[PATCH 00/10] iOS and Apple Silicon host support

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

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` and `CONFIG_IOS_JIT` defined when building for iOS and
  iOS specific changes (as well as unsupported code) are gated behind it.
* slirp updated to support DNS resolving using libresolv; a separate patch will
  be submitted to the project. To allow for builds to succeed, the .gitmodule
  is temporarily changed. We're not entirely sure how cross-project patches
  should be handled here.
* 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. These changes are gated by the
  `CONFIG_IOS_JIT`.
* 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.
* An option to build QEMU as a shared library is added because iOS does not
  support fork().

These patches are also on Github:
  https://github.com/utmapp/qemu/tree/ios-support-master

-j

osy (10):
  configure: option to disable host block devices
  configure: cross-compiling without cross_prefix
  qemu: add support for iOS host
  meson: option to build as shared library
  slirp: update for iOS resolv fix
  coroutine: add libucontext as external library
  tcg: implement bulletproof JIT
  tcg: mirror mapping RWX pages for iOS optional
  tcg: support JIT on Apple Silicon
  block: check availablity for preadv/pwritev on mac

 .gitmodules                  |   5 +-
 accel/tcg/cpu-exec-common.c  |   2 +
 accel/tcg/cpu-exec.c         |   9 +-
 accel/tcg/tcg-all.c          |  27 +++++-
 accel/tcg/translate-all.c    | 169 ++++++++++++++++++++++++++++++++---
 block.c                      |   2 +-
 block/file-posix.c           |  50 ++++++++---
 bsd-user/main.c              |   2 +-
 configure                    | 118 ++++++++++++++++++++++--
 docs/devel/ios.rst           |  40 +++++++++
 include/exec/exec-all.h      |  10 +++
 include/sysemu/tcg.h         |   2 +-
 include/tcg/tcg-apple-jit.h  |  85 ++++++++++++++++++
 include/tcg/tcg.h            |  21 ++++-
 libucontext                  |   1 +
 linux-user/main.c            |   2 +-
 meson.build                  |  74 +++++++++++++--
 meson_options.txt            |   4 +
 net/slirp.c                  |  16 ++--
 qemu-options.hx              |  11 +++
 qga/commands-posix.c         |   6 ++
 slirp                        |   2 +-
 target/arm/arm-semi.c        |   2 +
 target/m68k/m68k-semi.c      |   2 +
 target/nios2/nios2-semi.c    |   2 +
 tcg/aarch64/tcg-target.c.inc |  48 ++++++----
 tcg/aarch64/tcg-target.h     |  23 ++++-
 tcg/arm/tcg-target.c.inc     |  33 ++++---
 tcg/arm/tcg-target.h         |   9 +-
 tcg/i386/tcg-target.c.inc    |  28 +++---
 tcg/i386/tcg-target.h        |  24 ++++-
 tcg/mips/tcg-target.c.inc    |  64 +++++++------
 tcg/mips/tcg-target.h        |   8 +-
 tcg/ppc/tcg-target.c.inc     |  55 +++++++-----
 tcg/ppc/tcg-target.h         |   8 +-
 tcg/riscv/tcg-target.c.inc   |  51 ++++++-----
 tcg/riscv/tcg-target.h       |   9 +-
 tcg/s390/tcg-target.c.inc    |  25 +++---
 tcg/s390/tcg-target.h        |  13 ++-
 tcg/sparc/tcg-target.c.inc   |  33 ++++---
 tcg/sparc/tcg-target.h       |   8 +-
 tcg/tcg-ldst.c.inc           |   2 +-
 tcg/tcg-pool.c.inc           |   9 +-
 tcg/tcg.c                    |  64 ++++++++-----
 tcg/tci/tcg-target.c.inc     |   8 +-
 tcg/tci/tcg-target.h         |   9 +-
 tests/qtest/meson.build      |   7 +-
 util/coroutine-ucontext.c    |   9 ++
 48 files changed, 965 insertions(+), 246 deletions(-)
 create mode 100644 docs/devel/ios.rst
 create mode 100644 include/tcg/tcg-apple-jit.h
 create mode 160000 libucontext

-- 
2.24.3 (Apple Git-128)