[0/3] Emulate MRS instructions by parsing ESR_ELx.ISS

Message

Anshuman Khandual Sept. 19, 2018, 3:34 a.m. UTC

Armv8.4-A extension enables MRS instruction encodings inside ESR_ELx.ISS
during exception class ESR_ELx_EC_SYS64 (0x18). This encoding can be used
to emulate MRS instructions which can avoid fetch/decode from user space
thus improving performance. The patch series here enables this new method
of emulating MRS instruction. For this purpose we factorizes the existing
emulate_mrs() function and while here, add new macro ESR_ELx_SYS64_ISS_RT.

Anshuman Khandual (3):
  arm64/cpufeatures: Introduce ESR_ELx_SYS64_ISS_RT()
  arm64/cpufeatures: Factorize emulate_mrs()
  arm64/cpufeatures: Emulate MRS instructions by parsing ESR_ELx.ISS

 arch/arm64/include/asm/cpufeature.h  |  1 +
 arch/arm64/include/asm/esr.h         | 14 ++++++++++++++
 arch/arm64/include/asm/kvm_emulate.h |  2 +-
 arch/arm64/kernel/cpufeature.c       | 23 ++++++++++++++---------
 arch/arm64/kernel/traps.c            | 25 +++++++++++++++++++++----
 5 files changed, 51 insertions(+), 14 deletions(-)