Re: Boot into Xen on debian11

[Leigh Brown <leigh@xxxxxxxxxxxxx>]

Hi Bruno,

On 2022-07-19 15:42, Bruno wrote:
> > Hello.
> >
> > Is there a way to boot into Xen on debian11 installing Xen the way 
> > documented, please?
> > Multiboot2 is not doing the trick with initrd. Is there a workaround 
> > or a way to?
> > Do we need a patch to grub to make Xen usable on this scenario? Does 
> > anyone boot into Xen? On debian? Debian11, please?
Debian 11 should work out of the box.

> > I have posted it on stackexchange:
> >
> > https://unix.stackexchange.com/q/710400/375983
> >
> > Linux xd 5.10.0-16-amd64 #1 SMP Debian 5.10.127-1 (2022-06-30) x86_64 
> > GNU/Linux
> > On my debian11, I have installed xen-hypervisor-4.14-amd64, 
> > xen-hypervisor-common, xen-system-amd64, and xen-utils-4.14
Is xen-utils-common installed? I would expect it to be, but worth 
checking.
> > But I cannot boot into Xen, please help.
What do you mean by that? Does it crash, reboot, blank screen, something 
else?
> > Theoretically, after installing Xen, according to 
> > https://wiki.debian.org/Xen , I should only run:
> > dpkg-divert --divert /etc/grub.d/08_linux_xen --rename 
> > /etc/grub.d/20_linux_xen
> > update-grub
According to the Wiki, that step is only for Wheezy / Squeeze and is not 
required for Debian 11. I'd undo that, and re-run update-grub.
> > Unfortunately, boot breaks and grub mailing list had a very deep 
> > debate on it last March-April - apparently multiboot2 will NOT do the 
> > trick:
> > https://www.mail-archive.com/grub-devel@xxxxxxx/msg32020.html
> >
> > I need some help, please. Is this inconclusive? Is there a work-around 
> > I could use (some partial boot on Xen and manually loading on the 
> > prompt the rest of what is needed for Xen to work)? How should I 
> > proceed? I will try to register this on grub, debian xen packages and 
> > Xen as requests/bugs - any further ideas on actions, please?
It should just work, if you provide more information on what you are 
seeing, it should be possible to resolve.
> > The discussion on grub mailing list points to this:
> >
> > https://wiki.debian.org/DebianInstaller/NetbootFirmware#The_Solution:_Add_Firmware_to_Initramfs
> >
> > This seems very complicated and risky... is this the way forward?
> >
> > Did anyone patch grub2 to be able to support what's needed for Xen, 
> > please?
There's no need.

