[PATCH 00/19] Enable QEMU TCI to run 32bit guests on browsers

[PATCH 00/19] Enable QEMU TCI to run 32bit guests on browsers

[Kohei Tokunaga]

This patch series is split from the original "Enable QEMU to run on
browsers" series, focusing solely on the essential code changes needed to
compile QEMU TCI with Emscripten. It also inclues fixes based on feedback
received in the original series, thank you for the comments.

# Supported features in this series

This patch series enables TCI interpreter mode with 32bit guest
support. While the original series included the non-TCI backend and 9pfs
patches, those components are not included here. They will be reintroduced
in follow-up series after the foundational patches have been merged.

# Emscripten-Based Coroutine Backend

Emscripten does not support couroutine methods currently used by QEMU but
provides a coroutine implementation called "fiber". This patch series
introduces a coroutine backend using fiber. However, fiber does not support
submitting coroutines to other threads. As a result, this patch series
doesn't support components like hw/9pfs, which rely on that behavior.

# Overview of build process

This section provides an overview of the build process for compiling QEMU
using Emscripten. Full instructions are available in the sample
repository[1].

To compile QEMU with Emscripten, the following dependencies are required.
The emsdk-wasm32-cross.docker environment includes all necessary components
and can be used as the build environment:

- Emscripten SDK (emsdk) v3.1.50
- Libraries cross-compiled with Emscripten (refer to
  emsdk-wasm32-cross.docker for build steps)
  - GLib v2.84.0
  - zlib v1.3.1
  - libffi v3.4.7
  - Pixman v0.44.2

QEMU can be compiled using Emscripten's emconfigure and emmake, which
automatically set environment variables such as CC for targeting Emscripten.

emconfigure configure --static --disable-tools \
                      --target-list=arm-softmmu --enable-tcg-interpreter
emmake make -j$(nproc)

This process generates the following files:

- qemu-system-arm.js
- qemu-system-arm.wasm
- qemu-system-arm.worker.js

Guest images can be packaged using Emscripten's file_packager.py tool.
For example, if the images are stored in a directory named "pack", the
following command packages them, allowing QEMU to access them through
Emscripten's virtual filesystem:

/path/to/file_packager.py qemu-system-arm.data --preload pack > load.js

This process generates the following files:

- qemu-system-arm.data
- load.js

Emscripten allows passing arguments to the QEMU command via the Module
object in JavaScript:

Module['arguments'] = [
    '-nographic', '-m', '512M', '-machine', 'virt',
    '-L', 'pack/',
    '-global', 'virtio-mmio.force-legacy=false',
    '-device', 'virtio-blk-device,drive=d0',
    '-drive', 'file=pack/rootfs.bin,if=none,format=raw,id=d0',
    '-kernel', 'pack/kernel.img',
    '-append', 'console=ttyAMA0 root=/dev/vda loglevel=7',
];

The sample repository[1] provides a complete setup, including an HTML file
that implements a terminal UI.

[1] https://github.com/ktock/qemu-wasm-sample/tree/tcidev

# Additional references

- Original patch series "Enable QEMU to run on browsers":
  https://patchew.org/QEMU/cover.1744032780.git.ktokunaga.mail@gmail.com/
- A talk at FOSDEM 2025:
  https://fosdem.org/2025/schedule/event/fosdem-2025-6290-running-qemu-inside-browser/

Kohei Tokunaga (19):
  hw/core/loader.c: Fix type conflict of GLib function pointers
  qom/object.c: Fix type conflict of GLib function pointers
  system/vl.c: Fix type conflict of GLib function pointers
  target/arm/helper.c: Fix type conflict of GLib function pointers
  target/i386/cpu.c: Fix type conflict of GLib function pointers
  contrib/plugins: Fix type conflict of GLib function pointers
  hw/net/can: Fix type conflict of GLib function pointers
  target/ppc: Fix type conflict of GLib function pointers
  target/s390x: Fix type conflict of GLib function pointers
  include/glib-compat.h: Poison g_list_sort and g_slist_sort
  util/cacheflush.c: Update cache flushing mechanism for Emscripten
  block: Update block to compile with Emscripten
  include/qemu/osdep.h: Add Emscripten-specific OS dependencies
  Disable options unsupported on Emscripten
  util/mmap-alloc: Add qemu_ram_mmap implementation for emscripten
  util: Add coroutine backend for emscripten
  meson: Add wasm build in build scripts
  gitlab: Enable CI for wasm build
  MAINTAINERS: Update MAINTAINERS file for wasm-related files

 .gitlab-ci.d/buildtest-template.yml           |  27 ++++
 .gitlab-ci.d/buildtest.yml                    |   9 ++
 .gitlab-ci.d/container-cross.yml              |   5 +
 MAINTAINERS                                   |  10 ++
 block/file-posix.c                            |   6 +
 configs/meson/emscripten.txt                  |   8 +
 configure                                     |   7 +
 contrib/plugins/cache.c                       |  12 +-
 contrib/plugins/cflow.c                       |  10 +-
 contrib/plugins/hotblocks.c                   |   4 +-
 contrib/plugins/hotpages.c                    |   4 +-
 contrib/plugins/howvec.c                      |   4 +-
 contrib/plugins/hwprofile.c                   |   8 +-
 hw/core/loader.c                              |   4 +-
 hw/net/can/xlnx-versal-canfd.c                |   4 +-
 include/glib-compat.h                         |   6 +
 include/qemu/cacheflush.h                     |   3 +-
 include/qemu/osdep.h                          |   8 +-
 include/system/os-posix.h                     |   3 +-
 include/system/os-wasm.h                      | 105 +++++++++++++
 meson.build                                   |  25 ++-
 meson_options.txt                             |   2 +-
 os-wasm.c                                     | 119 ++++++++++++++
 qemu-options.hx                               |   4 +-
 qom/object.c                                  |   7 +-
 scripts/meson-buildoptions.sh                 |   2 +-
 stubs/emscripten.c                            |  13 ++
 stubs/meson.build                             |   4 +
 system/vl.c                                   |   8 +-
 target/arm/helper.c                           |   4 +-
 target/i386/cpu.c                             |  11 +-
 target/ppc/cpu_init.c                         |   4 +-
 target/s390x/cpu_models.c                     |   4 +-
 .../dockerfiles/emsdk-wasm32-cross.docker     | 145 ++++++++++++++++++
 tests/tcg/plugins/mem.c                       |   4 +-
 tests/tcg/plugins/syscall.c                   |   4 +-
 util/cacheflush.c                             |   3 +-
 util/coroutine-wasm.c                         | 127 +++++++++++++++
 util/mmap-alloc.c                             |  18 +++
 39 files changed, 697 insertions(+), 58 deletions(-)
 create mode 100644 configs/meson/emscripten.txt
 create mode 100644 include/system/os-wasm.h
 create mode 100644 os-wasm.c
 create mode 100644 stubs/emscripten.c
 create mode 100644 tests/docker/dockerfiles/emsdk-wasm32-cross.docker
 create mode 100644 util/coroutine-wasm.c

-- 
2.25.1

[PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_list_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 hw/core/loader.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 2e35f0aa90..93a8b45d28 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -1410,7 +1410,7 @@ typedef struct RomSec {
  * work, but this way saves a little work later by avoiding
  * dealing with "gaps" of 0 length.
  */
-static gint sort_secs(gconstpointer a, gconstpointer b)
+static gint sort_secs(gconstpointer a, gconstpointer b, gpointer d)
 {
     RomSec *ra = (RomSec *) a;
     RomSec *rb = (RomSec *) b;
@@ -1463,7 +1463,7 @@ RomGap rom_find_largest_gap_between(hwaddr base, size_t size)
     /* sentinel */
     secs = add_romsec_to_list(secs, base + size, 1);
 
-    secs = g_list_sort(secs, sort_secs);
+    secs = g_list_sort_with_data(secs, sort_secs, NULL);
 
     for (it = g_list_first(secs); it; it = g_list_next(it)) {
         cand = (RomSec *) it->data;
-- 
2.25.1

Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Daniel P. Berrangé]

On Wed, Apr 16, 2025 at 05:14:06PM +0900, Kohei Tokunaga wrote:
> On emscripten, function pointer casts can cause function call failure.
> This commit fixes the function definition to match to the type of the
> function call using g_list_sort_with_data.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>  hw/core/loader.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index 2e35f0aa90..93a8b45d28 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -1410,7 +1410,7 @@ typedef struct RomSec {
>   * work, but this way saves a little work later by avoiding
>   * dealing with "gaps" of 0 length.
>   */
> -static gint sort_secs(gconstpointer a, gconstpointer b)
> +static gint sort_secs(gconstpointer a, gconstpointer b, gpointer d)
>  {
>      RomSec *ra = (RomSec *) a;
>      RomSec *rb = (RomSec *) b;
> @@ -1463,7 +1463,7 @@ RomGap rom_find_largest_gap_between(hwaddr base, size_t size)
>      /* sentinel */
>      secs = add_romsec_to_list(secs, base + size, 1);
>  
> -    secs = g_list_sort(secs, sort_secs);
> +    secs = g_list_sort_with_data(secs, sort_secs, NULL);

I don't see what the problem is with the original code.

The commit message says we have a bad function cast, but the original
method decl is

  GList *g_list_sort(GList*list, GCompareFunc compare_func);

where the callback is

   typedef gint (*GCompareFunc)(gconstpointer a, gconstpointer b);

Our code complies with that GCompareFunc signature.

For comparison the new code uses:

  GList *g_list_sort_with_data(GList *list, GCompareDataFunc  compare_func, gpointer user_data);

where the callback is

  typedef gint (*GCompareDataFunc)(gconstpointer a, gconstpointer b, gpointer user_data);

which the new code complies with, but it is undesirable since we
have no use for the data parameter.

With regards,
Daniel
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Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Paolo Bonzini]

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Il mer 16 apr 2025, 10:29 Daniel P. Berrangé <berrange@redhat.com> ha
scritto:

> > -    secs = g_list_sort(secs, sort_secs);
> > +    secs = g_list_sort_with_data(secs, sort_secs, NULL);
>
> I don't see what the problem is with the original code.
>
> The commit message says we have a bad function cast, but the original
> method decl is
>
>   GList *g_list_sort(GList*list, GCompareFunc compare_func);
>
> where the callback is
>
>    typedef gint (*GCompareFunc)(gconstpointer a, gconstpointer b);
>
> Our code complies with that GCompareFunc signature.
>

The cast is inside glib; g_list_sort casts the function pointer and calls
g_list_sort_with_data.

I suggested this solution to Kohei because it's easy to check that we're
converting all users and not introducing new ones in the future (see
poisoning in patch 10).

Paolo

For comparison the new code uses:
>
>   GList *g_list_sort_with_data(GList *list, GCompareDataFunc
> compare_func, gpointer user_data);
>
> where the callback is
>
>   typedef gint (*GCompareDataFunc)(gconstpointer a, gconstpointer b,
> gpointer user_data);
>
> which the new code complies with, but it is undesirable since we
> have no use for the data parameter.
>
> With regards,
> Daniel
> --
> |: https://berrange.com      -o-
> https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-
> https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-
> https://www.instagram.com/dberrange :|
>
>

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Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Daniel P. Berrangé]

On Wed, Apr 16, 2025 at 11:00:37AM +0200, Paolo Bonzini wrote:
> Il mer 16 apr 2025, 10:29 Daniel P. Berrangé <berrange@redhat.com> ha
> scritto:
> 
> > > -    secs = g_list_sort(secs, sort_secs);
> > > +    secs = g_list_sort_with_data(secs, sort_secs, NULL);
> >
> > I don't see what the problem is with the original code.
> >
> > The commit message says we have a bad function cast, but the original
> > method decl is
> >
> >   GList *g_list_sort(GList*list, GCompareFunc compare_func);
> >
> > where the callback is
> >
> >    typedef gint (*GCompareFunc)(gconstpointer a, gconstpointer b);
> >
> > Our code complies with that GCompareFunc signature.
> >
> 
> The cast is inside glib; g_list_sort casts the function pointer and calls
> g_list_sort_with_data.

Sigh, the commit message should have said that, as it reads like the
problem is in QEMU code, not glib code.

> I suggested this solution to Kohei because it's easy to check that we're
> converting all users and not introducing new ones in the future (see
> poisoning in patch 10).

It is easy to check this /one/ example, but this pattern of bad casts
is typical in glib with likely many more examples, so avoidance in this
way does not feel like a sustainable long term strategy to me.


With regards,
Daniel
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Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Paolo Bonzini]

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Il mer 16 apr 2025, 11:12 Daniel P. Berrangé <berrange@redhat.com> ha
scritto:

> > I suggested this solution to Kohei because it's easy to check that we're
> > converting all users and not introducing new ones in the future (see
> > poisoning in patch 10).
>
> It is easy to check this /one/ example, but this pattern of bad casts
> is typical in glib with likely many more examples, so avoidance in this
> way does not feel like a sustainable long term strategy to me.
>

If you refer to the general case of function casting then yes, I agree that
there could be other problems in the future but that would have to be
solved in glib.

