On 09/10/2017 11:38 AM, Paolo Bonzini wrote:
On 28/08/2017 13:11, Michal Privoznik wrote:
On 08/25/2017 12:41 AM, Paolo Bonzini wrote:
On 22/08/2017 18:27, Paolo Bonzini wrote:
Hi all,
The XML to use the helper with a predefined socket could be:
<disk ...> <pr mode='connect'>/path/to/unix.socket'</pr> </disk>
This looks okay-ish. But from future proof POV, I'd have the path as an attribute, or as a separate sub-element of <pr/> so that we can stick more elements into it if we need to.
Do we want to/need to expose the path here? I mean, is user expected to do something with it? We don't expose monitor path anywhere but keep it private (of course we store it in so called status XML which is a persistent storage solely for purpose of reloading the internal state when daemon is restarted).
In this case, yes. This is for the case of a global daemon.
I'm thinking if we should just use virDomainChrSourceDefPtr for this. I mean, if you take look at the vhost-user XML format it looks something like this: <interface type='vhostuser'> <mac address='52:54:00:3b:83:1b'/> <source type='unix' path='/tmp/vhost2.sock' mode='client'/> <model type='virtio'/> <driver queues='5'/> </interface> http://libvirt.org/formatdomain.html#elementVhostuser So we could have: <disk> <pr> <source type='unix' path='/path/to/unix.socket' mode='client'/> </pr> </disk> The advantage of this is that we can express other connection modes if the pr-helper is ever going to support them (although, if you need to pass FDs around, UNIX socket is the only way for you). Then again, I think it follows what we have elsewhere. Also, if we go this way, we can forbid any type='' but unix and mode='server'.
while to use it with a dedicated daemon
<disk ...> <pr mode='private'>/path/to/qemu-pr-helper</pr> </disk>
Ah, this breaks my design. I guess <disk> <pr> <source type='unix' path='/path/to/qemu-pr-helper' mode='server'/> </pr> </disk> is pure madness, isn't it? Michal