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Re: [Qemu-devel] Should we auto-generate IDs?
From: |
Jeff Cody |
Subject: |
Re: [Qemu-devel] Should we auto-generate IDs? |
Date: |
Wed, 26 Aug 2015 13:25:50 -0400 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Wed, Aug 26, 2015 at 06:31:57PM +0200, Markus Armbruster wrote:
> Did you drop cc's intentionally? I put them right back.
>
> Programmingkid <address@hidden> writes:
>
> > On Aug 25, 2015, at 8:38 AM, Markus Armbruster wrote:
> >
> >> You're proposing to revise a qdev design decision, namely the purpose of
> >> IDs. This has been discussed before, and IDs remained unchanged.
> >> Perhaps it's time to revisit this issue. Cc'ing a few more people.
> >>
> >> Relevant prior threads:
> >> * [PATCH] qdev: Reject duplicate and anti-social device IDs
> >> http://thread.gmane.org/gmane.comp.emulators.qemu/71230/focus=72272
> >> * [PATCH 6/6] qdev: Generate IDs for anonymous devices
> >> http://thread.gmane.org/gmane.comp.emulators.qemu/114853/focus=114858
> >> * [PATCH] qdev: Assign a default device ID when none is provided.
> >> http://thread.gmane.org/gmane.comp.emulators.qemu/249702
> >> * IDs in QOM (was: [PATCH] util: Emancipate id_wellformed() from QemuOpt
> >> http://thread.gmane.org/gmane.comp.emulators.qemu/299945/focus=300381
> >>
> >
> > After reading all the threads, I realize why all the attempts to
> > accept a device ID patch failed.
> > It is because it was assumed everyone would agree on one patch to
> > accept. This is
> > very unlikely. It would take someone in a leadership position to
> > decide which patch
> > should be accepted. From one of the threads above, I saw Anthony
> > Liguori participate.
> > He was in the perfect position to make the choice. The person who is
> > in his position now
> > is Peter Maydell. Maybe we should just ask him to look at all the
> > candidate patches and
> > have him pick one to use.
>
> Yes, when no consensus emerges, problems tend to go unsolved.
>
> Before we appeal to authority to break the deadlock, we should make
> another attempt at finding consensus.
>
> I know that we've entertained the idea of automatically generated IDs
> for block layer objects (that's why I cc'ed some block guys).
Yeah, I was one of the ones that proposed some auto-generated IDs for
the block layer, specifically for BlockDriverState, making use of the
node-name field that Benoit introduced a while ago. Here is my patch
(not sure if this is the latest version, but it is sufficient for this
discussion):
http://patchwork.ozlabs.org/patch/355990/
I'm not sure about the requirements needed by device ID names, and
they may of course differ from what I was thinking for BDS entries.
Here is what I was after with my patch for node-name auto-generation:
* Identifiable as QEMU generated / reserved namespace
* Guaranteed uniqueness
* Non-predictable (don't want users trying to guess / assume
generated node-names)
My approach was overkill in some ways (24 characters!). But for
better or worse, what I had was:
__qemu##00000000IAIYNXXR
^^^^^^^^
QEMU namespace ----| ^^^^^^^^
| ^^^^^^^^^
Increment counter, unique | |
|
Random string, to spoil prediction |
>
> I definitely want to hear Andreas's and Paolo's opinion (also cc'ed), if
> they have one.
- Re: [Qemu-devel] Should we auto-generate IDs? (was: [PATCH] qdev-monitor.c: Add device id generation), (continued)
- Re: [Qemu-devel] Should we auto-generate IDs? (was: [PATCH] qdev-monitor.c: Add device id generation), Programmingkid, 2015/08/25
- Re: [Qemu-devel] Should we auto-generate IDs? (was: [PATCH] qdev-monitor.c: Add device id generation), Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Markus Armbruster, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Peter Maydell, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, John Snow, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Markus Armbruster, 2015/08/27
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/27
- Re: [Qemu-devel] Should we auto-generate IDs?,
Jeff Cody <=
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Jeff Cody, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Jeff Cody, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, John Snow, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/26
- Re: [Qemu-devel] Should we auto-generate IDs?, Jeff Cody, 2015/08/27
- Re: [Qemu-devel] Should we auto-generate IDs?, Eric Blake, 2015/08/27
- Re: [Qemu-devel] Should we auto-generate IDs?, Programmingkid, 2015/08/27