However QEMU's use of glib is overall relatively limited and for now this
seems to be the only case we hit. What this patch is doing is both
effective at solving the immediate issue, and future proof.

Paolo


>
> With regards,
> Daniel
> --
> |: https://berrange.com      -o-
> https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-
> https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-
> https://www.instagram.com/dberrange :|
>
>

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Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 1152 bytes --]

Hi Daniel, Paolo and Thomas,

> > > I suggested this solution to Kohei because it's easy to check that
we're
> > > converting all users and not introducing new ones in the future (see
> > > poisoning in patch 10).
> >
> > It is easy to check this /one/ example, but this pattern of bad casts
> > is typical in glib with likely many more examples, so avoidance in this
> > way does not feel like a sustainable long term strategy to me.
>
> If you refer to the general case of function casting then yes, I agree
that there could be other problems in the future but that would have to be
solved in glib.
>
> However QEMU's use of glib is overall relatively limited and for now this
seems to be the only case we hit. What this patch is doing is both
effective at solving the immediate issue, and future proof.

The current patch addresses the cases we've encountered so far, and the
poisoning will help catch the usage of them in future development.

That said, it's worth continuing to explore a more robust solution. I've
submitted an issue to the GLib repository to investigate a long-term fix[1].

[1] https://gitlab.gnome.org/GNOME/glib/-/issues/3670

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Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Thomas Huth]

On 16/04/2025 11.00, Paolo Bonzini wrote:
> 
> 
> Il mer 16 apr 2025, 10:29 Daniel P. Berrangé <berrange@redhat.com 
> <mailto:berrange@redhat.com>> ha scritto:
> 
>      > -    secs = g_list_sort(secs, sort_secs);
>      > +    secs = g_list_sort_with_data(secs, sort_secs, NULL);
> 
>     I don't see what the problem is with the original code.
> 
>     The commit message says we have a bad function cast, but the original
>     method decl is
> 
>        GList *g_list_sort(GList*list, GCompareFunc compare_func);
> 
>     where the callback is
> 
>         typedef gint (*GCompareFunc)(gconstpointer a, gconstpointer b);
> 
>     Our code complies with that GCompareFunc signature.
> 
> 
> The cast is inside glib; g_list_sort casts the function pointer and calls 
> g_list_sort_with_data.

Did anybody already report this to the glib people? I guess it should get 
fixed there in the long run...?

  Thomas

Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Philippe Mathieu-Daudé]

On 16/4/25 10:28, Daniel P. Berrangé wrote:
> On Wed, Apr 16, 2025 at 05:14:06PM +0900, Kohei Tokunaga wrote:
>> On emscripten, function pointer casts can cause function call failure.
>> This commit fixes the function definition to match to the type of the
>> function call using g_list_sort_with_data.
>>
>> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
>> ---
>>   hw/core/loader.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/core/loader.c b/hw/core/loader.c
>> index 2e35f0aa90..93a8b45d28 100644
>> --- a/hw/core/loader.c
>> +++ b/hw/core/loader.c
>> @@ -1410,7 +1410,7 @@ typedef struct RomSec {
>>    * work, but this way saves a little work later by avoiding
>>    * dealing with "gaps" of 0 length.
>>    */
>> -static gint sort_secs(gconstpointer a, gconstpointer b)
>> +static gint sort_secs(gconstpointer a, gconstpointer b, gpointer d)
>>   {
>>       RomSec *ra = (RomSec *) a;
>>       RomSec *rb = (RomSec *) b;
>> @@ -1463,7 +1463,7 @@ RomGap rom_find_largest_gap_between(hwaddr base, size_t size)
>>       /* sentinel */
>>       secs = add_romsec_to_list(secs, base + size, 1);
>>   
>> -    secs = g_list_sort(secs, sort_secs);
>> +    secs = g_list_sort_with_data(secs, sort_secs, NULL);
> 
> I don't see what the problem is with the original code.

IIUC the rationale is in patch #10 where Kohei poisons g_list_sort():

   On emscripten, function pointer casts can cause function call
   failure. g_list_sort and g_slist_sort performs this internally
   so can't be used on Emscripten. Instead, g_list_sort_with_data
   and g_slist_sort_with_data should be used.

> 
> The commit message says we have a bad function cast, but the original
> method decl is
> 
>    GList *g_list_sort(GList*list, GCompareFunc compare_func);
> 
> where the callback is
> 
>     typedef gint (*GCompareFunc)(gconstpointer a, gconstpointer b);
> 
> Our code complies with that GCompareFunc signature.
> 
> For comparison the new code uses:
> 
>    GList *g_list_sort_with_data(GList *list, GCompareDataFunc  compare_func, gpointer user_data);
> 
> where the callback is
> 
>    typedef gint (*GCompareDataFunc)(gconstpointer a, gconstpointer b, gpointer user_data);
> 
> which the new code complies with, but it is undesirable since we
> have no use for the data parameter.
> 
> With regards,
> Daniel

Re: [PATCH 01/19] hw/core/loader.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 1769 bytes --]

Hi Daniel and Philippe,

>>> On emscripten, function pointer casts can cause function call failure.
>>> This commit fixes the function definition to match to the type of the
>>> function call using g_list_sort_with_data.
>>>
>>> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
>>> ---
>>>   hw/core/loader.c | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/hw/core/loader.c b/hw/core/loader.c
>>> index 2e35f0aa90..93a8b45d28 100644
>>> --- a/hw/core/loader.c
>>> +++ b/hw/core/loader.c
>>> @@ -1410,7 +1410,7 @@ typedef struct RomSec {
>>>    * work, but this way saves a little work later by avoiding
>>>    * dealing with "gaps" of 0 length.
>>>    */
>>> -static gint sort_secs(gconstpointer a, gconstpointer b)
>>> +static gint sort_secs(gconstpointer a, gconstpointer b, gpointer d)
>>>   {
>>>       RomSec *ra = (RomSec *) a;
>>>       RomSec *rb = (RomSec *) b;
>>> @@ -1463,7 +1463,7 @@ RomGap rom_find_largest_gap_between(hwaddr base,
size_t size)
>>>       /* sentinel */
>>>       secs = add_romsec_to_list(secs, base + size, 1);
>>>
>>> -    secs = g_list_sort(secs, sort_secs);
>>> +    secs = g_list_sort_with_data(secs, sort_secs, NULL);
>>
>> I don't see what the problem is with the original code.
>
>IIUC the rationale is in patch #10 where Kohei poisons g_list_sort():
>
>   On emscripten, function pointer casts can cause function call
>   failure. g_list_sort and g_slist_sort performs this internally
>   so can't be used on Emscripten. Instead, g_list_sort_with_data
>   and g_slist_sort_with_data should be used.

Thank you for the feedback. As Philippe pointed out, the rationale is
explained in the patch #10. I'll make sure to include the explanation in
the commit message of this patch as well.

[-- Attachment #2: Type: text/html, Size: 2342 bytes --]

[PATCH 02/19] qom/object.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 qom/object.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/qom/object.c b/qom/object.c
index 01618d06bd..87f84bac41 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -1191,7 +1191,7 @@ GSList *object_class_get_list(const char *implements_type,
     return list;
 }
 
-static gint object_class_cmp(gconstpointer a, gconstpointer b)
+static gint object_class_cmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     return strcasecmp(object_class_get_name((ObjectClass *)a),
                       object_class_get_name((ObjectClass *)b));
@@ -1200,8 +1200,9 @@ static gint object_class_cmp(gconstpointer a, gconstpointer b)
 GSList *object_class_get_list_sorted(const char *implements_type,
                                      bool include_abstract)
 {
-    return g_slist_sort(object_class_get_list(implements_type, include_abstract),
-                        object_class_cmp);
+    return g_slist_sort_with_data(
+        object_class_get_list(implements_type, include_abstract),
+        object_class_cmp, NULL);
 }
 
 Object *object_ref(void *objptr)
-- 
2.25.1

[PATCH 03/19] system/vl.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 system/vl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/system/vl.c b/system/vl.c
index ec93988a03..8d89394b45 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -1523,7 +1523,7 @@ static bool debugcon_parse(const char *devname, Error **errp)
     return true;
 }
 
-static gint machine_class_cmp(gconstpointer a, gconstpointer b)
+static gint machine_class_cmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     const MachineClass *mc1 = a, *mc2 = b;
     int res;
@@ -1573,7 +1573,7 @@ static void machine_help_func(const QDict *qdict)
     }
 
     printf("Supported machines are:\n");
-    machines = g_slist_sort(machines, machine_class_cmp);
+    machines = g_slist_sort_with_data(machines, machine_class_cmp, NULL);
     for (el = machines; el; el = el->next) {
         MachineClass *mc = el->data;
         if (mc->alias) {
-- 
2.25.1

[PATCH 04/19] target/arm/helper.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_list_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 target/arm/helper.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index bb445e30cd..05793a6c97 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -220,7 +220,7 @@ static void count_cpreg(gpointer key, gpointer opaque)
     }
 }
 
-static gint cpreg_key_compare(gconstpointer a, gconstpointer b)
+static gint cpreg_key_compare(gconstpointer a, gconstpointer b, void *d)
 {
     uint64_t aidx = cpreg_to_kvm_id((uintptr_t)a);
     uint64_t bidx = cpreg_to_kvm_id((uintptr_t)b);
@@ -244,7 +244,7 @@ void init_cpreg_list(ARMCPU *cpu)
     int arraylen;
 
     keys = g_hash_table_get_keys(cpu->cp_regs);
-    keys = g_list_sort(keys, cpreg_key_compare);
+    keys = g_list_sort_with_data(keys, cpreg_key_compare, NULL);
 
     cpu->cpreg_array_len = 0;
 
-- 
2.25.1

[PATCH 05/19] target/i386/cpu.c: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_list_sort_with_data and g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 target/i386/cpu.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 1b64ceaaba..2c494e4b0b 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6226,7 +6226,7 @@ static void listflags(GList *features)
 }
 
 /* Sort alphabetically by type name, respecting X86CPUClass::ordering. */
-static gint x86_cpu_list_compare(gconstpointer a, gconstpointer b)
+static gint x86_cpu_list_compare(gconstpointer a, gconstpointer b, gpointer d)
 {
     ObjectClass *class_a = (ObjectClass *)a;
     ObjectClass *class_b = (ObjectClass *)b;
@@ -6247,7 +6247,7 @@ static gint x86_cpu_list_compare(gconstpointer a, gconstpointer b)
 static GSList *get_sorted_cpu_model_list(void)
 {
     GSList *list = object_class_get_list(TYPE_X86_CPU, false);
-    list = g_slist_sort(list, x86_cpu_list_compare);
+    list = g_slist_sort_with_data(list, x86_cpu_list_compare, NULL);
     return list;
 }
 
@@ -6304,6 +6304,11 @@ static void x86_cpu_list_entry(gpointer data, gpointer user_data)
     qemu_printf("  %-20s  %s\n", name, desc);
 }
 
+static gint strcmp_wrap(gconstpointer a, gconstpointer b, gpointer d)
+{
+    return strcmp(a, b);
+}
+
 /* list available CPU models and flags */
 void x86_cpu_list(void)
 {
@@ -6326,7 +6331,7 @@ void x86_cpu_list(void)
         }
     }
 
-    names = g_list_sort(names, (GCompareFunc)strcmp);
+    names = g_list_sort_with_data(names, strcmp_wrap, NULL);
 
     qemu_printf("\nRecognized CPUID flags:\n");
     listflags(names);
-- 
2.25.1

[PATCH 06/19] contrib/plugins: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_list_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 contrib/plugins/cache.c     | 12 ++++++------
 contrib/plugins/cflow.c     | 10 +++++-----
 contrib/plugins/hotblocks.c |  4 ++--
 contrib/plugins/hotpages.c  |  4 ++--
 contrib/plugins/howvec.c    |  4 ++--
 contrib/plugins/hwprofile.c |  8 ++++----
 tests/tcg/plugins/mem.c     |  4 ++--
 tests/tcg/plugins/syscall.c |  4 ++--
 8 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/contrib/plugins/cache.c b/contrib/plugins/cache.c
index 7cfd3df249..56508587d3 100644
--- a/contrib/plugins/cache.c
+++ b/contrib/plugins/cache.c
@@ -576,7 +576,7 @@ static void sum_stats(void)
     }
 }
 
-static int dcmp(gconstpointer a, gconstpointer b)
+static int dcmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     InsnData *insn_a = (InsnData *) a;
     InsnData *insn_b = (InsnData *) b;
@@ -584,7 +584,7 @@ static int dcmp(gconstpointer a, gconstpointer b)
     return insn_a->l1_dmisses < insn_b->l1_dmisses ? 1 : -1;
 }
 
