bonziniIBM Announces Strategic Collaboration with Arm
Ah, that explains this patchset that was submitted to the Linux kernel today
"KVM: s390: Introduce arm64 KVM"
"By introducing a novel virtualization acceleration for the ARM architecture on
s390 architecture, we aim to expand the platform's software ecosystem. This
initial patch series lays the groundwork by enabling KVM-accelerated ARM CPU
virtualization on s390....."
https://patchwork.kernel.org/project/linux-arm-kernel/cover/...
Oh that's a weird way to do it; they used to have an x86 add on block for mainframes which was just a pile of x86 blades with some integration.