papr-pef.txt (1052B)
1POWER (PAPR) Protected Execution Facility (PEF) 2=============================================== 3 4Protected Execution Facility (PEF), also known as Secure Guest support 5is a feature found on IBM POWER9 and POWER10 processors. 6 7If a suitable firmware including an Ultravisor is installed, it adds 8an extra memory protection mode to the CPU. The ultravisor manages a 9pool of secure memory which cannot be accessed by the hypervisor. 10 11When this feature is enabled in QEMU, a guest can use ultracalls to 12enter "secure mode". This transfers most of its memory to secure 13memory, where it cannot be eavesdropped by a compromised hypervisor. 14 15Launching 16--------- 17 18To launch a guest which will be permitted to enter PEF secure mode: 19 20# ${QEMU} \ 21 -object pef-guest,id=pef0 \ 22 -machine confidential-guest-support=pef0 \ 23 ... 24 25Live Migration 26---------------- 27 28Live migration is not yet implemented for PEF guests. For 29consistency, we currently prevent migration if the PEF feature is 30enabled, whether or not the guest has actually entered secure mode.