-static int icmp(gconstpointer a, gconstpointer b)
+static int icmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     InsnData *insn_a = (InsnData *) a;
     InsnData *insn_b = (InsnData *) b;
@@ -592,7 +592,7 @@ static int icmp(gconstpointer a, gconstpointer b)
     return insn_a->l1_imisses < insn_b->l1_imisses ? 1 : -1;
 }
 
-static int l2_cmp(gconstpointer a, gconstpointer b)
+static int l2_cmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     InsnData *insn_a = (InsnData *) a;
     InsnData *insn_b = (InsnData *) b;
@@ -645,7 +645,7 @@ static void log_top_insns(void)
     InsnData *insn;
 
     miss_insns = g_hash_table_get_values(miss_ht);
-    miss_insns = g_list_sort(miss_insns, dcmp);
+    miss_insns = g_list_sort_with_data(miss_insns, dcmp, NULL);
     g_autoptr(GString) rep = g_string_new("");
     g_string_append_printf(rep, "%s", "address, data misses, instruction\n");
 
@@ -659,7 +659,7 @@ static void log_top_insns(void)
                                insn->l1_dmisses, insn->disas_str);
     }
 
-    miss_insns = g_list_sort(miss_insns, icmp);
+    miss_insns = g_list_sort_with_data(miss_insns, icmp, NULL);
     g_string_append_printf(rep, "%s", "\naddress, fetch misses, instruction\n");
 
     for (curr = miss_insns, i = 0; curr && i < limit; i++, curr = curr->next) {
@@ -676,7 +676,7 @@ static void log_top_insns(void)
         goto finish;
     }
 
-    miss_insns = g_list_sort(miss_insns, l2_cmp);
+    miss_insns = g_list_sort_with_data(miss_insns, l2_cmp, NULL);
     g_string_append_printf(rep, "%s", "\naddress, L2 misses, instruction\n");
 
     for (curr = miss_insns, i = 0; curr && i < limit; i++, curr = curr->next) {
diff --git a/contrib/plugins/cflow.c b/contrib/plugins/cflow.c
index 930ecb46fc..b5e33f25f9 100644
--- a/contrib/plugins/cflow.c
+++ b/contrib/plugins/cflow.c
@@ -98,7 +98,7 @@ static GHashTable *nodes;
 struct qemu_plugin_scoreboard *state;
 
 /* SORT_HOTTEST */
-static gint hottest(gconstpointer a, gconstpointer b)
+static gint hottest(gconstpointer a, gconstpointer b, gpointer d)
 {
     NodeData *na = (NodeData *) a;
     NodeData *nb = (NodeData *) b;
@@ -107,7 +107,7 @@ static gint hottest(gconstpointer a, gconstpointer b)
         na->dest_count == nb->dest_count ? 0 : 1;
 }
 
-static gint exception(gconstpointer a, gconstpointer b)
+static gint exception(gconstpointer a, gconstpointer b, gpointer d)
 {
     NodeData *na = (NodeData *) a;
     NodeData *nb = (NodeData *) b;
@@ -116,7 +116,7 @@ static gint exception(gconstpointer a, gconstpointer b)
         na->early_exit == nb->early_exit ? 0 : 1;
 }
 
-static gint popular(gconstpointer a, gconstpointer b)
+static gint popular(gconstpointer a, gconstpointer b, gpointer d)
 {
     NodeData *na = (NodeData *) a;
     NodeData *nb = (NodeData *) b;
@@ -138,7 +138,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
 {
     g_autoptr(GString) result = g_string_new("collected ");
     GList *data;
-    GCompareFunc sort = &hottest;
+    GCompareDataFunc sort = &hottest;
     int i = 0;
 
     g_mutex_lock(&node_lock);
@@ -162,7 +162,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
         break;
     }
 
-    data = g_list_sort(data, sort);
+    data = g_list_sort_with_data(data, sort, NULL);
 
     for (GList *l = data;
          l != NULL && i < topn;
diff --git a/contrib/plugins/hotblocks.c b/contrib/plugins/hotblocks.c
index f12bfb7a26..98404b6885 100644
--- a/contrib/plugins/hotblocks.c
+++ b/contrib/plugins/hotblocks.c
@@ -39,7 +39,7 @@ typedef struct {
     unsigned long insns;
 } ExecCount;
 
-static gint cmp_exec_count(gconstpointer a, gconstpointer b)
+static gint cmp_exec_count(gconstpointer a, gconstpointer b, gpointer d)
 {
     ExecCount *ea = (ExecCount *) a;
     ExecCount *eb = (ExecCount *) b;
@@ -79,7 +79,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     g_string_append_printf(report, "%d entries in the hash table\n",
                            g_hash_table_size(hotblocks));
     counts = g_hash_table_get_values(hotblocks);
-    it = g_list_sort(counts, cmp_exec_count);
+    it = g_list_sort_with_data(counts, cmp_exec_count, NULL);
 
     if (it) {
         g_string_append_printf(report, "pc, tcount, icount, ecount\n");
diff --git a/contrib/plugins/hotpages.c b/contrib/plugins/hotpages.c
index c6e6493719..9d48ac969e 100644
--- a/contrib/plugins/hotpages.c
+++ b/contrib/plugins/hotpages.c
@@ -48,7 +48,7 @@ typedef struct {
 static GMutex lock;
 static GHashTable *pages;
 
-static gint cmp_access_count(gconstpointer a, gconstpointer b)
+static gint cmp_access_count(gconstpointer a, gconstpointer b, gpointer d)
 {
     PageCounters *ea = (PageCounters *) a;
     PageCounters *eb = (PageCounters *) b;
@@ -83,7 +83,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     if (counts && g_list_next(counts)) {
         GList *it;
 
-        it = g_list_sort(counts, cmp_access_count);
+        it = g_list_sort_with_data(counts, cmp_access_count, NULL);
 
         for (i = 0; i < limit && it->next; i++, it = it->next) {
             PageCounters *rec = (PageCounters *) it->data;
diff --git a/contrib/plugins/howvec.c b/contrib/plugins/howvec.c
index 2aa9029c3f..42bddb6566 100644
--- a/contrib/plugins/howvec.c
+++ b/contrib/plugins/howvec.c
@@ -155,7 +155,7 @@ static ClassSelector class_tables[] = {
 static InsnClassExecCount *class_table;
 static int class_table_sz;
 
-static gint cmp_exec_count(gconstpointer a, gconstpointer b)
+static gint cmp_exec_count(gconstpointer a, gconstpointer b, gpointer d)
 {
     InsnExecCount *ea = (InsnExecCount *) a;
     InsnExecCount *eb = (InsnExecCount *) b;
@@ -208,7 +208,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     counts = g_hash_table_get_values(insns);
     if (counts && g_list_next(counts)) {
         g_string_append_printf(report, "Individual Instructions:\n");
-        counts = g_list_sort(counts, cmp_exec_count);
+        counts = g_list_sort_with_data(counts, cmp_exec_count, NULL);
 
         for (i = 0; i < limit && g_list_next(counts);
              i++, counts = g_list_next(counts)) {
diff --git a/contrib/plugins/hwprofile.c b/contrib/plugins/hwprofile.c
index 2a4cbc47d4..a9838ccc87 100644
--- a/contrib/plugins/hwprofile.c
+++ b/contrib/plugins/hwprofile.c
@@ -71,7 +71,7 @@ static void plugin_init(void)
     devices = g_hash_table_new(NULL, NULL);
 }
 
-static gint sort_cmp(gconstpointer a, gconstpointer b)
+static gint sort_cmp(gconstpointer a, gconstpointer b, gpointer d)
 {
     DeviceCounts *ea = (DeviceCounts *) a;
     DeviceCounts *eb = (DeviceCounts *) b;
@@ -79,7 +79,7 @@ static gint sort_cmp(gconstpointer a, gconstpointer b)
            eb->totals.reads + eb->totals.writes ? -1 : 1;
 }
 
-static gint sort_loc(gconstpointer a, gconstpointer b)
+static gint sort_loc(gconstpointer a, gconstpointer b, gpointer d)
 {
     IOLocationCounts *ea = (IOLocationCounts *) a;
     IOLocationCounts *eb = (IOLocationCounts *) b;
@@ -126,13 +126,13 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     if (counts && g_list_next(counts)) {
         GList *it;
 
-        it = g_list_sort(counts, sort_cmp);
+        it = g_list_sort_with_data(counts, sort_cmp, NULL);
 
         while (it) {
             DeviceCounts *rec = (DeviceCounts *) it->data;
             if (rec->detail) {
                 GList *accesses = g_hash_table_get_values(rec->detail);
-                GList *io_it = g_list_sort(accesses, sort_loc);
+                GList *io_it = g_list_sort_with_data(accesses, sort_loc, NULL);
                 const char *prefix = pattern ? "off" : "pc";
                 g_string_append_printf(report, "%s @ 0x%"PRIx64"\n",
                                        rec->name, rec->base);
diff --git a/tests/tcg/plugins/mem.c b/tests/tcg/plugins/mem.c
index d87d6628e0..ca4e8883dd 100644
--- a/tests/tcg/plugins/mem.c
+++ b/tests/tcg/plugins/mem.c
@@ -67,7 +67,7 @@ static enum qemu_plugin_mem_rw rw = QEMU_PLUGIN_MEM_RW;
 static GMutex lock;
 static GHashTable *regions;
 
-static gint addr_order(gconstpointer a, gconstpointer b)
+static gint addr_order(gconstpointer a, gconstpointer b, gpointer d)
 {
     RegionInfo *na = (RegionInfo *) a;
     RegionInfo *nb = (RegionInfo *) b;
@@ -94,7 +94,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
     if (do_region_summary) {
         GList *counts = g_hash_table_get_values(regions);
 
-        counts = g_list_sort(counts, addr_order);
+        counts = g_list_sort_with_data(counts, addr_order, NULL);
 
         g_string_printf(out, "Region Base, Reads, Writes, Seen all\n");
 
diff --git a/tests/tcg/plugins/syscall.c b/tests/tcg/plugins/syscall.c
index 47aad55fc1..42801f5c86 100644
--- a/tests/tcg/plugins/syscall.c
+++ b/tests/tcg/plugins/syscall.c
@@ -180,7 +180,7 @@ static void print_entry(gpointer val, gpointer user_data)
     qemu_plugin_outs(out);
 }
 
-static gint comp_func(gconstpointer ea, gconstpointer eb)
+static gint comp_func(gconstpointer ea, gconstpointer eb, gpointer d)
 {
     SyscallStats *ent_a = (SyscallStats *) ea;
     SyscallStats *ent_b = (SyscallStats *) eb;
@@ -197,7 +197,7 @@ static void plugin_exit(qemu_plugin_id_t id, void *p)
 
     g_mutex_lock(&lock);
     GList *entries = g_hash_table_get_values(statistics);
-    entries = g_list_sort(entries, comp_func);
+    entries = g_list_sort_with_data(entries, comp_func, NULL);
     qemu_plugin_outs("syscall no.  calls  errors\n");
 
     g_list_foreach(entries, print_entry, NULL);
-- 
2.25.1

[PATCH 07/19] hw/net/can: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 hw/net/can/xlnx-versal-canfd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/net/can/xlnx-versal-canfd.c b/hw/net/can/xlnx-versal-canfd.c
index dc242e9215..013ebc10dc 100644
--- a/hw/net/can/xlnx-versal-canfd.c
+++ b/hw/net/can/xlnx-versal-canfd.c
@@ -1278,7 +1278,7 @@ static void tx_fifo_stamp(XlnxVersalCANFDState *s, uint32_t tb0_regid)
     }
 }
 
-static gint g_cmp_ids(gconstpointer data1, gconstpointer data2)
+static gint g_cmp_ids(gconstpointer data1, gconstpointer data2, gpointer d)
 {
     tx_ready_reg_info *tx_reg_1 = (tx_ready_reg_info *) data1;
     tx_ready_reg_info *tx_reg_2 = (tx_ready_reg_info *) data2;
@@ -1318,7 +1318,7 @@ static GSList *prepare_tx_data(XlnxVersalCANFDState *s)
             temp->can_id = s->regs[reg_num];
             temp->reg_num = reg_num;
             list = g_slist_prepend(list, temp);
-            list = g_slist_sort(list, g_cmp_ids);
+            list = g_slist_sort_with_data(list, g_cmp_ids, NULL);
         }
 
         reg_ready >>= 1;
-- 
2.25.1

[PATCH 08/19] target/ppc: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 target/ppc/cpu_init.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index f81cb680fc..f03e48ba31 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -7115,7 +7115,7 @@ PowerPCCPUClass *ppc_cpu_get_family_class(PowerPCCPUClass *pcc)
 }
 
