[PATCH for 11.0 00/11] First batch of Meson/Rust build system changes

[PATCH for 11.0 00/11] First batch of Meson/Rust build system changes

[Paolo Bonzini]

By bumping the minimum supported version of Meson to 1.10.0 (at least
when --enable-rust is used), C objects can be passed to Rust targets.
This allows to simplify the build process, and possibly also to link
the executables dynamically linking to Rust's libstd which makes them
smaller.

The major snag here is that QEMU wants to be very explicit about the order
of libraries on the command line.  rustc has a normally useful feature
where it records dependent static libraries and adds them to the linker
automatically, but for us it messes up libqemuutil.a's stubs mechanism.
This is fixed (or worked around depending on how you see it) by patches
4 and 5.

Meson 1.10.0 also contains some bugfixes such that Rust can now also be
added to the Windows and macOS CI jobs.  This reveals a few more bugs,
such as the ones fixed in patch 1 and 8.

Finally, Meson 1.10.0 improves Meson's embedded Cargo.toml/Cargo.lock
interpreter, but those changes are still mostly internal and the
interpreter cannot be used yet.  The required changes are planned for
1.11.0; Marc-André already played with them for his GStreamer audio
backend, and a couple more users are hanging out and helping on the
#meson IRC channel, too.  Once this functionality is merged, it will
replace a few hundreds lines of meson.build code and will make it simpler
to add new devices.

I still expect that the --enable-rust option will require bleeding
edge Meson for a good part of next year.  However, as was the case for
the original switch to Meson, this will smooth out and Meson will have
improved much for the whole ecosystem.

Paolo

Marc-André Lureau (2):
  cirrus/macos: enable Rust
  gitlab-ci: enable rust for msys2-64bit

Martin Kletzander (1):
  rust: Do not link qemuutil into Rust rlibs

Paolo Bonzini (8):
  build: do not include @block.syms/@qemu.sys with modules disabled
  tests/meson: do not reuse migration_files variable
  bump meson wheel to 1.10.0
  rust: only link the Rust part of the code into devices
  rust: Meson now adds -Cdefault-linker-libraries
  meson: let Meson handle mixed-language linking of Rust and C objects
  rust: skip compilation if there are no system emulators
  lcitool: enable Rust for Windows cross targets

 configure                                     |   4 +-
 meson.build                                   |  36 +++++++-----------
 .gitlab-ci.d/cirrus.yml                       |   2 +-
 .gitlab-ci.d/windows.yml                      |   7 +++-
 python/scripts/vendor.py                      |   4 +-
 python/wheels/meson-1.10.0-py3-none-any.whl   | Bin 0 -> 1057029 bytes
 pythondeps.toml                               |   4 +-
 rust/chardev/meson.build                      |   2 +-
 rust/hw/char/pl011/meson.build                |  18 +++++----
 rust/hw/timer/hpet/meson.build                |  18 ++++-----
 rust/meson.build                              |   7 ++++
 rust/qom/meson.build                          |   2 +-
 rust/util/meson.build                         |   4 +-
 scripts/rust/rust_root_crate.sh               |   1 +
 .../dockerfiles/fedora-win64-cross.docker     |   2 +
 tests/lcitool/refresh                         |   5 +--
 tests/qtest/meson.build                       |   6 +--
 17 files changed, 64 insertions(+), 58 deletions(-)
 create mode 100644 python/wheels/meson-1.10.0-py3-none-any.whl

-- 
2.52.0

[PATCH 01/11] build: do not include @block.syms/@qemu.sys with modules disabled

[Paolo Bonzini]

