From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B09C015B0 for ; Fri, 23 Sep 2022 00:48:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1663894085; x=1695430085; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=sCEnmrg9GWDdV+abb6W1IKSbIi92j5+nKGixxLBe/4o=; b=Xs6lJdWCDY/3hpct+5ItR9bTipdPIZW8ruivGLGFJpJXQsKhs2+6kMBP rPUhua/uNoYJuUxgzjDPuA61wUv8t10YyU/hkYTnskwms9CYJTD9A+qen i/s+Iw7HCZIvRezwKNdJ05qeSa87uVv5MBgPIwdEIrb5ZUaZvOXh10Pda hkPQsU+aeE3MsSAPnpAWY+W4jG6VWkoP1GunesnIL186EFeIeqNTdPVIH sq+IDwV6WhLQM8/c0+Inipb1eM6CF1fgX4sCIUhyWsQdQ26vBMn7RC1LS SLgfAWxUDIwEQCrrsqsDO31uzz5Tb/tyRDmjWJA5nYHbkP5Gh7ZGH7y9p A==; X-IronPort-AV: E=McAfee;i="6500,9779,10478"; a="362278846" X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="362278846" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2022 17:48:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="650759932" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga008.jf.intel.com with ESMTP; 22 Sep 2022 17:48:04 -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: Fri, 23 Sep 2022 08:42:01 +0800 Message-Id: <20220923004206.3630441-2-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220923004206.3630441-1-baolu.lu@linux.intel.com> References: <20220923004206.3630441-1-baolu.lu@linux.intel.com> Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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.intel.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 PASIDs */ #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); } -static struct intel_svm_dev * -svm_lookup_device_by_sid(struct intel_svm *svm, u16 sid) -{ - struct intel_svm_dev *sdev = NULL, *t; - - rcu_read_lock(); - list_for_each_entry_rcu(t, &svm->devs, list) { - if (t->sid == sid) { - sdev = 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, static irqreturn_t prq_event_thread(int irq, void *d) { - struct intel_svm_dev *sdev = NULL; struct intel_iommu *iommu = d; - struct intel_svm *svm = NULL; struct page_req_dsc *req; int head, tail, handled; + struct pci_dev *pdev; u64 address; /* @@ -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 = NULL; - sdev = 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; - if (!svm || svm->pasid != req->pasid) { - /* - * It can't go away, because the driver is not permitted - * to unbind the mm while any page faults are outstanding. - */ - svm = pasid_private_find(req->pasid); - if (IS_ERR_OR_NULL(svm) || (svm->flags & SVM_FLAG_SUPERVISOR_MODE)) - goto bad_req; - } - - if (!sdev || sdev->sid != req->rid) { - sdev = svm_lookup_device_by_sid(svm, req->rid); - if (!sdev) - goto bad_req; - } - - sdev->prq_seq_number++; - + pdev = 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); - 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 = (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 = NULL; - struct intel_svm *svm = 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; - mutex_lock(&pasid_mutex); - prm = &evt->fault.prm; sid = PCI_DEVID(bus, devfn); pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID; @@ -919,12 +880,6 @@ int intel_svm_page_response(struct device *dev, goto out; } - ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); - if (ret || !sdev) { - ret = -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; } -- 2.34.1