From patchwork Tue Aug 27 19:16:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11117397 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 355A014E5 for ; Tue, 27 Aug 2019 19:17:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1762E2186A for ; Tue, 27 Aug 2019 19:17:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730992AbfH0TRI (ORCPT ); Tue, 27 Aug 2019 15:17:08 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:38863 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730958AbfH0TRI (ORCPT ); Tue, 27 Aug 2019 15:17:08 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Aug 2019 22:17:01 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x7RJGuGr026842; Tue, 27 Aug 2019 22:16:59 +0300 From: Parav Pandit To: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Parav Pandit Subject: [PATCH v1 1/5] mdev: Introduce sha1 based mdev alias Date: Tue, 27 Aug 2019 14:16:50 -0500 Message-Id: <20190827191654.41161-2-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190827191654.41161-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190827191654.41161-1-parav@mellanox.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Some vendor drivers want an identifier for an mdev device that is shorter than the UUID, due to length restrictions in the consumers of that identifier. Add a callback that allows a vendor driver to request an alias of a specified length to be generated for an mdev device. If generated, that alias is checked for collisions. It is an optional attribute. mdev alias is generated using sha1 from the mdev name. Signed-off-by: Parav Pandit --- Changelog: v0->v1: - Moved alias length check outside of the parent lock - Moved alias and digest allocation from kvzalloc to kzalloc - &alias[0] changed to alias - alias_length check is nested under get_alias_length callback check - Changed comments to start with an empty line - Fixed cleaunup of hash if mdev_bus_register() fails - Added comment where alias memory ownership is handed over to mdev device - Updated commit log to indicate motivation for this feature --- drivers/vfio/mdev/mdev_core.c | 110 ++++++++++++++++++++++++++++++- drivers/vfio/mdev/mdev_private.h | 5 +- drivers/vfio/mdev/mdev_sysfs.c | 13 ++-- include/linux/mdev.h | 4 ++ 4 files changed, 122 insertions(+), 10 deletions(-) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index b558d4cfd082..62d29f57fe0c 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -10,9 +10,11 @@ #include #include #include +#include #include #include #include +#include #include "mdev_private.h" @@ -27,6 +29,8 @@ static struct class_compat *mdev_bus_compat_class; static LIST_HEAD(mdev_list); static DEFINE_MUTEX(mdev_list_lock); +static struct crypto_shash *alias_hash; + struct device *mdev_parent_dev(struct mdev_device *mdev) { return mdev->parent->dev; @@ -150,6 +154,16 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups) return -EINVAL; + if (ops->get_alias_length) { + unsigned int digest_size; + unsigned int aligned_len; + + aligned_len = roundup(ops->get_alias_length(), 2); + digest_size = crypto_shash_digestsize(alias_hash); + if (aligned_len / 2 > digest_size) + return -EINVAL; + } + dev = get_device(dev); if (!dev) return -EINVAL; @@ -259,6 +273,7 @@ static void mdev_device_free(struct mdev_device *mdev) mutex_unlock(&mdev_list_lock); dev_dbg(&mdev->dev, "MDEV: destroying\n"); + kfree(mdev->alias); kfree(mdev); } @@ -269,18 +284,88 @@ static void mdev_device_release(struct device *dev) mdev_device_free(mdev); } -int mdev_device_create(struct kobject *kobj, - struct device *dev, const guid_t *uuid) +static const char * +generate_alias(const char *uuid, unsigned int max_alias_len) +{ + struct shash_desc *hash_desc; + unsigned int digest_size; + unsigned char *digest; + unsigned int alias_len; + char *alias; + int ret = 0; + + /* + * Align to multiple of 2 as bin2hex will generate + * even number of bytes. + */ + alias_len = roundup(max_alias_len, 2); + alias = kzalloc(alias_len + 1, GFP_KERNEL); + if (!alias) + return NULL; + + /* Allocate and init descriptor */ + hash_desc = kvzalloc(sizeof(*hash_desc) + + crypto_shash_descsize(alias_hash), + GFP_KERNEL); + if (!hash_desc) + goto desc_err; + + hash_desc->tfm = alias_hash; + + digest_size = crypto_shash_digestsize(alias_hash); + + digest = kzalloc(digest_size, GFP_KERNEL); + if (!digest) { + ret = -ENOMEM; + goto digest_err; + } + crypto_shash_init(hash_desc); + crypto_shash_update(hash_desc, uuid, UUID_STRING_LEN); + crypto_shash_final(hash_desc, digest); + bin2hex(alias, digest, min_t(unsigned int, digest_size, alias_len / 2)); + /* + * When alias length is odd, zero out and additional last byte + * that bin2hex has copied. + */ + if (max_alias_len % 2) + alias[max_alias_len] = 0; + + kfree(digest); + kvfree(hash_desc); + return alias; + +digest_err: + kvfree(hash_desc); +desc_err: + kfree(alias); + return NULL; +} + +int mdev_device_create(struct kobject *kobj, struct device *dev, + const char *uuid_str, const guid_t *uuid) { int ret; struct mdev_device *mdev, *tmp; struct mdev_parent *parent; struct mdev_type *type = to_mdev_type(kobj); + const char *alias = NULL; parent = mdev_get_parent(type->parent); if (!parent) return -EINVAL; + if (parent->ops->get_alias_length) { + unsigned int alias_len; + + alias_len = parent->ops->get_alias_length(); + if (alias_len) { + alias = generate_alias(uuid_str, alias_len); + if (!alias) { + ret = -ENOMEM; + goto alias_fail; + } + } + } mutex_lock(&mdev_list_lock); /* Check for duplicate */ @@ -300,6 +385,12 @@ int mdev_device_create(struct kobject *kobj, } guid_copy(&mdev->uuid, uuid); + mdev->alias = alias; + /* + * At this point alias memory is owned by the mdev. + * Mark it NULL, so that only mdev can free it. + */ + alias = NULL; list_add(&mdev->next, &mdev_list); mutex_unlock(&mdev_list_lock); @@ -346,6 +437,8 @@ int mdev_device_create(struct kobject *kobj, up_read(&parent->unreg_sem); put_device(&mdev->dev); mdev_fail: + kfree(alias); +alias_fail: mdev_put_parent(parent); return ret; } @@ -406,7 +499,17 @@ EXPORT_SYMBOL(mdev_get_iommu_device); static int __init mdev_init(void) { - return mdev_bus_register(); + int ret; + + alias_hash = crypto_alloc_shash("sha1", 0, 0); + if (!alias_hash) + return -ENOMEM; + + ret = mdev_bus_register(); + if (ret) + crypto_free_shash(alias_hash); + + return ret; } static void __exit mdev_exit(void) @@ -415,6 +518,7 @@ static void __exit mdev_exit(void) class_compat_unregister(mdev_bus_compat_class); mdev_bus_unregister(); + crypto_free_shash(alias_hash); } module_init(mdev_init) diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 7d922950caaf..cf1c0d9842c6 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -33,6 +33,7 @@ struct mdev_device { struct kobject *type_kobj; struct device *iommu_device; bool active; + const char *alias; }; #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev) @@ -57,8 +58,8 @@ void parent_remove_sysfs_files(struct mdev_parent *parent); int mdev_create_sysfs_files(struct device *dev, struct mdev_type *type); void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type); -int mdev_device_create(struct kobject *kobj, - struct device *dev, const guid_t *uuid); +int mdev_device_create(struct kobject *kobj, struct device *dev, + const char *uuid_str, const guid_t *uuid); int mdev_device_remove(struct device *dev); #endif /* MDEV_PRIVATE_H */ diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c index 7570c7602ab4..43afe0e80b76 100644 --- a/drivers/vfio/mdev/mdev_sysfs.c +++ b/drivers/vfio/mdev/mdev_sysfs.c @@ -63,15 +63,18 @@ static ssize_t create_store(struct kobject *kobj, struct device *dev, return -ENOMEM; ret = guid_parse(str, &uuid); - kfree(str); if (ret) - return ret; + goto err; - ret = mdev_device_create(kobj, dev, &uuid); + ret = mdev_device_create(kobj, dev, str, &uuid); if (ret) - return ret; + goto err; - return count; + ret = count; + +err: + kfree(str); + return ret; } MDEV_TYPE_ATTR_WO(create); diff --git a/include/linux/mdev.h b/include/linux/mdev.h index 0ce30ca78db0..f036fe9854ee 100644 --- a/include/linux/mdev.h +++ b/include/linux/mdev.h @@ -72,6 +72,9 @@ struct device *mdev_get_iommu_device(struct device *dev); * @mmap: mmap callback * @mdev: mediated device structure * @vma: vma structure + * @get_alias_length: Generate alias for the mdevs of this parent based on the + * mdev device name when it returns non zero alias length. + * It is optional. * Parent device that support mediated device should be registered with mdev * module with mdev_parent_ops structure. **/ @@ -92,6 +95,7 @@ struct