Bug 1219504

Summary: [doc] Issue in "The file /etc/default/grub"
Product: [openSUSE] PUBLIC SUSE Linux Enterprise Server 15 SP5 Reporter: Jiri Belka <jiri.belka>
Component: DocumentationAssignee: Tomáš Bažant <tbazant>
Status: RESOLVED FIXED QA Contact: Frank Sundermeyer <fs>
Severity: Normal    
Priority: P5 - None CC: jiri.belka
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
Whiteboard: https://jira.suse.com/browse/DOCTEAM-1259
Found By: --- Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description Jiri Belka 2024-02-02 13:06:36 UTC 
The file /etc/default/grub:

https://documentation.suse.com/sles/15-SP5/single-html/SLES-administration/#sec-grub2-etc-default-grub

Hi, description of GRUB_CMDLINE_XEN{,_DEFAULT} seems wrong:

- our docs:

---%>---
GRUB_CMDLINE_XEN
This entry specifies the kernel parameters for the Xen guest kernel only—the operation principle is the same as for GRUB_CMDLINE_LINUX.

GRUB_CMDLINE_XEN_DEFAULT
Same as GRUB_CMDLINE_XEN—the operation principle is the same as for GRUB_CMDLINE_LINUX_DEFAULT.
---%<---


- GRUB2 manual:

---%>---
‘GRUB_CMDLINE_XEN’
‘GRUB_CMDLINE_XEN_DEFAULT’
The values of these options are passed to Xen hypervisor Xen menu entries, for all respectively normal entries.
---%<---

Thus, it is clear that these are _options_ passed to Xen hypervisor, not (Linux) kernel paramters for the "Xen guest kernel" (should this mean domU, if so, then this is even more wrong).

Thus, there should be options as specified at:

https://xenbits.xen.org/docs/unstable/misc/xen-command-line.html

An example:

---%>---
GRUB_CMDLINE_XEN_DEFAULT="loglvl=all guest_loglvl=all com1=115200,8n1 console=com1,vga"
---%<---

^^ these are not boot params for Linux kernel. Linux does not know, IIUC, 'com1'. See xenbints.xen.org link.

Thank you for correcting and improving this. (I haven't checked other description though.)
Comment 1 Jiri Belka 2024-02-02 14:07:01 UTC 
Could you also please state what "" inside "" should be escaped?

An example:

GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT="splash=none security=apparmor mitigations=auto debug loglevel=9 log_buf_len=5M \"ddebug_query=file drivers/xen/xen-acpi-processor.c +p\""

We asked one customer and he, of course, did not escape it :/ So, maybe, let's educate them a bit.
Comment 2 Tomáš Bažant 2024-02-08 11:29:41 UTC 
Thank you for reporting this bug!
It is being tracked and processed as part of our queue.
Comment 3 Tomáš Bažant 2024-02-20 11:18:56 UTC 
progress is tracked in https://github.com/SUSE/doc-sle/pull/1663/files

@Jiri, can you review pls?
Comment 4 Jiri Belka 2024-02-20 11:32:21 UTC 
reads fine, thx
Comment 5 Tomáš Bažant 2024-02-20 11:39:13 UTC 
fixed, closing