Including specific symbols used by modules is not necessary for
monolithic executables.  This avoids a failure where emcc does not
support @file syntax inside a response file---which in turn breaks
the WebAssembly build if the command line is long enough that meson
decides to use a response file.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/meson.build b/meson.build
index e6a11cefdb7..02738c9765f 100644
--- a/meson.build
+++ b/meson.build
@@ -4270,7 +4270,7 @@ foreach target : target_dirs
 
     c_args += ['-DCONFIG_DEVICES="@0@-config-devices.h"'.format(target)]
     arch_srcs += config_devices_h[target]
-    link_args += ['@block.syms', '@qemu.syms']
+    link_args += enable_modules ? ['@block.syms', '@qemu.syms'] : []
   else
     abi = config_target['TARGET_ABI_DIR']
     target_type='user'
@@ -4499,14 +4499,15 @@ if xkbcommon.found()
 endif
 
 if have_tools
+  link_args = enable_modules ? ['@block.syms'] : []
   qemu_img = executable('qemu-img', [files('qemu-img.c'), hxdep],
-             link_args: '@block.syms', link_depends: block_syms,
+             link_args: link_args, link_depends: block_syms,
              dependencies: [authz, block, crypto, io, qom, qemuutil], install: true)
   qemu_io = executable('qemu-io', files('qemu-io.c'),
-             link_args: '@block.syms', link_depends: block_syms,
+             link_args: link_args, link_depends: block_syms,
              dependencies: [block, qemuutil], install: true)
   qemu_nbd = executable('qemu-nbd', files('qemu-nbd.c'),
-               link_args: '@block.syms', link_depends: block_syms,
+               link_args: link_args, link_depends: block_syms,
                dependencies: [blockdev, qemuutil, selinux],
                install: true)
 
-- 
2.52.0

[PATCH 02/11] tests/meson: do not reuse migration_files variable

[Paolo Bonzini]

The variable is defined in migration/meson.build, reusing it is confusing.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tests/qtest/meson.build | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 669d07c06bd..08fba9695b9 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -343,7 +343,7 @@ endif
 
 tpmemu_files = ['tpm-emu.c', 'tpm-util.c', 'tpm-tests.c']
 
-migration_files = [files(
+test_migration_files = [files(
   'migration/bootfile.c',
   'migration/framework.c',
   'migration/migration-qmp.c',
@@ -377,7 +377,7 @@ qtests = {
                              'migration/migration-util.c') + dbus_vmstate1,
   'erst-test': files('erst-test.c'),
   'ivshmem-test': [rt, '../../contrib/ivshmem-server/ivshmem-server.c'],
-  'migration-test': migration_files + migration_tls_files,
+  'migration-test': test_migration_files + migration_tls_files,
   'pxe-test': files('boot-sector.c'),
   'pnv-xive2-test': files('pnv-xive2-common.c', 'pnv-xive2-flush-sync.c',
                           'pnv-xive2-nvpg_bar.c'),
@@ -389,7 +389,7 @@ qtests = {
   'tpm-tis-i2c-test': [io, tpmemu_files, 'qtest_aspeed.c'],
   'tpm-tis-device-swtpm-test': [io, tpmemu_files, 'tpm-tis-util.c'],
   'tpm-tis-device-test': [io, tpmemu_files, 'tpm-tis-util.c'],
-  'virtio-net-failover': migration_files,
+  'virtio-net-failover': test_migration_files,
   'vmgenid-test': files('boot-sector.c', 'acpi-utils.c'),
   'netdev-socket': files('netdev-socket.c', '../unit/socket-helpers.c'),
 }
-- 
2.52.0

[PATCH 04/11] rust: Do not link qemuutil into Rust rlibs

[Paolo Bonzini]

From: Martin Kletzander <mkletzan@redhat.com>

Commit de037ab8d83d removed qemuutil dependency from chardev and util
rust crates.  However it stayed in the _util_rs static library.  The
dependency is also defined as `link_with`, which is fine for C targets,
where the resulting archive gets linked as another parameter on the
command line when it is a static library.

However, when a C library is linked into a Rust rlib, rustc remembers
the dependency into the metadata and adds the library to the linker
command line.

Unfortunately, static libraries are sensitive to their
position on the command line and rustc does not always get it right.
Fortunately, simply removing it from dependencies of any rust libraries
and instead adding them into the dependencies of executables and
doctests fixes the behaviour.

