[PATCH 0/3] powerpc/kvm: Enable HV KVM guests to use prefixed instructions to access emulated MMIO

Paul Mackerras
2023-03-08T06:36:34Z

This series changes the powerpc KVM code so that HV KVM can fetch
prefixed instructions from the guest in those situations where there
is a need to emulate an instruction, which for HV KVM means emulating
loads and stores to emulated MMIO devices. (Prefixed instructions
were introduced with POWER10 and Power ISA v3.1, and consist of two
32-bit words, called the prefix and the suffix.)

The instruction analysis code in arch/powerpc/lib/sstep.c has already
been extended to handle prefixed loads and stores, so all we have to
do in HV KVM is to fetch the suffix when necessary and pass it to
analyse_instr().

Since PR KVM doesn't yet handle prefixed instructions, we disable PR
KVM guests from using prefixed instructions (this is done using the
FSCR).

Paul.

arch/powerpc/include/asm/kvm_host.h | 4 ++--
arch/powerpc/include/asm/kvm_ppc.h | 37 +++++++++++++++++++++++---------
arch/powerpc/include/asm/reg.h | 1 +
arch/powerpc/kvm/book3s.c | 32 ++++++++++++++++++++++-----
arch/powerpc/kvm/book3s_64_mmu_hv.c | 26 ++++++++++++++++------
arch/powerpc/kvm/book3s_hv.c | 24 ++++++++++++++-------
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 6 +++---
arch/powerpc/kvm/book3s_paired_singles.c | 4 +++-
arch/powerpc/kvm/book3s_pr.c | 22 ++++++++++---------
arch/powerpc/kvm/book3s_rmhandlers.S | 1 +
arch/powerpc/kvm/booke.c | 12 +++++++----
arch/powerpc/kvm/bookehv_interrupts.S | 2 +-
arch/powerpc/kvm/e500_mmu_host.c | 4 ++--
arch/powerpc/kvm/emulate.c | 8 ++++++-
arch/powerpc/kvm/emulate_loadstore.c | 8 +++----
arch/powerpc/kvm/powerpc.c | 4 ++--
16 files changed, 136 insertions(+), 59 deletions(-)