 /* Sort by PVR, ordering special case "host" last. */
-static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b)
+static gint ppc_cpu_list_compare(gconstpointer a, gconstpointer b, gpointer d)
 {
     ObjectClass *oc_a = (ObjectClass *)a;
     ObjectClass *oc_b = (ObjectClass *)b;
@@ -7183,7 +7183,7 @@ void ppc_cpu_list(void)
 
     qemu_printf("Available CPUs:\n");
     list = object_class_get_list(TYPE_POWERPC_CPU, false);
-    list = g_slist_sort(list, ppc_cpu_list_compare);
+    list = g_slist_sort_with_data(list, ppc_cpu_list_compare, NULL);
     g_slist_foreach(list, ppc_cpu_list_entry, NULL);
     g_slist_free(list);
 
-- 
2.25.1

[PATCH 09/19] target/s390x: Fix type conflict of GLib function pointers

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call failure.
This commit fixes the function definition to match to the type of the
function call using g_slist_sort_with_data.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 target/s390x/cpu_models.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index 93a05e43d7..48cdef285d 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -373,7 +373,7 @@ static void s390_print_cpu_model_list_entry(gpointer data, gpointer user_data)
     g_free(name);
 }
 
-static gint s390_cpu_list_compare(gconstpointer a, gconstpointer b)
+static gint s390_cpu_list_compare(gconstpointer a, gconstpointer b, gpointer d)
 {
     const S390CPUClass *cc_a = S390_CPU_CLASS((ObjectClass *)a);
     const S390CPUClass *cc_b = S390_CPU_CLASS((ObjectClass *)b);
@@ -415,7 +415,7 @@ void s390_cpu_list(void)
 
     qemu_printf("Available CPUs:\n");
     list = object_class_get_list(TYPE_S390_CPU, false);
-    list = g_slist_sort(list, s390_cpu_list_compare);
+    list = g_slist_sort_with_data(list, s390_cpu_list_compare, NULL);
     g_slist_foreach(list, s390_print_cpu_model_list_entry, NULL);
     g_slist_free(list);
 
-- 
2.25.1

[PATCH 10/19] include/glib-compat.h: Poison g_list_sort and g_slist_sort

[Kohei Tokunaga]

On emscripten, function pointer casts can cause function call
failure. g_list_sort and g_slist_sort performs this internally so can't be
used on Emscripten. Instead, g_list_sort_with_data and
g_slist_sort_with_data should be used.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 include/glib-compat.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/glib-compat.h b/include/glib-compat.h
index 86be439ba0..e441b396ef 100644
--- a/include/glib-compat.h
+++ b/include/glib-compat.h
@@ -36,6 +36,12 @@
 #include <pwd.h>
 #endif
 
+/* These functions perform function pointer casts which can cause function call
+ * failure on Emscripten. Use g_slist_sort_with_data and g_list_sort_with_data
+ * insted of these functions.
+ */
+#pragma GCC poison g_slist_sort g_list_sort
+
 /*
  * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
  * use of functions from newer GLib via this compat header needs a little
-- 
2.25.1

Re: [PATCH 10/19] include/glib-compat.h: Poison g_list_sort and g_slist_sort

[BALATON Zoltan]

On Wed, 16 Apr 2025, Kohei Tokunaga wrote:
> On emscripten, function pointer casts can cause function call
> failure. g_list_sort and g_slist_sort performs this internally so can't be
> used on Emscripten. Instead, g_list_sort_with_data and
> g_slist_sort_with_data should be used.
>
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
> include/glib-compat.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/glib-compat.h b/include/glib-compat.h
> index 86be439ba0..e441b396ef 100644
> --- a/include/glib-compat.h
> +++ b/include/glib-compat.h
> @@ -36,6 +36,12 @@
> #include <pwd.h>
> #endif
>
> +/* These functions perform function pointer casts which can cause function call
> + * failure on Emscripten. Use g_slist_sort_with_data and g_list_sort_with_data
> + * insted of these functions.

Typo: instead

Regards,
BALATON Zoltan

> + */
> +#pragma GCC poison g_slist_sort g_list_sort
> +
> /*
>  * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
>  * use of functions from newer GLib via this compat header needs a little
>

Re: [PATCH 10/19] include/glib-compat.h: Poison g_list_sort and g_slist_sort

[Kohei Tokunaga]

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Hi Balaton,

> Typo: instead

Thank you for the feedback. I'll fix this in the next version of the series.

[-- Attachment #2: Type: text/html, Size: 168 bytes --]

[PATCH 11/19] util/cacheflush.c: Update cache flushing mechanism for Emscripten

[Kohei Tokunaga]

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 include/qemu/cacheflush.h | 3 ++-
 util/cacheflush.c         | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/qemu/cacheflush.h b/include/qemu/cacheflush.h
index ae20bcda73..84969801e3 100644
--- a/include/qemu/cacheflush.h
+++ b/include/qemu/cacheflush.h
@@ -19,7 +19,8 @@
  * mappings of the same physical page(s).
  */
 
-#if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
+#if defined(__i386__) || defined(__x86_64__) || defined(__s390__) \
+    || defined(EMSCRIPTEN)
 
 static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
 {
diff --git a/util/cacheflush.c b/util/cacheflush.c
index 1d12899a39..e5aa256cd8 100644
--- a/util/cacheflush.c
+++ b/util/cacheflush.c
@@ -225,7 +225,8 @@ static void __attribute__((constructor)) init_cache_info(void)
  * Architecture (+ OS) specific cache flushing mechanisms.
  */
 
-#if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
+#if defined(__i386__) || defined(__x86_64__) || defined(__s390__) || \
+    defined(EMSCRIPTEN)
 
 /* Caches are coherent and do not require flushing; symbol inline. */
 
-- 
2.25.1

Re: [PATCH 11/19] util/cacheflush.c: Update cache flushing mechanism for Emscripten

[Philippe Mathieu-Daudé]

The "why?" isn't clearly described.

On 16/4/25 10:14, Kohei Tokunaga wrote:
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   include/qemu/cacheflush.h | 3 ++-
>   util/cacheflush.c         | 3 ++-
>   2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/include/qemu/cacheflush.h b/include/qemu/cacheflush.h
> index ae20bcda73..84969801e3 100644
> --- a/include/qemu/cacheflush.h
> +++ b/include/qemu/cacheflush.h
> @@ -19,7 +19,8 @@
>    * mappings of the same physical page(s).
>    */
>   
> -#if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
> +#if defined(__i386__) || defined(__x86_64__) || defined(__s390__) \
> +    || defined(EMSCRIPTEN)
>   
>   static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
>   {
> diff --git a/util/cacheflush.c b/util/cacheflush.c
> index 1d12899a39..e5aa256cd8 100644
> --- a/util/cacheflush.c
> +++ b/util/cacheflush.c
> @@ -225,7 +225,8 @@ static void __attribute__((constructor)) init_cache_info(void)
>    * Architecture (+ OS) specific cache flushing mechanisms.
>    */
>   
> -#if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
> +#if defined(__i386__) || defined(__x86_64__) || defined(__s390__) || \
> +    defined(EMSCRIPTEN)
>   
>   /* Caches are coherent and do not require flushing; symbol inline. */
>   

Re: [PATCH 11/19] util/cacheflush.c: Update cache flushing mechanism for Emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 886 bytes --]

Hi Philippe,

> The "why?" isn't clearly described.

Although __builtin___clear_cache is used to flush the instruction cache for
a specified memory region[1], this operation doesn't apply to wasm, as its
memory isn't executable. Moreover, Emscripten does not support this builtin
and fails to compile it with the following error.

> fatal error: error in backend: llvm.clear_cache is not supported on wasm

To resolve this, I've removed the call to __builtin___clear_cache.

I'll update this patch to include an explicit "#elif" branch with an
explanation, like the following:

+#elif defined(EMSCRIPTEN)
+
+/* Wasm does not have an executable memory region. */
+

Please let me know if I'm missing something or if there is a preferred way
to handle this case.

[1]
https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005f_005f_005fclear_005fcache

[-- Attachment #2: Type: text/html, Size: 1193 bytes --]

Re: [PATCH 11/19] util/cacheflush.c: Update cache flushing mechanism for Emscripten

[Philippe Mathieu-Daudé]

On 17/4/25 11:27, Kohei Tokunaga wrote:
> Hi Philippe,
> 
>  > The "why?" isn't clearly described.
> 

I'm happy with the following ...

> Although __builtin___clear_cache is used to flush the instruction cache for
> a specified memory region[1], this operation doesn't apply to wasm, as its
> memory isn't executable. Moreover, Emscripten does not support this builtin
> and fails to compile it with the following error.
> 
>  > fatal error: error in backend: llvm.clear_cache is not supported on wasm
> 
> To resolve this, I've removed the call to __builtin___clear_cache.

... used as commit description,

> 
> I'll update this patch to include an explicit "#elif" branch with an
> explanation, like the following:
> 
> +#elif defined(EMSCRIPTEN)
> +
> +/* Wasm does not have an executable memory region. */
> +

and this comment in the code. Thanks!

> 
> Please let me know if I'm missing something or if there is a preferred way
> to handle this case.
> 
> [1] https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/Other- 
> Builtins.html#index-_005f_005fbuiltin_005f_005f_005fclear_005fcache 
> <https://gcc.gnu.org/onlinedocs/gcc-14.2.0/gcc/Other- 
> Builtins.html#index-_005f_005fbuiltin_005f_005f_005fclear_005fcache>
> 

[PATCH 12/19] block: Update block to compile with Emscripten

[Kohei Tokunaga]

emscripten exposes copy_file_range declaration but doesn't provide the
implementation in the final link. Define the emscripten-specific stub
function to avoid type conflict with the emscripten's header.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 block/file-posix.c |  6 ++++++
 stubs/emscripten.c | 13 +++++++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 stubs/emscripten.c

diff --git a/block/file-posix.c b/block/file-posix.c
index 56d1972d15..22e0ed5069 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -110,6 +110,10 @@
 #include <sys/diskslice.h>
 #endif
 
+#ifdef EMSCRIPTEN
+#include <sys/ioctl.h>
+#endif
+
 /* OS X does not have O_DSYNC */
 #ifndef O_DSYNC
 #ifdef O_SYNC
@@ -2010,6 +2014,7 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
     return handle_aiocb_write_zeroes(aiocb);
 }
 
+#ifndef EMSCRIPTEN
 #ifndef HAVE_COPY_FILE_RANGE
 static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
                              off_t *out_off, size_t len, unsigned int flags)
@@ -2023,6 +2028,7 @@ static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
 #endif
 }
 #endif
+#endif
 
 /*
  * parse_zone - Fill a zone descriptor
diff --git a/stubs/emscripten.c b/stubs/emscripten.c
new file mode 100644
index 0000000000..2157d6349b
--- /dev/null
+++ b/stubs/emscripten.c
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#include "qemu/osdep.h"
+/*
+ * emscripten exposes copy_file_range declaration but doesn't provide the
+ * implementation in the final link. Define the stub here but avoid type
+ * conflict with the emscripten's header.
+ */
+ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
+                             off_t *out_off, size_t len, unsigned int flags)
+{
+    errno = ENOSYS;
+    return -1;
+}
-- 
2.25.1

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Philippe Mathieu-Daudé]

On 16/4/25 10:14, Kohei Tokunaga wrote:
> emscripten exposes copy_file_range declaration but doesn't provide the
> implementation in the final link. Define the emscripten-specific stub
> function to avoid type conflict with the emscripten's header.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   block/file-posix.c |  6 ++++++
>   stubs/emscripten.c | 13 +++++++++++++
>   2 files changed, 19 insertions(+)
>   create mode 100644 stubs/emscripten.c
> 
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 56d1972d15..22e0ed5069 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -110,6 +110,10 @@
>   #include <sys/diskslice.h>
>   #endif
>   
> +#ifdef EMSCRIPTEN
> +#include <sys/ioctl.h>
> +#endif
> +
>   /* OS X does not have O_DSYNC */
>   #ifndef O_DSYNC
>   #ifdef O_SYNC
> @@ -2010,6 +2014,7 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
>       return handle_aiocb_write_zeroes(aiocb);
>   }
>   
> +#ifndef EMSCRIPTEN
>   #ifndef HAVE_COPY_FILE_RANGE
>   static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>                                off_t *out_off, size_t len, unsigned int flags)
> @@ -2023,6 +2028,7 @@ static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>   #endif
>   }
>   #endif
> +#endif
>   
>   /*
>    * parse_zone - Fill a zone descriptor
> diff --git a/stubs/emscripten.c b/stubs/emscripten.c
> new file mode 100644
> index 0000000000..2157d6349b
> --- /dev/null
> +++ b/stubs/emscripten.c
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +#include "qemu/osdep.h"
> +/*
> + * emscripten exposes copy_file_range declaration but doesn't provide the
> + * implementation in the final link. Define the stub here but avoid type
> + * conflict with the emscripten's header.
> + */
> +ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
> +                             off_t *out_off, size_t len, unsigned int flags)
> +{
> +    errno = ENOSYS;
> +    return -1;
> +}

