[libvirt] virNetSocketNewListenTCP tries just one address

Ján Tomko jtomko at redhat.com
Tue Mar 27 17:46:30 UTC 2018

On Tue, Mar 27, 2018 at 11:18:10AM +0200, Olaf Hering wrote:
>On Tue, Mar 27, Ján Tomko wrote:
>> Why does your hostname resolve to an unavailable address?
>How can the DNS server possibly know how a host has configured itself?

It cannot, but the admin of the network should be able to control both.
How can libvirt tell whether this is a misconfiguration of DNS or host's

But we can possibly apply different rules for different callers:
virNetServerServiceNewTCP where silently ignoring a failure for one
address on daemon/system startup might be hard to catch and
libxlDomainMigrationDstPrepare which was called by an API
or by data source - whether it was user provided in the migration URI
or libvirtd tried to figure it out

For QEMU migration, we allow overriding the default listen address
via the migrate_host qemu.conf option, this is passed to QEMU
and looking at the code, it goes for best-effort and does not report
an error as long as binding to one of the addresses succeeds.

Anyway, globally ignoring EADDRNOTAVAIL feels too lenient for me.


>In this case I had BOOTPROTO='dhcp4' instead of 'dhcp' in
>/etc/sysconfig/network/ifcfg-br0 due to all the migration issues I'm
>seeing. It turned out they are unrelated to such setting.

>libvir-list mailing list
>libvir-list at redhat.com

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