Without this patch the error I get is:

  FAILED: [code=1] rust/tests/rust-integration
  ...
  = note: rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          rust-lld: error: unable to find library -l:libqemuutil.a
          rust-lld: error: unable to find library -l:libvhost-user-glib.a
          rust-lld: error: unable to find library -l:libvhost-user.a
          collect2: error: ld returned 1 exit status

Meson could work around it itself by never adding these static libraries
to the rlibs (after all, Meson tracks the transitive dependencies already
and knows how to add them to dependents of those rlibs); at least for now,
do it in QEMU: never link C libraries into Rust rlibs, and add them to the
final build products only.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/chardev/meson.build | 2 +-
 rust/qom/meson.build     | 2 +-
 rust/util/meson.build    | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/rust/chardev/meson.build b/rust/chardev/meson.build
index 54bb2962528..2e4f4670bd8 100644
--- a/rust/chardev/meson.build
+++ b/rust/chardev/meson.build
@@ -38,4 +38,4 @@ _chardev_rs = static_library(
   dependencies: [glib_sys_rs, common_rs, qemu_macros],
 )
 
-chardev_rs = declare_dependency(link_with: [_chardev_rs], dependencies: [chardev])
+chardev_rs = declare_dependency(link_with: [_chardev_rs], dependencies: [chardev, qemuutil])
diff --git a/rust/qom/meson.build b/rust/qom/meson.build
index 551c4f0bf5f..dda26c3f981 100644
--- a/rust/qom/meson.build
+++ b/rust/qom/meson.build
@@ -30,7 +30,7 @@ _qom_rs = static_library(
   dependencies: [common_rs, glib_sys_rs, qemu_macros],
 )
 
-qom_rs = declare_dependency(link_with: [_qom_rs], dependencies: [qemu_macros, qom])
+qom_rs = declare_dependency(link_with: [_qom_rs], dependencies: [qemu_macros, qom, qemuutil])
 
 # Doctests are essentially integration tests, so they need the same dependencies.
 # Note that running them requires the object files for C code, so place them
diff --git a/rust/util/meson.build b/rust/util/meson.build
index 95b44f7c670..98629394afb 100644
--- a/rust/util/meson.build
+++ b/rust/util/meson.build
@@ -39,10 +39,10 @@ _util_rs = static_library(
     ],
     {'.': _util_bindings_inc_rs}
   ),
-  dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs, qom, qemuutil],
+  dependencies: [anyhow_rs, libc_rs, foreign_rs, glib_sys_rs, common_rs],
 )
 
-util_rs = declare_dependency(link_with: [_util_rs])
+util_rs = declare_dependency(link_with: [_util_rs], dependencies: [qemuutil, qom])
 
 rust.test('rust-util-tests', _util_rs,
           dependencies: [qemuutil, qom],
-- 
2.52.0

Re: [PATCH 04/11] rust: Do not link qemuutil into Rust rlibs

[Zhao Liu]

On Mon, Dec 15, 2025 at 08:49:53AM +0100, Paolo Bonzini wrote:
> Date: Mon, 15 Dec 2025 08:49:53 +0100
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 04/11] rust: Do not link qemuutil into Rust rlibs
> X-Mailer: git-send-email 2.52.0
> 
> From: Martin Kletzander <mkletzan@redhat.com>
> 
> Commit de037ab8d83d removed qemuutil dependency from chardev and util
> rust crates.  However it stayed in the _util_rs static library.  The
> dependency is also defined as `link_with`, which is fine for C targets,
> where the resulting archive gets linked as another parameter on the
> command line when it is a static library.
> 
> However, when a C library is linked into a Rust rlib, rustc remembers
> the dependency into the metadata and adds the library to the linker
> command line.
> 
> Unfortunately, static libraries are sensitive to their
> position on the command line and rustc does not always get it right.
> Fortunately, simply removing it from dependencies of any rust libraries
> and instead adding them into the dependencies of executables and
> doctests fixes the behaviour.
> 
> Without this patch the error I get is:
> 
>   FAILED: [code=1] rust/tests/rust-integration
>   ...
>   = note: rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           rust-lld: error: unable to find library -l:libqemuutil.a
>           rust-lld: error: unable to find library -l:libvhost-user-glib.a
>           rust-lld: error: unable to find library -l:libvhost-user.a
>           collect2: error: ld returned 1 exit status
> 
> Meson could work around it itself by never adding these static libraries
> to the rlibs (after all, Meson tracks the transitive dependencies already
> and knows how to add them to dependents of those rlibs); at least for now,
> do it in QEMU: never link C libraries into Rust rlibs, and add them to the
> final build products only.
> 
> Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  rust/chardev/meson.build | 2 +-
>  rust/qom/meson.build     | 2 +-
>  rust/util/meson.build    | 4 ++--
>  3 files changed, 4 insertions(+), 4 deletions(-)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

[PATCH 05/11] rust: only link the Rust part of the code into devices

[Paolo Bonzini]

Do not include libqemuutil in the device crates for the same
reason as in the previous commit.  Static libraries like qemuutil
are sensitive to their position on the command line and rustc does not
always get it right.

