[v3,00/28] accel/tcg: Introduce translator_use_goto_tb

Message

Richard Henderson July 8, 2021, 4:40 p.m. UTC

There are a number of inconsistencies with goto_tb usage, and I
plan to make changes in order to better support breakpoints.

(1) Testing CF_LAST_IO is a hold-over from since before ba3e7926691
    ("icount: clean up cpu_can_io at the entry to the block").
    Several targets still have this test.

(2) Testing singlestep is superfluous, as it doesn't mean anything
    besides limiting max_insns to 1.

(3) Not testing page crossing for CONFIG_USER_ONLY is wrong, because
    mmap and mprotect can change page permissions.  It's a very
    uncommon case wrt executables, but it's still wrong.

(4) Not testing page crossing for non-mmu targets (where page
    permissions literally cannot change) is not currently wrong,
    but will be after the breakpoint changes.

(5) When the TB does cross two pages, considering non-page crossing
    from the second page is not currently wrong, but will be after
    the breakpoint changes.

Changes for v3:
  * Adjust aarch32 ISB, SB change to simply set is_jmp.

Changes for v2:
  * Fix aarch32 ISB, SB insns vs single-stepping.
  * Drop use_goto_tb for aarch32
  * Retain use_goto_tb for aarch64.

Patches lacking review:
  05-target-arm-Use-DISAS_TOO_MANY-for-ISB-and-SB.patch


r~


Richard Henderson (28):
  accel/tcg: Introduce translator_use_goto_tb
  target/alpha: Remove use_exit_tb
  target/alpha: Remove in_superpage
  target/alpha: Use translator_use_goto_tb
  target/arm: Use DISAS_TOO_MANY for ISB and SB
  target/arm: Use translator_use_goto_tb for aarch64
  target/arm: Use translator_use_goto_tb for aarch32
  target/avr: Use translator_use_goto_tb
  target/avr: Mark some helpers noreturn
  target/cris: Use translator_use_goto_tb
  target/hppa: Use translator_use_goto_tb
  target/i386: Use translator_use_goto_tb
  target/m68k: Use translator_use_goto_tb
  target/microblaze: Use translator_use_goto_tb
  target/mips: Use translator_use_goto_tb
  target/mips: Fix missing else in gen_goto_tb
  target/nios2: Use translator_use_goto_tb
  target/openrisc: Use translator_use_goto_tb
  target/ppc: Use translator_use_goto_tb
  target/riscv: Use translator_use_goto_tb
  target/rx: Use translator_use_goto_tb
  target/s390x: Use translator_use_goto_tb
  target/s390x: Remove use_exit_tb
  target/sh4: Use translator_use_goto_tb
  target/sparc: Use translator_use_goto_tb
  target/tricore: Use translator_use_goto_tb
  target/tricore: Use tcg_gen_lookup_and_goto_ptr
  target/xtensa: Use translator_use_goto_tb

 include/exec/translator.h     | 10 ++++++++
 target/avr/helper.h           |  8 +++---
 accel/tcg/translator.c        | 11 +++++++++
 target/alpha/translate.c      | 46 ++++-------------------------------
 target/arm/translate-a64.c    | 25 ++++---------------
 target/arm/translate.c        | 16 +++---------
 target/avr/translate.c        |  9 ++++---
 target/cris/translate.c       |  5 ++--
 target/hppa/translate.c       |  5 +---
 target/i386/tcg/translate.c   | 14 ++---------
 target/m68k/translate.c       | 12 +--------
 target/microblaze/translate.c | 11 +--------
 target/mips/tcg/translate.c   | 20 +++------------
 target/nios2/translate.c      | 15 +-----------
 target/openrisc/translate.c   | 15 ++++++------
 target/ppc/translate.c        | 10 +-------
 target/riscv/translate.c      | 20 +--------------
 target/rx/translate.c         | 11 +--------
 target/s390x/translate.c      | 18 +++-----------
 target/sh4/translate.c        | 11 +++------
 target/sparc/translate.c      | 19 ++++-----------
 target/tricore/translate.c    | 20 +++------------
 target/xtensa/translate.c     |  6 +----
 23 files changed, 83 insertions(+), 254 deletions(-)