I'd include in this patch this hunk from patch 17:

-- >8 --
diff --git a/stubs/meson.build b/stubs/meson.build
index 63392f5e78..4fd4d362f9 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -89,3 +89,7 @@ if have_system or have_user
    stub_ss.add(files('hotplug-stubs.c'))
    stub_ss.add(files('sysbus.c'))
  endif
+
+if host_os == 'emscripten'
+  stub_ss.add(files('emscripten.c'))
+endif
---

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Philippe Mathieu-Daudé]

On 16/4/25 11:00, Philippe Mathieu-Daudé wrote:
> On 16/4/25 10:14, Kohei Tokunaga wrote:
>> emscripten exposes copy_file_range declaration but doesn't provide the
>> implementation in the final link. Define the emscripten-specific stub
>> function to avoid type conflict with the emscripten's header.
>>
>> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
>> ---
>>   block/file-posix.c |  6 ++++++
>>   stubs/emscripten.c | 13 +++++++++++++
>>   2 files changed, 19 insertions(+)
>>   create mode 100644 stubs/emscripten.c
>>
>> diff --git a/block/file-posix.c b/block/file-posix.c
>> index 56d1972d15..22e0ed5069 100644
>> --- a/block/file-posix.c
>> +++ b/block/file-posix.c
>> @@ -110,6 +110,10 @@
>>   #include <sys/diskslice.h>
>>   #endif
>> +#ifdef EMSCRIPTEN
>> +#include <sys/ioctl.h>
>> +#endif
>> +
>>   /* OS X does not have O_DSYNC */
>>   #ifndef O_DSYNC
>>   #ifdef O_SYNC
>> @@ -2010,6 +2014,7 @@ static int handle_aiocb_write_zeroes_unmap(void 
>> *opaque)
>>       return handle_aiocb_write_zeroes(aiocb);
>>   }
>> +#ifndef EMSCRIPTEN
>>   #ifndef HAVE_COPY_FILE_RANGE
>>   static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>>                                off_t *out_off, size_t len, unsigned 
>> int flags)
>> @@ -2023,6 +2028,7 @@ static off_t copy_file_range(int in_fd, off_t 
>> *in_off, int out_fd,
>>   #endif
>>   }
>>   #endif
>> +#endif
>>   /*
>>    * parse_zone - Fill a zone descriptor
>> diff --git a/stubs/emscripten.c b/stubs/emscripten.c
>> new file mode 100644
>> index 0000000000..2157d6349b
>> --- /dev/null
>> +++ b/stubs/emscripten.c
>> @@ -0,0 +1,13 @@
>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>> +#include "qemu/osdep.h"
>> +/*
>> + * emscripten exposes copy_file_range declaration but doesn't provide 
>> the
>> + * implementation in the final link. Define the stub here but avoid type
>> + * conflict with the emscripten's header.
>> + */
>> +ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>> +                             off_t *out_off, size_t len, unsigned int 
>> flags)
>> +{
>> +    errno = ENOSYS;
>> +    return -1;
>> +}
> 
> I'd include in this patch this hunk from patch 17:
> 
> -- >8 --
> diff --git a/stubs/meson.build b/stubs/meson.build
> index 63392f5e78..4fd4d362f9 100644
> --- a/stubs/meson.build
> +++ b/stubs/meson.build
> @@ -89,3 +89,7 @@ if have_system or have_user
>     stub_ss.add(files('hotplug-stubs.c'))
>     stub_ss.add(files('sysbus.c'))
>   endif
> +
> +if host_os == 'emscripten'
> +  stub_ss.add(files('emscripten.c'))
> +endif
> ---

Actually what about checking the symbol presence in meson?
Something like (untested):

-- >8 --
diff --git a/meson.build b/meson.build
index b18c46d16a2..33185fdf315 100644
--- a/meson.build
+++ b/meson.build
@@ -2654,3 +2654,2 @@ config_host_data.set('CONFIG_TIMERFD', 
cc.has_function('timerfd_create'))
  config_host_data.set('CONFIG_GETLOADAVG', cc.has_function('getloadavg'))
-config_host_data.set('HAVE_COPY_FILE_RANGE', 
cc.has_function('copy_file_range'))
  config_host_data.set('HAVE_GETIFADDRS', cc.has_function('getifaddrs'))
@@ -2756,2 +2755,6 @@ config_host_data.set('HAVE_UTMPX',

+config_host_data.set('HAVE_COPY_FILE_RANGE', cc.links(gnu_source_prefix 
+ '''
+  #include <unistd.h>
+  int main(void) { return copy_file_range(-1, NULL, -1, NULL, 0, 0); }'''))
  config_host_data.set('CONFIG_EVENTFD', cc.links('''
---

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Richard Henderson]

On 4/16/25 02:33, Philippe Mathieu-Daudé wrote:
> On 16/4/25 11:00, Philippe Mathieu-Daudé wrote:
>> On 16/4/25 10:14, Kohei Tokunaga wrote:
>>> emscripten exposes copy_file_range declaration but doesn't provide the
>>> implementation in the final link. Define the emscripten-specific stub
>>> function to avoid type conflict with the emscripten's header.
>>>
>>> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
>>> ---
>>>   block/file-posix.c |  6 ++++++
>>>   stubs/emscripten.c | 13 +++++++++++++
>>>   2 files changed, 19 insertions(+)
>>>   create mode 100644 stubs/emscripten.c
>>>
>>> diff --git a/block/file-posix.c b/block/file-posix.c
>>> index 56d1972d15..22e0ed5069 100644
>>> --- a/block/file-posix.c
>>> +++ b/block/file-posix.c
>>> @@ -110,6 +110,10 @@
>>>   #include <sys/diskslice.h>
>>>   #endif
>>> +#ifdef EMSCRIPTEN
>>> +#include <sys/ioctl.h>
>>> +#endif
>>> +
>>>   /* OS X does not have O_DSYNC */
>>>   #ifndef O_DSYNC
>>>   #ifdef O_SYNC
>>> @@ -2010,6 +2014,7 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
>>>       return handle_aiocb_write_zeroes(aiocb);
>>>   }
>>> +#ifndef EMSCRIPTEN
>>>   #ifndef HAVE_COPY_FILE_RANGE
>>>   static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>>>                                off_t *out_off, size_t len, unsigned int flags)
>>> @@ -2023,6 +2028,7 @@ static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>>>   #endif
>>>   }
>>>   #endif
>>> +#endif
>>>   /*
>>>    * parse_zone - Fill a zone descriptor
>>> diff --git a/stubs/emscripten.c b/stubs/emscripten.c
>>> new file mode 100644
>>> index 0000000000..2157d6349b
>>> --- /dev/null
>>> +++ b/stubs/emscripten.c
>>> @@ -0,0 +1,13 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>>> +#include "qemu/osdep.h"
>>> +/*
>>> + * emscripten exposes copy_file_range declaration but doesn't provide the
>>> + * implementation in the final link. Define the stub here but avoid type
>>> + * conflict with the emscripten's header.
>>> + */
>>> +ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>>> +                             off_t *out_off, size_t len, unsigned int flags)
>>> +{
>>> +    errno = ENOSYS;
>>> +    return -1;
>>> +}
>>
>> I'd include in this patch this hunk from patch 17:
>>
>> -- >8 --
>> diff --git a/stubs/meson.build b/stubs/meson.build
>> index 63392f5e78..4fd4d362f9 100644
>> --- a/stubs/meson.build
>> +++ b/stubs/meson.build
>> @@ -89,3 +89,7 @@ if have_system or have_user
>>     stub_ss.add(files('hotplug-stubs.c'))
>>     stub_ss.add(files('sysbus.c'))
>>   endif
>> +
>> +if host_os == 'emscripten'
>> +  stub_ss.add(files('emscripten.c'))
>> +endif
>> ---
> 
> Actually what about checking the symbol presence in meson?
> Something like (untested):
> 
> -- >8 --
> diff --git a/meson.build b/meson.build
> index b18c46d16a2..33185fdf315 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -2654,3 +2654,2 @@ config_host_data.set('CONFIG_TIMERFD', 
> cc.has_function('timerfd_create'))
>   config_host_data.set('CONFIG_GETLOADAVG', cc.has_function('getloadavg'))
> -config_host_data.set('HAVE_COPY_FILE_RANGE', cc.has_function('copy_file_range'))
>   config_host_data.set('HAVE_GETIFADDRS', cc.has_function('getifaddrs'))
> @@ -2756,2 +2755,6 @@ config_host_data.set('HAVE_UTMPX',
> 
> +config_host_data.set('HAVE_COPY_FILE_RANGE', cc.links(gnu_source_prefix + '''
> +  #include <unistd.h>
> +  int main(void) { return copy_file_range(-1, NULL, -1, NULL, 0, 0); }'''))
>   config_host_data.set('CONFIG_EVENTFD', cc.links('''
> ---

Yes indeed.  We should be making sure HAVE_COPY_FILE_RANGE is unset, not providing stubs.


r~

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 1934 bytes --]

Hi Philippe and Richard, thank you for the feedback.

> Actually what about checking the symbol presence in meson?
> Something like (untested):
>
> -- >8 --
> diff --git a/meson.build b/meson.build
> index b18c46d16a2..33185fdf315 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -2654,3 +2654,2 @@ config_host_data.set('CONFIG_TIMERFD',
> cc.has_function('timerfd_create'))
>   config_host_data.set('CONFIG_GETLOADAVG', cc.has_function('getloadavg'))
> -config_host_data.set('HAVE_COPY_FILE_RANGE',
> cc.has_function('copy_file_range'))
>   config_host_data.set('HAVE_GETIFADDRS', cc.has_function('getifaddrs'))
> @@ -2756,2 +2755,6 @@ config_host_data.set('HAVE_UTMPX',
>
> +config_host_data.set('HAVE_COPY_FILE_RANGE', cc.links(gnu_source_prefix
> + '''
> +  #include <unistd.h>
> +  int main(void) { return copy_file_range(-1, NULL, -1, NULL, 0, 0);
}'''))
>   config_host_data.set('CONFIG_EVENTFD', cc.links('''
> ---

Emscripten doesn't provide copy_file_range implementation but it declares
this function in its headers. Meson correctly detects the missing
implementation and unsets HAVE_COPY_FILE_RANGE. However, the stub defined in
file-posix.c causes a type conflict with the declaration from Emscripten
during compilation:

> ../qemu/block/file-posix.c:2019:14: error: static declaration of
'copy_file_range' follows non-static declaration
>  2019 | static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
>       |              ^
> /emsdk/upstream/emscripten/cache/sysroot/include/unistd.h:207:9: note:
previous declaration is here
>   207 | ssize_t copy_file_range(int, off_t *, int, off_t *, size_t,
unsigned);
>       |         ^
> 1 error generated.

If introducing a new stub isn't preferable, we could update the existing
stub in file-posix.c to match the declaration used by Emscripten. The
manpage[1] also aligns with this signature.

[1] https://man7.org/linux/man-pages/man2/copy_file_range.2.html

[-- Attachment #2: Type: text/html, Size: 2491 bytes --]

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Philippe Mathieu-Daudé]

On 17/4/25 11:32, Kohei Tokunaga wrote:
> 
> Hi Philippe and Richard, thank you for the feedback.
> 
>  > Actually what about checking the symbol presence in meson?
>  > Something like (untested):
>  >
>  > -- >8 --
>  > diff --git a/meson.build b/meson.build
>  > index b18c46d16a2..33185fdf315 100644
>  > --- a/meson.build
>  > +++ b/meson.build
>  > @@ -2654,3 +2654,2 @@ config_host_data.set('CONFIG_TIMERFD',
>  > cc.has_function('timerfd_create'))
>  >   config_host_data.set('CONFIG_GETLOADAVG', 
> cc.has_function('getloadavg'))
>  > -config_host_data.set('HAVE_COPY_FILE_RANGE',
>  > cc.has_function('copy_file_range'))
>  >   config_host_data.set('HAVE_GETIFADDRS', cc.has_function('getifaddrs'))
>  > @@ -2756,2 +2755,6 @@ config_host_data.set('HAVE_UTMPX',
>  >
>  > +config_host_data.set('HAVE_COPY_FILE_RANGE', cc.links(gnu_source_prefix
>  > + '''
>  > +  #include <unistd.h>
>  > +  int main(void) { return copy_file_range(-1, NULL, -1, NULL, 0, 
> 0); }'''))
>  >   config_host_data.set('CONFIG_EVENTFD', cc.links('''
>  > ---
> 
> Emscripten doesn't provide copy_file_range implementation but it declares
> this function in its headers. Meson correctly detects the missing
> implementation and unsets HAVE_COPY_FILE_RANGE. However, the stub defined in
> file-posix.c causes a type conflict with the declaration from Emscripten
> during compilation:
> 
>  > ../qemu/block/file-posix.c:2019:14: error: static declaration of 
> 'copy_file_range' follows non-static declaration
>  >  2019 | static off_t copy_file_range(int in_fd, off_t *in_off, int 
> out_fd,
>  >       |              ^
>  > /emsdk/upstream/emscripten/cache/sysroot/include/unistd.h:207:9: 
> note: previous declaration is here
>  >   207 | ssize_t copy_file_range(int, off_t *, int, off_t *, size_t, 
> unsigned);
>  >       |         ^
>  > 1 error generated.
> 
> If introducing a new stub isn't preferable, we could update the existing
> stub in file-posix.c to match the declaration used by Emscripten. The
> manpage[1] also aligns with this signature.

