From: Jiri Pirko <jiri@resnulli.us>
To: Parav Pandit <parav@mellanox.com>
Cc: alex.williamson@redhat.com, davem@davemloft.net,
kvm@vger.kernel.org, netdev@vger.kernel.org, saeedm@mellanox.com,
kwankhede@nvidia.com, leon@kernel.org, cohuck@redhat.com,
jiri@mellanox.com, linux-rdma@vger.kernel.org
Subject: Re: [PATCH net-next 07/19] vfio/mdev: Introduce sha1 based mdev alias
Date: Fri, 8 Nov 2019 12:04:56 +0100 [thread overview]
Message-ID: <20191108110456.GH6990@nanopsycho> (raw)
In-Reply-To: <20191107160834.21087-7-parav@mellanox.com>
Thu, Nov 07, 2019 at 05:08:22PM CET, parav@mellanox.com wrote:
>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.
>
>Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
>Signed-off-by: Parav Pandit <parav@mellanox.com>
>---
> drivers/vfio/mdev/mdev_core.c | 123 ++++++++++++++++++++++++++++++-
> drivers/vfio/mdev/mdev_private.h | 5 +-
> drivers/vfio/mdev/mdev_sysfs.c | 13 ++--
> include/linux/mdev.h | 4 +
> 4 files changed, 135 insertions(+), 10 deletions(-)
>
>diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>index b558d4cfd082..3bdff0469607 100644
>--- a/drivers/vfio/mdev/mdev_core.c
>+++ b/drivers/vfio/mdev/mdev_core.c
>@@ -10,9 +10,11 @@
[...]
>-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;
>+
>+ /*
>+ * Align to multiple of 2 as bin2hex will generate
>+ * even number of bytes.
>+ */
>+ alias_len = roundup(max_alias_len, 2);
This is odd, see below.
>+ alias = kzalloc(alias_len + 1, GFP_KERNEL);
>+ if (!alias)
>+ return ERR_PTR(-ENOMEM);
>+
>+ /* Allocate and init descriptor */
>+ hash_desc = kvzalloc(sizeof(*hash_desc) +
>+ crypto_shash_descsize(alias_hash),
>+ GFP_KERNEL);
>+ if (!hash_desc) {
>+ ret = -ENOMEM;
>+ 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;
>+ }
>+ ret = crypto_shash_init(hash_desc);
>+ if (ret)
>+ goto hash_err;
>+
>+ ret = crypto_shash_update(hash_desc, uuid, UUID_STRING_LEN);
>+ if (ret)
>+ goto hash_err;
>+
>+ ret = crypto_shash_final(hash_desc, digest);
>+ if (ret)
>+ goto hash_err;
>+
>+ bin2hex(alias, digest, min_t(unsigned int, digest_size, alias_len / 2));
>+ /*
>+ * When alias length is odd, zero out an additional last byte
>+ * that bin2hex has copied.
>+ */
>+ if (max_alias_len % 2)
>+ alias[max_alias_len] = 0;
>+
>+ kfree(digest);
>+ kvfree(hash_desc);
>+ return alias;
>+
>+hash_err:
>+ kfree(digest);
>+digest_err:
>+ kvfree(hash_desc);
>+desc_err:
>+ kfree(alias);
>+ return ERR_PTR(ret);
>+}
>+
>+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) {
I think this should be with WARN_ON. Driver should not never return such
0 and if it does, it's a bug.
Also I think this check should be extended by checking value is multiple
of 2. Then you can avoid the roundup() above. No need to allow even len.
>+ alias = generate_alias(uuid_str, alias_len);
>+ if (IS_ERR(alias)) {
>+ ret = PTR_ERR(alias);
>+ goto alias_fail;
>+ }
>+ }
>+ }
> mutex_lock(&mdev_list_lock);
>
> /* Check for duplicate */
[...]
>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);
Why to pass the same thing twice? Move the guid_parse() call to the
beginning of mdev_device_create() function.
> if (ret)
>- return ret;
>+ goto err;
>
>- return count;
>+ ret = count;
>+
>+err:
>+ kfree(str);
>+ return ret;
> }
>
> MDEV_TYPE_ATTR_WO(create);
[...]
next prev parent reply other threads:[~2019-11-08 11:05 UTC|newest]
Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-07 16:04 [PATCH net-next 00/19] Mellanox, mlx5 sub function support Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 01/19] net/mlx5: E-switch, Move devlink port close to eswitch port Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 02/19] net/mlx5: E-Switch, Add SF vport, vport-rep support Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 03/19] net/mlx5: Introduce SF table framework Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 04/19] net/mlx5: Introduce SF life cycle APIs to allocate/free Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 05/19] net/mlx5: E-Switch, Enable/disable SF's vport during SF life cycle Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 06/19] net/mlx5: Add support for mediated devices in switchdev mode Parav Pandit
2019-11-08 10:32 ` Jiri Pirko
2019-11-08 16:03 ` Parav Pandit
2019-11-08 16:22 ` Jiri Pirko
2019-11-08 16:29 ` Parav Pandit
2019-11-08 18:01 ` Jiri Pirko
2019-11-08 18:04 ` Jiri Pirko
2019-11-08 18:21 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 07/19] vfio/mdev: Introduce sha1 based mdev alias Parav Pandit
2019-11-08 11:04 ` Jiri Pirko [this message]
2019-11-08 15:59 ` Parav Pandit
2019-11-08 16:28 ` Jiri Pirko
2019-11-08 11:10 ` Cornelia Huck
2019-11-08 16:03 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 08/19] vfio/mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-11-08 10:49 ` Jiri Pirko
2019-11-08 15:13 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 09/19] vfio/mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-11-08 13:22 ` Jiri Pirko
2019-11-08 18:03 ` Alex Williamson
2019-11-08 18:16 ` Jiri Pirko
2019-11-07 16:08 ` [PATCH net-next 10/19] vfio/mdev: Introduce an API mdev_alias Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 11/19] vfio/mdev: Improvise mdev life cycle and parent removal scheme Parav Pandit
2019-11-08 13:01 ` Cornelia Huck
2019-11-08 16:12 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 12/19] devlink: Introduce mdev port flavour Parav Pandit
2019-11-07 20:38 ` Jakub Kicinski
2019-11-07 21:03 ` Parav Pandit
2019-11-08 1:17 ` Jakub Kicinski
2019-11-08 1:44 ` Parav Pandit
2019-11-08 2:20 ` Jakub Kicinski
2019-11-08 2:31 ` Parav Pandit
2019-11-08 9:46 ` Jiri Pirko
2019-11-08 15:45 ` Parav Pandit
2019-11-08 16:31 ` Jiri Pirko
2019-11-08 16:43 ` Parav Pandit
2019-11-08 18:11 ` Jiri Pirko
2019-11-08 18:23 ` Parav Pandit
2019-11-08 18:34 ` Jiri Pirko
2019-11-08 18:56 ` Parav Pandit
2019-11-08 9:30 ` Jiri Pirko
2019-11-08 15:41 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 13/19] net/mlx5: Register SF devlink port Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 14/19] net/mlx5: Share irqs between SFs and parent PCI device Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 15/19] net/mlx5: Add load/unload routines for SF driver binding Parav Pandit