If rustc places the library too early on the command line, the stubs
are included in the final link product, which results in duplicate
symbols.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/hw/char/pl011/meson.build | 18 ++++++++++--------
 rust/hw/timer/hpet/meson.build | 18 +++++++++---------
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/rust/hw/char/pl011/meson.build b/rust/hw/char/pl011/meson.build
index 33b91f21911..9c0e8290e9a 100644
--- a/rust/hw/char/pl011/meson.build
+++ b/rust/hw/char/pl011/meson.build
@@ -28,20 +28,22 @@ _libpl011_rs = static_library(
   ),
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
+  link_with: [
+    _util_rs,
+    _migration_rs,
+    _bql_rs,
+    _qom_rs,
+    _chardev_rs,
+    _system_rs,
+    _hwcore_rs,
+    _trace_rs
+  ],
   dependencies: [
     bilge_rs,
     bilge_impl_rs,
     bits_rs,
     common_rs,
     glib_sys_rs,
-    util_rs,
-    migration_rs,
-    bql_rs,
-    qom_rs,
-    chardev_rs,
-    system_rs,
-    hwcore_rs,
-    trace_rs
   ],
 )
 
diff --git a/rust/hw/timer/hpet/meson.build b/rust/hw/timer/hpet/meson.build
index 9a3dd62caa3..3bb7ce2a6ca 100644
--- a/rust/hw/timer/hpet/meson.build
+++ b/rust/hw/timer/hpet/meson.build
@@ -3,16 +3,16 @@ _libhpet_rs = static_library(
   files('src/lib.rs'),
   override_options: ['rust_std=2021', 'build.rust_std=2021'],
   rust_abi: 'rust',
-  dependencies: [
-    common_rs,
-    util_rs,
-    migration_rs,
-    bql_rs,
-    qom_rs,
-    system_rs,
-    hwcore_rs,
-    trace_rs,
+  link_with: [
+    _util_rs,
+    _migration_rs,
+    _bql_rs,
+    _qom_rs,
+    _system_rs,
+    _hwcore_rs,
+    _trace_rs,
   ],
+  dependencies: [common_rs],
 )
 
 rust_devices_ss.add(when: 'CONFIG_X_HPET_RUST', if_true: [declare_dependency(
-- 
2.52.0

Re: [PATCH 05/11] rust: only link the Rust part of the code into devices

[Zhao Liu]

On Mon, Dec 15, 2025 at 08:49:54AM +0100, Paolo Bonzini wrote:
> Date: Mon, 15 Dec 2025 08:49:54 +0100
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 05/11] rust: only link the Rust part of the code into
>  devices
> X-Mailer: git-send-email 2.52.0
> 
> Do not include libqemuutil in the device crates for the same
> reason as in the previous commit.  Static libraries like qemuutil
> are sensitive to their position on the command line and rustc does not
> always get it right.
> 
> If rustc places the library too early on the command line, the stubs
> are included in the final link product, which results in duplicate
> symbols.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  rust/hw/char/pl011/meson.build | 18 ++++++++++--------
>  rust/hw/timer/hpet/meson.build | 18 +++++++++---------
>  2 files changed, 19 insertions(+), 17 deletions(-)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

[PATCH 06/11] rust: Meson now adds -Cdefault-linker-libraries

[Paolo Bonzini]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/meson.build b/meson.build
index 02738c9765f..e2de3832ac3 100644
--- a/meson.build
+++ b/meson.build
@@ -136,13 +136,7 @@ if have_rust
     rustc_lint_args += ['-Dwarnings', '-Funknown_lints']
   endif
 
