iOS does not support ucontext natively for aarch64 and the sigaltstack is
also unsupported (even worse, it fails silently, see:
https://openradar.appspot.com/13002712 )
As a workaround we include a library implementation of ucontext and add it
as a build option.
Signed-off-by: Joelle van Dyne <j...@getutm.app>
---
configure | 23 ++++++++++++++++++++---
meson.build | 28 +++++++++++++++++++++++++++-
util/coroutine-ucontext.c | 9 +++++++++
.gitmodules | 3 +++
libucontext | 1 +
meson_options.txt | 2 ++
6 files changed, 62 insertions(+), 4 deletions(-)
create mode 160000 libucontext
diff --git a/configure b/configure
index 2a6db88a46..d1c6aa9750 100755
--- a/configure
+++ b/configure
@@ -1750,7 +1750,7 @@ Advanced options (experts only):
--oss-lib path to OSS library
--cpu=CPU Build for host CPU [$cpu]
--with-coroutine=BACKEND coroutine backend. Supported options:
- ucontext, sigaltstack, windows
+ ucontext, libucontext, sigaltstack, windows
--enable-gcov enable test coverage analysis with gcov
--disable-blobs disable installing provided firmware blobs
--with-vss-sdk=SDK-path enable Windows VSS support in QEMU Guest Agent
@@ -4883,6 +4883,8 @@ if test "$coroutine" = ""; then
coroutine=win32
elif test "$ucontext_works" = "yes"; then
coroutine=ucontext
+ elif test "$ios" = "yes"; then
+ coroutine=libucontext
else
coroutine=sigaltstack
fi
@@ -4906,12 +4908,27 @@ else
error_exit "only the 'windows' coroutine backend is valid for Windows"
fi
;;
+ libucontext)
+ ;;
*)
error_exit "unknown coroutine backend $coroutine"
;;
esac
fi
+case $coroutine in
+libucontext)
+ git_submodules="${git_submodules} libucontext"
+ mkdir -p libucontext
+ coroutine_impl=ucontext
+ libucontext="enabled"
+ ;;
+*)
+ coroutine_impl=$coroutine
+ libucontext="disabled"
+ ;;
+esac
+
if test "$coroutine_pool" = ""; then
coroutine_pool=yes
fi
@@ -6457,7 +6474,7 @@ if test "$rbd" = "yes" ; then
echo "RBD_LIBS=$rbd_libs" >> $config_host_mak
fi
-echo "CONFIG_COROUTINE_BACKEND=$coroutine" >> $config_host_mak
+echo "CONFIG_COROUTINE_BACKEND=$coroutine_impl" >> $config_host_mak
if test "$coroutine_pool" = "yes" ; then
echo "CONFIG_COROUTINE_POOL=1" >> $config_host_mak
else
@@ -7035,7 +7052,7 @@ NINJA=$ninja $meson setup \
-Dcocoa=$cocoa -Dmpath=$mpath -Dsdl=$sdl -Dsdl_image=$sdl_image \
-Dvnc=$vnc -Dvnc_sasl=$vnc_sasl -Dvnc_jpeg=$vnc_jpeg
-Dvnc_png=$vnc_png \
-Dgettext=$gettext -Dxkbcommon=$xkbcommon -Du2f=$u2f
-Dvirtiofsd=$virtiofsd \
- -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt \
+ -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt -Ducontext=$libucontext
\
-Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
-Ddocs=$docs -Dsphinx_build=$sphinx_build -Dinstall_blobs=$blobs \
$cross_arg \
diff --git a/meson.build b/meson.build
index 8894171bd1..e62324d5ac 100644
--- a/meson.build
+++ b/meson.build
@@ -1259,9 +1259,34 @@ if not fdt.found() and fdt_required.length() > 0
error('fdt not available but required by targets ' + ', '.join(fdt_required))
endif
+ucontext = not_found
+if get_option('ucontext').enabled()
+ if not fs.is_dir(meson.current_source_dir() / 'libucontext/arch' / cpu)
+ error('libucontext is wanted but not implemented for host ' + cpu)
+ endif
+ arch = host_machine.cpu()
+ ucontext_cargs = ['-DG_LOG_DOMAIN="ucontext"', '-DCUSTOM_IMPL']
+ ucontext_files = [
+ 'libucontext/arch' / arch / 'getcontext.S',
