The more I looked into system call emulation, the harder it seems to get. Second proposal is remove it entirely because it's already broken, and just boot-time restrict SCV support if we run with PR possible, in hash mode, on pseries. Unfortunately that catches Power9 PowerVM, but at least OpenPOWER and Power10 by default is okay.
We probably have to do this as a minimal backport at first even if we did later decide we need to fix things in a better way because it looks like it would take a lot of work. Any comments? mpe helped with looking at the tracing logic and history of the code (thanks) but any mistakes are mine, Naveen are we on the right track here? Thanks, Nick Nicholas Piggin (2): powerpc/64: remove system call instruction emulation KVM: PPC: Book3S PR: Disable SCV when running AIL is disabled arch/powerpc/kernel/exceptions-64s.S | 4 ++++ arch/powerpc/kernel/setup_64.c | 15 ++++++++++++ arch/powerpc/kvm/book3s_pr.c | 20 +++++++++++----- arch/powerpc/lib/sstep.c | 36 ---------------------------- 4 files changed, 33 insertions(+), 42 deletions(-) -- 2.23.0
