[PATCH v3 0/7] iOS and Apple Silicon host support

[Joelle van Dyne <j@getutm.app>]

Based-on: 20201026191540.12434-1-j@getutm.app
([PATCH RESEND 0/4] Mirror map JIT memory for TCG)

These set of changes brings QEMU TCG to iOS devices and future Apple Silicon
devices. They were originally developed last year and have been working in the
UTM app. Recently, we ported the changes to master, re-wrote a lot of the build
script changes for meson, and broke up the patches into more distinct units.

A summary of the changes:

* `CONFIG_IOS` defined when building for iOS and iOS specific changes (as well
  as unsupported code) are gated behind it.
* A new dependency, libucontext is added since iOS does not have native ucontext
  and broken support for sigaltstack. libucontext is available as a new option
  for coroutine backend.
* On stock iOS devices, there is a workaround for running JIT code without
  any special entitlement. It requires the JIT region to be mirror mapped with
  one region RW and another one RX. To support this style of JIT, TCG is changed
  to support writing to a different code_ptr. This change is submitted in a
  different patch set and this one depends on it.
* For (recent) jailbroken iOS devices as well as upcoming Apple Silicon devices,
  there are new rules for applications supporting JIT (with the proper
  entitlement). These rules are implemented as well.

Since v3:

* Moved mirror JIT support to a different patch set.
* Removed dependency on `pthread_jit_write_protect_np` because it was redundent
  and also crashes if called on a non-jailbroken iOS device.
* Removed `--enable-cross-compile` option
* Fixed checkpatch errors
* Fixed iOS build on master due to new test recently added which calls system()

Since v2:

* Changed getting mirror pointer from a macro to inline functions
* Split constification of TCG code pointers to separate patch
* Removed slirp updates (will send future patch once slirp changes are in)
* Removed shared library patch (will send future patch)

-j

Joelle van Dyne (7):
  configure: option to disable host block devices
  configure: cross-compiling with empty cross_prefix
  qemu: add support for iOS host
  coroutine: add libucontext as external library
  slirp: update build flags for iOS resolv fix
  tcg: implement JIT for iOS and Apple Silicon
  block: check availablity for preadv/pwritev on mac

 docs/devel/index.rst           |   1 +
 docs/devel/ios.rst             |  39 ++++++++++++
 configure                      |  77 ++++++++++++++++++++++--
 meson.build                    |  34 ++++++++++-
 include/exec/exec-all.h        |   2 +
 include/tcg/tcg-apple-jit.h    | 106 +++++++++++++++++++++++++++++++++
 include/tcg/tcg.h              |   3 +
 tcg/aarch64/tcg-target.h       |   7 +++
 accel/tcg/cpu-exec-common.c    |   2 +
 accel/tcg/cpu-exec.c           |   2 +
 accel/tcg/translate-all.c      |  87 ++++++++++++++++++++++++++-
 block.c                        |   2 +-
 block/file-posix.c             |  51 ++++++++++++----
 net/slirp.c                    |  16 ++---
 qga/commands-posix.c           |   6 ++
 target/arm/arm-semi.c          |   2 +
 target/m68k/m68k-semi.c        |   2 +
 target/nios2/nios2-semi.c      |   2 +
 tcg/tcg.c                      |   4 ++
 tests/qtest/libqos/virtio-9p.c |   8 +++
 util/coroutine-ucontext.c      |   9 +++
 .gitmodules                    |   3 +
 libucontext                    |   1 +
 meson_options.txt              |   2 +
 tests/qtest/meson.build        |   7 +--
 25 files changed, 440 insertions(+), 35 deletions(-)
 create mode 100644 docs/devel/ios.rst
 create mode 100644 include/tcg/tcg-apple-jit.h
 create mode 160000 libucontext

-- 
2.28.0