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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 99EB4C4CEC9 for ; Tue, 17 Sep 2019 10:03:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 76BFE2189D for ; Tue, 17 Sep 2019 10:03:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726687AbfIQKDk (ORCPT ); Tue, 17 Sep 2019 06:03:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42418 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726482AbfIQKDk (ORCPT ); Tue, 17 Sep 2019 06:03:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 71B2583F3C; Tue, 17 Sep 2019 10:03:39 +0000 (UTC) Received: from gondolin (dhcp-192-230.str.redhat.com [10.33.192.230]) by smtp.corp.redhat.com (Postfix) with ESMTP id 77FB660923; Tue, 17 Sep 2019 10:03:35 +0000 (UTC) Date: Tue, 17 Sep 2019 12:03:33 +0200 From: Cornelia Huck To: Parav Pandit Cc: alex.williamson@redhat.com, jiri@mellanox.com, kwankhede@nvidia.com, davem@davemloft.net, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH v3 1/5] mdev: Introduce sha1 based mdev alias Message-ID: <20190917120333.3449f62e.cohuck@redhat.com> In-Reply-To: <20190902042436.23294-2-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> <20190902042436.23294-1-parav@mellanox.com> <20190902042436.23294-2-parav@mellanox.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 17 Sep 2019 10:03:39 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 1 Sep 2019 23:24:32 -0500 Parav Pandit 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. > > Signed-off-by: Parav Pandit > > --- > Changelog: > v1->v2: > - Kept mdev_device naturally aligned > - Added error checking for crypt_*() calls > - Corrected a typo from 'and' to 'an' > - Changed return type of generate_alias() from int to char* > 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 | 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/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. "Optional: If a non-zero alias length is returned, generate an alias for this parent's mdevs based upon the mdev device name." ? > + * 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 */ Reviewed-by: Cornelia Huck