priv = mem; > + } > + > +#ifdef CONFIG_DEBUG_FS > + if (!io_tlb_default_mem->debugfs) > + io_tlb_default_mem->debugfs = > + debugfs_create_dir("swiotlb", NULL); At this point it's possible for io_tlb_default_mem to be NULL, leading to a splat. But even then if it's not and we have the situation where debugfs==NULL then the debugfs_create_dir() here will cause a subsequent attempt in swiotlb_create_debugfs() to fail (directory already exists) leading to mem->debugfs being assigned an error value. I suspect the creation of the debugfs directory needs to be separated from io_tlb_default_mem being set. Other than that I gave this series a go with our prototype of Arm's Confidential Computer Architecture[1] - since the majority of the guest's memory is protected from the host the restricted DMA pool allows (only) a small area to be shared with the host. After fixing (well hacking round) the above it all seems to be working fine with virtio drivers. Thanks, Steve [1] https://www.arm.com/why-arm/architecture/security-features/arm-confidential-compute-architecture _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx