[PATCH 0/4] Mirror map JIT memory for TCG

[Joelle van Dyne]

To aid in debugging TCG, we enable a "mirror map" feature that, when enabled,
will use memfd_create() to create two mappings of the same memory for RW and RX.
The feature is only built when targeting system emulation on Linux and
configured with --enable-debug-tcg. It can be disabled with the runtime argument
`-accel tcg,mirror-jit=off`.

Although this patch only enables this feature for Linux, the main goal of this
is to enable, through a future patch, iOS JIT on older devices which require
strict W^X separation.

-j

Joelle van Dyne (4):
  tcg: add const hints for code pointers
  tcg: implement mirror mapped JIT for Linux
  tcg: use mirror map JIT in code generation
  tcg: make mirror mapped JIT optional

 configure                    |  13 +++++
 meson.build                  |   1 +
 include/exec/exec-all.h      |   8 +++
 include/sysemu/tcg.h         |   2 +-
 include/tcg/tcg.h            |  26 +++++++--
 tcg/aarch64/tcg-target.h     |  18 +++++-
 tcg/arm/tcg-target.h         |  15 ++++-
 tcg/i386/tcg-target.h        |  26 ++++++++-
 tcg/mips/tcg-target.h        |  12 +++-
 tcg/ppc/tcg-target.h         |  12 +++-
 tcg/riscv/tcg-target.h       |  13 ++++-
 tcg/s390/tcg-target.h        |  17 +++++-
 tcg/sparc/tcg-target.h       |  12 +++-
 tcg/tci/tcg-target.h         |   9 ++-
 accel/tcg/cpu-exec.c         |   7 ++-
 accel/tcg/tcg-all.c          |  31 +++++++++-
 accel/tcg/translate-all.c    | 106 +++++++++++++++++++++++++++++------
 bsd-user/main.c              |   2 +-
 linux-user/main.c            |   2 +-
 tcg/tcg.c                    |  60 +++++++++++++-------
 qemu-options.hx              |  11 ++++
 tcg/aarch64/tcg-target.c.inc |  48 +++++++++-------
 tcg/arm/tcg-target.c.inc     |  33 ++++++-----
 tcg/i386/tcg-target.c.inc    |  28 ++++-----
 tcg/mips/tcg-target.c.inc    |  64 ++++++++++++---------
 tcg/ppc/tcg-target.c.inc     |  57 ++++++++++++-------
 tcg/riscv/tcg-target.c.inc   |  51 +++++++++--------
 tcg/s390/tcg-target.c.inc    |  25 +++++----
 tcg/sparc/tcg-target.c.inc   |  33 ++++++-----
 tcg/tcg-ldst.c.inc           |   2 +-
 tcg/tcg-pool.c.inc           |   9 +--
 tcg/tci/tcg-target.c.inc     |   8 +--
 32 files changed, 555 insertions(+), 206 deletions(-)

-- 
2.28.0