Erm, check out Wikipedia https://en.wikipedia.org/wiki/Meltdown_(security_vulnerabili... and follow the links? Meltdown is CVE-2017-5754, see: https://developer.arm.com/support/arm-security-updates/specu... where as I recall ARM initially described the Cortex-A75 as having a "variant", but now just lumps it in with the CVE. And the IBM info is also there, POWER7+ through POWER9, and per Red Hat, mainframe/System Z.