2019-11-08 9:48 ` Jiri Pirko
2019-11-08 11:13 ` Jiri Pirko
2019-11-07 16:08 ` [PATCH net-next 16/19] net/mlx5: Implement dma ops and params for mediated device Parav Pandit
2019-11-07 20:42 ` Jakub Kicinski
2019-11-07 21:30 ` Parav Pandit
2019-11-08 1:16 ` Jakub Kicinski
2019-11-08 6:37 ` Christoph Hellwig
2019-11-08 15:29 ` Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 17/19] net/mlx5: Add mdev driver to bind to mdev devices Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 18/19] Documentation: net: mlx5: Add mdev usage documentation Parav Pandit
2019-11-07 16:08 ` [PATCH net-next 19/19] mtty: Optionally support mtty alias Parav Pandit
2019-11-08 6:26 ` Leon Romanovsky
2019-11-08 10:45 ` Jiri Pirko
2019-11-08 15:08 ` Parav Pandit
2019-11-08 15:15 ` Jiri Pirko
2019-11-08 13:46 ` Cornelia Huck
2019-11-08 15:10 ` Parav Pandit
2019-11-08 15:28 ` Cornelia Huck
2019-11-08 15:30 ` Parav Pandit
2019-11-08 17:54 ` Alex Williamson
2019-11-08 9:51 ` [PATCH net-next 01/19] net/mlx5: E-switch, Move devlink port close to eswitch port Jiri Pirko
2019-11-08 15:50 ` Parav Pandit
2019-11-07 17:03 ` [PATCH net-next 00/19] Mellanox, mlx5 sub function support Leon Romanovsky
2019-11-07 20:10 ` Parav Pandit
2019-11-08 6:20 ` Leon Romanovsky
2019-11-08 15:01 ` Parav Pandit
2019-11-07 20:32 ` Jakub Kicinski
2019-11-07 20:52 ` Parav Pandit
2019-11-08 1:16 ` Jakub Kicinski
2019-11-08 1:49 ` Parav Pandit
2019-11-08 2:12 ` Jakub Kicinski
2019-11-08 12:12 ` Jiri Pirko
2019-11-08 14:40 ` Jason Gunthorpe
2019-11-08 15:40 ` Parav Pandit
2019-11-08 19:12 ` Jakub Kicinski
2019-11-08 20:12 ` Jason Gunthorpe
2019-11-08 20:20 ` Parav Pandit
2019-11-08 20:32 ` Jason Gunthorpe
2019-11-08 20:52 ` gregkh
2019-11-08 20:34 ` Alex Williamson
2019-11-08 21:05 ` Jason Gunthorpe
2019-11-08 21:19 ` gregkh
2019-11-08 21:52 ` Alex Williamson
2019-11-08 22:48 ` Parav Pandit
2019-11-09 0:57 ` Jason Gunthorpe
2019-11-09 17:41 ` Jakub Kicinski
2019-11-10 19:04 ` Jason Gunthorpe
2019-11-10 19:48 ` Parav Pandit
2019-11-11 14:17 ` Jiri Pirko
2019-11-11 14:58 ` Parav Pandit
2019-11-11 15:06 ` Jiri Pirko
2019-11-19 4:51 ` Parav Pandit
2019-11-09 0:12 ` Jason Gunthorpe
2019-11-09 0:45 ` Parav Pandit
2019-11-11 2:19 ` Jason Wang
2019-11-08 21:45 ` Jakub Kicinski
2019-11-09 0:44 ` Jason Gunthorpe
2019-11-09 8:46 ` gregkh
2019-11-09 11:18 ` Jiri Pirko
2019-11-09 17:28 ` Jakub Kicinski
2019-11-10 9:16 ` gregkh
2019-11-09 17:27 ` Jakub Kicinski
2019-11-10 9:18 ` gregkh
2019-11-11 3:46 ` Jakub Kicinski
2019-11-11 5:18 ` Parav Pandit
2019-11-11 13:30 ` Jiri Pirko
2019-11-11 14:14 ` gregkh
2019-11-11 14:37 ` Jiri Pirko
2019-11-10 19:37 ` Jason Gunthorpe
2019-11-11 3:57 ` Jakub Kicinski
2019-11-08 16:06 ` Parav Pandit
2019-11-08 19:06 ` Jakub Kicinski
2019-11-08 19:34 ` Parav Pandit
2019-11-08 19:48 ` Jakub Kicinski
2019-11-08 19:41 ` Jiri Pirko
2019-11-08 20:40 ` Parav Pandit
2019-11-08 21:21 ` Jakub Kicinski
2019-11-08 21:39 ` Jiri Pirko
2019-11-08 21:51 ` Jakub Kicinski
2019-11-08 22:21 ` Jiri Pirko
2019-11-07 23:57 ` David Miller
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