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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham 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 1678BC43331 for ; Wed, 1 Apr 2020 22:44:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8B4720719 for ; Wed, 1 Apr 2020 22:44:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388401AbgDAWo2 (ORCPT ); Wed, 1 Apr 2020 18:44:28 -0400 Received: from mga04.intel.com ([192.55.52.120]:48593 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388386AbgDAWo1 (ORCPT ); Wed, 1 Apr 2020 18:44:27 -0400 IronPort-SDR: NNSNTHSGI0Dl6w8YPN4s5KEiu5/Lyd3PTMV5+3Wd/aKAJFUmmoufShgGfz3kkH1JqJtQ+kHmhc fExyRv1bV1zQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2020 15:44:26 -0700 IronPort-SDR: zkdHSM9lj9RG+TCgrQGNl9DJiOh5LdoXcru112HuXNimShCk6VYW+Fmyawdg5b+53sAe07ES/A wXa/65VULsgw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,333,1580803200"; d="scan'208";a="284569522" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by fmsmga002.fm.intel.com with ESMTP; 01 Apr 2020 15:44:25 -0700 Date: Wed, 1 Apr 2020 15:50:13 -0700 From: Jacob Pan To: Jean-Philippe Brucker Cc: Joerg Roedel , Alex Williamson , Lu Baolu , iommu@lists.linux-foundation.org, LKML , David Woodhouse , Jean-Philippe Brucker , Yi Liu , "Tian, Kevin" , Raj Ashok , Christoph Hellwig , Jonathan Cameron , Eric Auger , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH 01/10] iommu/ioasid: Introduce system-wide capacity Message-ID: <20200401155013.7386b2ad@jacob-builder> In-Reply-To: <20200401134552.GD882512@myrica> References: <1585158931-1825-1-git-send-email-jacob.jun.pan@linux.intel.com> <1585158931-1825-2-git-send-email-jacob.jun.pan@linux.intel.com> <20200401134552.GD882512@myrica> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jean, On Wed, 1 Apr 2020 15:45:52 +0200 Jean-Philippe Brucker wrote: > On Wed, Mar 25, 2020 at 10:55:22AM -0700, Jacob Pan wrote: > > IOASID is a limited system-wide resource that can be allocated at > > runtime. This limitation can be enumerated during boot. For > > example, on x86 platforms, PCI Process Address Space ID (PASID) > > allocation uses IOASID service. The number of supported PASID bits > > are enumerated by extended capability register as defined in the > > VT-d spec. > > > > This patch adds a helper to set the system capacity, it expected to > > be set during boot prior to any allocation request. > > This one-time setting is a bit awkward. Since multiple IOMMU drivers > may be loaded, this can't be a module_init() thing. And we generally > have multiple SMMU instances in the system. So we'd need to call > install_capacity() only for the first SMMU loaded with an arbitrary > 1<<20, even though each SMMU can support different numbers of PASID > bits. Furthermore, modules such as iommu-sva will want to initialize > their IOASID set at module_init(), which will happen before the SMMU > can set up the capacity, so ioasid_alloc_set() will return an error. > > How about hardcoding ioasid_capacity to 20 bits for now? It's the > PCIe limit and probably won't have to increase for a while. > Sound good. Default to 20 bits but can be adjusted if needed. > Thanks, > Jean > > > > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/ioasid.c | 15 +++++++++++++++ > > include/linux/ioasid.h | 5 ++++- > > 2 files changed, 19 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 0f8dd377aada..4026e52855b9 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -17,6 +17,21 @@ struct ioasid_data { > > struct rcu_head rcu; > > }; > > > > +static ioasid_t ioasid_capacity; > > +static ioasid_t ioasid_capacity_avail; > > + > > +/* System capacity can only be set once */ > > +void ioasid_install_capacity(ioasid_t total) > > +{ > > + if (ioasid_capacity) { > > + pr_warn("IOASID capacity already set at %d\n", > > ioasid_capacity); > > + return; > > + } > > + > > + ioasid_capacity = ioasid_capacity_avail = total; > > +} > > +EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > + > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 6f000d7a0ddc..9711fa0dc357 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -40,7 +40,7 @@ void *ioasid_find(struct ioasid_set *set, > > ioasid_t ioasid, int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); void > > ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_set_data(ioasid_t ioasid, void *data); - > > +void ioasid_install_capacity(ioasid_t total); > > #else /* !CONFIG_IOASID */ > > static inline ioasid_t ioasid_alloc(struct ioasid_set *set, > > ioasid_t