From patchwork Tue Jan 30 08:08:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 13536974 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (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 1BF20679FC; Tue, 30 Jan 2024 08:15:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706602505; cv=none; b=ajNsH8H44czN8dUChU8aYsdgo4HW1Ul8eWaCjDheAZP/hiupqVWzEFDozEMHnyg2eJj7XHMIcAG9yPrZfh/nWo+E0ztFhhv+WKZk3vr6+Osd2oE5wP/6Wbjx/lmqev1g9ZRwEMGxq0bbWEGE5DKK+QS+gscCygFJRPsj36S3A4c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706602505; c=relaxed/simple; bh=eynhCIed9/weS0mwTxqMY1dQrxlU+C17Xz2HQyB+fR8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pHnm3nkSkthFMbEAeTa7o08F/XwW/oD/bDypeJVxtlwN5Bcaw/myjY5VsjiVfOMq77jOdCYOEA0XCztO/pRESw9AXP+U1KL22Cj+iVfvwyQSPiaHoNnljB0/IYx/7mv2ytNUB6AEMSna7QOnUzpRJHHStNIF1o91+7TiLbdtDCQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=PfaS8UoB; arc=none smtp.client-ip=198.175.65.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="PfaS8UoB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706602505; x=1738138505; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=eynhCIed9/weS0mwTxqMY1dQrxlU+C17Xz2HQyB+fR8=; b=PfaS8UoBDCPcEEXVkVRKrjBOSlvTus1V3NZgoubL/+5I+D9/d8nzBR+x tt2GxZ9zPE7ZjJkOpUvtczdChrP7l98iVME6/c8Vv/l4GJYnAQQts50Bo KpmAm1UVNsjhCy7OfgDiaccNX4wKUNNyR5MbGyCOXqZGwzzcd28TqvE7U L7DdFQJodCuSgAvGsZ/emoZxQ3Y3dAoZz6ly/G6nRDx5R4Lh+rvKcanBF H+IskF7vGhHRafuFqRQVw4O/kz30oRSQ4uSwa9dmZ0s91MTfxHz7vHRj7 Bq8lqIQx9ocLp09E63L6ue7UpgBsf9z+FE3VYWI0PcZXIzQcLaerU5Y9Y A==; X-IronPort-AV: E=McAfee;i="6600,9927,10968"; a="10588491" X-IronPort-AV: E=Sophos;i="6.05,707,1701158400"; d="scan'208";a="10588491" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jan 2024 00:15:04 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,707,1701158400"; d="scan'208";a="3633892" Received: from allen-box.sh.intel.com ([10.239.159.127]) by fmviesa003.fm.intel.com with ESMTP; 30 Jan 2024 00:15:00 -0800 From: Lu Baolu To: Joerg Roedel , Will Deacon , Robin Murphy , Jason Gunthorpe , Kevin Tian , Jean-Philippe Brucker , Nicolin Chen Cc: Yi Liu , Jacob Pan , Longfang Liu , Yan Zhao , Joel Granados , iommu@lists.linux.dev, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu , Jason Gunthorpe Subject: [PATCH v11 13/16] iommu: Improve iopf_queue_remove_device() Date: Tue, 30 Jan 2024 16:08:32 +0800 Message-Id: <20240130080835.58921-14-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240130080835.58921-1-baolu.lu@linux.intel.com> References: <20240130080835.58921-1-baolu.lu@linux.intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Convert iopf_queue_remove_device() to return void instead of an error code, as the return value is never used. This removal helper is designed to be never-failed, so there's no need for error handling. Ack all outstanding page requests from the device with the response code of IOMMU_PAGE_RESP_INVALID, indicating device should not attempt any retry. Add comments to this helper explaining the steps involved in removing a device from the iopf queue and disabling its PRI. Suggested-by: Jason Gunthorpe Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Tested-by: Yan Zhao --- include/linux/iommu.h | 5 ++-- drivers/iommu/intel/iommu.c | 7 +---- drivers/iommu/io-pgfault.c | 59 ++++++++++++++++++++++++------------- 3 files changed, 41 insertions(+), 30 deletions(-) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 396d7b0d88b2..d9a99a978ffa 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -1542,7 +1542,7 @@ iommu_sva_domain_alloc(struct device *dev, struct mm_struct *mm) #ifdef CONFIG_IOMMU_IOPF int iopf_queue_add_device(struct iopf_queue *queue, struct device *dev); -int iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev); +void iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev); int iopf_queue_flush_dev(struct device *dev); struct iopf_queue *iopf_queue_alloc(const char *name); void iopf_queue_free(struct iopf_queue *queue); @@ -1558,10 +1558,9 @@ iopf_queue_add_device(struct iopf_queue *queue, struct device *dev) return -ENODEV; } -static inline int +static inline void iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev) { - return -ENODEV; } static inline int iopf_queue_flush_dev(struct device *dev) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 29a12f289e2e..a81a2be9b870 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4455,12 +4455,7 @@ static int intel_iommu_disable_iopf(struct device *dev) */ pci_disable_pri(to_pci_dev(dev)); info->pri_enabled = 0; - - /* - * With PRI disabled and outstanding PRQs drained, removing device - * from iopf queue should never fail. - */ - WARN_ON(iopf_queue_remove_device(iommu->iopf_queue, dev)); + iopf_queue_remove_device(iommu->iopf_queue, dev); return 0; } diff --git a/drivers/iommu/io-pgfault.c b/drivers/iommu/io-pgfault.c index ce7058892b59..26e100ca3221 100644 --- a/drivers/iommu/io-pgfault.c +++ b/drivers/iommu/io-pgfault.c @@ -448,50 +448,67 @@ EXPORT_SYMBOL_GPL(iopf_queue_add_device); * @queue: IOPF queue * @dev: device to remove * - * Caller makes sure that no more faults are reported for this device. + * Removing a device from an iopf_queue. It's recommended to follow these + * steps when removing a device: * - * Return: 0 on success and <0 on error. + * - Disable new PRI reception: Turn off PRI generation in the IOMMU hardware + * and flush any hardware page request queues. This should be done before + * calling into this helper. + * - Acknowledge all outstanding PRQs to the device: Respond to all outstanding + * page requests with IOMMU_PAGE_RESP_INVALID, indicating the device should + * not retry. This helper function handles this. + * - Disable PRI on the device: After calling this helper, the caller could + * then disable PRI on the device. + * - Tear down the iopf infrastructure: Calling iopf_queue_remove_device() + * essentially disassociates the device. The fault_param might still exist, + * but iommu_page_response() will do nothing. The device fault parameter + * reference count has been properly passed from iommu_report_device_fault() + * to the fault handling work, and will eventually be released after + * iommu_page_response(). */ -int iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev) +void iopf_queue_remove_device(struct iopf_queue *queue, struct device *dev) { - int ret = 0; struct iopf_fault *iopf, *next; + struct iommu_page_response resp; struct dev_iommu *param = dev->iommu; struct iommu_fault_param *fault_param; + const struct iommu_ops *ops = dev_iommu_ops(dev); mutex_lock(&queue->lock); mutex_lock(¶m->lock); fault_param = rcu_dereference_check(param->fault_param, lockdep_is_held(¶m->lock)); - if (!fault_param) { - ret = -ENODEV; - goto unlock; - } - - if (fault_param->queue != queue) { - ret = -EINVAL; - goto unlock; - } - if (!list_empty(&fault_param->faults)) { - ret = -EBUSY; + if (WARN_ON(!fault_param || fault_param->queue != queue)) goto unlock; - } - - list_del(&fault_param->queue_list); - /* Just in case some faults are still stuck */ + mutex_lock(&fault_param->lock); list_for_each_entry_safe(iopf, next, &fault_param->partial, list) kfree(iopf); + list_for_each_entry_safe(iopf, next, &fault_param->faults, list) { + memset(&resp, 0, sizeof(struct iommu_page_response)); + resp.pasid = iopf->fault.prm.pasid; + resp.grpid = iopf->fault.prm.grpid; + resp.code = IOMMU_PAGE_RESP_INVALID; + + if (iopf->fault.prm.flags & IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID) + resp.flags = IOMMU_PAGE_RESP_PASID_VALID; + + ops->page_response(dev, iopf, &resp); + list_del(&iopf->list); + kfree(iopf); + } + mutex_unlock(&fault_param->lock); + + list_del(&fault_param->queue_list); + /* dec the ref owned by iopf_queue_add_device() */ rcu_assign_pointer(param->fault_param, NULL); iopf_put_dev_fault_param(fault_param); unlock: mutex_unlock(¶m->lock); mutex_unlock(&queue->lock); - - return ret; } EXPORT_SYMBOL_GPL(iopf_queue_remove_device);