[RFC,v1,0/2] Allow the RAS feature bit in ID_AA64PFR0_EL1 writable from userspace

Message

Shaoqin Huang Sept. 26, 2024, 3:22 a.m. UTC

Currently the RAS feature bit is not writable in ID_AA64PFR0EL1, this makes
migration fail when migration from the machine which RAS is 1 to another machine
which RAS is 2.

Allow RAS writable from userspace would make the migration possible between two
machines which RAS is different.

Shaoqin Huang (2):
  KVM: arm64: Use kvm_has_feat() to check if FEAT_RAS is advertised to
    the guest
  KVM: arm64: Allow the RAS feature bit in ID_AA64PFR0_EL1 writable from
    userspace

 arch/arm64/kvm/guest.c                            | 4 ++--
 arch/arm64/kvm/handle_exit.c                      | 2 +-
 arch/arm64/kvm/hyp/include/hyp/switch.h           | 2 +-
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h        | 7 +++++--
 arch/arm64/kvm/sys_regs.c                         | 3 +--
 tools/testing/selftests/kvm/aarch64/set_id_regs.c | 1 +
 6 files changed, 11 insertions(+), 8 deletions(-)