[CentOS-virt] Centos7 Xen hypervisor console= options broken in default grub2 config

Sun May 5 09:29:03 UTC 2019
Pasi Kärkkäinen <pasik at iki.fi>


While testing Virt-SIG Xen 4.12 rpms on CentOS 7, I noticed the default Xen hypervisor console= option parameters are broken, and result in an error from Xen, and no output on the physical vga console:

>From xen dmesg:

(XEN) Bad console= option 'tty'
 Xen 4.12.0-1.el7
(XEN) Xen version 4.12.0-1.el7 (mockbuild at centos.org) (gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-36)) debug=n  Tue Apr  2 13:09:41 UTC 2019
(XEN) Latest ChangeSet:
(XEN) Bootloader: GRUB 2.02~beta2
(XEN) Command line: placeholder dom0_mem=1024M,max:1024M cpuinfo com1=115200,8n1 console=com1,tty loglvl=all guest_loglvl=all

.. and indeed, 'tty' is not a valid option for Xen hypervisor console= parameter. 
That can be easily fixed in "/etc/sysconfig/grub", and executing "grub2-mkconfig -o /boot/grub2/grub.cfg" afterwards, but we should fix the default..

Here is the working setting (console=com1,vga, instead of console=com1,tty):

# grep GRUB_CMDLINE_XEN_DEFAULT /etc/sysconfig/grub
GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M cpuinfo com1=115200,8n1 console=com1,vga loglvl=all guest_loglvl=all"


-- Pasi