From patchwork Fri Apr 19 08:35:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yan Zhao X-Patchwork-Id: 10909555 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5BA2613B5 for ; Fri, 19 Apr 2019 19:03:08 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4FA5328DF6 for ; Fri, 19 Apr 2019 19:03:08 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4280428DF9; Fri, 19 Apr 2019 19:03:08 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8871628DF8 for ; Fri, 19 Apr 2019 19:03:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbfDSTC2 (ORCPT ); Fri, 19 Apr 2019 15:02:28 -0400 Received: from mga07.intel.com ([134.134.136.100]:51012 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726290AbfDSTC1 (ORCPT ); Fri, 19 Apr 2019 15:02:27 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Apr 2019 01:40:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,368,1549958400"; d="scan'208";a="338990668" Received: from joy-optiplex-7040.sh.intel.com ([10.239.13.9]) by fmsmga005.fm.intel.com with ESMTP; 19 Apr 2019 01:40:38 -0700 From: Yan Zhao To: intel-gvt-dev@lists.freedesktop.org Cc: arei.gonglei@huawei.com, aik@ozlabs.ru, Zhengxiao.zx@alibaba-inc.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, eauger@redhat.com, yi.l.liu@intel.com, ziye.yang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, felipe@nutanix.com, changpeng.liu@intel.com, Ken.Xue@amd.com, jonathan.davies@nutanix.com, shaopeng.he@intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, libvir-list@redhat.com, alex.williamson@redhat.com, eskultet@redhat.com, dgilbert@redhat.com, cohuck@redhat.com, kevin.tian@intel.com, zhenyuw@linux.intel.com, zhi.a.wang@intel.com, cjia@nvidia.com, kwankhede@nvidia.com, Yan Zhao Subject: [PATCH 1/2] vfio/mdev: add version field as mandatory attribute for mdev device Date: Fri, 19 Apr 2019 04:35:04 -0400 Message-Id: <20190419083505.19654-1-yan.y.zhao@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190419083258.19580-1-yan.y.zhao@intel.com> References: <20190419083258.19580-1-yan.y.zhao@intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP device version attribute in mdev sysfs is used by user space software (e.g. libvirt) to query device compatibility for live migration of VFIO mdev devices. This attribute is mandatory if a mdev device supports live migration. It consists of two parts: common part and vendor proprietary part. common part: 32 bit. lower 16 bits is vendor id and higher 16 bits identifies device type. e.g., for pci device, it is "pci vendor id" | (VFIO_DEVICE_FLAGS_PCI << 16). vendor proprietary part: this part is varied in length. vendor driver can specify any string to identify a device. When reading this attribute, it should show device version string of the device of type . If a device does not support live migration, it should return errno. When writing a string to this attribute, it returns errno for incompatibility or returns written string length in compatibility case. If a device does not support live migration, it always returns errno. For user space software to use: 1. Before starting live migration, user space software first reads source side mdev device's version. e.g. "#cat \ /sys/bus/pci/devices/0000\:00\:02.0/5ac1fb20-2bbf-4842-bb7e-36c58c3be9cd/mdev_type/version" 00028086-193b-i915-GVTg_V5_4 2. Then, user space software writes the source side returned version string to device version attribute in target side, and checks the return value. If a negative errno is returned in the target side, then mdev devices in source and target sides are not compatible; If a positive number is returned and it equals to the length of written string, then the two mdev devices in source and target side are compatible. e.g. (a) compatibility case "# echo 00028086-193b-i915-GVTg_V5_4 > /sys/bus/pci/devices/0000\:00\:02.0/882cc4da-dede-11e7-9180-078a62063ab1/mdev_type/version" (b) incompatibility case "#echo 00028086-193b-i915-GVTg_V5_1 > /sys/bus/pci/devices/0000\:00\:02.0/882cc4da-dede-11e7-9180-078a62063ab1/mdev_type/version" -bash: echo: write error: Invalid argument 3. if two mdev devices are compatible, user space software can start live migration, and vice versa. Note: if a mdev device does not support live migration, it either does not provide a version attribute, or always returns errno when its version attribute is read/written. Cc: Alex Williamson Cc: Erik Skultety Cc: "Dr. David Alan Gilbert" Cc: Cornelia Huck Cc: "Tian, Kevin" Cc: Zhenyu Wang Cc: "Wang, Zhi A" Cc: Neo Jia Cc: Kirti Wankhede Signed-off-by: Yan Zhao --- Documentation/vfio-mediated-device.txt | 36 ++++++++++++++++++++++++++ samples/vfio-mdev/mbochs.c | 17 ++++++++++++ samples/vfio-mdev/mdpy.c | 16 ++++++++++++ samples/vfio-mdev/mtty.c | 16 ++++++++++++ 4 files changed, 85 insertions(+) diff --git a/Documentation/vfio-mediated-device.txt b/Documentation/vfio-mediated-device.txt index c3f69bcaf96e..bc28471c0667 100644 --- a/Documentation/vfio-mediated-device.txt +++ b/Documentation/vfio-mediated-device.txt @@ -202,6 +202,7 @@ Directories and files under the sysfs for Each Physical Device | | |--- available_instances | | |--- device_api | | |--- description + | | |--- version | | |--- [devices] | |--- [] | | |--- create @@ -209,6 +210,7 @@ Directories and files under the sysfs for Each Physical Device | | |--- available_instances | | |--- device_api | | |--- description + | | |--- version | | |--- [devices] | |--- [] | |--- create @@ -216,6 +218,7 @@ Directories and files under the sysfs for Each Physical Device | |--- available_instances | |--- device_api | |--- description + | |--- version | |--- [devices] * [mdev_supported_types] @@ -225,6 +228,8 @@ Directories and files under the sysfs for Each Physical Device [], device_api, and available_instances are mandatory attributes that should be provided by vendor driver. + version is a mandatory attribute if a mdev device supports live migration. + * [] The [] name is created by adding the device driver string as a prefix @@ -246,6 +251,35 @@ Directories and files under the sysfs for Each Physical Device This attribute should show the number of devices of type that can be created. +* version + + This attribute is rw. It is used to check whether two devices are compatible + for live migration. If this attribute is missing, then the corresponding mdev + device is regarded as not supporting live migration. + + It consists of two parts: common part and vendor proprietary part. + common part: 32 bit. lower 16 bits is vendor id and higher 16 bits identifies + device type. e.g., for pci device, it is + "pci vendor id" | (VFIO_DEVICE_FLAGS_PCI << 16). + vendor proprietary part: this part is varied in length. vendor driver can + specify any string to identify a device. + + When reading this attribute, it should show device version string of the device + of type . If a device does not support live migration, it should + return errno. + When writing a string to this attribute, it returns errno for incompatibility + or returns written string length in compatibility case. If a device does not + support live migration, it always returns errno. + + for example. + # cat \ + /sys/bus/pci/devices/0000\:00\:02.0/mdev_supported_types/i915-GVTg_V5_2/version + 00028086-193b-i915-GVTg_V5_2 + + #echo 00028086-193b-i915-GVTg_V5_2 > \ + /sys/bus/pci/devices/0000\:00\:02.0/mdev_supported_types/i915-GVTg_V5_4/version + -bash: echo: write error: Invalid argument + * [device] This directory contains links to the devices of type that have been @@ -327,12 +361,14 @@ card. | | |-- available_instances | | |-- create | | |-- device_api + | | |-- version | | |-- devices | | `-- name | `-- mtty-2 | |-- available_instances | |-- create | |-- device_api + | |-- version | |-- devices | `-- name |-- mtty_dev diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c index b038aa9f5a70..2f5ba96b91a2 100644 --- a/samples/vfio-mdev/mbochs.c +++ b/samples/vfio-mdev/mbochs.c @@ -1391,11 +1391,28 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev, } MDEV_TYPE_ATTR_RO(device_api); +static ssize_t version_show(struct kobject *kobj, struct device *dev, + char *buf) +{ + /* do not support live migration */ + return -EINVAL; +} + +static ssize_t version_store(struct kobject *kobj, struct device *dev, + const char *buf, size_t count) +{ + /* do not support live migration */ + return -EINVAL; +} + +static MDEV_TYPE_ATTR_RW(version); + static struct attribute *mdev_types_attrs[] = { &mdev_type_attr_name.attr, &mdev_type_attr_description.attr, &mdev_type_attr_device_api.attr, &mdev_type_attr_available_instances.attr, + &mdev_type_attr_version.attr, NULL, }; diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index cc86bf6566e4..ff15fdfc7d46 100644 --- a/samples/vfio-mdev/mdpy.c +++ b/samples/vfio-mdev/mdpy.c @@ -695,11 +695,27 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev, } MDEV_TYPE_ATTR_RO(device_api); +static ssize_t version_show(struct kobject *kobj, struct device *dev, + char *buf) +{ + /* do not support live migration */ + return -EINVAL; +} + +static ssize_t version_store(struct kobject *kobj, struct device *dev, + const char *buf, size_t count) +{ + /* do not support live migration */ + return -EINVAL; +} +static MDEV_TYPE_ATTR_RW(version); + static struct attribute *mdev_types_attrs[] = { &mdev_type_attr_name.attr, &mdev_type_attr_description.attr, &mdev_type_attr_device_api.attr, &mdev_type_attr_available_instances.attr, + &mdev_type_attr_version.attr, NULL, }; diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index 1c77c370c92f..4ae3aad3474d 100644 --- a/samples/vfio-mdev/mtty.c +++ b/samples/vfio-mdev/mtty.c @@ -1390,10 +1390,26 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev, MDEV_TYPE_ATTR_RO(device_api); +static ssize_t version_show(struct kobject *kobj, struct device *dev, + char *buf) +{ + /* do not support live migration */ + return -EINVAL; +} + +static ssize_t version_store(struct kobject *kobj, struct device *dev, + const char *buf, size_t count) +{ + /* do not support live migration */ + return -EINVAL; +} + +static MDEV_TYPE_ATTR_RW(version); static struct attribute *mdev_types_attrs[] = { &mdev_type_attr_name.attr, &mdev_type_attr_device_api.attr, &mdev_type_attr_available_instances.attr, + &mdev_type_attr_version.attr, NULL, };