+ 'libucontext/arch' / arch / 'setcontext.S',
+ 'libucontext/arch' / arch / 'makecontext.c',
+ 'libucontext/arch' / arch / 'startcontext.S',
+ 'libucontext/arch' / arch / 'swapcontext.S',
+ ]
+
+ ucontext_inc = include_directories('libucontext/include')
+ libucontext = static_library('ucontext',
+ sources: ucontext_files,
+ c_args: ucontext_cargs,
+ include_directories: ucontext_inc)
+ ucontext = declare_dependency(link_with: libucontext,
+ include_directories: ucontext_inc)
+endif
+
config_host_data.set('CONFIG_CAPSTONE', capstone.found())
config_host_data.set('CONFIG_FDT', fdt.found())
config_host_data.set('CONFIG_SLIRP', slirp.found())
+config_host_data.set('CONFIG_LIBUCONTEXT', ucontext.found())
#####################
# Generated sources #
@@ -1477,7 +1502,7 @@ util_ss.add_all(trace_ss)
util_ss = util_ss.apply(config_all, strict: false)
libqemuutil = static_library('qemuutil',
sources: util_ss.sources() + stub_ss.sources() +
genh,
- dependencies: [util_ss.dependencies(), m, glib,
socket, malloc])
+ dependencies: [util_ss.dependencies(), m, glib,
socket, malloc, ucontext])
qemuutil = declare_dependency(link_with: libqemuutil,
sources: genh + version_res)
@@ -2135,6 +2160,7 @@ if targetos == 'windows'
summary_info += {'QGA MSI support': config_host.has_key('CONFIG_QGA_MSI')}
endif
summary_info += {'seccomp support': config_host.has_key('CONFIG_SECCOMP')}
+summary_info += {'libucontext support': ucontext.found()}
summary_info += {'coroutine backend': config_host['CONFIG_COROUTINE_BACKEND']}
summary_info += {'coroutine pool': config_host['CONFIG_COROUTINE_POOL'] ==
'1'}
summary_info += {'debug stack usage':
config_host.has_key('CONFIG_DEBUG_STACK_USAGE')}
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c
index 904b375192..1e1dd43512 100644
--- a/util/coroutine-ucontext.c
+++ b/util/coroutine-ucontext.c
@@ -23,7 +23,16 @@
#undef _FORTIFY_SOURCE
#endif
#include "qemu/osdep.h"
+#if defined(CONFIG_LIBUCONTEXT)
+#include <libucontext.h>
+#define ucontext_t libucontext_ucontext_t
+#define getcontext libucontext_getcontext
+#define setcontext libucontext_setcontext
+#define swapcontext libucontext_swapcontext
+#define makecontext libucontext_makecontext
+#else
#include <ucontext.h>
+#endif
#include "qemu/coroutine_int.h"
#ifdef CONFIG_VALGRIND_H
diff --git a/.gitmodules b/.gitmodules
index 2bdeeacef8..065b52867f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -64,3 +64,6 @@
[submodule "roms/vbootrom"]
path = roms/vbootrom
url = https://git.qemu.org/git/vbootrom.git
+[submodule "libucontext"]
+ path = libucontext
+ url = https://github.com/utmapp/libucontext.git
diff --git a/libucontext b/libucontext
new file mode 160000
index 0000000000..7094e4c427
--- /dev/null
+++ b/libucontext
@@ -0,0 +1 @@
+Subproject commit 7094e4c42723b6178a4e2b60d4631d8a88f40719
diff --git a/meson_options.txt b/meson_options.txt
index b4f1801875..da24102898 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -64,6 +64,8 @@ option('xkbcommon', type : 'feature', value : 'auto',
description: 'xkbcommon support')
option('virtiofsd', type: 'feature', value: 'auto',
description: 'build virtiofs daemon (virtiofsd)')
+option('ucontext', type : 'feature', value : 'disabled',
+ description: 'libucontext support')
option('capstone', type: 'combo', value: 'auto',
choices: ['disabled', 'enabled', 'auto', 'system', 'internal'],
--
2.28.0
