KVM Archive on lore.kernel.org
 help / color / Atom feed
From: Cornelia Huck <cohuck@redhat.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"Libvirt Devel" <libvir-list@redhat.com>,
	"Kirti Wankhede" <kwankhede@nvidia.com>,
	"Erik Skultety" <eskultet@redhat.com>,
	"Pavel Hrdina" <phrdina@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Sylvain Bauza" <sbauza@redhat.com>,
	"Christophe de Dinechin" <dinechin@redhat.com>,
	"Matthew Rosato" <mjrosato@linux.ibm.com>
Subject: Re: mdevctl: A shoestring mediated device management and persistence utility
Date: Thu, 27 Jun 2019 14:26:26 +0200
Message-ID: <20190627142626.415138da.cohuck@redhat.com> (raw)
In-Reply-To: <20190626195350.2e9c81d3@x1.home>

On Wed, 26 Jun 2019 19:53:50 -0600
Alex Williamson <alex.williamson@redhat.com> wrote:

> On Wed, 26 Jun 2019 08:37:20 -0600
> Alex Williamson <alex.williamson@redhat.com> wrote:
> 
> > On Wed, 26 Jun 2019 11:58:06 +0200
> > Cornelia Huck <cohuck@redhat.com> wrote:
> >   
> > > On Tue, 25 Jun 2019 16:52:51 -0600
> > > Alex Williamson <alex.williamson@redhat.com> wrote:
> > >     
> > > > Hi,
> > > > 
> > > > Based on the discussions we've had, I've rewritten the bulk of
> > > > mdevctl.  I think it largely does everything we want now, modulo
> > > > devices that will need some sort of 1:N values per key for
> > > > configuration in the config file versus the 1:1 key:value setup we
> > > > currently have (so don't consider the format final just yet).      
> > > 
> > > We might want to factor out that config format handling while we're
> > > trying to finalize it.
> > > 
> > > cc:ing Matt for his awareness. I'm currently not quite sure how to
> > > handle those vfio-ap "write several values to an attribute one at a
> > > time" requirements. Maybe 1:N key:value is the way to go; maybe we
> > > need/want JSON or something like that.    
> > 
> > Maybe we should just do JSON for future flexibility.  I assume there
> > are lots of helpers that should make it easy even from a bash script.
> > I'll look at that next.  
> 
> Done.  Throw away any old mdev config files, we use JSON now. 

The code changes look quite straightforward, thanks.

> The per
> mdev config now looks like this:
> 
> {
>   "mdev_type": "i915-GVTg_V4_8",
>   "start": "auto"
> }
> 
> My expectation, and what I've already pre-enabled support in set_key
> and get_key functions, is that we'd use arrays for values, so we might
> have:
> 
>   "new_key": ["value1", "value2"]
> 
> set_key will automatically convert a comma separated list of values
> into such an array, so I'm thinking this would be specified by the user
> as:
> 
> # mdevctl modify -u UUID --key=new_key --value=value1,value2

Looks sensible.

For vfio-ap, we'd probably end up with something like the following:

{
  "mdev_type": "vfio_ap-passthrough",
  "start": "auto",
  "assign_adapter": ["5", "6"],
  "assign_domain": ["4", "0xab"]
}

(following the Guest1 example in the kernel documentation)

<As an aside, what should happen if e.g "assign_adapter" is set to
["6", "7"]? Remove 5, add 7? Remove all values, then set the new ones?
Similar for deleting the "assign_adapter" key. We have an
"unassign_adapter" attribute, but this is not something we can infer
automatically; we need to know that we're dealing with an vfio-ap
matrix device...>

> 
> We should think about whether ordering is important and maybe
> incorporate that into key naming conventions or come up with some
> syntax for specifying startup blocks.  Thanks,
> 
> Alex

Hm...

{
  "foo": "1",
  "bar": "42",
  "baz": {
    "depends": ["foo", "bar"],
    "value": "plahh"
  }
}

Something like that?

  reply index

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-23 23:20 Alex Williamson
2019-05-24 10:11 ` Cornelia Huck
2019-05-24 14:43   ` Alex Williamson
2019-06-07 16:06   ` Halil Pasic
2019-06-11 19:45     ` Cornelia Huck
2019-06-11 20:28       ` Alex Williamson
2019-06-12  7:14         ` Cornelia Huck
2019-06-12 15:54           ` Halil Pasic
2019-06-13 10:02             ` Cornelia Huck
2019-06-12 15:07       ` Halil Pasic
2019-06-13 16:17 ` Christophe de Dinechin
2019-06-13 16:35   ` Alex Williamson
2019-06-14  9:54     ` [libvirt] " Christophe de Dinechin
2019-06-14 14:23       ` Alex Williamson
2019-06-14 15:06         ` Christophe de Dinechin
2019-06-14 16:04           ` Alex Williamson
2019-06-17 16:03             ` Cornelia Huck
2019-06-17 14:00 ` Daniel P. Berrangé
2019-06-17 14:54   ` Alex Williamson
2019-06-17 15:10     ` Daniel P. Berrangé
2019-06-17 17:05       ` Alex Williamson
2019-06-18  8:44         ` Daniel P. Berrangé
2019-06-18 11:01         ` Cornelia Huck
     [not found]           ` <CALOCmukPWiXiM+mN0hCTvSwfdHy5UdERU8WnvOXiBrMQ9tH3VA@mail.gmail.com>
2019-06-18 22:12             ` Alex Williamson
2019-06-19  7:28               ` Daniel P. Berrangé
2019-06-19  9:46                 ` Cornelia Huck
2019-06-19 18:46                   ` Alex Williamson
2019-06-20  8:24                     ` Daniel P. Berrangé
     [not found]               ` <CALOCmu=6Xmw-_-SVXujCEcgPY2CQiBQKgfUMJ45WnZ_9XORyUw@mail.gmail.com>
2019-06-19  9:57                 ` Cornelia Huck
2019-06-19 19:53                 ` Alex Williamson
2019-06-25 22:52 ` Alex Williamson
2019-06-26  9:58   ` Cornelia Huck
2019-06-26 14:37     ` Alex Williamson
2019-06-27  1:53       ` Alex Williamson
2019-06-27 12:26         ` Cornelia Huck [this message]
2019-06-27 15:00           ` Matthew Rosato
2019-06-27 15:38             ` Alex Williamson
2019-06-27 16:13               ` Matthew Rosato
2019-06-27 21:15               ` Alex Williamson
2019-06-28  1:57                 ` Alex Williamson
2019-06-28  9:06                   ` Cornelia Huck
2019-06-28 14:01                     ` Matthew Rosato
2019-06-28 17:05                     ` Alex Williamson
2019-07-01  8:20                       ` Cornelia Huck
2019-07-01 14:40                         ` Alex Williamson
2019-07-01 17:13                           ` Cornelia Huck

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=20190627142626.415138da.cohuck@redhat.com \
    --to=cohuck@redhat.com \
    --cc=alex.williamson@redhat.com \
    --cc=berrange@redhat.com \
    --cc=dinechin@redhat.com \
    --cc=eskultet@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=kwankhede@nvidia.com \
    --cc=libvir-list@redhat.com \
    --cc=mjrosato@linux.ibm.com \
    --cc=phrdina@redhat.com \
    --cc=sbauza@redhat.com \
    /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
	public-inbox-index kvm

Example config snippet for mirrors

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.git