CoCo VMs Will Now Panic If RdRand Is Broken in Linux 6.9

A significant change has been merged into the x86 fixes for Linux 6.9, requiring the seeding of RNG (Random Number Generation) with RdRand for CoCo (Confidential Computing) environments. The change focuses on CoCo virtual machines , designed to be as isolated as possible, assuming the VM host is untrusted. RdRand is critical as a hardware random number generator instruction for entropy to guest VMs. Security expert and WireGuard developer Jason Donenfeld authored this change.