| Message ID | 20250203031821.741477-13-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | meson: Deprecate 32-bit host support | expand |
On 03/02/2025 04.18, Richard Henderson wrote: > For system mode, we can rarely support the amount of RAM that > the guest requires. Emulation is restricted to round-robin > mode, which solves many of the atomicity issues, but not those > associated with virtio. In any case, round-robin does nothing > to help the speed of emulation. > > For user mode, most emulation does not succeed at all. Most > of the time we cannot even load 64-bit non-PIE binaries due > to lack of a 64-bit address space. Threads are run in > parallel, not round-robin, which means that atomicity > is not handled. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > meson.build | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) Reviewed-by: Thomas Huth <thuth@redhat.com>
Richard Henderson <richard.henderson@linaro.org> writes: > For system mode, we can rarely support the amount of RAM that > the guest requires. Emulation is restricted to round-robin > mode, which solves many of the atomicity issues, but not those > associated with virtio. In any case, round-robin does nothing > to help the speed of emulation. > > For user mode, most emulation does not succeed at all. Most > of the time we cannot even load 64-bit non-PIE binaries due > to lack of a 64-bit address space. Threads are run in > parallel, not round-robin, which means that atomicity > is not handled. I think in itself is not enough, on aarch64.ci.org: ./../configure --disable-docs --disable-tools --cross-prefix=arm-linux-gnueabihf- Should only build 32 bit binaries. Which it does: 13:52:57 [alex@aarch64:~/l/q/b/arm32.crossbuild] review/deprecate-64-on-32-v2|… + ls qemu-* qemu-arm qemu-keymap qemu-mipsel qemu-sh4 qemu-system-i386 qemu-system-ppc qemu-system-sparc qemu-xtensa qemu-armeb qemu-m68k qemu-options.def qemu-sh4eb qemu-system-m68k qemu-system-riscv32 qemu-system-tricore qemu-xtensaeb qemu-hexagon qemu-microblaze qemu-or1k qemu-sparc qemu-system-mips qemu-system-rx qemu-system-xtensa qemu-i386 qemu-microblazeel qemu-ppc qemu-system-arm qemu-system-mipsel qemu-system-sh4 qemu-system-xtensaeb qemu-img-cmds.h qemu-mips qemu-riscv32 qemu-system-avr qemu-system-or1k qemu-system-sh4eb qemu-version.h However make check-tcg fails because: 13:53:09 [alex@aarch64:~/l/q/b/arm32.crossbuild] review/deprecate-64-on-32-v2|… + cat config-host.mak # Automatically generated by configure - do not modify all: SRC_PATH=/home/alex/lsrc/qemu.git TARGET_DIRS=aarch64-linux-user aarch64_be-linux-user alpha-linux-user arm-linux-user armeb-linux-user hexagon-linux-user hppa-linux-user i386-linux-user loongarch64-linux-user m68k-linux-user microblaze-linux-user microblazeel-linux-user mips-linux-user mips64-linux-user mips64el-linux-user mipsel-linux-user mipsn32-linux-user mipsn32el-linux-user or1k-linux-user ppc-linux-user ppc64-linux-user ppc64le-linux-user riscv32-linux-user riscv64-linux-user s390x-linux-user sh4-linux-user sh4eb-linux-user sparc-linux-user sparc32plus-linux-user sparc64-linux-user x86_64-linux-user xtensa-linux-user xtensaeb-linux-user aarch64-softmmu alpha-softmmu arm-softmmu avr-softmmu hppa-softmmu i386-softmmu loongarch64-softmmu m68k-softmmu microblaze-softmmu microblazeel-softmmu mips-softmmu mips64-softmmu mips64el-softmmu mipsel-softmmu or1k-softmmu ppc-softmmu ppc64-softmmu riscv32-softmmu riscv64-softmmu rx-softmmu s390x-softmmu sh4-softmmu sh4eb-softmmu sparc-softmmu sparc64-softmmu tricore-softmmu x86_64-softmmu xtensa-softmmu xtensaeb-softmmu GDB=/usr/bin/gdb-multiarch RUNC=docker SUBDIRS= pc-bios/optionrom pc-bios/s390-ccw PYTHON=/home/alex/lsrc/qemu.git/builds/arm32.crossbuild/pyvenv/bin/python3 -B MKVENV_ENSUREGROUP=/home/alex/lsrc/qemu.git/builds/arm32.crossbuild/pyvenv/bin/python3 -B /home/alex/lsrc/qemu.git/python/scripts/mkvenv.py ensuregroup --online GENISOIMAGE=/usr/bin/genisoimage MESON=/home/alex/lsrc/qemu.git/builds/arm32.crossbuild/pyvenv/bin/meson NINJA=/usr/bin/ninja EXESUF= CONFIG_DEFAULT_TARGETS=y TCG_TESTS_TARGETS= aarch64-linux-user arm-linux-user i386-linux-user mips64el-linux-user mipsel-linux-user riscv64-linux-user