mdev_parent_ops { long (*ioctl)(struct mdev_device *mdev, unsigned int cmd, unsigned long arg); int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma); + unsigned int (*get_alias_length)(void); }; /* interface for exporting mdev supported type attributes */ From patchwork Tue Aug 27 19:16:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11117395 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BC05214E5 for ; Tue, 27 Aug 2019 19:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E9ED2189D for ; Tue, 27 Aug 2019 19:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731017AbfH0TRJ (ORCPT ); Tue, 27 Aug 2019 15:17:09 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:38880 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730965AbfH0TRI (ORCPT ); Tue, 27 Aug 2019 15:17:08 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Aug 2019 22:17:03 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x7RJGuGs026842; Tue, 27 Aug 2019 22:17:01 +0300 From: Parav Pandit To: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Parav Pandit Subject: [PATCH v1 2/5] mdev: Make mdev alias unique among all mdevs Date: Tue, 27 Aug 2019 14:16:51 -0500 Message-Id: <20190827191654.41161-3-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190827191654.41161-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190827191654.41161-1-parav@mellanox.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Mdev alias should be unique among all the mdevs, so that when such alias is used by the mdev users to derive other objects, there is no collision in a given system. Signed-off-by: Parav Pandit --- Changelog: v0->v1: - Fixed inclusiong of alias for NULL check - Added ratelimited debug print for sha1 hash collision error --- drivers/vfio/mdev/mdev_core.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 62d29f57fe0c..4b9899e40665 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -375,6 +375,13 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, ret = -EEXIST; goto mdev_fail; } + if (tmp->alias && alias && strcmp(tmp->alias, alias) == 0) { + mutex_unlock(&mdev_list_lock); + ret = -EEXIST; + dev_dbg_ratelimited(dev, "Hash collision in alias creation for UUID %pUl\n", + uuid); + goto mdev_fail; + } } mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); From patchwork Tue Aug 27 19:16:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11117401 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DD94D14E5 for ; Tue, 27 Aug 2019 19:17:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BFE4C2186A for ; Tue, 27 Aug 2019 19:17:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731182AbfH0TRg (ORCPT ); Tue, 27 Aug 2019 15:17:36 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:38884 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730964AbfH0TRI (ORCPT ); Tue, 27 Aug 2019 15:17:08 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Aug 2019 22:17:05 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x7RJGuGt026842; Tue, 27 Aug 2019 22:17:03 +0300 From: Parav Pandit To: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Parav Pandit Subject: [PATCH v1 3/5] mdev: Expose mdev alias in sysfs tree Date: Tue, 27 Aug 2019 14:16:52 -0500 Message-Id: <20190827191654.41161-4-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190827191654.41161-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190827191654.41161-1-parav@mellanox.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Expose the optional alias for an mdev device as a sysfs attribute. This way, userspace tools such as udev may make use of the alias, for example to create a netdevice name for the mdev. Signed-off-by: Parav Pandit --- Changelog: v0->v1: - Addressed comments from Cornelia Huck - Updated commit description --- drivers/vfio/mdev/mdev_sysfs.