-  # Apart from procedural macros, our Rust executables will often link
-  # with C code, so include all the libraries that C code needs.  This
-  # is safe; https://github.com/rust-lang/rust/pull/54675 says that
-  # passing -nodefaultlibs to the linker "was more ideological to
-  # start with than anything".
-  add_project_arguments(rustc_lint_args +
-      ['--cfg', 'MESON', '-C', 'default-linker-libraries'],
+  add_project_arguments(rustc_lint_args + ['--cfg', 'MESON'],
       native: false, language: 'rust')
   add_project_arguments(rustc_lint_args + ['--cfg', 'MESON'],
       native: true, language: 'rust')
-- 
2.52.0

Re: [PATCH 06/11] rust: Meson now adds -Cdefault-linker-libraries

[Zhao Liu]

On Mon, Dec 15, 2025 at 08:49:55AM +0100, Paolo Bonzini wrote:
> Date: Mon, 15 Dec 2025 08:49:55 +0100
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 06/11] rust: Meson now adds -Cdefault-linker-libraries
> X-Mailer: git-send-email 2.52.0
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  meson.build | 8 +-------
>  1 file changed, 1 insertion(+), 7 deletions(-)

Reviwed-by: Zhao Liu <zhao1.liu@intel.com>

[PATCH 07/11] meson: let Meson handle mixed-language linking of Rust and C objects

[Paolo Bonzini]

With the bump to Meson 1.10.0, C objects can be passed to rust targets.
This way, the Rust libstd will be added by rustc itself in its final
linker invocation.  Use that to eliminate the staticlib and allow
dynamic linking with libstd (also introduced by Meson 1.9.0, but not
for staticlib crates due to lack of support in rustc).

The main() function is still provided by C, which is possible by
declaring the main source file of the Rust executable (which is
still created by scripts/rust/rust_root_crate.sh) as #![no_main].

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 meson.build                     | 19 ++++++++-----------
 scripts/rust/rust_root_crate.sh |  1 +
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/meson.build b/meson.build
index e2de3832ac3..3790cf15f51 100644
--- a/meson.build
+++ b/meson.build
@@ -4352,25 +4352,22 @@ foreach target : target_dirs
   arch_srcs += target_specific.sources()
   arch_deps += target_specific.dependencies()
 
+  main_rs = []
+  crates = []
   if have_rust and target_type == 'system'
     target_rust = rust_devices_ss.apply(config_target, strict: false)
-    crates = []
+    arch_deps += target_rust.dependencies()
     foreach dep : target_rust.dependencies()
       crates += dep.get_variable('crate')
     endforeach
     if crates.length() > 0
-      rlib_rs = custom_target('rust_' + target.underscorify() + '.rs',
+      main_rs = custom_target('rust_' + target.underscorify() + '.rs',
                               output: 'rust_' + target.underscorify() + '.rs',
                               command: [rust_root_crate, crates],
                               capture: true,
                               build_by_default: true,
                               build_always_stale: true)
-      rlib = static_library('rust_' + target.underscorify(),
-                            structured_sources([], {'.': rlib_rs}),
-                            dependencies: target_rust.dependencies(),
-                            override_options: ['rust_std=2021', 'build.rust_std=2021'],
-                            rust_abi: 'c')
-      arch_deps += declare_dependency(link_whole: [rlib])
+      main_rs = structured_sources(main_rs)
     endif
   endif
 
@@ -4394,14 +4391,14 @@ foreach target : target_dirs
     execs = [{
       'name': 'qemu-system-' + target_name,
       'win_subsystem': 'console',
-      'sources': files('system/main.c'),
+      'sources': [main_rs, files('system/main.c')],
       'dependencies': [sdl]
     }]
     if host_os == 'windows' and (sdl.found() or gtk.found())
       execs += [{
         'name': 'qemu-system-' + target_name + 'w',
         'win_subsystem': 'windows',
-        'sources': files('system/main.c'),
+        'sources': [main_rs, files('system/main.c')],
         'dependencies': [sdl]
       }]
     endif
@@ -4410,7 +4407,7 @@ foreach target : target_dirs
       execs += [{
         'name': 'qemu-fuzz-' + target_name,
         'win_subsystem': 'console',
-        'sources': specific_fuzz.sources(),
+        'sources': [main_rs, specific_fuzz.sources()],
         'dependencies': specific_fuzz.dependencies(),
       }]
     endif
diff --git a/scripts/rust/rust_root_crate.sh b/scripts/rust/rust_root_crate.sh
index f05b8d02108..13ef7c1be5d 100755
--- a/scripts/rust/rust_root_crate.sh
+++ b/scripts/rust/rust_root_crate.sh
@@ -6,6 +6,7 @@ cat <<EOF
 // @generated
 // This file is autogenerated by scripts/rust/rust_root_crate.sh
 
