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 2E6D0CA9EBC for ; Fri, 25 Oct 2019 04:38:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 059F820867 for ; Fri, 25 Oct 2019 04:38:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389763AbfJYEiw (ORCPT ); Fri, 25 Oct 2019 00:38:52 -0400 Received: from mga18.intel.com ([134.134.136.126]:21871 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388090AbfJYEiu (ORCPT ); Fri, 25 Oct 2019 00:38:50 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Oct 2019 21:38:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,227,1569308400"; d="scan'208";a="282150315" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga001.jf.intel.com with ESMTP; 24 Oct 2019 21:38:49 -0700 Date: Thu, 24 Oct 2019 21:43:11 -0700 From: Jacob Pan To: Lu Baolu Cc: iommu@lists.linux-foundation.org, LKML , Joerg Roedel , David Woodhouse , Alex Williamson , Jean-Philippe Brucker , Yi Liu , "Tian, Kevin" , Raj Ashok , Christoph Hellwig , Jonathan Cameron , Eric Auger , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH v7 03/11] iommu/vt-d: Add custom allocator for IOASID Message-ID: <20191024214311.43d76a5c@jacob-builder> In-Reply-To: References: <1571946904-86776-1-git-send-email-jacob.jun.pan@linux.intel.com> <1571946904-86776-4-git-send-email-jacob.jun.pan@linux.intel.com> 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 Baolu, Thanks for the review. please see my comments inline. On Fri, 25 Oct 2019 10:30:48 +0800 Lu Baolu wrote: > Hi Jacob, > > On 10/25/19 3:54 AM, Jacob Pan wrote: > > When VT-d driver runs in the guest, PASID allocation must be > > performed via virtual command interface. This patch registers a > > custom IOASID allocator which takes precedence over the default > > XArray based allocator. The resulting IOASID allocation will always > > come from the host. This ensures that PASID namespace is system- > > wide. > > > > Signed-off-by: Lu Baolu > > Signed-off-by: Liu, Yi L > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/Kconfig | 1 + > > drivers/iommu/intel-iommu.c | 67 > > +++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/intel-iommu.h | 2 ++ 3 files changed, 70 > > insertions(+) > > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index fd50ddffffbf..961fe5795a90 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -211,6 +211,7 @@ config INTEL_IOMMU_SVM > > bool "Support for Shared Virtual Memory with Intel IOMMU" > > depends on INTEL_IOMMU && X86 > > select PCI_PASID > > + select IOASID > > select MMU_NOTIFIER > > help > > Shared Virtual Memory (SVM) provides a facility for > > devices diff --git a/drivers/iommu/intel-iommu.c > > b/drivers/iommu/intel-iommu.c index 3f974919d3bd..ced1d89ef977 > > 100644 --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -1706,6 +1706,9 @@ static void free_dmar_iommu(struct > > intel_iommu *iommu) if (ecap_prs(iommu->ecap)) > > intel_svm_finish_prq(iommu); > > } > > + if (ecap_vcs(iommu->ecap) && vccap_pasid(iommu->vccap)) > > + > > ioasid_unregister_allocator(&iommu->pasid_allocator); > > Since scalable mode is disabled if pasid allocator failed to register, > add sm_support(iommu) check here will be better. > I was thinking to be symmetric with register call, checking for the same conditions. Also, I like your advice below to only disable SVA instead of scalable mode. > > + > > #endif > > } > > > > @@ -4910,6 +4913,44 @@ static int __init > > probe_acpi_namespace_devices(void) return 0; > > } > > > > +#ifdef CONFIG_INTEL_IOMMU_SVM > > +static ioasid_t intel_ioasid_alloc(ioasid_t min, ioasid_t max, > > void *data) +{ > > + struct