Enable config requirements for IDM ivshmem + virtio-vsock transport

[sveith]

For KVM, we currently have a prototype IDM implementation running over
virtio-console. Due to performance issues, we might replace it with an
implementation based on ivshmem + virtio-vsock.

Enable the kernel options that have been found to be necessary for this
implementation.

Suggested-by: Steven Noonan steven@edera.dev
Signed-off-by: Simon Veith simon@edera.dev

Testing

Confirmed that the configuration options ended up enabled in the .config file for a local v6.18 kernel build.

x86

[linux-kernel-oci]$ cp configs/x86_64/zone.config ~/linux/.config
[linux-kernel-oci]$ cd ~/linux
[linux]$ git checkout v6.18.23
HEAD is now at 47a33eea6d51 Linux 6.18.23
[linux]$ make -j12 olddefconfig
.config:2379:warning: override: reassigning to symbol MLX4_EN
.config:2380:warning: override: reassigning to symbol MLX5_CORE
.config:2381:warning: override: reassigning to symbol MLX5_CORE_EN
.config:2390:warning: override: reassigning to symbol IAVF
.config:2391:warning: override: reassigning to symbol I40E
.config:2392:warning: override: reassigning to symbol I40EVF
.config:2399:warning: override: reassigning to symbol DEBUG_INFO_NONE
#
# configuration written to .config
#
[linux]$ grep -e '^CONFIG_VFIO=y' -e '^CONFIG_VFIO_PCI=y' -e '^CONFIG_VIRTIO_IOMMU=y' -e '^CONFIG_VIRTIO_VFIO_PCI=y' -e '^CONFIG_VSOCKETS=y' -e ^CNFIG_VIRTIO_VSOCKETS' 
[linux]$ grep CONFIG_VFIO CONFIG_VFIO_PCI CONFIG_VIRTIO_IOMMU CONFIG_VIRTIO_VFIO_PCI CONFIG_VSOCKETS CONFIG_VIRTIO_VSOCKETS ^C
[linux]$ grep -e CONFIG_VFIO -e CONFIG_VFIO_PCI -e CONFIG_VIRTIO_IOMMU -e CONFIG_VIRTIO_VFIO_PCI -e CONFIG_VSOCKETS -e CONFIG_VIRTIO_VSOCKETS .config
CONFIG_VSOCKETS=y
CONFIG_VSOCKETS_DIAG=y
CONFIG_VSOCKETS_LOOPBACK=y
CONFIG_VIRTIO_VSOCKETS=y
CONFIG_VIRTIO_VSOCKETS_COMMON=y
CONFIG_VFIO=y
CONFIG_VFIO_GROUP=y
CONFIG_VFIO_CONTAINER=y
CONFIG_VFIO_IOMMU_TYPE1=y
# CONFIG_VFIO_NOIOMMU is not set
CONFIG_VFIO_VIRQFD=y
# CONFIG_VFIO_DEBUGFS is not set
CONFIG_VFIO_PCI_CORE=y
CONFIG_VFIO_PCI_INTX=y
CONFIG_VFIO_PCI=y
# CONFIG_VFIO_PCI_VGA is not set
CONFIG_VFIO_PCI_IGD=y
CONFIG_VIRTIO_VFIO_PCI=y
CONFIG_VIRTIO_VFIO_PCI_ADMIN_LEGACY=y
CONFIG_VIRTIO_IOMMU=y

aarch64

[linux-kernel-oci]$ cp configs/aarch64/zone.config ~/linux/.config
[linux-kernel-oci]$ cd ~/linux
[linux]$ git checkout v6.18.23
HEAD is now at 47a33eea6d51 Linux 6.18.23
[linux]$ make -j12 olddefconfig
.config:102:warning: override: reassigning to symbol NET_ACT_BPF
.config:151:warning: override: reassigning to symbol CGROUPS
.config:597:warning: symbol value '0' invalid for BASE_SMALL
.config:974:warning: override: reassigning to symbol NET_CLS_ACT
.config:1095:warning: override: reassigning to symbol FW_LOADER_COMPRESS
.config:1096:warning: override: reassigning to symbol FW_LOADER_COMPRESS_XZ
.config:1690:warning: override: reassigning to symbol GENERIC_PCI_IOMAP
.config:1846:warning: override: reassigning to symbol SCHEDSTATS
.config:1892:warning: override: reassigning to symbol DEBUG_INFO
.config:1896:warning: override: reassigning to symbol DEBUG_INFO_NONE
#
# configuration written to .config
#
[linux]$ grep -e CONFIG_VFIO -e CONFIG_VFIO_PCI -e CONFIG_VIRTIO_IOMMU -e CONFIG_VIRTIO_VFIO_PCI -e CONFIG_VSOCKETS -e CONFIG_VIRTIO_VSOCKETS .config
CONFIG_VSOCKETS=y
CONFIG_VSOCKETS_DIAG=y
CONFIG_VSOCKETS_LOOPBACK=y
CONFIG_VIRTIO_VSOCKETS=y
CONFIG_VIRTIO_VSOCKETS_COMMON=y
CONFIG_VFIO=y
CONFIG_VFIO_GROUP=y
CONFIG_VFIO_CONTAINER=y
CONFIG_VFIO_IOMMU_TYPE1=y
# CONFIG_VFIO_NOIOMMU is not set
CONFIG_VFIO_VIRQFD=y
CONFIG_VFIO_PCI_CORE=y
CONFIG_VFIO_PCI_INTX=y
CONFIG_VFIO_PCI=y
# CONFIG_VFIO_PCI_VGA is not set
CONFIG_VFIO_PCI_IGD=y
CONFIG_VIRTIO_VFIO_PCI=y
CONFIG_VIRTIO_VFIO_PCI_ADMIN_LEGACY=y
CONFIG_VIRTIO_IOMMU=y