Gentoo Linux: Docker container doesn't start: cgroup v2

I've the issue that my Gentoo system (Kernel 5.4.97) docker container do not start.

I tried following command:

docker run kubler/mariadb

The error message is:

docker: Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "process_linux.go:449: container init caused \"process_linux.go:415: setting cgroup config for procHooks process caused \\\"error while setting cgroup v2: [failed to load program: function not implemented]\\\"\"": unknown. ERRO[0000] error waiting for container: context canceled

docker daemon is active (systemd)

Kernel: 5.4.97

When I execute the docker check script I get this output

warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /boot/config-5.4.97-gentoo ...

Generally Necessary:
- cgroup hierarchy: cgroupv2
- CONFIG_NAMESPACES: enabled
- CONFIG_NET_NS: enabled
- CONFIG_PID_NS: enabled
- CONFIG_IPC_NS: enabled
- CONFIG_UTS_NS: enabled
- CONFIG_CGROUPS: enabled
- CONFIG_CGROUP_CPUACCT: enabled
- CONFIG_CGROUP_DEVICE: enabled
- CONFIG_CGROUP_FREEZER: enabled
- CONFIG_CGROUP_SCHED: enabled
- CONFIG_CPUSETS: enabled
- CONFIG_MEMCG: enabled
- CONFIG_KEYS: enabled
- CONFIG_VETH: enabled
- CONFIG_BRIDGE: enabled
- CONFIG_BRIDGE_NETFILTER: enabled (as module)
- CONFIG_IP_NF_FILTER: enabled
- CONFIG_IP_NF_TARGET_MASQUERADE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_ADDRTYPE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_CONNTRACK: enabled
- CONFIG_NETFILTER_XT_MATCH_IPVS: missing
- CONFIG_NETFILTER_XT_MARK: enabled (as module)
- CONFIG_IP_NF_NAT: enabled (as module)
- CONFIG_NF_NAT: enabled
- CONFIG_POSIX_MQUEUE: enabled

Optional Features:
- CONFIG_USER_NS: enabled
- CONFIG_SECCOMP: enabled
- CONFIG_CGROUP_PIDS: enabled
- CONFIG_MEMCG_SWAP: enabled
- CONFIG_MEMCG_SWAP_ENABLED: enabled
- CONFIG_BLK_CGROUP: enabled
- CONFIG_BLK_DEV_THROTTLING: enabled
- CONFIG_CGROUP_PERF: enabled
- CONFIG_CGROUP_HUGETLB: enabled
- CONFIG_NET_CLS_CGROUP: enabled
- CONFIG_CGROUP_NET_PRIO: enabled
- CONFIG_CFS_BANDWIDTH: missing
- CONFIG_FAIR_GROUP_SCHED: enabled
- CONFIG_RT_GROUP_SCHED: missing
- CONFIG_IP_NF_TARGET_REDIRECT: missing
- CONFIG_IP_VS: enabled
- CONFIG_IP_VS_NFCT: missing
- CONFIG_IP_VS_PROTO_TCP: missing
- CONFIG_IP_VS_PROTO_UDP: missing
- CONFIG_IP_VS_RR: missing
- CONFIG_EXT4_FS: enabled
- CONFIG_EXT4_FS_POSIX_ACL: enabled
- CONFIG_EXT4_FS_SECURITY: enabled
- Network Drivers:
- "overlay":
- CONFIG_VXLAN: missing
- CONFIG_BRIDGE_VLAN_FILTERING: missing
Optional (for encrypted networks):
- CONFIG_CRYPTO: enabled
- CONFIG_CRYPTO_AEAD: enabled
- CONFIG_CRYPTO_GCM: enabled
- CONFIG_CRYPTO_SEQIV: enabled
- CONFIG_CRYPTO_GHASH: enabled
- CONFIG_XFRM: enabled
- CONFIG_XFRM_USER: enabled
- CONFIG_XFRM_ALGO: enabled
- CONFIG_INET_ESP: missing
- "ipvlan":
- CONFIG_IPVLAN: missing
- "macvlan":
- CONFIG_MACVLAN: missing
- CONFIG_DUMMY: missing
- "ftp,tftp client in container":
- CONFIG_NF_NAT_FTP: enabled
- CONFIG_NF_CONNTRACK_FTP: enabled
- CONFIG_NF_NAT_TFTP: missing
- CONFIG_NF_CONNTRACK_TFTP: missing
- Storage Drivers:
- "aufs":
- CONFIG_AUFS_FS: missing
- "btrfs":
- CONFIG_BTRFS_FS: enabled
- CONFIG_BTRFS_FS_POSIX_ACL: enabled
- "devicemapper":
- CONFIG_BLK_DEV_DM: enabled
- CONFIG_DM_THIN_PROVISIONING: missing
- "overlay":
- CONFIG_OVERLAY_FS: enabled
- "zfs":
- /dev/zfs: missing
- zfs command: missing
- zpool command: missing

Limits:
- /proc/sys/kernel/keys/root_maxkeys: 1000000

There are settings as "MISSING" declared that leads to some problems:

CONFIG_NETFILTER_XT_MATCH_IPVS This option is not present in the kernel config
CONFIG_RT_GROUP_SCHED: When I enable this option the system does not start anymore. Is hangs after the last message ("[OK] terminate plymouth..."). No login prompt and no sddm

The Docker Gentoo-Wiki page does not match my kernel version. The Wiki page says that CFQ IO Scheduler should be enabled, but I do not have this option in my kernel config (there is BFQ instead)

I tried with the kernel boot option "systemd.unified_cgroup_hierarchy=0" and "systemd.unified_cgroup_hierarchy=1" as well. But nothing helped.

Solution

The required options will show as "green" when you have compiled the kernel with required options (and dependencies of those options)

$ curl -L https://github.com/moby/moby/raw/master/contrib/check-config.sh | bash | sed -n -e 1,10p -e /CONFIG_NETFILTER/p -e /CONFIG_RT_GROUP/p
warning: /proc/config.gz does not exist, searching other paths for kernel config ...
info: reading kernel config from /usr/src/linux/.config ...

Generally Necessary:
- cgroup hierarchy: properly mounted [/sys/fs/cgroup]
- CONFIG_NAMESPACES: enabled
- CONFIG_NET_NS: enabled
- CONFIG_PID_NS: enabled
- CONFIG_IPC_NS: enabled
- CONFIG_UTS_NS: enabled
- CONFIG_CGROUPS: enabled
- CONFIG_NETFILTER_XT_MATCH_ADDRTYPE: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_CONNTRACK: enabled (as module)
- CONFIG_NETFILTER_XT_MATCH_IPVS: enabled (as module)
- CONFIG_NETFILTER_XT_MARK: enabled (as module)
- CONFIG_RT_GROUP_SCHED: enabled