From nobody Fri Dec 19 18:44:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62392C07E9D for ; Mon, 26 Sep 2022 14:55:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235256AbiIZOzJ (ORCPT ); Mon, 26 Sep 2022 10:55:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235173AbiIZOy3 (ORCPT ); Mon, 26 Sep 2022 10:54:29 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7690193799 for ; Mon, 26 Sep 2022 06:21:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664198493; x=1695734493; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sCEnmrg9GWDdV+abb6W1IKSbIi92j5+nKGixxLBe/4o=; b=aVrbTHsg6pVXcS0dsAhjvspOFQc2SDKpuuDnpnFx0hM11EhNtqymHNLJ AlPjtNyyKzttlzMYBfmFSuRG0pvKxYEY/NbwSCNkJZyr24XcZad7zWIPL Bhgid9pk/Xaaf0CP1Ug4XnuKJkAj6j+3v4uCvjLhXul+nhKvjGQrrgAQj n02e3ZiKwP0RTPTwg4bM/lY3ou5tINuNSAmaU92XSqRmPi2Kq2x7IeMuq wrvYOsmB5kPB9PAPAXN8OzmidTTjc16N3dboLbJp4gbIsdVlth1aZAkXm 3lmbKFmhnf7JEWfcLPB84fNYwW1BywDyVmomaIfQmZSL9J7AdfaSTlg5k A==; X-IronPort-AV: E=McAfee;i="6500,9779,10482"; a="280750284" X-IronPort-AV: E=Sophos;i="5.93,346,1654585200"; d="scan'208";a="280750284" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Sep 2022 06:21:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10482"; a="683525649" X-IronPort-AV: E=Sophos;i="5.93,346,1654585200"; d="scan'208";a="683525649" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga008.fm.intel.com with ESMTP; 26 Sep 2022 06:21:31 -0700 From: Lu Baolu To: Joerg Roedel Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 1/6] iommu/vt-d: Remove unnecessary SVA data accesses in page fault path Date: Mon, 26 Sep 2022 21:15:24 +0800 Message-Id: <20220926131529.4045281-2-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220926131529.4045281-1-baolu.lu@linux.intel.com> References: <20220926131529.4045281-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The existing I/O page fault handling code accesses the per-PASID SVA data structures. This is unnecessary and makes the fault handling code only suitable for SVA scenarios. This removes the SVA data accesses from the I/O page fault reporting and responding code, so that the fault handling code could be generic. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220914011821.400986-1-baolu.lu@linux.inte= l.com --- drivers/iommu/intel/iommu.h | 2 +- drivers/iommu/intel/svm.c | 60 +++++-------------------------------- 2 files changed, 8 insertions(+), 54 deletions(-) diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h index 74b0e19e23ee..b5fb7706e97c 100644 --- a/drivers/iommu/intel/iommu.h +++ b/drivers/iommu/intel/iommu.h @@ -586,6 +586,7 @@ struct intel_iommu { #ifdef CONFIG_INTEL_IOMMU_SVM struct page_req_dsc *prq; unsigned char prq_name[16]; /* Name for PRQ interrupt */ + unsigned long prq_seq_number; struct completion prq_complete; struct ioasid_allocator_ops pasid_allocator; /* Custom allocator for PASI= Ds */ #endif @@ -761,7 +762,6 @@ struct intel_svm_dev { struct device *dev; struct intel_iommu *iommu; struct iommu_sva sva; - unsigned long prq_seq_number; u32 pasid; int users; u16 did; diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 8bcfb93dda56..d1cab931dcb0 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -48,23 +48,6 @@ static void *pasid_private_find(ioasid_t pasid) return xa_load(&pasid_private_array, pasid); } =20 -static struct