intel_iommu *iommu = data; > > + ioasid_t ioasid; > > + > > + /* > > + * VT-d virtual command interface always uses the full 20 > > bit > > + * PASID range. Host can partition guest PASID range based > > on > > + * policies but it is out of guest's control. > > + */ > > + if (min < PASID_MIN || max > intel_pasid_max_id) > > + return INVALID_IOASID; > > + > > + if (vcmd_alloc_pasid(iommu, &ioasid)) > > + return INVALID_IOASID; > > + > > + return ioasid; > > +} > > + > > +static void intel_ioasid_free(ioasid_t ioasid, void *data) > > +{ > > + struct intel_iommu *iommu = data; > > + > > + if (!iommu) > > + return; > > + /* > > + * Sanity check the ioasid owner is done at upper layer, > > e.g. VFIO > > + * We can only free the PASID when all the devices are > > unbond. > > + */ > > + if (ioasid_find(NULL, ioasid, NULL)) { > > + pr_alert("Cannot free active IOASID %d\n", ioasid); > > + return; > > + } > > + vcmd_free_pasid(iommu, ioasid); > > +} > > +#endif > > + > > int __init intel_iommu_init(void) > > { > > int ret = -ENODEV; > > @@ -5020,6 +5061,32 @@ int __init intel_iommu_init(void) > > "%s", iommu->name); > > iommu_device_set_ops(&iommu->iommu, > > &intel_iommu_ops); iommu_device_register(&iommu->iommu); > > +#ifdef CONFIG_INTEL_IOMMU_SVM > > + if (ecap_vcs(iommu->ecap) && > > vccap_pasid(iommu->vccap)) { > > + pr_info("Register custom PASID > > allocator\n"); > > + /* > > + * Register a custom ASID allocator if we > > are running > > + * in a guest, the purpose is to have a > > system wide PASID > > + * namespace among all PASID users. > > + * There can be multiple vIOMMUs in each > > guest but only > > + * one allocator is active. All vIOMMU > > allocators will > > + * eventually be calling the same host > > allocator. > > + */ > > + iommu->pasid_allocator.alloc = > > intel_ioasid_alloc; > > + iommu->pasid_allocator.free = > > intel_ioasid_free; > > + iommu->pasid_allocator.pdata = (void > > *)iommu; > > + ret = > > ioasid_register_allocator(&iommu->pasid_allocator); > > + if (ret) { > > + pr_warn("Custom PASID allocator > > registeration failed\n"); > > + /* > > + * Disable scalable mode on this > > IOMMU if there > > + * is no custom allocator. Mixing > > SM capable vIOMMU > > + * and non-SM vIOMMU are not > > supported. > > + */ > > + intel_iommu_sm = 0; > > It's insufficient to disable scalable mode by only clearing > intel_iommu_sm. The DMA_RTADDR_SMT bit in root entry has already been > set. Probably, you need to > > for each iommu > clear DMA_RTADDR_SMT in root entry > > Alternatively, since vSVA is the only customer of this custom PASID > allocator, is it possible to only disable SVA here? > Yeah, I think disable SVA is better. We can still do gIOVA in SM. I guess we need to introduce a flag for sva_enabled. > > + } > > + } > > +#endif > > } > > > > bus_set_iommu(&pci_bus_type, &intel_iommu_ops); > > diff --git a/include/linux/intel-iommu.h > > b/include/linux/intel-iommu.h index 1d4b8dcdc5d8..c624733cb2e6 > > 100644 --- a/include/linux/intel-iommu.h > > +++ b/include/linux/intel-iommu.h > > @@ -19,6 +19,7 @@ > > #include > > #include > > #include > > +#include > > > > #include > > #include > > @@ -546,6 +547,7 @@ struct intel_iommu { > > #ifdef CONFIG_INTEL_IOMMU_SVM > > struct page_req_dsc *prq; > > unsigned char prq_name[16]; /* Name for PRQ interrupt > > */ > > + struct ioasid_allocator_ops pasid_allocator; /* Custom > > allocator for PASIDs */ #endif > > struct q_inval *qi; /* Queued invalidation > > info */ u32 *iommu_state; /* Store iommu states between suspend and > > resume.*/ > > Best regards, > baolu [Jacob Pan]