> > Note: I'm using pure Xen, NOT Eve.
> >
> > /etc/default/grub file contents:
> >
> > # If you change this file, run 'update-grub' afterwards to update
> > # /boot/grub/grub.cfg.
> > # For full documentation of the options in this file, see:
> > #   info -f grub -n 'Simple configuration'
> >
> > GRUB_DEFAULT=0
> > GRUB_TIMEOUT=5
> > GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
> > GRUB_CMDLINE_LINUX_DEFAULT="quiet"
> > GRUB_CMDLINE_LINUX=""
> >
> > # Uncomment to enable BadRAM filtering, modify to suit your needs
> > # This works with Linux (no patch required) and with any kernel that 
> > obtains
> > # the memory map information from GRUB (GNU Mach, kernel of FreeBSD 
> > ...)
> > #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"
> >
> > # Uncomment to disable graphical terminal (grub-pc only)
> > #GRUB_TERMINAL=console
> >
> > # The resolution used on graphical terminal
> > # note that you can use only modes which your graphic card supports 
> > via VBE
> > # you can see them in real GRUB with the command `vbeinfo'
> > #GRUB_GFXMODE=640x480
> >
> > # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter 
> > to Linux
> > #GRUB_DISABLE_LINUX_UUID=true
> >
> > # Uncomment to disable generation of recovery mode menu entries
> > #GRUB_DISABLE_RECOVERY="true"
> >
> > # Uncomment to get a beep at grub start
> > #GRUB_INIT_TUNE="480 440 1"
> >
> > /boot/grub/grub.cfg file contents:
> >
> > #
> > # DO NOT EDIT THIS FILE
> > #
> > # It is automatically generated by grub-mkconfig using templates
> > # from /etc/grub.d and settings from /etc/default/grub
> > #
> >
> > ### BEGIN /etc/grub.d/00_header ###
> > if [ -s $prefix/grubenv ]; then
> > set have_grubenv=true
> > load_env
> > fi
> > if [ "${next_entry}" ] ; then
> > set default="${next_entry}"
> > set next_entry=
> > save_env next_entry
> > set boot_once=true
> > else
> > set default="Debian GNU/Linux, with Xen hypervisor"
> > fi
> >
> > if [ x"${feature_menuentry_id}" = xy ]; then
> > menuentry_id_option="--id"
> > else
> > menuentry_id_option=""
> > fi
> >
> > export menuentry_id_option
> >
> > if [ "${prev_saved_entry}" ]; then
> > set saved_entry="${prev_saved_entry}"
> > save_env saved_entry
> > set prev_saved_entry=
> > save_env prev_saved_entry
> > set boot_once=true
> > fi
> >
> > function savedefault {
> > if [ -z "${boot_once}" ]; then
> > saved_entry="${chosen}"
> > save_env saved_entry
> > fi
> > }
> > function load_video {
> > if [ x$feature_all_video_module = xy ]; then
> > insmod all_video
> > else
> > insmod efi_gop
> > insmod efi_uga
> > insmod ieee1275_fb
> > insmod vbe
> > insmod vga
> > insmod video_bochs
> > insmod video_cirrus
> > fi
> > }
> >
> > if [ x$feature_default_font_path = xy ] ; then
> > font=unicode
> > else
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > font="/usr/share/grub/unicode.pf2"
> > fi
> >
> > if loadfont $font ; then
> > set gfxmode=auto
> > load_video
> > insmod gfxterm
> > set locale_dir=$prefix/locale
> > set lang=en_GB
> > insmod gettext
> > fi
> > terminal_output gfxterm
> > if [ "${recordfail}" = 1 ] ; then
> > set timeout=30
> > else
> > if [ x$feature_timeout_style = xy ] ; then
> > set timeout_style=menu
> > set timeout=5
> > # Fallback normal timeout code in case the timeout_style feature is
> > # unavailable.
> > else
> > set timeout=5
> > fi
> > fi
> > ### END /etc/grub.d/00_header ###
> >
> > ### BEGIN /etc/grub.d/05_debian_theme ###
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > insmod png
> > if background_image 
> > /usr/share/desktop-base/homeworld-theme/grub/grub-4x3.png; then
> > set color_normal=white/black
> > set color_highlight=black/white
> > else
> > set menu_color_normal=cyan/blue
> > set menu_color_highlight=white/blue
> > fi
> > ### END /etc/grub.d/05_debian_theme ###
> >
> > ### BEGIN /etc/grub.d/08_linux_xen ###
> > menuentry 'Debian GNU/Linux, with Xen hypervisor' --class debian 
> > --class gnu-linux --class gnu --class os --class xen 
> > $menuentry_id_option 'xen-gnulinux-simple-0123abcd' {
So the menu entry is created - can you see it in the grub menu?

> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Xen 4.14-amd64 ...'
> > if [ "$grub_platform" = "pc" -o "$grub_platform" = "" ]; then
> > xen_rm_opts=
> > else
> > xen_rm_opts="no-real-mode edd=off"
> > fi
> > multiboot2  /xen-4.14-amd64.gz placeholder   ${xen_rm_opts}
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > module2 /vmlinuz-5.10.0-16-amd64 placeholder root=UUID=0123abcd ro  
> > quiet
> > echo    'Loading initial ramdisk ...'
> > module2 --nounzip   /initrd.img-5.10.0-16-amd64
> > }
> > submenu 'Advanced options for Debian GNU/Linux (with Xen hypervisor)' 
> > $menuentry_id_option 'gnulinux-advanced-0123abcd' {
> > submenu 'Xen hypervisor, version 4.14-amd64' $menuentry_id_option 
> > 'xen-hypervisor-4.14-amd64-0123abcd' {
> > menuentry 'Debian GNU/Linux, with Xen 4.14-amd64 and Linux 
> > 5.10.0-16-amd64' --class debian --class gnu-linux --class gnu --class 
> > os --class xen $menuentry_id_option 
> > 'xen-gnulinux-5.10.0-16-amd64-advanced-0123abcd' {
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Xen 4.14-amd64 ...'
> > if [ "$grub_platform" = "pc" -o "$grub_platform" = "" ]; then
> > xen_rm_opts=
> > else
> > xen_rm_opts="no-real-mode edd=off"
> > fi
> > multiboot2  /xen-4.14-amd64.gz placeholder   ${xen_rm_opts}
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > module2 /vmlinuz-5.10.0-16-amd64 placeholder root=UUID=0123abcd ro  
> > quiet
> > echo    'Loading initial ramdisk ...'
> > module2 --nounzip   /initrd.img-5.10.0-16-amd64
> > }
> > menuentry 'Debian GNU/Linux, with Xen 4.14-amd64 and Linux 
> > 5.10.0-16-amd64 (recovery mode)' --class debian --class gnu-linux 
> > --class gnu --class os --class xen $menuentry_id_option 
> > 'xen-gnulinux-5.10.0-16-amd64-recovery-0123abcd' {
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Xen 4.14-amd64 ...'
> > if [ "$grub_platform" = "pc" -o "$grub_platform" = "" ]; then
> > xen_rm_opts=
> > else
> > xen_rm_opts="no-real-mode edd=off"
> > fi
> > multiboot2  /xen-4.14-amd64.gz placeholder  ${xen_rm_opts}
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > module2 /vmlinuz-5.10.0-16-amd64 placeholder root=UUID=0123abcd ro 
> > single
> > echo    'Loading initial ramdisk ...'
> > module2 --nounzip   /initrd.img-5.10.0-16-amd64
> > }
> > }
> > submenu 'Xen hypervisor, version 4.14-amd64.efi' $menuentry_id_option 
> > 'xen-hypervisor-4.14-amd64.efi-0123abcd' {
> > menuentry 'Debian GNU/Linux, with Xen 4.14-amd64.efi and Linux 
> > 5.10.0-16-amd64' --class debian --class gnu-linux --class gnu --class 
> > os --class xen $menuentry_id_option 
> > 'xen-gnulinux-5.10.0-16-amd64-advanced-0123abcd' {
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Xen 4.14-amd64.efi ...'
> > if [ "$grub_platform" = "pc" -o "$grub_platform" = "" ]; then
> > xen_rm_opts=
> > else
> > xen_rm_opts="no-real-mode edd=off"
> > fi
> > multiboot2  /xen-4.14-amd64.efi placeholder   ${xen_rm_opts}
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > module2 /vmlinuz-5.10.0-16-amd64 placeholder root=UUID=0123abcd ro  
> > quiet
> > echo    'Loading initial ramdisk ...'
> > module2 --nounzip   /initrd.img-5.10.0-16-amd64
> > }
> > menuentry 'Debian GNU/Linux, with Xen 4.14-amd64.efi and Linux 
> > 5.10.0-16-amd64 (recovery mode)' --class debian --class gnu-linux 
> > --class gnu --class os --class xen $menuentry_id_option 