You are correct we should use ssize_t instead of off_t.

If meson fails to link, it won't define HAVE_COPY_FILE_RANGE, so you
shouldn't get "static declaration of 'copy_file_range' follows 
non-static declaration" right?

> 
> [1] https://man7.org/linux/man-pages/man2/copy_file_range.2.html 
> <https://man7.org/linux/man-pages/man2/copy_file_range.2.html>
> 

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Kohei Tokunaga]

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Hi Philippe,

> If meson fails to link, it won't define HAVE_COPY_FILE_RANGE,

Yes, meson correctly detects the link failure when checking for
copy_file_range, as shown in meson-log.txt:

> wasm-ld: error: /tmp/emscripten_temp_oqvz296m/testfile_0.o: undefined
symbol: copy_file_range

and reflects this in the configure output:

> Checking for function "copy_file_range" : NO

> so you
> shouldn't get "static declaration of 'copy_file_range' follows
> non-static declaration" right?

To fix this error, I needed to update the stub implementation in
file-posix.c to exactly match the declaration in Emscripten's
headers. Specifically, I changed the return type from off_t to ssize_t and
removed the "static" qualifier. With this change, file-posix.c builds
correctly under Emscripten, and there is no need to add a new stub in
stubs/emscripten.c

The following is the patch updates file-posix.c to solve this error:

 #ifndef HAVE_COPY_FILE_RANGE
-static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
-                             off_t *out_off, size_t len, unsigned int
flags)
+ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
+                               off_t *out_off, size_t len, unsigned int
flags)
 {
 #ifdef __NR_copy_file_range
     return syscall(__NR_copy_file_range, in_fd, in_off, out_fd,

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Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Philippe Mathieu-Daudé]

On 18/4/25 08:53, Kohei Tokunaga wrote:

> The following is the patch updates file-posix.c to solve this error:
> 
>   #ifndef HAVE_COPY_FILE_RANGE
> -static off_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
> -                             off_t *out_off, size_t len, unsigned int 
> flags)
> +ssize_t copy_file_range(int in_fd, off_t *in_off, int out_fd,
> +                               off_t *out_off, size_t len, unsigned int 
> flags)
>   {
>   #ifdef __NR_copy_file_range
>       return syscall(__NR_copy_file_range, in_fd, in_off, out_fd,
> 

Yes, LGTM!

Re: [PATCH 12/19] block: Update block to compile with Emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 495 bytes --]

Hi Philippe,

> I'd include in this patch this hunk from patch 17:
>
> -- >8 --
> diff --git a/stubs/meson.build b/stubs/meson.build
> index 63392f5e78..4fd4d362f9 100644
> --- a/stubs/meson.build
> +++ b/stubs/meson.build
> @@ -89,3 +89,7 @@ if have_system or have_user
>     stub_ss.add(files('hotplug-stubs.c'))
>     stub_ss.add(files('sysbus.c'))
>   endif
> +
> +if host_os == 'emscripten'
> +  stub_ss.add(files('emscripten.c'))
> +endif
> ---

Sure, I'll move that hunk into this patch.

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[PATCH 13/19] include/qemu/osdep.h: Add Emscripten-specific OS dependencies

[Kohei Tokunaga]

On emscripten, some implementations in os-posix.c can't be used such as
daemonizing and changing user. This commit introduces os-wasm.c and
os-wasm.h which are forked from os-posix.c and os-posix.h and patched for
targetting Emscripten.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 include/qemu/osdep.h      |   8 ++-
 include/system/os-posix.h |   3 +-
 include/system/os-wasm.h  | 105 +++++++++++++++++++++++++++++++++
 os-wasm.c                 | 119 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 232 insertions(+), 3 deletions(-)
 create mode 100644 include/system/os-wasm.h
 create mode 100644 os-wasm.c

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 4397a90680..96fe51bc39 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -8,7 +8,7 @@
  * To avoid getting into possible circular include dependencies, this
  * file should not include any other QEMU headers, with the exceptions
  * of config-host.h, config-target.h, qemu/compiler.h,
- * system/os-posix.h, system/os-win32.h, glib-compat.h and
+ * system/os-posix.h, system/os-win32.h, system/os-wasm.h, glib-compat.h and
  * qemu/typedefs.h, all of which are doing a similar job to this file
  * and are under similar constraints.
  *
@@ -164,10 +164,14 @@ QEMU_EXTERN_C int daemon(int, int);
 #include "system/os-win32.h"
 #endif
 
-#ifdef CONFIG_POSIX
+#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
 #include "system/os-posix.h"
 #endif
 
+#if defined(EMSCRIPTEN)
+#include "system/os-wasm.h"
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/include/system/os-posix.h b/include/system/os-posix.h
index ce5b3bccf8..e87cc36a3a 100644
--- a/include/system/os-posix.h
+++ b/include/system/os-posix.h
@@ -1,5 +1,6 @@
 /*
- * posix specific declarations
+ * posix specific declarations forked from os-posix.c, removing functions not
+ * working on Emscripten
  *
  * Copyright (c) 2003-2008 Fabrice Bellard
  * Copyright (c) 2010 Jes Sorensen <Jes.Sorensen@redhat.com>
diff --git a/include/system/os-wasm.h b/include/system/os-wasm.h
new file mode 100644
index 0000000000..061c123c6f
--- /dev/null
+++ b/include/system/os-wasm.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * posix specific declarations
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2010 Jes Sorensen <Jes.Sorensen@redhat.com>
+ *
+ * Forked from os-posix.h, removing functions not working on Emscripten
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef QEMU_OS_WASM_H
+#define QEMU_OS_WASM_H
+
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <sys/un.h>
+
+#ifdef CONFIG_SYSMACROS
+#include <sys/sysmacros.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void os_set_line_buffering(void);
+void os_setup_early_signal_handling(void);
+void os_set_proc_name(const char *s);
+void os_setup_signal_handling(void);
+void os_setup_limits(void);
+void os_setup_post(void);
+int os_mlock(bool on_fault);
+static inline int os_set_daemonize(bool d)
+{
+    return -1;
+};
+bool is_daemonized(void);
+static inline void os_daemonize(void) {}
+
+/**
+ * qemu_alloc_stack:
+ * @sz: pointer to a size_t holding the requested usable stack size
+ *
+ * Allocate memory that can be used as a stack, for instance for
+ * coroutines. If the memory cannot be allocated, this function
+ * will abort (like g_malloc()). This function also inserts an
+ * additional guard page to catch a potential stack overflow.
+ * Note that the memory required for the guard page and alignment
+ * and minimal stack size restrictions will increase the value of sz.
+ *
+ * The allocated stack must be freed with qemu_free_stack().
+ *
+ * Returns: pointer to (the lowest address of) the stack memory.
+ */
+void *qemu_alloc_stack(size_t *sz);
+
+/**
+ * qemu_free_stack:
+ * @stack: stack to free
+ * @sz: size of stack in bytes
+ *
+ * Free a stack allocated via qemu_alloc_stack(). Note that sz must
+ * be exactly the adjusted stack size returned by qemu_alloc_stack.
+ */
+void qemu_free_stack(void *stack, size_t sz);
+
+/* POSIX and Mingw32 differ in the name of the stdio lock functions.  */
+
+static inline void qemu_flockfile(FILE *f)
+{
+    flockfile(f);
+}
+
+static inline void qemu_funlockfile(FILE *f)
+{
+    funlockfile(f);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/os-wasm.c b/os-wasm.c
new file mode 100644
index 0000000000..d240c180c5
--- /dev/null
+++ b/os-wasm.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * os-wasm.c
+ * Forked from os-posix.c, removing functions not working on Emscripten
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2010 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <pwd.h>
+#include <grp.h>
+#include <libgen.h>
+
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "system/runstate.h"
+#include "qemu/cutils.h"
+
+void os_setup_post(void){}
+void os_set_line_buffering(void)
+{
+    setvbuf(stdout, NULL, _IOLBF, 0);
+}
+void os_setup_early_signal_handling(void)
+{
+    struct sigaction act;
+    sigfillset(&act.sa_mask);
+    act.sa_flags = 0;
+    act.sa_handler = SIG_IGN;
+    sigaction(SIGPIPE, &act, NULL);
+}
+void os_set_proc_name(const char *s)
+{
+    error_report("Change of process name not supported by your OS");
+    exit(1);
+}
+static void termsig_handler(int signal, siginfo_t *info, void *c)
+{
+    qemu_system_killed(info->si_signo, info->si_pid);
+}
+
+void os_setup_signal_handling(void)
+{
+    struct sigaction act;
+
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = termsig_handler;
+    act.sa_flags = SA_SIGINFO;
+    sigaction(SIGINT,  &act, NULL);
+    sigaction(SIGHUP,  &act, NULL);
+    sigaction(SIGTERM, &act, NULL);
+}
+void os_setup_limits(void)
+{
+    struct rlimit nofile;
+
+    if (getrlimit(RLIMIT_NOFILE, &nofile) < 0) {
+        warn_report("unable to query NOFILE limit: %s", strerror(errno));
+        return;
+    }
+
+    if (nofile.rlim_cur == nofile.rlim_max) {
+        return;
+    }
+
+    nofile.rlim_cur = nofile.rlim_max;
+
+    if (setrlimit(RLIMIT_NOFILE, &nofile) < 0) {
+        warn_report("unable to set NOFILE limit: %s", strerror(errno));
+        return;
+    }
+}
+int os_mlock(bool on_fault)
+{
+#ifdef HAVE_MLOCKALL
+    int ret = 0;
+    int flags = MCL_CURRENT | MCL_FUTURE;
+
+    if (on_fault) {
+#ifdef HAVE_MLOCK_ONFAULT
+        flags |= MCL_ONFAULT;
+#else
+        error_report("mlockall: on_fault not supported");
+        return -EINVAL;
+#endif
+    }
+
+    ret = mlockall(flags);
+    if (ret < 0) {
+        error_report("mlockall: %s", strerror(errno));
+    }
+
+    return ret;
+#else
+    (void)on_fault;
+    return -ENOSYS;
+#endif
+}
-- 
2.25.1

Re: [PATCH 13/19] include/qemu/osdep.h: Add Emscripten-specific OS dependencies

[Philippe Mathieu-Daudé]

Hi Kohei,

On 16/4/25 10:14, Kohei Tokunaga wrote:
> On emscripten, some implementations in os-posix.c can't be used such as
> daemonizing and changing user. This commit introduces os-wasm.c and
> os-wasm.h which are forked from os-posix.c and os-posix.h and patched for
> targetting Emscripten.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   include/qemu/osdep.h      |   8 ++-
>   include/system/os-posix.h |   3 +-
>   include/system/os-wasm.h  | 105 +++++++++++++++++++++++++++++++++
>   os-wasm.c                 | 119 ++++++++++++++++++++++++++++++++++++++
>   4 files changed, 232 insertions(+), 3 deletions(-)
>   create mode 100644 include/system/os-wasm.h
>   create mode 100644 os-wasm.c


> diff --git a/include/system/os-posix.h b/include/system/os-posix.h
> index ce5b3bccf8..e87cc36a3a 100644
> --- a/include/system/os-posix.h
> +++ b/include/system/os-posix.h
> @@ -1,5 +1,6 @@
>   /*
> - * posix specific declarations
> + * posix specific declarations forked from os-posix.c, removing functions not
> + * working on Emscripten

You shouldn't have to modify this file, likely a rebase typo.

>    *
>    * Copyright (c) 2003-2008 Fabrice Bellard
>    * Copyright (c) 2010 Jes Sorensen <Jes.Sorensen@redhat.com>

Re: [PATCH 13/19] include/qemu/osdep.h: Add Emscripten-specific OS dependencies

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 161 bytes --]

Hi Philippe,

> You shouldn't have to modify this file, likely a rebase typo.

Thank you for pointing this out. I'll fix this in the next version of the
series.