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c index 43afe0e80b76..59f4e3cc5233 100644 --- a/drivers/vfio/mdev/mdev_sysfs.c +++ b/drivers/vfio/mdev/mdev_sysfs.c @@ -246,7 +246,20 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_WO(remove); +static ssize_t alias_show(struct device *device, + struct device_attribute *attr, char *buf) +{ + struct mdev_device *dev = mdev_from_dev(device); + + if (!dev->alias) + return -EOPNOTSUPP; + + return sprintf(buf, "%s\n", dev->alias); +} +static DEVICE_ATTR_RO(alias); + static const struct attribute *mdev_device_attrs[] = { + &dev_attr_alias.attr, &dev_attr_remove.attr, NULL, }; From patchwork Tue Aug 27 19:16:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11117391 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8210A14E5 for ; Tue, 27 Aug 2019 19:17:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E4D022CF5 for ; Tue, 27 Aug 2019 19:17:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731132AbfH0TRP (ORCPT ); Tue, 27 Aug 2019 15:17:15 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:38904 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731071AbfH0TRN (ORCPT ); Tue, 27 Aug 2019 15:17:13 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Aug 2019 22:17:07 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x7RJGuGu026842; Tue, 27 Aug 2019 22:17:05 +0300 From: Parav Pandit To: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Parav Pandit Subject: [PATCH v1 4/5] mdev: Update sysfs documentation Date: Tue, 27 Aug 2019 14:16:53 -0500 Message-Id: <20190827191654.41161-5-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190827191654.41161-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190827191654.41161-1-parav@mellanox.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Updated documentation for optional read only sysfs attribute. Signed-off-by: Parav Pandit --- Documentation/driver-api/vfio-mediated-device.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 25eb7d5b834b..0ab03d3f5629 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -270,6 +270,7 @@ Directories and Files Under the sysfs for Each mdev Device |--- remove |--- mdev_type {link to its type} |--- vendor-specific-attributes [optional] + |--- alias [optional] * remove (write only) @@ -281,6 +282,10 @@ Example:: # echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove +* alias (read only) +Whenever a parent requested to generate an alias, each mdev is assigned a unique +alias by the mdev core. This file shows the alias of the mdev device. + Mediated device Hot plug ------------------------ From patchwork Tue Aug 27 19:16:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11117393 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6C80414E5 for ; Tue, 27 Aug 2019 19:17:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 595C72189D for ; Tue, 27 Aug 2019 19:17:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731116AbfH0TRO (ORCPT ); Tue, 27 Aug 2019 15:17:14 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:38910 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731082AbfH0TRN (ORCPT ); Tue, 27 Aug 2019 15:17:13 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 27 Aug 2019 22:17:09 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x7RJGuGv026842; Tue, 27 Aug 2019 22:17:08 +0300 From: Parav Pandit To: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Parav Pandit Subject: [PATCH v1 5/5] mtty: Optionally support mtty alias Date: Tue, 27 Aug 2019 14:16:54 -0500 Message-Id: <20190827191654.41161-6-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190827191654.41161-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190827191654.41161-1-parav@mellanox.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Provide a module parameter to set alias length to optionally generate mdev alias. Example to request mdev alias. $ modprobe mtty alias_length=12 Signed-off-by: Parav Pandit --- samples/vfio-mdev/mtty.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index 92e770a06ea2..92208245b057 100644 --- a/samples/vfio-mdev/mtty.c +++ b/samples/vfio-mdev/mtty.c @@ -1410,6 +1410,15 @@ static struct attribute_group *mdev_type_groups[] = { NULL, }; +static unsigned int mtty_alias_length; +module_param_named(alias_length, mtty_alias_length, uint, 0444); +MODULE_PARM_DESC(alias_length, "mdev alias length; default=0"); + +static unsigned int mtty_get_alias_length(void) +{ + return mtty_alias_length; +} + static const struct mdev_parent_ops mdev_fops = { .owner = THIS_MODULE, .dev_attr_groups = mtty_dev_groups, @@ -1422,6 +1431,7 @@ static const struct mdev_parent_ops mdev_fops = { .read = mtty_read, .write = mtty_write, .ioctl = mtty_ioctl, + .get_alias_length = mtty_get_alias_length }; static void mtty_device_release(struct device *dev)