s390x-linux-user aarch64-softmmu arm-softmmu i386-softmmu riscv64-softmmu s390x-softmmu So possible TCG_TESTS_TARGET needs to be merged with the meson code? Also do we still use TARGET_DIRS? > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > meson.build | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/meson.build b/meson.build > index 5ca3cc3f34..866b8ce477 100644 > --- a/meson.build > +++ b/meson.build > @@ -3176,6 +3176,9 @@ if host_os == 'windows' > endif > endif > > +# Detect host pointer size for the target configuration loop. > +host_long_bits = cc.sizeof('void *') * 8 > + > ######################## > # Target configuration # > ######################## > @@ -3268,11 +3271,18 @@ foreach target : target_dirs > } > endif > > + config_target += keyval.load('configs/targets' / target + '.mak') > + > target_kconfig = [] > foreach sym: accelerators > if sym == 'CONFIG_TCG' > + # Disallow 64-bit on 32-bit TCG emulation. > + if host_long_bits < config_target['TARGET_LONG_BITS'].to_int() > + continue > + endif > config_target += { 'CONFIG_TCG_TARGET': 'y' } > elif target not in accelerator_targets.get(sym, []) > + # Other accelerators are handled by accelerator_targets. > continue > endif > config_target += { sym: 'y' } > @@ -3286,9 +3296,6 @@ foreach target : target_dirs > error('No accelerator available for target @0@'.format(target)) > endif > > - config_target += keyval.load('configs/targets' / target + '.mak') > - config_target += { 'TARGET_' + config_target['TARGET_ARCH'].to_upper(): 'y' } > - > if 'TARGET_NEED_FDT' in config_target and not fdt.found() > if default_targets > warning('Disabling ' + target + ' due to missing libfdt') > @@ -3301,6 +3308,7 @@ foreach target : target_dirs > actual_target_dirs += target > > # Add default keys > + config_target += { 'TARGET_' + config_target['TARGET_ARCH'].to_upper(): 'y' } > if 'TARGET_BASE_ARCH' not in config_target > config_target += {'TARGET_BASE_ARCH': config_target['TARGET_ARCH']} > endif
diff --git a/meson.build b/meson.build index 5ca3cc3f34..866b8ce477 100644 --- a/meson.build +++ b/meson.build @@ -3176,6 +3176,9 @@ if host_os == 'windows' endif endif +# Detect host pointer size for the target configuration loop. +host_long_bits = cc.sizeof('void *') * 8 + ######################## # Target configuration # ######################## @@ -3268,11 +3271,18 @@ foreach target : target_dirs } endif + config_target += keyval.load('configs/targets' / target + '.mak') + target_kconfig = [] foreach sym: accelerators if sym == 'CONFIG_TCG' + # Disallow 64-bit on 32-bit TCG emulation. + if host_long_bits < config_target['TARGET_LONG_BITS'].to_int() + continue + endif config_target += { 'CONFIG_TCG_TARGET': 'y' } elif target not in accelerator_targets.get(sym, []) + # Other accelerators are handled by accelerator_targets. continue endif config_target += { sym: 'y' } @@ -3286,9 +3296,6 @@ foreach target : target_dirs error('No accelerator available for target @0@'.format(target)) endif - config_target += keyval.load('configs/targets' / target + '.mak') - config_target += { 'TARGET_' + config_target['TARGET_ARCH'].to_upper(): 'y' } - if 'TARGET_NEED_FDT' in config_target and not fdt.found() if default_targets warning('Disabling ' + target + ' due to missing libfdt') @@ -3301,6 +3308,7 @@ foreach target : target_dirs actual_target_dirs += target # Add default keys + config_target += { 'TARGET_' + config_target['TARGET_ARCH'].to_upper(): 'y' } if 'TARGET_BASE_ARCH' not in config_target config_target += {'TARGET_BASE_ARCH': config_target['TARGET_ARCH']} endif
For system mode, we can rarely support the amount of RAM that the guest requires. Emulation is restricted to round-robin mode, which solves many of the atomicity issues, but not those associated with virtio. In any case, round-robin does nothing to help the speed of emulation. For user mode, most emulation does not succeed at all. Most of the time we cannot even load 64-bit non-PIE binaries due to lack of a 64-bit address space. Threads are run in parallel, not round-robin, which means that atomicity is not handled. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- meson.build | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)