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[PATCH 14/19] Disable options unsupported on Emscripten

[Kohei Tokunaga]

Daemonizing and run-with aren't supported on Emscripten so disable these
flags.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 qemu-options.hx | 4 +++-
 system/vl.c     | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/qemu-options.hx b/qemu-options.hx
index dc694a99a3..20ed22afe2 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4863,9 +4863,11 @@ SRST
 ERST
 
 #ifndef _WIN32
+#ifndef EMSCRIPTEN
 DEF("daemonize", 0, QEMU_OPTION_daemonize, \
     "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
 #endif
+#endif
 SRST
 ``-daemonize``
     Daemonize the QEMU process after initialization. QEMU will not
@@ -5249,7 +5251,7 @@ HXCOMM Internal use
 DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
 DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
 
-#ifdef CONFIG_POSIX
+#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
 DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
     "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\n"
     "                Set miscellaneous QEMU process lifecycle options:\n"
diff --git a/system/vl.c b/system/vl.c
index 8d89394b45..255ea3be6b 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -766,7 +766,7 @@ static QemuOptsList qemu_smp_opts = {
     },
 };
 
-#if defined(CONFIG_POSIX)
+#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
 static QemuOptsList qemu_run_with_opts = {
     .name = "run-with",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_run_with_opts.head),
@@ -3677,7 +3677,7 @@ void qemu_init(int argc, char **argv)
             case QEMU_OPTION_nouserconfig:
                 /* Nothing to be parsed here. Especially, do not error out below. */
                 break;
-#if defined(CONFIG_POSIX)
+#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
             case QEMU_OPTION_daemonize:
                 os_set_daemonize(true);
                 break;
-- 
2.25.1

Re: [PATCH 14/19] Disable options unsupported on Emscripten

[Philippe Mathieu-Daudé]

On 16/4/25 10:14, Kohei Tokunaga wrote:
> Daemonizing and run-with aren't supported on Emscripten so disable these
> flags.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   qemu-options.hx | 4 +++-
>   system/vl.c     | 4 ++--
>   2 files changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/qemu-options.hx b/qemu-options.hx
> index dc694a99a3..20ed22afe2 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4863,9 +4863,11 @@ SRST
>   ERST
>   
>   #ifndef _WIN32
> +#ifndef EMSCRIPTEN

#if !defined(_WIN32) && !defined(EMSCRIPTEN)

?

>   DEF("daemonize", 0, QEMU_OPTION_daemonize, \
>       "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
>   #endif
> +#endif
>   SRST
>   ``-daemonize``
>       Daemonize the QEMU process after initialization. QEMU will not
> @@ -5249,7 +5251,7 @@ HXCOMM Internal use
>   DEF("qtest", HAS_ARG, QEMU_OPTION_qtest, "", QEMU_ARCH_ALL)
>   DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "", QEMU_ARCH_ALL)
>   
> -#ifdef CONFIG_POSIX
> +#if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
>   DEF("run-with", HAS_ARG, QEMU_OPTION_run_with,
>       "-run-with [async-teardown=on|off][,chroot=dir][user=username|uid:gid]\n"
>       "                Set miscellaneous QEMU process lifecycle options:\n"

Re: [PATCH 14/19] Disable options unsupported on Emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 197 bytes --]

Hi Philippe,

> >   #ifndef _WIN32
> > +#ifndef EMSCRIPTEN
>
> #if !defined(_WIN32) && !defined(EMSCRIPTEN)
>
> ?

Thank you for the sueggestion. I'll apply this in the next version of the
series.

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[PATCH 15/19] util/mmap-alloc: Add qemu_ram_mmap implementation for emscripten

[Kohei Tokunaga]

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 util/mmap-alloc.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index ed14f9c64d..91f33682e8 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -145,6 +145,7 @@ static bool map_noreserve_effective(int fd, uint32_t qemu_map_flags)
     return false;
 }
 
+#ifndef EMSCRIPTEN
 /*
  * Reserve a new memory region of the requested size to be used for mapping
  * from the given fd (if any).
@@ -176,6 +177,7 @@ static void *mmap_reserve(size_t size, int fd)
 
     return mmap(0, size, PROT_NONE, flags, fd, 0);
 }
+#endif
 
 /*
  * Activate memory in a reserved region from the given fd (if any), to make
@@ -244,6 +246,21 @@ static inline size_t mmap_guard_pagesize(int fd)
 #endif
 }
 
+#ifdef EMSCRIPTEN
+void *qemu_ram_mmap(int fd,
+                    size_t size,
+                    size_t align,
+                    uint32_t qemu_map_flags,
+                    off_t map_offset)
+{
+    /*
+     * emscripten doesn't support non-zero first argument for mmap so
+     * mmap a larger region without the hint and return an aligned pointer.
+     */
+    void *ptr = mmap_activate(0, size + align, fd, qemu_map_flags, map_offset);
+    return (void *)QEMU_ALIGN_UP((uintptr_t)ptr, align);
+}
+#else
 void *qemu_ram_mmap(int fd,
                     size_t size,
                     size_t align,
@@ -293,6 +310,7 @@ void *qemu_ram_mmap(int fd,
 
     return ptr;
 }
+#endif /* EMSCRIPTEN */
 
 void qemu_ram_munmap(int fd, void *ptr, size_t size)
 {
-- 
2.25.1

Re: [PATCH 15/19] util/mmap-alloc: Add qemu_ram_mmap implementation for emscripten

[Philippe Mathieu-Daudé]

On 16/4/25 10:14, Kohei Tokunaga wrote:
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   util/mmap-alloc.c | 18 ++++++++++++++++++
>   1 file changed, 18 insertions(+)
> 
> diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
> index ed14f9c64d..91f33682e8 100644
> --- a/util/mmap-alloc.c
> +++ b/util/mmap-alloc.c
> @@ -145,6 +145,7 @@ static bool map_noreserve_effective(int fd, uint32_t qemu_map_flags)
>       return false;
>   }
>   
> +#ifndef EMSCRIPTEN
>   /*
>    * Reserve a new memory region of the requested size to be used for mapping
>    * from the given fd (if any).
> @@ -176,6 +177,7 @@ static void *mmap_reserve(size_t size, int fd)
>   
>       return mmap(0, size, PROT_NONE, flags, fd, 0);
>   }
> +#endif
>   
>   /*
>    * Activate memory in a reserved region from the given fd (if any), to make
> @@ -244,6 +246,21 @@ static inline size_t mmap_guard_pagesize(int fd)
>   #endif
>   }
>   
> +#ifdef EMSCRIPTEN
> +void *qemu_ram_mmap(int fd,
> +                    size_t size,
> +                    size_t align,
> +                    uint32_t qemu_map_flags,
> +                    off_t map_offset)
> +{
> +    /*
> +     * emscripten doesn't support non-zero first argument for mmap so
> +     * mmap a larger region without the hint and return an aligned pointer.
> +     */
> +    void *ptr = mmap_activate(0, size + align, fd, qemu_map_flags, map_offset);
> +    return (void *)QEMU_ALIGN_UP((uintptr_t)ptr, align);
> +}
> +#else
>   void *qemu_ram_mmap(int fd,
>                       size_t size,
>                       size_t align,
> @@ -293,6 +310,7 @@ void *qemu_ram_mmap(int fd,
>   
>       return ptr;
>   }
> +#endif /* EMSCRIPTEN */
>   
>   void qemu_ram_munmap(int fd, void *ptr, size_t size)
>   {

Can we keep this code generic? I.e. with something in the lines
of (only build-tested):

-- >8 --
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index ed14f9c64de..0e52cce5b29 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -238,3 +238,10 @@ static inline size_t mmap_guard_pagesize(int fd)
  {
-#if defined(__powerpc64__) && defined(__linux__)
+#if defined(EMSCRIPTEN)
+    /*
+     * emscripten doesn't support non-zero first argument for mmap so we
+     * don't use any guard, returning 0 to mmap a larger region without the
+     * hint and return an aligned pointer in qemu_ram_mmap().
+     */
+    return 0;
+#elif defined(__powerpc64__) && defined(__linux__)
      /* Mappings in the same segment must share the same page size */
@@ -246,2 +253,3 @@ static inline size_t mmap_guard_pagesize(int fd)

+
  void *qemu_ram_mmap(int fd,
@@ -253,4 +261,8 @@ void *qemu_ram_mmap(int fd,
      const size_t guard_pagesize = mmap_guard_pagesize(fd);
-    size_t offset, total;
-    void *ptr, *guardptr;
+    size_t offset = 0, total;
+    void *ptr, *guardptr = NULL;
+
+    assert(is_power_of_2(align));
+    /* Always align to host page size */
+    assert(align >= guard_pagesize);

@@ -262,13 +274,11 @@ void *qemu_ram_mmap(int fd,

-    guardptr = mmap_reserve(total, fd);
-    if (guardptr == MAP_FAILED) {
-        return MAP_FAILED;
+    if (guard_pagesize) {
+        guardptr = mmap_reserve(total, fd);
+        if (guardptr == MAP_FAILED) {
+            return MAP_FAILED;
+        }
+
+        offset = QEMU_ALIGN_UP((uintptr_t)guardptr, align) - 
(uintptr_t)guardptr;
      }

-    assert(is_power_of_2(align));
-    /* Always align to host page size */
-    assert(align >= guard_pagesize);
-
-    offset = QEMU_ALIGN_UP((uintptr_t)guardptr, align) - 
(uintptr_t)guardptr;
-
      ptr = mmap_activate(guardptr + offset, size, fd, qemu_map_flags,
---

Re: [PATCH 15/19] util/mmap-alloc: Add qemu_ram_mmap implementation for emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 161 bytes --]

Hi Philippe,

> Can we keep this code generic? I.e. with something in the lines
> of (only build-tested):

Thank you for the suggestion. I'll try this approach.

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Re: [PATCH 15/19] util/mmap-alloc: Add qemu_ram_mmap implementation for emscripten

[Kohei Tokunaga]

[-- Attachment #1: Type: text/plain, Size: 3068 bytes --]

Hi Philippe,

While working on mmap-alloc.c, I found that Emscripten does not support
partial unmapping of memory regions [1]. This limitation prevents correct
implementation of qemu_ram_mmap and qemu_ram_munmap, which rely on partial
unmap behavior.

[1]
https://github.com/emscripten-core/emscripten/blob/d4a74336f23214bf3304d9eb0d03966786b30a36/system/lib/libc/emscripten_mmap.c#L61

As a workaround, I'm considering excluding mmap-alloc.c from the Emscripten
build. Instead, for Emscripten build, we can modify qemu_anon_ram_alloc (in
oslib-posix.c) to use qemu_memalign in place of qemu_ram_mmap, and disable
memory backends that rely on mmap, such as memory-backend-file and
memory-backend-shm.

I plan to include this fix in the next version of the patch series. I'm
happy to hear any suggestions if there is a better way to address this
limitation.

The change in oslib-posix.c will look like this:

diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index a697c602c6..8eb0e53458 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -58,6 +58,7 @@
 #include <lwp.h>
 #endif

+#include "qemu/memalign.h"
 #include "qemu/mmap-alloc.h"

 #define MAX_MEM_PREALLOC_THREAD_COUNT 16
@@ -210,11 +211,21 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t
*alignment, bool shared,
     const uint32_t qemu_map_flags = (shared ? QEMU_MAP_SHARED : 0) |
                                     (noreserve ? QEMU_MAP_NORESERVE : 0);
     size_t align = QEMU_VMALLOC_ALIGN;
+#ifndef EMSCRIPTEN
     void *ptr = qemu_ram_mmap(-1, size, align, qemu_map_flags, 0);

     if (ptr == MAP_FAILED) {
         return NULL;
     }
+#else
+    /*
+     * qemu_ram_mmap is not implemented for Emscripten. Use qemu_memalign
+     * for the anonymous allocation. noreserve is ignored as there is no
swap
+     * space on Emscripten, and shared is ignored as there is no other
+     * processes on Emscripten.
+     */
+    void *ptr = qemu_memalign(align, size);
+#endif

     if (alignment) {
         *alignment = align;
@@ -227,7 +238,16 @@ void *qemu_anon_ram_alloc(size_t size, uint64_t
*alignment, bool shared,
 void qemu_anon_ram_free(void *ptr, size_t size)
 {
     trace_qemu_anon_ram_free(ptr, size);
+#ifndef EMSCRIPTEN
     qemu_ram_munmap(-1, ptr, size);
+#else
+    /*
+     * qemu_ram_munmap is not implemented for Emscripten and qemu_memalign
+     * was used for the allocation. Use the corresponding freeing function
+     * here.
+     */
+    qemu_vfree(ptr);
+#endif
 }

 void qemu_socket_set_block(int fd)
@@ -588,7 +608,15 @@ bool qemu_prealloc_mem(int fd, char *area, size_t sz,
int max_threads,
 {
     static gsize initialized;
     int ret;
+#ifndef EMSCRIPTEN
     size_t hpagesize = qemu_fd_getpagesize(fd);
+#else
+    /*
+     * mmap-alloc.c is excluded from Emscripten build, so
qemu_fd_getpagesize
+     * is unavailable. Fallback to the lower level implementation.
+     */
+    size_t hpagesize = qemu_real_host_page_size();
+#endif
     size_t numpages = DIV_ROUND_UP(sz, hpagesize);
     bool use_madv_populate_write;
     struct sigaction act;

