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=-9.8 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_GIT autolearn=ham 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 2CD11C10DCE for ; Fri, 13 Mar 2020 03:19:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A7FA20658 for ; Fri, 13 Mar 2020 03:19:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726659AbgCMDTT (ORCPT ); Thu, 12 Mar 2020 23:19:19 -0400 Received: from mga07.intel.com ([134.134.136.100]:27635 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726371AbgCMDTT (ORCPT ); Thu, 12 Mar 2020 23:19:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Mar 2020 20:19:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,546,1574150400"; d="scan'208";a="278065395" Received: from joy-optiplex-7040.sh.intel.com ([10.239.13.16]) by fmsmga002.fm.intel.com with ESMTP; 12 Mar 2020 20:19:16 -0700 From: Yan Zhao To: intel-gvt-dev@lists.freedesktop.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: alex.williamson@redhat.com, zhenyuw@linux.intel.com, pbonzini@redhat.com, kevin.tian@intel.com, peterx@redhat.com, Yan Zhao Subject: [PATCH v4 3/7] vfio: avoid inefficient operations on VFIO group in vfio_pin/unpin_pages Date: Thu, 12 Mar 2020 23:09:47 -0400 Message-Id: <20200313030947.7884-1-yan.y.zhao@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200313030548.7705-1-yan.y.zhao@intel.com> References: <20200313030548.7705-1-yan.y.zhao@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org vfio_group_pin_pages() and vfio_group_unpin_pages() are introduced to avoid inefficient search/check/ref/deref opertions associated with VFIO group as those in each calling into vfio_pin_pages() and vfio_unpin_pages(). VFIO group is taken as arg directly. The callers combine search/check/ref/deref operations associated with VFIO group by calling vfio_group_get_external_user()/vfio_group_get_external_user_from_dev() beforehand, and vfio_group_put_external_user() afterwards. Suggested-by: Alex Williamson Signed-off-by: Yan Zhao --- drivers/vfio/vfio.c | 91 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/vfio.h | 6 +++ 2 files changed, 97 insertions(+) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 6997f711b925..210fcf426643 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1999,6 +1999,97 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage) } EXPORT_SYMBOL(vfio_unpin_pages); +/* + * Pin a set of guest IOVA PFNs and return their associated host PFNs for a + * VFIO group. + * + * The caller needs to call vfio_group_get_external_user() or + * vfio_group_get_external_user_from_dev() prior to calling this interface, + * so as to prevent the VFIO group from disposal in the middle of the call. + * But it can keep the reference to the VFIO group for several calls into + * this interface. + * After finishing using of the VFIO group, the caller needs to release the + * VFIO group by calling vfio_group_put_external_user(). + * + * @group [in] : VFIO group + * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be pinned. + * @npage [in] : count of elements in user_iova_pfn array. + * This count should not be greater + * VFIO_PIN_PAGES_MAX_ENTRIES. + * @prot [in] : protection flags + * @phys_pfn [out] : array of host PFNs + * Return error or number of pages pinned. + */ +int vfio_group_pin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage, + int prot, unsigned long *phys_pfn) +{ + struct vfio_container *container; + struct vfio_iommu_driver *driver; + int ret; + + if (!group || !user_iova_pfn || !phys_pfn || !npage) + return -EINVAL; + + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) + return -E2BIG; + + container = group->container; + driver = container->iommu_driver; + if (likely(driver && driver->ops->pin_pages)) + ret = driver->ops->pin_pages(container->iommu_data, + user_iova_pfn, npage, + prot, phys_pfn); + else + ret = -ENOTTY; + + return ret; +} +EXPORT_SYMBOL(vfio_group_pin_pages); + +/* + * Unpin a set of guest IOVA PFNs for a VFIO group. + * + * The caller needs to call vfio_group_get_external_user() or + * vfio_group_get_external_user_from_dev() prior to calling this interface, + * so as to prevent the VFIO group from disposal in the middle of the call. + * But it can keep the reference to the VFIO group for several calls into + * this interface. + * After finishing using of the VFIO group, the caller needs to release the + * VFIO group by calling vfio_group_put_external_user(). + * + * @group [in] : vfio group + * @user_iova_pfn [in] : array of user/guest IOVA PFNs to be unpinned. + * @npage [in] : count of elements in user_iova_pfn array. + * This count should not be greater than + * VFIO_PIN_PAGES_MAX_ENTRIES. + * Return error or number of pages unpinned. + */ +int vfio_group_unpin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage) +{ + struct vfio_container *container; + struct vfio_iommu_driver *driver; + int ret; + + if (!group || !user_iova_pfn || !npage) + return -EINVAL; + + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES) + return -E2BIG; + + container = group->container; + driver = container->iommu_driver; + if (likely(driver && driver->ops->unpin_pages)) + ret = driver->ops->unpin_pages(container->iommu_data, + user_iova_pfn, npage); + else + ret = -ENOTTY; + + return ret; +} +EXPORT_SYMBOL(vfio_group_unpin_pages); + /* * This interface allows the CPUs to perform some sort of virtual DMA on diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 34b2fdf4de6e..be2bd358b952 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -111,6 +111,12 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage); +extern int vfio_group_pin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage, + int prot, unsigned long *phys_pfn); +extern int vfio_group_unpin_pages(struct vfio_group *group, + unsigned long *user_iova_pfn, int npage); + extern int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova, void *data, size_t len, bool write); -- 2.17.1