kvm kernel missing nvme block support

[Luqman]

The KVM flavour kernel is missing NVMe block support. This means one can't boot the minimal cloud images off an (emulated) nvme drive (as supported in qemu and other VMMs).

root@ubuntu:~# modprobe nvme
modprobe: FATAL: Module nvme not found in directory /lib/modules/5.15.0-1048-kvm

Seems like CONFIG_BLK_DEV_NVME should be set, compare linux-kvm vs linux-gcp:

debian.kvm/config/amd64/config.flavour.kvm:
...
#
# NVME Support
#
CONFIG_NVME_CORE=m
# CONFIG_BLK_DEV_NVME is not set
CONFIG_NVME_MULTIPATH=y
CONFIG_NVME_FABRICS=m
# CONFIG_NVME_FC is not set
CONFIG_NVME_TCP=m
# CONFIG_NVME_TARGET is not set
# end of NVME Support
...

debian.gcp/config/amd64/config.flavour.gcp:
...
# NVME Support
#
CONFIG_NVME_CORE=y
CONFIG_BLK_DEV_NVME=y
CONFIG_NVME_MULTIPATH=y
CONFIG_NVME_FABRICS=m
CONFIG_NVME_RDMA=m
CONFIG_NVME_FC=m
CONFIG_NVME_TCP=m
CONFIG_NVME_TARGET=m
CONFIG_NVME_TARGET_LOOP=m
CONFIG_NVME_TARGET_RDMA=m
CONFIG_NVME_TARGET_FC=m
# CONFIG_NVME_TARGET_FCLOOP is not set
CONFIG_NVME_TARGET_TCP=m
# end of NVME Support
...

root@ubuntu:~# uname -a
Linux ubuntu 5.15.0-1048-kvm #53-Ubuntu SMP Sun Nov 19 15:56:32 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux
root@ubuntu:~# apt-cache policy linux-kvm
linux-kvm:
  Installed: 5.15.0.1048.44
  Candidate: 5.15.0.1048.44
  Version table:
 *** 5.15.0.1048.44 100
        100 /var/lib/dpkg/status

root@ubuntu:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.3 LTS
Release: 22.04
Codename: jammy