Re: [Xen-devel] pvgrub2 is merged

[Fabio Fantoni]

Il 27/11/2013 18:35, Andrey Borzenkov ha scritto:
> В Wed, 27 Nov 2013 17:24:53 +0100
> Fabio Fantoni <address@hidden> пишет:
>
> > Il 27/11/2013 17:03, Vladimir 'φ-coder/phcoder' Serbinenko ha scritto:
> > > On 27.11.2013 16:59, Fabio Fantoni wrote:
> > > > Il 27/11/2013 12:50, Vladimir 'φ-coder/phcoder' Serbinenko ha scritto:
> > > > > That pretty much explains what happened: you don't have any
> > > > > /boot/grub2/grub.cfg and when looking for /boot/grub/grub.cfg GRUB found
> > > > > its own memdisk and fell into recursion. I'm not sure what should be the
> > > > > proper way to solve this recursion.
> Yes, it was a bit naive on my side. Recursion in principle can be
> stopped by using global variable, but search is limited to the first
> match only anyway, so I guess it is not worth it.
>
> > > > Anyone know how to exclude memdisk from the search please?
> Please look in grub2 sources at docs/osdetect.cfg. It implements
> advanced run-time detection of possible bootable files from
> various operating systems. It boils down to loop across all devices,
> and of course you can either limit device names (like looking for hd*
> only) or explicitly exclude known ones (like memdisk).
>
> > Is it possible to specify a different default grub.cfg path (different
> > from all other distributions) changing this command:
> > ./grub-mkstandalone --grub-mkimage=./grub-mkimage -o pvgrub2.xen -O
> > x86_64-xen -d grub-core/ boot/grub/grub.cfg
> > Is it hardcoded as /boot/grub/grub.cfg for grub memdisk or can be set?
> Not really. Currently the situation is
>
> - grub-mkstandalone hardcodes $prefix as (memdisk)/boot/grub
> - after launch grub unconditionally starts "normal" module if at all
>    possible
> - normal module always tries to load and execute $prefix/grub.cfg if no
>    explicit configuration file name is given as argument
>
> But I think that using osdetect.cfg or something based on this idea
> won't require changing defaults at all.

Thanks for your reply.

I did this script that is working about finding and include the grub.cfg 
of pv domUs with many cases:

cat > boot/grub/grub.cfg <<EOF
insmod lvm
insmod ext2
insmod part_msdos
insmod part_gpt
insmod btrfs

insmod regexp
for dev in (*); do
    # $device: parenthesis removed from $dev
    regexp -s device '\((.*)\)' $dev
    set root=$device
    for file in /boot/vmlinuz-* /boot/linux-*; do
        if test -f $file; then
            set saved_root=$root
        fi
    done
done
set root=$saved_root

if test -f /boot/grub2/grub.cfg ; then
    configfile /boot/grub2/grub.cfg
elif test -f /boot/grub/grub.cfg ; then
    configfile /boot/grub/grub.cfg
fi
EOF

@xen developer: Are there other modules to insert for other partitions 
or file systems, other grub cfg path for other distributions or other 
kernel type to search that support xen pv domUs?
I think is good do and post complete pvgrub2 cfg that support all pv domUs.

@xen and grub developer: I'm still unable to boot any entry of Sid pv 
domU using official kernel:
xl -vvv create -c /etc/xen/sid.cfg
...
Caricamento Linux 3.11-1-amd64...
Caricamento ramdisk iniziale...
xc: debug: hypercall buffer: total allocations:247 total releases:247
xc: debug: hypercall buffer: current allocations:0 maximum allocations:4
xc: debug: hypercall buffer: cache current size:4
xc: debug: hypercall buffer: cache hits:236 misses:4 toobig:7

Any ideas?

If you need more tests/informations tell me and I'll post them.

Thanks for any reply.