From patchwork Tue Jul 18 10:55:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13316996 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 551D5EB64DD for ; Tue, 18 Jul 2023 10:56:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231841AbjGRK4N (ORCPT ); Tue, 18 Jul 2023 06:56:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231723AbjGRKzv (ORCPT ); Tue, 18 Jul 2023 06:55:51 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A79710C4; Tue, 18 Jul 2023 03:55:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689677750; x=1721213750; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=8JOUsKGObo09iLtnZdrQCaUrUBlHZzD6b6Hk1GdqAec=; b=Ppg3QiHkGyrIOmKJ0tHhl51PpDaiUOkbwpetTqGqUfig/RS3bPQjv9p5 F1qAB5MicGDdoVUDIbdnbG+w+7PGX6rz3fU54E8F6SG489wTcXebItDcU hZnfTuxz04ZiAHBbdDJOUm75JfpYMheplTO6oi1EfI7HZ4qNEbHwdSXqK i/v0kBMHlczPO6tSaaXWJyzuR+Kd8ULOUW5AOKeB1zi6m8GBKrNGtO3i3 aUcjRT6mwkF4aTdz2hWAlV39MWLhnw3JnZwzyQJEZwp9wQR3HzMRBSL6K 2xnObhgQTgGSEFJaklwh+pj3QRTEYYDm0yooxhdXYdP2ouPccCLjGk+B+ Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="452553607" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="452553607" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 03:55:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="673863820" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="673863820" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by orsmga003.jf.intel.com with ESMTP; 18 Jul 2023 03:55:49 -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 v10 09/10] vfio/pci: Copy hot-reset device info to userspace in the devices loop Date: Tue, 18 Jul 2023 03:55:41 -0700 Message-Id: <20230718105542.4138-10-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230718105542.4138-1-yi.l.liu@intel.com> References: <20230718105542.4138-1-yi.l.liu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This copies the vfio_pci_dependent_device to userspace during looping each affected device for reporting vfio_pci_hot_reset_info. This avoids counting the affected devices and allocating a potential large buffer to store the vfio_pci_dependent_device of all the affected devices before copying them to userspace. Suggested-by: Jason Gunthorpe Tested-by: Yanting Jiang Tested-by: Zhenzhong Duan Signed-off-by: Jason Gunthorpe Signed-off-by: Yi Liu Reviewed-by: Jason Gunthorpe --- drivers/vfio/pci/vfio_pci_core.c | 93 ++++++++++++-------------------- 1 file changed, 33 insertions(+), 60 deletions(-) diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c index 32506c5539b9..f4a0ea01559e 100644 --- a/drivers/vfio/pci/vfio_pci_core.c +++ b/drivers/vfio/pci/vfio_pci_core.c @@ -777,19 +777,25 @@ static int vfio_pci_count_devs(struct pci_dev *pdev, void *data) } struct vfio_pci_fill_info { - int max; - int cur; - struct vfio_pci_dependent_device *devices; + struct vfio_pci_dependent_device __user *devices; + struct vfio_pci_dependent_device __user *devices_end; struct vfio_device *vdev; + u32 count; u32 flags; }; static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) { + struct vfio_pci_dependent_device info = { + .segment = pci_domain_nr(pdev->bus), + .bus = pdev->bus->number, + .devfn = pdev->devfn, + }; struct vfio_pci_fill_info *fill = data; - if (fill->cur == fill->max) - return -EAGAIN; /* Something changed, try again */ + fill->count++; + if (fill->devices >= fill->devices_end) + return 0; if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) { struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev); @@ -802,19 +808,19 @@ static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) */ vdev = vfio_find_device_in_devset(dev_set, &pdev->dev); if (!vdev) { - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + info.devid = VFIO_PCI_DEVID_NOT_OWNED; } else { int id = vfio_iommufd_get_dev_id(vdev, iommufd); if (id > 0) - fill->devices[fill->cur].devid = id; + info.devid = id; else if (id == -ENOENT) - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_OWNED; + info.devid = VFIO_PCI_DEVID_OWNED; else - fill->devices[fill->cur].devid = VFIO_PCI_DEVID_NOT_OWNED; + info.devid = VFIO_PCI_DEVID_NOT_OWNED; } /* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */ - if (fill->devices[fill->cur].devid == VFIO_PCI_DEVID_NOT_OWNED) + if (info.devid == VFIO_PCI_DEVID_NOT_OWNED) fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED; } else { struct iommu_group *iommu_group; @@ -823,13 +829,13 @@ static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data) if (!iommu_group) return -EPERM; /* Cannot reset non-isolated devices */ - fill->devices[fill->cur].group_id = iommu_group_id(iommu_group); + info.group_id = iommu_group_id(iommu_group); iommu_group_put(iommu_group); } - fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus); - fill->devices[fill->cur].bus = pdev->bus->number; - fill->devices[fill->cur].devfn = pdev->devfn; - fill->cur++; + + if (copy_to_user(fill->devices, &info, sizeof(info))) + return -EFAULT; + fill->devices++; return 0; } @@ -1259,8 +1265,7 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( unsigned long minsz = offsetofend(struct vfio_pci_hot_reset_info, count); struct vfio_pci_hot_reset_info hdr; - struct vfio_pci_fill_info fill = { 0 }; - struct vfio_pci_dependent_device *devices = NULL; + struct vfio_pci_fill_info fill = {}; bool slot = false; int ret = 0; @@ -1278,29 +1283,9 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( else if (pci_probe_reset_bus(vdev->pdev->bus)) return -ENODEV; - /* How many devices are affected? */ - ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs, - &fill.max, slot); - if (ret) - return ret; - - WARN_ON(!fill.max); /* Should always be at least one */ - - /* - * If there's enough space, fill it now, otherwise return -ENOSPC and - * the number of devices affected. - */ - if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) { - ret = -ENOSPC; - hdr.count = fill.max; - goto reset_info_exit; - } - - devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL); - if (!devices) - return -ENOMEM; - - fill.devices = devices; + fill.devices = arg->devices; + fill.devices_end = arg->devices + + (hdr.argsz - sizeof(hdr)) / sizeof(arg->devices[0]); fill.vdev = &vdev->vdev; if (vfio_device_cdev_opened(&vdev->vdev)) @@ -1311,29 +1296,17 @@ static int vfio_pci_ioctl_get_pci_hot_reset_info( ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs, &fill, slot); mutex_unlock(&vdev->vdev.dev_set->lock); + if (ret) + return ret; - /* - * If a device was removed between counting and filling, we may come up - * short of fill.max. If a device was added, we'll have a return of - * -EAGAIN above. - */ - if (!ret) { - hdr.count = fill.cur; - hdr.flags = fill.flags; - } - -reset_info_exit: + hdr.count = fill.count; + hdr.flags = fill.flags; if (copy_to_user(arg, &hdr, minsz)) - ret = -EFAULT; - - if (!ret) { - if (copy_to_user(&arg->devices, devices, - hdr.count * sizeof(*devices))) - ret = -EFAULT; - } + return -EFAULT; - kfree(devices); - return ret; + if (fill.count > fill.devices - arg->devices) + return -ENOSPC; + return 0; } static int