[Qemu-devel] Is guest agent socket being closed upon reboot?

[Qemu-devel] Is guest agent socket being closed upon reboot?

[Michal Privoznik]

Hi,

I'd like you to ask if/why is guest agent socked being closed upon guest
reboot. I am using virtserialport to talk to guest agent:

-chardev
socket,id=charchannel0,path=/var/lib/libvirt/qemu/f16x86_64.agent,server,nowait
-device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0

I would understand if socket accept connection iff GA is up and running.
However, this is not the case. One is perfectly able to connect to GA
socket even without any GA inside guest.

I think that GA socket should be as persistent as monitor. Even despite
fact they address different areas. Application issuing monitor commands
shouldn't be forced to reconnect on every guest reboot, should they?

Or have I misunderstood the concept?

Michal

Re: [Qemu-devel] Is guest agent socket being closed upon reboot?

[Michael Roth]

On 01/16/2012 07:26 AM, Michal Privoznik wrote:
> Hi,
>
> I'd like you to ask if/why is guest agent socked being closed upon guest
> reboot. I am using virtserialport to talk to guest agent:
>
> -chardev
> socket,id=charchannel0,path=/var/lib/libvirt/qemu/f16x86_64.agent,server,nowait
> -device
> virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0
>
> I would understand if socket accept connection iff GA is up and running.
> However, this is not the case. One is perfectly able to connect to GA
> socket even without any GA inside guest.
>
> I think that GA socket should be as persistent as monitor. Even despite
> fact they address different areas. Application issuing monitor commands
> shouldn't be forced to reconnect on every guest reboot, should they?
>
> Or have I misunderstood the concept?
>
> Michal
>

Hi Michal,

In my testing this doesn't seem to be the case, the host socket 
connection persists throughout reboots, guest agent restarts, etc.

I'm not sure what would trigger the close either, the 
chr->chr_guest_close/chr->chr_guest_open events do not seem to be 
initialised at any point, which AFAICT are the only things that would 
affect the char frontend/socket connection during reboot.

Can you provide more details on your setup? What version/commit you're 
running and what sequence induces the behavior?

Thanks!

[Qemu-devel] Is guest agent socket being closed upon reboot?

[Michal Privoznik]

Hi,

I'd like you to ask if/why is guest agent socked being closed upon guest
reboot. I am using virtserialport to talk to guest agent:

-chardev
socket,id=charchannel0,path=/var/lib/libvirt/qemu/f16x86_64.agent,server,nowait
-device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0

I would understand if socket accept connection iff GA is up and running.
However, this is not the case. One is perfectly able to connect to GA
socket even without any GA inside guest.

I think that GA socket should be as persistent as monitor. Even despite
fact they address different areas. Application issuing monitor commands
shouldn't be forced to reconnect on every guest reboot, should they?

Or have I misunderstood the concept?

Michal

(Please keep me CC'ed as I am not registered to the mailing list)