Please vote Yes if you agree with all of the following.
If you disagree, please vote No.
If you don't have an opinion, please vote Abstain.
I move that:
The TC agrees to resolve the following specification issue:
VIRTIO-143: balloon: allow transitional devices
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Virtio 1.0 cs02 doesn't include a modern balloon device. At some
point we'll likely define an incompatible interface with a
different ID and different semantics. But for now, it's not a
big effort to support a transitional balloon device: this has the
advantage of supporting existing drivers, transparently, as well
as transports that don't allow mixing virtio 0 and virtio 1
devices. And balloon is an easy device to test, so it's also
useful for people to test virtio core handling of transitional
devices.
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The TC accepts the following proposed changes to the specification:
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mid.gmane.org/1430235439-3812-1-git-send-email-mst@redhat.com
[PATCH v3] balloon: transitional device support
Support a transitional balloon device: this has the advantage of supporting
existing drivers, transparently, as well as transports that don't allow mixing
virtio 0 and virtio 1 devices. And balloon is an easy device to test, so it's
also useful for people to test virtio core handling of transitional devices.
Three issues with legacy hypervisors have been identified:
1. Actual value is actually used, and is necessary for management
to work. Luckily 4 byte config space writes are now atomic.
When using old guests, hypervisors can detect access to the last byte.
When using old hypervisors, drivers can use atomic 4-byte accesses.
2. Hypervisors actually didn't ignore the stats from the first
buffer supplied. This means the values there would be
incorrect until hypervisor resends the request.
Add a note suggesting hypervisors ignore the 1st buffer.
3. QEMU simply over-writes stats from each buffer it gets.
Thus if driver supplies a different subset of stats
on each request, stale values will be there.
Require drivers to supply the same subset on each
request. This also gives us a simple way to figure out
which stats are supported.
Additionally, this fixes a typo:
- the driver SHOULD omit unsupported statistics.
should be:
+ devices omit unsupported statistics.
Note that we have a normative statement with this requirement
already, this is just general high-level description.
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The TC agrees to include the above change(s) in specification version(s) "virtio 1.0 cs03", and future versions of the
specification.
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Reminder: A Voting Member must be active in a TC to maintain voting rights. As
the Virtio TC has adopted a standing rule to conduct business only by
electronic ballot, without Meetings, a Voting Member who fails to cast a ballot
in two consecutive Work Product Ballots loses his or her voting rights at the
close of the second ballot missed.
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