Re: [libvirt PATCH 4/9] conf: add passt XML additions to schema
On 1/11/23 1:33 PM, Daniel P. Berrangé wrote:
On Sun, Jan 08, 2023 at 11:11:07PM -0500, Laine Stump wrote:
> Initial support for network devices using passt (https://passt.top)
> for the backend connection will require:
>
> * new attributes of the <backend> subelement:
> * "type" that can have the value "passt" (to differentiate
from
> slirp, because both slirp and passt will use <interface
> type='user'>)
> * "logFile" (a path to a file that passt should use for its logging)
> * "upstream" (a netdev name, e.g. "eth0").
IMHO this attribute is inappropriate for <backend>....
[...]
> + <interface type='user'>
> + <mac address='00:11:22:33:44:55'/>
> + <ip address='172.17.2.0' family='ipv4'
prefix='24'/>
> + <ip address='2001:db8:ac10:fd01::feed' family='ipv6'/>
> + <portForward proto='tcp'
address='2001:db8:ac10:fd01::1:10'>
> + <range start='22' to='2022'/>
> + <range start='1000' end='1050'/>
> + <range start='1020' exclude='yes'/>
> + <range start='1030' end='1040'
exclude='yes'/>
> + </portForward>
> + <portForward proto='udp' address='1.2.3.4'
dev='eth0'>
> + <range start='5000' end='5020' to='6000'/>
> + <range start='5010' end='5015'
exclude='yes'/>
> + </portForward>
> + <portForward proto='tcp'>
> + <range start='80'/>
> + </portForward>
> + <portForward proto='tcp'>
> + <range start='443' to='344'/>
> + </portForward>
> + <model type='rtl8139'/>
> + <backend type='passt' logFile='/var/log/loglaw.blog'
upstream='eth42'/>
I don't think that 'upstream' is really describing a property of the
backend.
This is expressing a traffic routing restriction for the 'user'
networking type. IMHO it should probably be using the existing
<source dev="xxxx"/> element, that is currently used by the
'direct' networking type.
I'm still not sure *exactly* what it does; it apparently grabs the
routes that are fed to the guest from the given host interface; I should
probably ask Stefano to explain it to me again (he described it once,
but that was along with explanations of several other things).
So it's not *exactly* the same as <source dev='xxx'/> for
type='direct'
(which determines the link-level connection rather than IP routing), but
definitely very similar.
Can we see about fixing this before release.
Yes, that makes sense. I'm not sure why I didn't think of it (usually I
try *too* hard to re-use existing XML).
I'll make a patch and send it later today.