[libvirt-users] hvc - hypervisor virtual console & virsh

[poma]

On 03.10.2015 00:07, poma wrote:
> Hi Fi,
> 
> cmdline: console=hvc0 systemd.wants=getty at hvc0
> 
> Connect via virt-manager - View / Text Consoles / Text Console no.:
> 
> Fedora 24 (Rawhide)
> Kernel 4.3.0-0.rc3.git2.4.fc24.x86_64 on an x86_64 (hvc0)
> 
> localhost login: root
> Last login: Fri Oct  2 17:28:36 on hvc0
> # tty
> /dev/hvc0
> # systemctl status getty at hvc0.service 
> ● getty at hvc0.service - Getty on hvc0
>    Loaded: loaded (/usr/lib/systemd/system/getty at .service; enabled; vendor preset: enabled)
>    Active: active (running) since Fri 2015-10-02 17:28:39 EDT; 26s ago
>      Docs: man:agetty(8)
>            man:systemd-getty-generator(8)
>            http://0pointer.de/blog/projects/serial-console.html
>  Main PID: 2034 (login)
>    CGroup: /system.slice/system-getty.slice/getty at hvc0.service
>            ‣ 2034 login -- root
> 
> Oct 02 17:28:39 localhost systemd[1]: Started Getty on hvc0.
> 
> It obviously works.
> 
> 
> Connect via virsh:
> 
> # virsh console <domain> console1
> Connected to domain <domain>
> Escape character is ^]
> error: operation failed: Active console session exists for this domain
> 
> # virsh console --devname console1 <domain>
> Connected to domain <domain>
> Escape character is ^]
> error: operation failed: Active console session exists for this domain
> 
> Obviously does not work.
> 
> Is it possible to connect hvc via virsh, if domain/guest is started with the virt-manager?
> Is it possible at all, to connect hypervisor virtual console via virsh?
> 


The answer is, of course!


Connect via virt-manager - View / Text Consoles / Text Console 1:

Fedora 24 (Rawhide)
Kernel 4.3.0-0.rc3.git2.4.fc24.x86_64 on an x86_64 (hvc0)

localhost login: root
# tty
/dev/hvc0
# cat /proc/cmdline 
BOOT_IMAGE=vmlinuz0 initrd=initrd0.img root=live:CDLABEL=Rawhide-Xfce-Live-1001 rootfstype=auto ro rd.live.image console=hvc0 systemd.wants=getty at hvc0 console=hvc1 systemd.wants=getty at hvc1


Connect via virsh to "Text Console 2":

# virsh console <domain> console0
Connected to domain <domain>
Escape character is ^]
error: operation failed: Active console session exists for this domain

- This console is obviously busy!

# virsh console <domain> console1
Connected to domain <domain>
Escape character is ^]

Fedora 24 (Rawhide)
Kernel 4.3.0-0.rc3.git2.4.fc24.x86_64 on an x86_64 (hvc1)

localhost login: root
Last login: Fri Oct  2 18:41:46 on hvc0
# tty
/dev/hvc1


Conclusion:

It is necessary to shutdown domain/guest and disconnect from hypervisor, after the connection established via virt-manager, to free up a slot for next connection, via virsh.
And vice versa.

Even better is if defined more "Text Consoles" i.e. hypervisor virtual consoles, as shown here.