> > 'xen-gnulinux-5.10.0-16-amd64-recovery-0123abcd' {
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Xen 4.14-amd64.efi ...'
> > if [ "$grub_platform" = "pc" -o "$grub_platform" = "" ]; then
> > xen_rm_opts=
> > else
> > xen_rm_opts="no-real-mode edd=off"
> > fi
> > multiboot2  /xen-4.14-amd64.efi placeholder  ${xen_rm_opts}
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > module2 /vmlinuz-5.10.0-16-amd64 placeholder root=UUID=0123abcd ro 
> > single
> > echo    'Loading initial ramdisk ...'
> > module2 --nounzip   /initrd.img-5.10.0-16-amd64
> > }
> > }
> > }
> >
> > ### END /etc/grub.d/08_linux_xen ###
> >
> > ### BEGIN /etc/grub.d/10_linux ###
> > function gfxmode {
> > set gfxpayload="${1}"
> > }
> > set linux_gfx_mode=
> > export linux_gfx_mode
> > menuentry 'Debian GNU/Linux' --class debian --class gnu-linux --class 
> > gnu --class os $menuentry_id_option 'gnulinux-simple-0123abcd' {
> > load_video
> > insmod gzio
> > if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > linux   /vmlinuz-5.10.0-16-amd64 root=UUID=0123abcd ro  quiet
> > echo    'Loading initial ramdisk ...'
> > initrd  /initrd.img-5.10.0-16-amd64
> > }
> > submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option 
> > 'gnulinux-advanced-0123abcd' {
> > menuentry 'Debian GNU/Linux, with Linux 5.10.0-16-amd64' --class 
> > debian --class gnu-linux --class gnu --class os $menuentry_id_option 
> > 'gnulinux-5.10.0-16-amd64-advanced-0123abcd' {
> > load_video
> > insmod gzio
> > if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > linux   /vmlinuz-5.10.0-16-amd64 root=UUID=0123abcd ro  quiet
> > echo    'Loading initial ramdisk ...'
> > initrd  /initrd.img-5.10.0-16-amd64
> > }
> > menuentry 'Debian GNU/Linux, with Linux 5.10.0-16-amd64 (recovery 
> > mode)' --class debian --class gnu-linux --class gnu --class os 
> > $menuentry_id_option 'gnulinux-5.10.0-16-amd64-recovery-0123abcd' {
> > load_video
> > insmod gzio
> > if [ x$grub_platform = xxen ]; then insmod xzio; insmod lzopio; fi
> > insmod part_gpt
> > insmod ext2
> > if [ x$feature_platform_search_hint = xy ]; then
> > search --no-floppy --fs-uuid --set=root  0123abcd
> > else
> > search --no-floppy --fs-uuid --set=root 0123abcd
> > fi
> > echo    'Loading Linux 5.10.0-16-amd64 ...'
> > linux   /vmlinuz-5.10.0-16-amd64 root=UUID=0123abcd ro single
> > echo    'Loading initial ramdisk ...'
> > initrd  /initrd.img-5.10.0-16-amd64
> > }
> > }
> >
> > ### END /etc/grub.d/10_linux ###
> >
> > ### BEGIN /etc/grub.d/30_os-prober ###
> > ### END /etc/grub.d/30_os-prober ###
> >
> > ### BEGIN /etc/grub.d/30_uefi-firmware ###
> > menuentry 'System setup' $menuentry_id_option 'uefi-firmware' {
> > fwsetup
> > }
> > ### END /etc/grub.d/30_uefi-firmware ###
> >
> > ### BEGIN /etc/grub.d/40_custom ###
> > # This file provides an easy way to add custom menu entries.  Simply 
> > type the
> > # menu entries you want to add after this comment.  Be careful not to 
> > change
> > # the 'exec tail' line above.
> > ### END /etc/grub.d/40_custom ###
> >
> > ### BEGIN /etc/grub.d/41_custom ###
> > if [ -f  ${config_directory}/custom.cfg ]; then
> > source ${config_directory}/custom.cfg
> > elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
> > source $prefix/custom.cfg;
> > fi
> > ### END /etc/grub.d/41_custom ###
Regards,

Leigh.