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, UNPARSEABLE_RELAY,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 E4865C3A59F for ; Mon, 26 Aug 2019 20:41:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B82B72184D for ; Mon, 26 Aug 2019 20:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729441AbfHZUlg (ORCPT ); Mon, 26 Aug 2019 16:41:36 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:37878 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728053AbfHZUlf (ORCPT ); Mon, 26 Aug 2019 16:41:35 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 26 Aug 2019 23:41:30 +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 x7QKfPDP021168; Mon, 26 Aug 2019 23:41:28 +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 1/4] mdev: Introduce sha1 based mdev alias Date: Mon, 26 Aug 2019 15:41:16 -0500 Message-Id: <20190826204119.54386-2-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190826204119.54386-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Whenever a parent requests to generate mdev alias, generate a mdev alias. It is an optional attribute that parent can request to generate for each of its child mdev. mdev alias is generated using sha1 from the mdev name. Signed-off-by: Parav Pandit --- drivers/vfio/mdev/mdev_core.c | 98 +++++++++++++++++++++++++++++++- drivers/vfio/mdev/mdev_private.h | 5 +- drivers/vfio/mdev/mdev_sysfs.c | 13 +++-- include/linux/mdev.h | 4 ++ 4 files changed, 111 insertions(+), 9 deletions(-) diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index b558d4cfd082..e825ff38b037 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; @@ -164,6 +168,18 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) goto add_dev_err; } + 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) { + ret = -EINVAL; + goto add_dev_err; + } + } + parent = kzalloc(sizeof(*parent), GFP_KERNEL); if (!parent) { ret = -ENOMEM; @@ -259,6 +275,7 @@ static void mdev_device_free(struct mdev_device *mdev) mutex_unlock(&mdev_list_lock); dev_dbg(&mdev->dev, "MDEV: destroying\n"); + kvfree(mdev->alias); kfree(mdev); } @@ -269,18 +286,86 @@ 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 = kvzalloc(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 = kvzalloc(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[0], 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; + + kvfree(digest); + kvfree(hash_desc); + return alias; + +digest_err: + kvfree(hash_desc); +desc_err: + kvfree(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); + unsigned int alias_len = 0; + const char *alias = NULL; parent = mdev_get_parent(type->parent); if (!parent) return -EINVAL; + if (parent->ops->get_alias_length) + 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 +385,8 @@ int mdev_device_create(struct kobject *kobj, } guid_copy(&mdev->uuid, uuid); + mdev->alias = alias; + alias = NULL; list_add(&mdev->next, &mdev_list); mutex_unlock(&mdev_list_lock); @@ -346,6 +433,8 @@ int mdev_device_create(struct kobject *kobj, up_read(&parent->unreg_sem); put_device(&mdev->dev); mdev_fail: + kvfree(alias); +alias_fail: mdev_put_parent(parent); return ret; } @@ -406,6 +495,10 @@ EXPORT_SYMBOL(mdev_get_iommu_device); static int __init mdev_init(void) { + alias_hash = crypto_alloc_shash("sha1", 0, 0); + if (!alias_hash) + return -ENOMEM; + return mdev_bus_register(); } @@ -415,6 +508,7 @@ 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 */ -- 2.19.2