[RFC PATCH 0/3] Deprecate the qemu-system-i386 binary

[Thomas Huth <thuth@redhat.com>]

Allow running qemu-system-x86_64 in 32-bit-only mode (by renaming
or symlinking the binary to "qemu-system-i386"). After doing this,
qemu-system-x86_64 should be a proper superset of qemu-system-i386
(apart from 32-bit KVM support, which however is not really required
anymore, see https://lore.kernel.org/kvm/Y%2ffkTs5ajFy0hP1U@google.com/ ).
Thus we can finally deprecate the qemu-system-i386 binary. This will
help to avoid that we have to compile a lot of the x86 stuff twice
once we'll finally be able to drop qemu-system-i386.

Marked as RFC since there are likely still a bunch of spots around
that need attention, e.g.:

- CPU types have different suffixes between the -x86_64 and -i386
  variant (see TYPE_X86_CPU in cpu-qom.h) ... do we need to care
  about this in the new qemu-system-i386 symlink run mode?

- The code in target/i386/tcg/sysemu/smm_helper.c looks like it
  maybe needs a runtime switch, too ... or is it ok to leave this
  hard-coded to the x86_64 version?

Anyway, I'd like to get some feedback on this idea here... What
do you think of the idea of getting rid of the qemu-system-i386
binary this way in the future?

Thomas Huth (3):
  cpu: Add a way to detect 32-bit mode from argv0
  target/i386/cpu: Allow to limit the 64-bit binary to 32-bit mode only
  docs/about/deprecated: Deprecate the qemu-system-i386 binary

 docs/about/deprecated.rst | 16 ++++++++++++++++
 include/hw/core/cpu.h     | 10 ++++++++++
 target/i386/cpu.h         |  4 ++--
 cpu.c                     | 13 +++++++++++++
 softmmu/vl.c              |  1 +
 target/i386/cpu.c         | 28 +++++++++++++---------------
 target/i386/gdbstub.c     |  8 +-------
 7 files changed, 56 insertions(+), 24 deletions(-)

-- 
2.31.1