Building xen-image-minmal for raspberrypi3-64: kernel-module-xen-* not being built

Building xen-image-minmal for raspberrypi3-64: kernel-module-xen-* not being built

[aljoscha.lautenbach]

Hi,

I am trying to build xen-image-minimal for a raspberrypi 3 B+, using
the official meta-virtualization [1] and meta-raspberrypi [2] layers
of the warrior branch.
For the record, core-image-base builds and boots fine with the
described setup (build config: [3]).
I should also add that I am new to yocto, so it is entirely possible
that I am missing something obvious.

When I try to build xen-image-minimal (build config: [4]), the
compilation seems to work, but I get the following error during the
final do_rootfs:

E: Unable to locate package kernel-module-xen-blkback
E: Unable to locate package kernel-module-xen-gntalloc
E: Unable to locate package kernel-module-xen-gntdev
E: Unable to locate package kernel-module-xen-netback
E: Unable to locate package kernel-module-xen-wdt

Relevant bits of local.conf: [5]
Build log: [6]

Out of curiosity I tried to build the image without those kernel
modules by removing them from IMAGE_INSTALL in xen-image-minimal.bb,
but although it builds the resulting image does not boot.

I have also tried to build with and without "virtualization" in
DISTRO_FEATURES, same result.

There is a related post on this mailing list from ~1.5 years ago
regarding a xilinx board [7]. Unfortunately I do not fully understand
the implications of the answer or what I would need to change.

The xen.cfg in meta-virtualization/recipes-kernel/linux/linux-yocto/xen.cfg
matches the one mentioned in that mailing list post almost one to one,
only that the meta-virtualization has 4 additional entries:
CONFIG_XEN_PVH=y
CONFIG_XEN_EFI=y
CONFIG_XEN_AUTO_XLATE=y
CONFIG_XEN_ACPI=y

I also tracked down the corresponding KCONFIG entry in
meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi.inc:
KCONFIG_MODE = "--alldefconfig"

I noted that, given my current understanding, this overrides all
previous configurations, so I tried the following variations, but they
all had the same outcome:
KCONFIG_MODE ?= "alldefconfig"
KCONFIG_MODE += "--alldefconfig"
KCONFIG_MODE = "alldefconfig"

I have been stuck on this for several days and I cannot figure out why
the expected xen kernel modules are not being built; any pointers
would be greatly appreciated!

[1] https://git.yoctoproject.org/git/meta-virtualization
[2] http://git.yoctoproject.org/cgit/cgit.cgi/meta-raspberrypi
[3] https://pastebin.com/nuC2EyjN
[4] https://pastebin.com/h9EijwPY
[5] https://pastebin.com/PqGFBfHy
[6] https://pastebin.com/n8H5UKj6
[7] https://www.yoctoproject.org/pipermail/meta-virtualization/2018-September/003698.html

Thanks,
Aljoscha