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 68215C433FF for ; Mon, 5 Aug 2019 19:58:47 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 41B3A2054F for ; Mon, 5 Aug 2019 19:58:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 41B3A2054F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 06937F37; Mon, 5 Aug 2019 19:58:47 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 38C2CEB4 for ; Mon, 5 Aug 2019 19:58:45 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id B379B8EA for ; Mon, 5 Aug 2019 19:58:44 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Aug 2019 12:58:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,350,1559545200"; d="scan'208";a="164754154" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga007.jf.intel.com with ESMTP; 05 Aug 2019 12:58:26 -0700 Date: Mon, 5 Aug 2019 13:02:04 -0700 From: Jacob Pan To: Auger Eric Subject: Re: [PATCH v4 14/22] iommu/vt-d: Add custom allocator for IOASID Message-ID: <20190805130204.21aca034@jacob-builder> In-Reply-To: <2f2ba561-793f-a6a0-5765-ef8e9a5a3ab6@redhat.com> References: <1560087862-57608-1-git-send-email-jacob.jun.pan@linux.intel.com> <1560087862-57608-15-git-send-email-jacob.jun.pan@linux.intel.com> <2f2ba561-793f-a6a0-5765-ef8e9a5a3ab6@redhat.com> 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 , iommu@lists.linux-foundation.org, LKML , Alex Williamson , Andriy Shevchenko , David Woodhouse X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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 Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Tue, 16 Jul 2019 11:30:14 +0200 Auger Eric wrote: > Hi Jacob, > > On 6/9/19 3:44 PM, 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 | 60 > > +++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/intel-iommu.h | 2 ++ 3 files changed, 63 > > insertions(+) > > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index c40c4b5..5d1bc2a 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -213,6 +213,7 @@ 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 > > select IOASID > > help > > diff --git a/drivers/iommu/intel-iommu.c > > b/drivers/iommu/intel-iommu.c index 09b8ff0..5b84994 100644 > > --- a/drivers/iommu/intel-iommu.c > > +++ b/drivers/iommu/intel-iommu.c > > @@ -1711,6 +1711,8 @@ static void free_dmar_iommu(struct > > intel_iommu *iommu) if (ecap_prs(iommu->ecap)) > > intel_svm_finish_prq(iommu); > > } > > + ioasid_unregister_allocator(&iommu->pasid_allocator); > > + > > #endif > > } > > > > @@ -4820,6 +4822,46 @@ static int __init > > platform_optin_force_iommu(void) return 1; > > } > > > > +#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 > PASID_MAX) > > + return -EINVAL; > ioasid_alloc() does not handle that error value, use INVALID_IOASID? > > + > > + if (vcmd_alloc_pasid(iommu, &ioasid)) > > + return INVALID_IOASID; > > + > > + return ioasid; > > +} > > + > > +static void intel_ioasid_free(ioasid_t ioasid, void *data) > > +{ > > + struct iommu_pasid_alloc_info *svm; > > + 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. > > + */ > > + svm = ioasid_find(NULL, ioasid, NULL); > > + if (!svm) { > > + pr_warn("Freeing unbond IOASID %d\n", ioasid); > > + return; > > + } > > + vcmd_free_pasid(iommu, ioasid); > > +} > > +#endif > > + > > int __init intel_iommu_init(void) > > { > > int ret = -ENODEV; > > @@ -4924,6 +4966,24 @@ 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 (cap_caching_mode(iommu->cap) && > > sm_supported(iommu)) { > > + /* > > + * 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"); > what if it fails, don't you want a tear down path? > Good point, we need to disable PASID usage, i.e. disable scalable mode if there is no virtual command based PASID allocator in the guest. Sorry for the late reply. > Thanks > > Eric > [...] [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu