KVM Archive on lore.kernel.org
 help / color / Atom feed
From: Parav Pandit <parav@mellanox.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Jiri Pirko <jiri@mellanox.com>,
	"kwankhede@nvidia.com" <kwankhede@nvidia.com>,
	"cohuck@redhat.com" <cohuck@redhat.com>,
	"davem@davemloft.net" <davem@davemloft.net>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: RE: [PATCH v3 0/5] Introduce variable length mdev alias
Date: Fri, 13 Sep 2019 23:19:54 +0000
Message-ID: <AM0PR05MB4866C8AA4383F264DB0C75DBD1B30@AM0PR05MB4866.eurprd05.prod.outlook.com> (raw)
In-Reply-To: <20190913153247.0309d016@x1.home>

Hi Alex,

> -----Original Message-----
> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Friday, September 13, 2019 4:33 PM
> To: Parav Pandit <parav@mellanox.com>
> Cc: Jiri Pirko <jiri@mellanox.com>; kwankhede@nvidia.com;
> cohuck@redhat.com; davem@davemloft.net; kvm@vger.kernel.org; linux-
> kernel@vger.kernel.org; netdev@vger.kernel.org
> Subject: Re: [PATCH v3 0/5] Introduce variable length mdev alias
> 
> On Wed, 11 Sep 2019 16:38:49 +0000
> Parav Pandit <parav@mellanox.com> wrote:
> 
> > > -----Original Message-----
> > > From: linux-kernel-owner@vger.kernel.org <linux-kernel-
> > > owner@vger.kernel.org> On Behalf Of Parav Pandit
> > > Sent: Wednesday, September 11, 2019 10:31 AM
> > > To: Alex Williamson <alex.williamson@redhat.com>
> > > Cc: Jiri Pirko <jiri@mellanox.com>; kwankhede@nvidia.com;
> > > cohuck@redhat.com; davem@davemloft.net; kvm@vger.kernel.org; linux-
> > > kernel@vger.kernel.org; netdev@vger.kernel.org
> > > Subject: RE: [PATCH v3 0/5] Introduce variable length mdev alias
> > >
> > > Hi Alex,
> > >
> > > > -----Original Message-----
> > > > From: Alex Williamson <alex.williamson@redhat.com>
> > > > Sent: Wednesday, September 11, 2019 8:56 AM
> > > > To: Parav Pandit <parav@mellanox.com>
> > > > Cc: Jiri Pirko <jiri@mellanox.com>; kwankhede@nvidia.com;
> > > > cohuck@redhat.com; davem@davemloft.net; kvm@vger.kernel.org;
> > > > linux- kernel@vger.kernel.org; netdev@vger.kernel.org
> > > > Subject: Re: [PATCH v3 0/5] Introduce variable length mdev alias
> > > >
> > > > On Mon, 9 Sep 2019 20:42:32 +0000
> > > > Parav Pandit <parav@mellanox.com> wrote:
> > > >
> > > > > Hi Alex,
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Parav Pandit <parav@mellanox.com>
> > > > > > Sent: Sunday, September 1, 2019 11:25 PM
> > > > > > To: alex.williamson@redhat.com; Jiri Pirko
> > > > > > <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 <parav@mellanox.com>
> > > > > > Subject: [PATCH v3 0/5] Introduce variable length mdev alias
> > > > > >
> > > > > > To have consistent naming for the netdevice of a mdev and to
> > > > > > have consistent naming of the devlink port [1] of a mdev,
> > > > > > which is formed using phys_port_name of the devlink port,
> > > > > > current UUID is not usable because UUID is too long.
> > > > > >
> > > > > > UUID in string format is 36-characters long and in binary 128-bit.
> > > > > > Both formats are not able to fit within 15 characters limit of
> > > > > > netdev
> > > > name.
> > > > > >
> > > > > > It is desired to have mdev device naming consistent using UUID.
> > > > > > So that widely used user space framework such as ovs [2] can
> > > > > > make use of mdev representor in similar way as PCIe SR-IOV VF
> > > > > > and PF
> > > > representors.
> > > > > >
> > > > > > Hence,
> > > > > > (a) mdev alias is created which is derived using sha1 from the
> > > > > > mdev
> > > > name.
> > > > > > (b) Vendor driver describes how long an alias should be for
> > > > > > the child mdev created for a given parent.
> > > > > > (c) Mdev aliases are unique at system level.
> > > > > > (d) alias is created optionally whenever parent requested.
> > > > > > This ensures that non networking mdev parents can function
> > > > > > without alias creation overhead.
> > > > > >
> > > > > > This design is discussed at [3].
> > > > > >
> > > > > > An example systemd/udev extension will have,
> > > > > >
> > > > > > 1. netdev name created using mdev alias available in sysfs.
> > > > > >
> > > > > > mdev UUID=83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
> > > > > > mdev 12 character alias=cd5b146a80a5
> > > > > >
> > > > > > netdev name of this mdev = enmcd5b146a80a5 Here en = Ethernet
> > > > > > link m = mediated device
> > > > > >
> > > > > > 2. devlink port phys_port_name created using mdev alias.
> > > > > > devlink phys_port_name=pcd5b146a80a5
> > > > > >
> > > > > > This patchset enables mdev core to maintain unique alias for a mdev.
> > > > > >
> > > > > > Patch-1 Introduces mdev alias using sha1.
> > > > > > Patch-2 Ensures that mdev alias is unique in a system.
> > > > > > Patch-3 Exposes mdev alias in a sysfs hirerchy, update
> > > > > > Documentation
> > > > > > Patch-4 Introduces mdev_alias() API.
> > > > > > Patch-5 Extends mtty driver to optionally provide alias generation.
> > > > > > This also enables to test UUID based sha1 collision and
> > > > > > trigger error handling for duplicate sha1 results.
> > > > > >
> > > > > > [1] http://man7.org/linux/man-pages/man8/devlink-port.8.html
> > > > > > [2]
> > > > > > https://docs.openstack.org/os-vif/latest/user/plugins/ovs.html
> > > > > > [3] https://patchwork.kernel.org/cover/11084231/
> > > > > >
> > > > > > ---
> > > > > > Changelog:
> > > > > > v2->v3:
> > > > > >  - Addressed comment from Yunsheng Lin
> > > > > >  - Changed strcmp() ==0 to !strcmp()
> > > > > >  - Addressed comment from Cornelia Hunk
> > > > > >  - Merged sysfs Documentation patch with syfs patch
> > > > > >  - Added more description for alias return value
> > > > >
> > > > > Did you get a chance review this updated series?
> > > > > I addressed Cornelia's and yours comment.
> > > > > I do not think allocating alias memory twice, once for
> > > > > comparison and once for storing is good idea or moving alias
> > > > > generation logic inside the mdev_list_lock(). So I didn't
> > > > > address that suggestion of
> > > Cornelia.
> > > >
> > > > Sorry, I'm at LPC this week.  I agree, I don't think the double
> > > > allocation is necessary, I thought the comment was sufficient to
> > > > clarify null'ing the variable.  It's awkward, but seems correct.
> > > >
> > > > I'm not sure what we do with this patch series though, has the real
> > > > consumer of this even been proposed?
> >
> > Jiri already acked to use mdev_alias() to generate phys_port_name several
> days back in the discussion we had in [1].
> > After concluding in the thread [1], I proceed with mdev_alias().
> > mlx5_core patches are not yet present on netdev mailing list, but we
> > all agree to use it in mdev_alias() in devlink phys_port_name
> > generation. So we have collective agreement on how to proceed forward.
> > I wasn't probably clear enough in previous email reply about it, so
> > adding link here.
> >
> > [1] https://patchwork.kernel.org/cover/11084231/#22838955
> 
> Jiri may have agreed to the concept, but without patches on the list proving an
> end to end solution, I think it's too early for us to commit to this by
> preemptively adding it to our API.  "Acked" and "collective agreement" seem
> like they overstate something that seems not to have seen the light of day yet.
> Instead I'll say, it looks reasonable, come back when the real consumer has
> actually been proposed upstream and has more buy-in from the community
> and we'll see if it still looks like the right approach from an mdev perspective
> then.  Thanks,
> 
Ok. I will combine these patches with the actual consumer patches of mdev_alias().
Thanks.

> Alex

  reply index

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-26 20:41 [PATCH 0/4] " Parav Pandit
2019-08-26 20:41 ` [PATCH 1/4] mdev: Introduce sha1 based " Parav Pandit
2019-08-27  1:44   ` Alex Williamson
2019-08-27  1:51     ` Alex Williamson
2019-08-27  4:24     ` Parav Pandit
2019-08-27 10:24   ` Cornelia Huck
2019-08-27 11:12     ` Parav Pandit
2019-08-27 11:24       ` Cornelia Huck
2019-08-27 11:33         ` Parav Pandit
2019-08-27 11:41           ` Cornelia Huck
2019-08-27 11:57             ` Parav Pandit
2019-08-27 13:35               ` Cornelia Huck
2019-08-27 16:50                 ` Alex Williamson
2019-08-27 11:16     ` Parav Pandit
2019-08-26 20:41 ` [PATCH 2/4] mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-08-26 23:02   ` Mark Bloch
2019-08-27  4:28     ` Parav Pandit
2019-08-27 15:23       ` Alex Williamson
2019-08-27 16:16         ` Parav Pandit
2019-08-27 10:29   ` Cornelia Huck
2019-08-27 11:08     ` Parav Pandit
2019-08-27 11:29       ` Cornelia Huck
2019-08-27 15:28         ` Alex Williamson
2019-08-27 15:39           ` Cornelia Huck
2019-08-27 16:13           ` Parav Pandit
2019-08-27 16:24             ` Alex Williamson
2019-08-27 18:54               ` Parav Pandit
2019-08-26 20:41 ` [PATCH 3/4] mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-08-27  1:53   ` Alex Williamson
2019-08-27  3:30     ` Parav Pandit
2019-08-27 10:47   ` Cornelia Huck
2019-08-27 11:07     ` Parav Pandit
2019-08-27 11:34       ` Cornelia Huck
2019-08-27 11:52         ` Parav Pandit
2019-08-27 11:55           ` Cornelia Huck
2019-08-27 12:00             ` Parav Pandit
2019-08-26 20:41 ` [PATCH 4/4] mtty: Optionally support mtty alias Parav Pandit
2019-08-27 13:11 ` [PATCH 0/4] Introduce variable length mdev alias Parav Pandit
2019-08-27 13:31   ` Cornelia Huck
2019-08-27 17:48   ` Alex Williamson
2019-08-27 18:11     ` Parav Pandit
2019-08-27 19:16 ` [PATCH v1 0/5] " Parav Pandit
2019-08-27 19:16   ` [PATCH v1 1/5] mdev: Introduce sha1 based " Parav Pandit
2019-08-28 21:25     ` Alex Williamson
2019-08-28 21:34       ` Alex Williamson
2019-08-29  9:07         ` Parav Pandit
2019-08-29  9:06       ` Parav Pandit
2019-08-27 19:16   ` [PATCH v1 2/5] mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-08-28 21:36     ` Alex Williamson
2019-08-29  9:07       ` Parav Pandit
2019-08-27 19:16   ` [PATCH v1 3/5] mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-08-27 19:16   ` [PATCH v1 4/5] mdev: Update sysfs documentation Parav Pandit
2019-08-27 19:16   ` [PATCH v1 5/5] mtty: Optionally support mtty alias Parav Pandit
2019-08-29 11:18 ` [PATCH v2 0/6] Introduce variable length mdev alias Parav Pandit
2019-08-29 11:18   ` [PATCH v2 1/6] mdev: Introduce sha1 based " Parav Pandit
2019-08-29 12:26     ` Yunsheng Lin
2019-08-30  2:27       ` Parav Pandit
