On 25/07/2024 18:50, Daniel P. Berrangé wrote:
On Mon, Jul 15, 2024 at 11:20:27AM +0200, Jocelyn Falempe wrote:
On 15/07/2024 10:30, Zbigniew Jędrzejewski-Szmek wrote:
There's just so many different and special ways in how people hook up
console logging from VMs and other systems. Disabling VT_CONSOLE at
compile time is hard to defend.
For VM, you have an easy access to the serial output, where you can copy the
debug message and google them. Having the same thing on graphic output is
less appealing, because it starts later than serial, you can't copy/paste,
you can't scroll back, and you can't save it to a file. (And a boot video
recording is much less useful than a text log).
Don't assume serial access is quiet that straightforward in all VMs.
The serial console might be setup in interactive mode, rather than
persistently logging all data. If you don't have the serial console
open at the time the VM crashes, the kernel messages are easily lost
forever. If you do have the serial console open, don't assume there
is terminal scrollback to see the top of the trace, you might only
see the bottom of it. If the crash scenario isn't reliably reproducible
this is all rather a pain.
In addition depending on permissions of the deployment, a user might
have rights to access the graphical console (VNC/SPICE/RDP/etc), but
have no access to the mgmt plane, thus preventing access to the serial
console logs. While it is ultimately the VM owners job to fix the
crash, it would still be nice if the VM user could see the info before
escalating the issue to the VM owner.
My experience of VM is mostly on my own workstation, I didn't think that
shared VM may not have the serial console accessible.
Thanks for adding this precision.
We do have the ability to provide a 'pstore' device to a VM, which is
an area of NVRAM storage to record panic logs. Potentially better than
the serial console, but access this data still has the permissions
problem if the user only has graphical console access.
IOW, I think it is interesting & useful to have this panic screen
feature in VMs.
With your QR code proposal, we could do something fun like having
virt-manager auto-detect the QR code on the virtual screen, extract
the information from it, and present it to the user in plain text
once more.
Oh, it looks like a very complicated way to transfert a few kB of text
data to the user, but technically it's feasible.
With regards,
Daniel
--
_______________________________________________
devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx
To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/
List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines
List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