min, ioasid_t max, void *private) > > @@ -72,5 +72,8 @@ static inline int ioasid_set_data(ioasid_t > > ioasid, void *data) return -ENOTSUPP; > > } > > > > +static inline void ioasid_install_capacity(ioasid_t total) > > +{ > > +} > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > > [Jacob Pan] 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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 BBAF6C2D0F0 for ; 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01 Apr 2020 15:44:26 -0700 IronPort-SDR: zkdHSM9lj9RG+TCgrQGNl9DJiOh5LdoXcru112HuXNimShCk6VYW+Fmyawdg5b+53sAe07ES/A wXa/65VULsgw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,333,1580803200"; d="scan'208";a="284569522" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by fmsmga002.fm.intel.com with ESMTP; 01 Apr 2020 15:44:25 -0700 Date: Wed, 1 Apr 2020 15:50:13 -0700 From: Jacob Pan To: Jean-Philippe Brucker Subject: Re: [PATCH 01/10] iommu/ioasid: Introduce system-wide capacity Message-ID: <20200401155013.7386b2ad@jacob-builder> In-Reply-To: <20200401134552.GD882512@myrica> References: <1585158931-1825-1-git-send-email-jacob.jun.pan@linux.intel.com> <1585158931-1825-2-git-send-email-jacob.jun.pan@linux.intel.com> <20200401134552.GD882512@myrica> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: "Tian, Kevin" , Raj Ashok , Jean-Philippe Brucker , LKML , iommu@lists.linux-foundation.org, Alex Williamson , David Woodhouse , Jonathan Cameron 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Jean, On Wed, 1 Apr 2020 15:45:52 +0200 Jean-Philippe Brucker wrote: > On Wed, Mar 25, 2020 at 10:55:22AM -0700, Jacob Pan wrote: > > IOASID is a limited system-wide resource that can be allocated at > > runtime. This limitation can be enumerated during boot. For > > example, on x86 platforms, PCI Process Address Space ID (PASID) > > allocation uses IOASID service. The number of supported PASID bits > > are enumerated by extended capability register as defined in the > > VT-d spec. > > > > This patch adds a helper to set the system capacity, it expected to > > be set during boot prior to any allocation request. > > This one-time setting is a bit awkward. Since multiple IOMMU drivers > may be loaded, this can't be a module_init() thing. And we generally > have multiple SMMU instances in the system. So we'd need to call > install_capacity() only for the first SMMU loaded with an arbitrary > 1<<20, even though each SMMU can support different numbers of PASID > bits. Furthermore, modules such as iommu-sva will want to initialize > their IOASID set at module_init(), which will happen before the SMMU > can set up the capacity, so ioasid_alloc_set() will return an error. > > How about hardcoding ioasid_capacity to 20 bits for now? It's the > PCIe limit and probably won't have to increase for a while. > Sound good. Default to 20 bits but can be adjusted if needed. > Thanks, > Jean > > > > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/ioasid.c | 15 +++++++++++++++ > > include/linux/ioasid.h | 5 ++++- > > 2 files changed, 19 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 0f8dd377aada..4026e52855b9 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -17,6 +17,21 @@ struct ioasid_data { > > struct rcu_head rcu; > > }; > > > > +static ioasid_t ioasid_capacity; > > +static ioasid_t ioasid_capacity_avail; > > + > > +/* System capacity can only be set once */ > > +void ioasid_install_capacity(ioasid_t total) > > +{ > > + if (ioasid_capacity) { > > + pr_warn("IOASID capacity already set at %d\n", > > ioasid_capacity); > > + return; > > + } > > + > > + ioasid_capacity = ioasid_capacity_avail = total; > > +} > > +EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > + > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 6f000d7a0ddc..9711fa0dc357 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -40,7 +40,7 @@ void *ioasid_find(struct ioasid_set *set, > > ioasid_t ioasid, int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); void > > ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_set_data(ioasid_t ioasid, void *data); - > > +void ioasid_install_capacity(ioasid_t total); > > #else /* !CONFIG_IOASID */ > > static inline ioasid_t ioasid_alloc(struct ioasid_set *set, > > ioasid_t min, ioasid_t max, void *private) > > @@ -72,5 +72,8 @@ static inline int ioasid_set_data(ioasid_t > > ioasid, void *data) return -ENOTSUPP; > > } > > > > +static inline void ioasid_install_capacity(ioasid_t total) > > +{ > > +} > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu