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: 1087977 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44lqFQ4jBcz9s3Z for ; Fri, 19 Apr 2019 18:41:14 +1000 (AEST) Received: from localhost ([127.0.0.1]:53403 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHP56-0004JQ-IQ for incoming@patchwork.ozlabs.org; Fri, 19 Apr 2019 04:41:12 -0400 Received: from eggs.gnu.org ([209.51.188.92]:34198) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hHP4h-0004Go-Vr for qemu-devel@nongnu.org; Fri, 19 Apr 2019 04:40:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hHP4g-00046T-3g for qemu-devel@nongnu.org; Fri, 19 Apr 2019 04:40:47 -0400 Received: from mga06.intel.com ([134.134.136.31]:32085) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hHP4e-00045W-FK for qemu-devel@nongnu.org; Fri, 19 Apr 2019 04:40:44 -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 orsmga104.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 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> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.31 Subject: [Qemu-devel] [PATCH 1/2] vfio/mdev: add version field as mandatory attribute for mdev device X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: cjia@nvidia.com, kvm@vger.kernel.org, aik@ozlabs.ru, Zhengxiao.zx@alibaba-inc.com, shuangtai.tst@alibaba-inc.com, qemu-devel@nongnu.org, kwankhede@nvidia.com, eauger@redhat.com, yi.l.liu@intel.com, eskultet@redhat.com, ziye.yang@intel.com, mlevitsk@redhat.com, pasic@linux.ibm.com, libvir-list@redhat.com, arei.gonglei@huawei.com, felipe@nutanix.com, Ken.Xue@amd.com, kevin.tian@intel.com, Yan Zhao , dgilbert@redhat.com, zhenyuw@linux.intel.com, alex.williamson@redhat.com, changpeng.liu@intel.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, zhi.a.wang@intel.com, jonathan.davies@nutanix.com, shaopeng.he@intel.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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, };