+#![no_main]
 EOF
 
 for crate in $*; do
-- 
2.52.0

[PATCH 08/11] rust: skip compilation if there are no system emulators

[Paolo Bonzini]

Otherwise, the Rust crates require the corresponding C code
(e.g. migration/ for rust/migration/) but the dependencies of
that C code, for example the trace files, have not been built.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 rust/meson.build | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/rust/meson.build b/rust/meson.build
index afbeeeb47a7..bacb7879102 100644
--- a/rust/meson.build
+++ b/rust/meson.build
@@ -1,3 +1,9 @@
+if not have_system
+  subdir_done()
+else
+  message('Rust enabled but it is only used by system emulators.')
+endif
+
 subproject('anyhow-1-rs', required: true)
 subproject('bilge-0.2-rs', required: true)
 subproject('bilge-impl-0.2-rs', required: true)
@@ -30,6 +36,7 @@ subdir('qemu-macros')
 
 subdir('common')
 subdir('bits')
+
 subdir('util')
 subdir('bql')
 subdir('migration')
-- 
2.52.0

Re: [PATCH 08/11] rust: skip compilation if there are no system emulators

[Zhao Liu]

On Mon, Dec 15, 2025 at 08:49:57AM +0100, Paolo Bonzini wrote:
> Date: Mon, 15 Dec 2025 08:49:57 +0100
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH 08/11] rust: skip compilation if there are no system
>  emulators
> X-Mailer: git-send-email 2.52.0
> 
> Otherwise, the Rust crates require the corresponding C code
> (e.g. migration/ for rust/migration/) but the dependencies of
> that C code, for example the trace files, have not been built.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  rust/meson.build | 7 +++++++
>  1 file changed, 7 insertions(+)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>

[PATCH 09/11] lcitool: enable Rust for Windows cross targets

[Paolo Bonzini]

The issue that is mentioned in the comment has been fixed.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 tests/docker/dockerfiles/fedora-win64-cross.docker | 2 ++
 tests/lcitool/refresh                              | 5 +----
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/tests/docker/dockerfiles/fedora-win64-cross.docker b/tests/docker/dockerfiles/fedora-win64-cross.docker
index 4f743c00434..c5e1fcebf51 100644
--- a/tests/docker/dockerfiles/fedora-win64-cross.docker
+++ b/tests/docker/dockerfiles/fedora-win64-cross.docker
@@ -120,3 +120,5 @@ ARG USER
 ARG UID
 RUN if [ "${USER}" ]; then \
   id ${USER} 2>/dev/null || useradd -u ${UID} -U ${USER}; fi
+
+ENV ENABLE_RUST 1
diff --git a/tests/lcitool/refresh b/tests/lcitool/refresh
index 9df607a55f8..01a71929542 100755
--- a/tests/lcitool/refresh
+++ b/tests/lcitool/refresh
@@ -291,10 +291,7 @@ try:
                         project='qemu,qemu-win-installer',
                         cross="mingw64",
                         trailer=cross_build("x86_64-w64-mingw32-",
-                                            "x86_64-softmmu"),
-                        # linking with rust is buggy:
-                        # https://github.com/mesonbuild/meson/pull/14991
-                        enable_rust=False)
+                                            "x86_64-softmmu"))
 
     # We also generate some docker files with minimal dependencies and
     # as many cross-compilers as Debian will package for building TCG
-- 
2.52.0

Re: [PATCH 09/11] lcitool: enable Rust for Windows cross targets

[Alex Bennée]

Paolo Bonzini <pbonzini@redhat.com> writes:

> The issue that is mentioned in the comment has been fixed.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Acked-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro

[PATCH 10/11] cirrus/macos: enable Rust

[Paolo Bonzini]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20250924120426.2158655-25-marcandre.lureau@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .gitlab-ci.d/cirrus.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.gitlab-ci.d/cirrus.yml b/.gitlab-ci.d/cirrus.yml
index 0d66a14186a..177bd684ef5 100644
--- a/.gitlab-ci.d/cirrus.yml
+++ b/.gitlab-ci.d/cirrus.yml
@@ -56,5 +56,5 @@ aarch64-macos-build:
     INSTALL_COMMAND: brew install
     PATH_EXTRA: /opt/homebrew/ccache/libexec:/opt/homebrew/gettext/bin
     PKG_CONFIG_PATH: /opt/homebrew/curl/lib/pkgconfig:/opt/homebrew/ncurses/lib/pkgconfig:/opt/homebrew/readline/lib/pkgconfig
-    CONFIGURE_ARGS: --target-list-exclude=arm-softmmu,i386-softmmu,microblazeel-softmmu,mips64-softmmu,mipsel-softmmu,mips-softmmu,ppc-softmmu,sh4-softmmu,xtensaeb-softmmu
+    CONFIGURE_ARGS: --target-list-exclude=arm-softmmu,i386-softmmu,microblazeel-softmmu,mips64-softmmu,mipsel-softmmu,mips-softmmu,ppc-softmmu,sh4-softmmu,xtensaeb-softmmu --enable-rust
     TEST_TARGETS: check-unit check-block check-qapi-schema check-softfloat check-qtest-x86_64
-- 
2.52.0

[PATCH 11/11] gitlab-ci: enable rust for msys2-64bit

[Paolo Bonzini]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Link: https://lore.kernel.org/r/20250924120426.2158655-24-marcandre.lureau@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 .gitlab-ci.d/windows.yml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/.gitlab-ci.d/windows.yml b/.gitlab-ci.d/windows.yml
index 5dbdabfbec0..5ef4d34d1ea 100644
--- a/.gitlab-ci.d/windows.yml
+++ b/.gitlab-ci.d/windows.yml
@@ -17,7 +17,7 @@ msys2-64bit:
     # This feature doesn't (currently) work with PowerShell, it stops
     # the echo'ing of commands being run and doesn't show any timing
     FF_SCRIPT_SECTIONS: 0
-    CONFIGURE_ARGS: --disable-system --enable-tools -Ddebug=false -Doptimization=0
+    CONFIGURE_ARGS: --disable-system --enable-tools -Ddebug=false -Doptimization=0 --enable-rust
     # The Windows git is a bit older so override the default
     GIT_FETCH_EXTRA_FLAGS: --no-tags --prune --quiet
   artifacts:
@@ -77,6 +77,7 @@ msys2-64bit:
       bison diffutils flex
       git grep make sed
       mingw-w64-x86_64-binutils
+      mingw-w64-x86_64-ca-certificates
       mingw-w64-x86_64-ccache
       mingw-w64-x86_64-curl-winssl
       mingw-w64-x86_64-gcc
@@ -87,6 +88,9 @@ msys2-64bit:
       mingw-w64-x86_64-pixman
       mingw-w64-x86_64-pkgconf
       mingw-w64-x86_64-python
+      mingw-w64-x86_64-python-certifi
+      mingw-w64-x86_64-rust
+      mingw-w64-x86_64-rust-bindgen
       mingw-w64-x86_64-zstd"
   - .\msys64\usr\bin\bash -lc "pacman -Sc --noconfirm"
   - Write-Output "Running build at $(Get-Date -Format u)"
@@ -98,6 +102,7 @@ msys2-64bit:
   - $env:CCACHE_MAXSIZE = "180M"
   - $env:CCACHE_DEPEND = 1 # cache misses are too expensive with preprocessor mode
   - $env:CC = "ccache gcc"
+  - $env:LIBCLANG_PATH = Join-Path -Path $PWD.Path -ChildPath "msys64/mingw64/bin"
   - mkdir build
   - cd build
   - ..\msys64\usr\bin\bash -lc "ccache --zero-stats"
-- 
2.52.0