2019-08-30  9:17     ` Cornelia Huck
2019-08-30 12:33       ` Parav Pandit
2019-08-30 12:39         ` Cornelia Huck
2019-08-30 12:58           ` Parav Pandit
2019-08-30 14:02             ` Cornelia Huck
2019-08-30 15:45               ` Parav Pandit
2019-09-02 14:46                 ` Cornelia Huck
2019-09-03  3:47                   ` Parav Pandit
2019-08-29 11:19   ` [PATCH v2 2/6] mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-08-29 12:31     ` Yunsheng Lin
2019-08-30 12:40     ` Cornelia Huck
2019-08-30 12:59       ` Parav Pandit
2019-08-29 11:19   ` [PATCH v2 3/6] mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-08-29 11:19   ` [PATCH v2 4/6] mdev: Introduce an API mdev_alias Parav Pandit
2019-08-29 11:19   ` [PATCH v2 5/6] mdev: Update sysfs documentation Parav Pandit
2019-08-30 12:49     ` Cornelia Huck
2019-08-30 13:10       ` Parav Pandit
2019-09-02 14:36         ` Cornelia Huck
2019-09-03  3:53           ` Parav Pandit
2019-08-29 11:19   ` [PATCH v2 6/6] mtty: Optionally support mtty alias Parav Pandit
2019-09-02  4:24 ` [PATCH v3 0/5] Introduce variable length mdev alias Parav Pandit
2019-09-02  4:24   ` [PATCH v3 1/5] mdev: Introduce sha1 based " Parav Pandit
2019-09-17 10:03     ` Cornelia Huck
2019-09-02  4:24   ` [PATCH v3 2/5] mdev: Make mdev alias unique among all mdevs Parav Pandit
2019-09-17 10:04     ` Cornelia Huck
2019-09-02  4:24   ` [PATCH v3 3/5] mdev: Expose mdev alias in sysfs tree Parav Pandit
2019-09-17 10:08     ` Cornelia Huck
2019-09-02  4:24   ` [PATCH v3 4/5] mdev: Introduce an API mdev_alias Parav Pandit
2019-09-17 10:10     ` Cornelia Huck
2019-09-02  4:24   ` [PATCH v3 5/5] mtty: Optionally support mtty alias Parav Pandit
2019-09-09 20:42   ` [PATCH v3 0/5] Introduce variable length mdev alias Parav Pandit
2019-09-11 13:56     ` Alex Williamson
2019-09-11 15:30       ` Parav Pandit
2019-09-11 16:29         ` Cornelia Huck
2019-09-11 16:38         ` Parav Pandit
2019-09-13 21:32           ` Alex Williamson
2019-09-13 23:19             ` Parav Pandit [this message]
2019-09-17 10:13   ` Cornelia Huck
2019-09-18 17:15     ` Parav Pandit

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=AM0PR05MB4866C8AA4383F264DB0C75DBD1B30@AM0PR05MB4866.eurprd05.prod.outlook.com \
    --to=parav@mellanox.com \
    --cc=alex.williamson@redhat.com \
    --cc=cohuck@redhat.com \
    --cc=davem@davemloft.net \
    --cc=jiri@mellanox.com \
    --cc=kvm@vger.kernel.org \
    --cc=kwankhede@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

KVM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/kvm/0 kvm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 kvm kvm/ https://lore.kernel.org/kvm \
		kvm@vger.kernel.org kvm@archiver.kernel.org
	public-inbox-index kvm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.kvm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox