Bhyve virtio-net: Allow backend type to be explicitly specified.
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Authored by nyan_myuji.xyz on May 6 2022, 7:47 PM.

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vmaffione
jhb

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bhyve

Commits

rGc0ca5055f323: bhyve virtio-net: Allow backend type to be explicitly specified.
rGb9c3e544c48e: bhyve virtio-net: Allow backend type to be explicitly specified.

Summary

Currently virtio-net is choosing the backend for virtio-net by the prefix of
the inteface. This patch allow an addition option "type" to choose backend type
explicitly. This allowed greater flexibility for end users to manage bhyve
specific resources (such as by naming the tap interfaces to more descriptive
names). The option "type" is optional. When it is not presented, the backend
will be derived by the name of the backend interface.

For example, the line -s 3,virtio-net,bsdvm0,type=tap will create a
virtio-net device for the guest using the tap interface "bsdvm0".

The idea behind adding the option "type" is to preserve the consistency
between the current (legacy) format. Which the next value after virtio-net
is set to be an identifier of an instance of a backend.

A drawback of this apporach is that; since tap interfaces cannot be created by
opening non "tap" prefixed device, if the backend tap interface is not presented
and such interface is not prefixed with "tap*", bhyve cannot automatically
create it. Since bhyve does not create the interfaces for other backends anyway,
it shouldn't be a big issue.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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No Test Coverage

Build Status

Buildable 45867
Build 42755: arc lint + arc unit

Event Timeline

nyan_myuji.xyz created this revision.May 6 2022, 7:47 PM

Herald added a reviewer: bhyve. · View Herald TranscriptMay 6 2022, 7:47 PM

Herald added subscribers: Contributor Reviews (src), bcran, rgrimes, imp. · View Herald Transcript

nyan_myuji.xyz requested review of this revision.May 6 2022, 7:47 PM

Harbormaster completed remote builds in B45492: Diff 105748.May 6 2022, 7:47 PM

change to use type as the option
yes I am an idiot and totally forgot bhyve-config(5)

Harbormaster completed remote builds in B45493: Diff 105750.May 6 2022, 8:19 PM

nyan_myuji.xyz retitled this revision from Bhyve virtio-net: Allow backend to be explicitly specified. to Bhyve virtio-net: Allow backend type to be explicitly specified..May 6 2022, 8:23 PM

nyan_myuji.xyz edited the summary of this revision. (Show Details)

afedorov added a subscriber: afedorov.May 7 2022, 10:26 AM

zlei added a subscriber: zlei.Jun 6 2022, 7:02 AM

zlei added inline comments.Jun 6 2022, 7:15 AM

usr.sbin/bhyve/net_backends.c
994	type = get_config_value_node(nvl, "type"); if (type == NULL) type = devname; is more straight IMO

change to use type as the option
simplify code

Harbormaster completed remote builds in B45867: Diff 106670.Jun 6 2022, 1:11 PM

vmaffione accepted this revision.Jun 8 2022, 9:42 PM

This revision is now accepted and ready to land.Jun 8 2022, 9:42 PM

jhb accepted this revision.Jun 29 2022, 10:04 PM

jhb added a subscriber: jhb.

jhb added inline comments.

usr.sbin/bhyve/net_backends.c
994–997

If there are no objections, I would go ahead and commit this, incorporating the style fixes by @jhb

I've already started on this, but in order to set the author of the commit correctly I'd like to confirm the original submitter's name. I believe it is "Michael Chiu" based on a ports commit I found?

@jhb Thank you so much for helping! I have submitted a few patches under "Yan Ka Chiu" lately so I guess I will use that instead for consistency.

usr.sbin/bhyve/net_backends.c
994	good point, changed

Closed by commit rGb9c3e544c48e: bhyve virtio-net: Allow backend type to be explicitly specified. (authored by nyan_myuji.xyz, committed by jhb). · Explain WhyJun 30 2022, 5:32 PM

This revision was automatically updated to reflect the committed changes.

jhb added a commit: rGb9c3e544c48e: bhyve virtio-net: Allow backend type to be explicitly specified..

While writing a followup manpage change to document this, it occurred to me that it would be simpler to explain if instead we added a new 'iface' keyword so that you could use 'backend=tap', and 'iface=bsdvm0'. I will work on a patch to convert to that instead I think as I it is more similar to what qemu does as well.

jhb added a commit: rGc0ca5055f323: bhyve virtio-net: Allow backend type to be explicitly specified..Nov 10 2022, 10:06 PM