From patchwork Tue Jul 18 13:55:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13317312 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 C3063EB64DC for ; Tue, 18 Jul 2023 13:58:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232291AbjGRN6V (ORCPT ); Tue, 18 Jul 2023 09:58:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233222AbjGRN6L (ORCPT ); Tue, 18 Jul 2023 09:58:11 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DBC4197; Tue, 18 Jul 2023 06:57:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689688669; x=1721224669; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7JlSkImz3ShAuDaiIZ+sh4zHfMa5cWhubnsyO0SRRR4=; b=Y7ivL4yyG0JFTPoI81YHAO6nbW0BIraFB0kT6NlX8KQ+qu0R6aRxAp12 8V0QfzwBNZfz2fDvH7JhI+7+T1hUplRFtrIdv0qjou+f8KacPxXNTh9TB jWwSpZm1YB3TFBAP2soRPZWLz5IlrTC01uuL7e9r8xWCQVrntsxmYF3uN CRhuPEayY7Gq5lTOpqMiNrBME1h6y8/9Y+8Wtnc7Wy+dbCaQ/432MrAGA Mk7T+nN4LdfyFHOi1f0ayA+xG0QH/43Qj4eBuncBE7wLUBKRJlisNNhoJ ZWK2JvZXtWy4RLnxzFS/0O8SfRwAGAdCgOIdGw7NnJ89bTnGSFyGrhrk9 w==; X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="452590787" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="452590787" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 06:56:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="970251096" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="970251096" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga006.fm.intel.com with ESMTP; 18 Jul 2023 06:56:09 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Cc: joro@8bytes.org, robin.murphy@arm.com, cohuck@redhat.com, eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org, mjrosato@linux.ibm.com, chao.p.peng@linux.intel.com, yi.l.liu@intel.com, yi.y.sun@linux.intel.com, peterx@redhat.com, jasowang@redhat.com, shameerali.kolothum.thodi@huawei.com, lulu@redhat.com, suravee.suthikulpanit@amd.com, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-s390@vger.kernel.org, xudong.hao@intel.com, yan.y.zhao@intel.com, terrence.xu@intel.com, yanting.jiang@intel.com, zhenzhong.duan@intel.com, clegoate@redhat.com Subject: [PATCH v15 20/26] iommufd: Add iommufd_ctx_from_fd() Date: Tue, 18 Jul 2023 06:55:45 -0700 Message-Id: <20230718135551.6592-21-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230718135551.6592-1-yi.l.liu@intel.com> References: <20230718135551.6592-1-yi.l.liu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org It's common to get a reference to the iommufd context from a given file descriptor. So adds an API for it. Existing users of this API are compiled only when IOMMUFD is enabled, so no need to have a stub for the IOMMUFD disabled case. Signed-off-by: Yi Liu Reviewed-by: Jason Gunthorpe --- drivers/iommu/iommufd/main.c | 24 ++++++++++++++++++++++++ include/linux/iommufd.h | 1 + 2 files changed, 25 insertions(+) diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 32ce7befc8dd..4bbb20dff430 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -377,6 +377,30 @@ struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) } EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_file, IOMMUFD); +/** + * iommufd_ctx_from_fd - Acquires a reference to the iommufd context + * @fd: File descriptor to obtain the reference from + * + * Returns a pointer to the iommufd_ctx, otherwise ERR_PTR. On success + * the caller is responsible to call iommufd_ctx_put(). + */ +struct iommufd_ctx *iommufd_ctx_from_fd(int fd) +{ + struct file *file; + + file = fget(fd); + if (!file) + return ERR_PTR(-EBADF); + + if (file->f_op != &iommufd_fops) { + fput(file); + return ERR_PTR(-EBADFD); + } + /* fget is the same as iommufd_ctx_get() */ + return file->private_data; +} +EXPORT_SYMBOL_NS_GPL(iommufd_ctx_from_fd, IOMMUFD); + /** * iommufd_ctx_put - Put back a reference * @ictx: Context to put back diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 3a3216cb9482..9657c58813dc 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -54,6 +54,7 @@ void iommufd_ctx_get(struct iommufd_ctx *ictx); #if IS_ENABLED(CONFIG_IOMMUFD) struct iommufd_ctx *iommufd_ctx_from_file(struct file *file); +struct iommufd_ctx *iommufd_ctx_from_fd(int fd); void iommufd_ctx_put(struct iommufd_ctx *ictx); bool iommufd_ctx_has_group(struct iommufd_ctx *ictx, struct iommu_group *group);