qemu/linux-user/i386
Daniel P. Berrangé d135f78140 linux-user: use 'max' instead of 'qemu32' / 'qemu64' by default
The 'qemu64' CPU model implements the least featureful x86_64 CPU that's
possible. Historically this hasn't been an issue since it was rare for
OS distros to build with a higher mandatory CPU baseline.

With RHEL-9, however, the entire distro is built for the x86_64-v2 ABI
baseline:

  https://developers.redhat.com/blog/2021/01/05/building-red-hat-enterprise-linux-9-for-the-x86-64-v2-microarchitecture-level

It is likely that other distros may take similar steps in the not too
distant future. For example, it has been suggested for Fedora on a
number of occasions.

This new baseline is not compatible with the qemu64 CPU model though.
While it is possible to pass a '-cpu xxx' flag to qemu-x86_64, the
usage of QEMU doesn't always allow for this. For example, the args
are typically controlled via binfmt rules that the user has no ability
to change. This impacts users who are trying to use podman on aarch64
platforms, to run containers with x86_64 content. There's no arg to
podman that can be used to change the qemu-x86_64 args, and a non-root
user of podman can not change binfmt rules without elevating privileges:

  https://github.com/containers/podman/issues/15456#issuecomment-1228210973

Changing to the 'max' CPU model gives 'qemu-x86_64' maximum
compatibility with binaries it is likely to encounter in the wild,
and not likely to have a significant downside for existing usage.

Most other architectures already use an 'any' CPU model, which is
often mapped to 'max' (or similar) already, rather than the oldest
possible CPU model.

For the sake of consistency the 'i386' architecture is also changed
from using 'qemu32' to 'max'.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220923110413.70593-1-berrange@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2022-09-23 14:04:17 +02:00
..
cpu_loop.c misc: fix commonly doubled up words 2022-08-01 11:58:02 +02:00
meson.build meson: linux-user 2020-08-21 06:30:38 -04:00
signal.c linux-user: Rename TARGET_QEMU_ESIGRETURN to QEMU_ESIGRETURN 2021-12-19 20:47:33 -08:00
sockbits.h linux-user: move socket.h generic definitions to generic/sockbits.h 2018-05-25 10:10:55 +02:00
syscall_32.tbl linux-user: update syscall.tbl to Linux v5.13 2021-07-13 13:59:59 +02:00
syscall_nr.h meson: linux-user 2020-08-21 06:30:38 -04:00
syscallhdr.sh linux-user, i386: add syscall table generation support 2020-03-20 16:02:00 +01:00
target_cpu.h linux user: Fix Lesser GPL version number 2020-11-15 16:41:26 +01:00
target_elf.h linux-user: use 'max' instead of 'qemu32' / 'qemu64' by default 2022-09-23 14:04:17 +02:00
target_errno_defs.h linux-user: Extract target errno to 'target_errno_defs.h' 2021-07-12 21:53:35 +02:00
target_fcntl.h linux-user: move generic fcntl definitions to generic/fcntl.h 2018-06-04 01:30:43 +02:00
target_prctl.h linux-user: Split out do_prctl and subroutines 2022-01-06 11:40:52 +01:00
target_resource.h linux-user: Move generic TARGET_RLIMIT* definitions to generic/target_resource.h 2022-02-01 08:01:38 +01:00
target_signal.h linux-user: Move target_signal.h generic definitions to generic/signal.h 2022-01-06 11:40:52 +01:00
target_structs.h linux-user: Move target_struct.h generic definitions to generic/ 2022-01-11 18:40:44 +01:00
target_syscall.h linux-user: target_syscall.h remove definition TARGET_MINSIGSTKSZ 2022-01-06 11:40:52 +01:00
termbits.h linux-user: Add generic 'termbits.h' for some archs 2020-08-27 12:29:50 +02:00