intel_svm_dev * -svm_lookup_device_by_sid(struct intel_svm *svm, u16 sid) -{ - struct intel_svm_dev *sdev =3D NULL, *t; - - rcu_read_lock(); - list_for_each_entry_rcu(t, &svm->devs, list) { - if (t->sid =3D=3D sid) { - sdev =3D t; - break; - } - } - rcu_read_unlock(); - - return sdev; -} - static struct intel_svm_dev * svm_lookup_device_by_dev(struct intel_svm *svm, struct device *dev) { @@ -706,11 +689,10 @@ static void handle_bad_prq_event(struct intel_iommu *= iommu, =20 static irqreturn_t prq_event_thread(int irq, void *d) { - struct intel_svm_dev *sdev =3D NULL; struct intel_iommu *iommu =3D d; - struct intel_svm *svm =3D NULL; struct page_req_dsc *req; int head, tail, handled; + struct pci_dev *pdev; u64 address; =20 /* @@ -730,8 +712,6 @@ static irqreturn_t prq_event_thread(int irq, void *d) pr_err("IOMMU: %s: Page request without PASID\n", iommu->name); bad_req: - svm =3D NULL; - sdev =3D NULL; handle_bad_prq_event(iommu, req, QI_RESP_INVALID); goto prq_advance; } @@ -758,34 +738,19 @@ static irqreturn_t prq_event_thread(int irq, void *d) if (unlikely(req->lpig && !req->rd_req && !req->wr_req)) goto prq_advance; =20 - if (!svm || svm->pasid !=3D req->pasid) { - /* - * It can't go away, because the driver is not permitted - * to unbind the mm while any page faults are outstanding. - */ - svm =3D pasid_private_find(req->pasid); - if (IS_ERR_OR_NULL(svm) || (svm->flags & SVM_FLAG_SUPERVISOR_MODE)) - goto bad_req; - } - - if (!sdev || sdev->sid !=3D req->rid) { - sdev =3D svm_lookup_device_by_sid(svm, req->rid); - if (!sdev) - goto bad_req; - } - - sdev->prq_seq_number++; - + pdev =3D pci_get_domain_bus_and_slot(iommu->segment, + PCI_BUS_NUM(req->rid), + req->rid & 0xff); /* * If prq is to be handled outside iommu driver via receiver of * the fault notifiers, we skip the page response here. */ - if (intel_svm_prq_report(iommu, sdev->dev, req)) + if (!pdev || intel_svm_prq_report(iommu, &pdev->dev, req)) handle_bad_prq_event(iommu, req, QI_RESP_INVALID); =20 - trace_prq_report(iommu, sdev->dev, req->qw_0, req->qw_1, + trace_prq_report(iommu, &pdev->dev, req->qw_0, req->qw_1, req->priv_data[0], req->priv_data[1], - sdev->prq_seq_number); + iommu->prq_seq_number++); prq_advance: head =3D (head + sizeof(*req)) & PRQ_RING_MASK; } @@ -881,8 +846,6 @@ int intel_svm_page_response(struct device *dev, struct iommu_page_response *msg) { struct iommu_fault_page_request *prm; - struct intel_svm_dev *sdev =3D NULL; - struct intel_svm *svm =3D NULL; struct intel_iommu *iommu; bool private_present; bool pasid_present; @@ -901,8 +864,6 @@ int intel_svm_page_response(struct device *dev, if (!msg || !evt) return -EINVAL; =20 - mutex_lock(&pasid_mutex); - prm =3D &evt->fault.prm; sid =3D PCI_DEVID(bus, devfn); pasid_present =3D prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; @@ -919,12 +880,6 @@ int intel_svm_page_response(struct device *dev, goto out; } =20 - ret =3D pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); - if (ret || !sdev) { - ret =3D -ENODEV; - goto out; - } - /* * Per VT-d spec. v3.0 ch7.7, system software must respond * with page group response if private data is present (PDP) @@ -954,6 +909,5 @@ int intel_svm_page_response(struct device *dev, qi_submit_sync(iommu, &desc, 1, 0); } out: - mutex_unlock(&pasid_mutex); return ret; } --=20 2.34.1