[-- Attachment #2: Type: text/html, Size: 3685 bytes --]

[PATCH 16/19] util: Add coroutine backend for emscripten

[Kohei Tokunaga]

Emscripten does not support couroutine methods currently used by QEMU but
provides a coroutine implementation called "fiber". This commit introduces a
coroutine backend using fiber. Note that fiber does not support submitting
coroutines to other threads.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 util/coroutine-wasm.c | 127 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100644 util/coroutine-wasm.c

diff --git a/util/coroutine-wasm.c b/util/coroutine-wasm.c
new file mode 100644
index 0000000000..cb1ec92509
--- /dev/null
+++ b/util/coroutine-wasm.c
@@ -0,0 +1,127 @@
+/*
+ * emscripten fiber coroutine initialization code
+ * based on coroutine-ucontext.c
+ *
+ * Copyright (C) 2006  Anthony Liguori <anthony@codemonkey.ws>
+ * Copyright (C) 2011  Kevin Wolf <kwolf@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.0 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/coroutine_int.h"
+#include "qemu/coroutine-tls.h"
+
+#include <emscripten/fiber.h>
+
+typedef struct {
+    Coroutine base;
+    void *stack;
+    size_t stack_size;
+
+    void *asyncify_stack;
+    size_t asyncify_stack_size;
+
+    CoroutineAction action;
+
+    emscripten_fiber_t fiber;
+} CoroutineEmscripten;
+
+/**
+ * Per-thread coroutine bookkeeping
+ */
+QEMU_DEFINE_STATIC_CO_TLS(Coroutine *, current);
+QEMU_DEFINE_STATIC_CO_TLS(CoroutineEmscripten *, leader);
+size_t leader_asyncify_stack_size = COROUTINE_STACK_SIZE;
+
+static void coroutine_trampoline(void *co_)
+{
+    Coroutine *co = co_;
+
+    while (true) {
+        co->entry(co->entry_arg);
+        qemu_coroutine_switch(co, co->caller, COROUTINE_TERMINATE);
+    }
+}
+
+Coroutine *qemu_coroutine_new(void)
+{
+    CoroutineEmscripten *co;
+
+    co = g_malloc0(sizeof(*co));
+
+    co->stack_size = COROUTINE_STACK_SIZE;
+    co->stack = qemu_alloc_stack(&co->stack_size);
+
+    co->asyncify_stack_size = COROUTINE_STACK_SIZE;
+    co->asyncify_stack = g_malloc0(co->asyncify_stack_size);
+    emscripten_fiber_init(&co->fiber, coroutine_trampoline, &co->base,
+                          co->stack, co->stack_size, co->asyncify_stack,
+                          co->asyncify_stack_size);
+
+    return &co->base;
+}
+
+void qemu_coroutine_delete(Coroutine *co_)
+{
+    CoroutineEmscripten *co = DO_UPCAST(CoroutineEmscripten, base, co_);
+
+    qemu_free_stack(co->stack, co->stack_size);
+    g_free(co->asyncify_stack);
+    g_free(co);
+}
+
+CoroutineAction qemu_coroutine_switch(Coroutine *from_, Coroutine *to_,
+                      CoroutineAction action)
+{
+    CoroutineEmscripten *from = DO_UPCAST(CoroutineEmscripten, base, from_);
+    CoroutineEmscripten *to = DO_UPCAST(CoroutineEmscripten, base, to_);
+
+    set_current(to_);
+    to->action = action;
+    emscripten_fiber_swap(&from->fiber, &to->fiber);
+    return from->action;
+}
+
+Coroutine *qemu_coroutine_self(void)
+{
+    Coroutine *self = get_current();
+
+    if (!self) {
+        CoroutineEmscripten *leaderp = get_leader();
+        if (!leaderp) {
+            leaderp = g_malloc0(sizeof(*leaderp));
+            leaderp->asyncify_stack = g_malloc0(leader_asyncify_stack_size);
+            leaderp->asyncify_stack_size = leader_asyncify_stack_size;
+            emscripten_fiber_init_from_current_context(
+                &leaderp->fiber,
+                leaderp->asyncify_stack,
+                leaderp->asyncify_stack_size);
+            leaderp->stack = leaderp->fiber.stack_limit;
+            leaderp->stack_size =
+                leaderp->fiber.stack_base - leaderp->fiber.stack_limit;
+            set_leader(leaderp);
+        }
+        self = &leaderp->base;
+        set_current(self);
+    }
+    return self;
+}
+
+bool qemu_in_coroutine(void)
+{
+    Coroutine *self = get_current();
+
+    return self && self->caller;
+}
-- 
2.25.1

[PATCH 17/19] meson: Add wasm build in build scripts

[Kohei Tokunaga]

has_int128_type is set to false on emscripten as of now to avoid errors by
libffi. Tests are disabled on emscripten because they rely on host
features that aren't supported by emscripten (e.g. fork and unix
socket).

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 configs/meson/emscripten.txt  |  8 ++++++++
 configure                     |  7 +++++++
 meson.build                   | 25 ++++++++++++++++++++-----
 meson_options.txt             |  2 +-
 scripts/meson-buildoptions.sh |  2 +-
 stubs/meson.build             |  4 ++++
 6 files changed, 41 insertions(+), 7 deletions(-)
 create mode 100644 configs/meson/emscripten.txt

diff --git a/configs/meson/emscripten.txt b/configs/meson/emscripten.txt
new file mode 100644
index 0000000000..4230e88005
--- /dev/null
+++ b/configs/meson/emscripten.txt
@@ -0,0 +1,8 @@
+[built-in options]
+c_args = ['-pthread']
+cpp_args = ['-pthread']
+objc_args = ['-pthread']
+# -sPROXY_TO_PTHREAD link time flag always requires -pthread even during
+# configuration so explicitly add the flag here.
+c_link_args = ['-pthread','-sASYNCIFY=1','-sPROXY_TO_PTHREAD=1','-sFORCE_FILESYSTEM','-sALLOW_TABLE_GROWTH','-sTOTAL_MEMORY=2GB','-sWASM_BIGINT','-sEXPORT_ES6=1','-sASYNCIFY_IMPORTS=ffi_call_js','-sEXPORTED_RUNTIME_METHODS=addFunction,removeFunction,TTY,FS']
+cpp_link_args = ['-pthread','-sASYNCIFY=1','-sPROXY_TO_PTHREAD=1','-sFORCE_FILESYSTEM','-sALLOW_TABLE_GROWTH','-sTOTAL_MEMORY=2GB','-sWASM_BIGINT','-sEXPORT_ES6=1','-sASYNCIFY_IMPORTS=ffi_call_js','-sEXPORTED_RUNTIME_METHODS=addFunction,removeFunction,TTY,FS']
diff --git a/configure b/configure
index 02f1dd2311..a1fe6e11cd 100755
--- a/configure
+++ b/configure
@@ -360,6 +360,10 @@ elif check_define __NetBSD__; then
   host_os=netbsd
 elif check_define __APPLE__; then
   host_os=darwin
+elif check_define EMSCRIPTEN ; then
+  host_os=emscripten
+  cpu=wasm32
+  cross_compile="yes"
 else
   # This is a fatal error, but don't report it yet, because we
   # might be going to just print the --help text, or it might
@@ -526,6 +530,9 @@ case "$cpu" in
     linux_arch=x86
     CPU_CFLAGS="-m64"
     ;;
+  wasm32)
+    CPU_CFLAGS="-m32"
+    ;;
 esac
 
 if test -n "$host_arch" && {
diff --git a/meson.build b/meson.build
index 41f68d3806..c9aa5016d6 100644
--- a/meson.build
+++ b/meson.build
@@ -50,9 +50,9 @@ genh = []
 qapi_trace_events = []
 
 bsd_oses = ['gnu/kfreebsd', 'freebsd', 'netbsd', 'openbsd', 'dragonfly', 'darwin']
-supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux']
+supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux', 'emscripten']
 supported_cpus = ['ppc', 'ppc64', 's390x', 'riscv32', 'riscv64', 'x86', 'x86_64',
-  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64']
+  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64', 'wasm32']
 
 cpu = host_machine.cpu_family()
 
@@ -353,6 +353,8 @@ foreach lang : all_languages
       # endif
       #endif''')
     # ok
+  elif compiler.get_id() == 'emscripten'
+    # ok
   else
     error('You either need GCC v7.4 or Clang v10.0 (or XCode Clang v15.0) to compile QEMU')
   endif
@@ -470,7 +472,10 @@ endif
 # instead, we can't add -no-pie because it overrides -shared: the linker then
 # tries to build an executable instead of a shared library and fails.  So
 # don't add -no-pie anywhere and cross fingers. :(
-if not get_option('b_pie')
+#
+# Emscripten doesn't support -no-pie but meson can't catch the compiler
+# warning. So explicitly omit the flag for Emscripten.
+if not get_option('b_pie') and host_os != 'emscripten'
   qemu_common_flags += cc.get_supported_arguments('-fno-pie', '-no-pie')
 endif
 
@@ -514,6 +519,8 @@ ucontext_probe = '''
 supported_backends = []
 if host_os == 'windows'
   supported_backends += ['windows']
+elif host_os == 'emscripten'
+  supported_backends += ['wasm']
 else
   if host_os != 'darwin' and cc.links(ucontext_probe)
     supported_backends += ['ucontext']
@@ -2962,7 +2969,9 @@ config_host_data.set('CONFIG_ATOMIC64', cc.links('''
     return 0;
   }''', args: qemu_isa_flags))
 
-has_int128_type = cc.compiles('''
+# has_int128_type is set to false on Emscripten to avoid errors by libffi
+# during runtime.
+has_int128_type = host_os != 'emscripten' and cc.compiles('''
   __int128_t a;
   __uint128_t b;
   int main(void) { b = a; }''')
@@ -3774,6 +3783,8 @@ if have_block
   # os-win32.c does not
   if host_os == 'windows'
     system_ss.add(files('os-win32.c'))
+  elif host_os == 'emscripten'
+    blockdev_ss.add(files('os-wasm.c'))
   else
     blockdev_ss.add(files('os-posix.c'))
   endif
@@ -4456,7 +4467,11 @@ subdir('scripts')
 subdir('tools')
 subdir('pc-bios')
 subdir('docs')
-subdir('tests')
+# Tests are disabled on emscripten because they rely on host features that aren't
+# supported by emscripten (e.g. fork and unix socket).
+if host_os != 'emscripten'
+  subdir('tests')
+endif
 if gtk.found()
   subdir('po')
 endif
diff --git a/meson_options.txt b/meson_options.txt
index 59d973bca0..45772484cc 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -34,7 +34,7 @@ option('fuzzing_engine', type : 'string', value : '',
 option('trace_file', type: 'string', value: 'trace',
        description: 'Trace file prefix for simple backend')
 option('coroutine_backend', type: 'combo',
-       choices: ['ucontext', 'sigaltstack', 'windows', 'auto'],
+       choices: ['ucontext', 'sigaltstack', 'windows', 'wasm', 'auto'],
        value: 'auto', description: 'coroutine backend to use')
 
 # Everything else can be set via --enable/--disable-* option
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index 3e8e00852b..0568385f00 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -80,7 +80,7 @@ meson_options_help() {
   printf "%s\n" '  --tls-priority=VALUE     Default TLS protocol/cipher priority string'
   printf "%s\n" '                           [NORMAL]'
   printf "%s\n" '  --with-coroutine=CHOICE  coroutine backend to use (choices:'
-  printf "%s\n" '                           auto/sigaltstack/ucontext/windows)'
+  printf "%s\n" '                           auto/sigaltstack/ucontext/windows/wasm)'
   printf "%s\n" '  --with-pkgversion=VALUE  use specified string as sub-version of the'
   printf "%s\n" '                           package'
   printf "%s\n" '  --with-suffix=VALUE      Suffix for QEMU data/modules/config directories'
diff --git a/stubs/meson.build b/stubs/meson.build
index 63392f5e78..4fd4d362f9 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -89,3 +89,7 @@ if have_system or have_user
   stub_ss.add(files('hotplug-stubs.c'))
   stub_ss.add(files('sysbus.c'))
 endif
+
+if host_os == 'emscripten'
+  stub_ss.add(files('emscripten.c'))
+endif
\ No newline at end of file
-- 
2.25.1

Re: [PATCH 17/19] meson: Add wasm build in build scripts

[Philippe Mathieu-Daudé]

Hi Kohei,

On 16/4/25 10:14, Kohei Tokunaga wrote:
> has_int128_type is set to false on emscripten as of now to avoid errors by
> libffi. Tests are disabled on emscripten because they rely on host
> features that aren't supported by emscripten (e.g. fork and unix
> socket).
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   configs/meson/emscripten.txt  |  8 ++++++++
>   configure                     |  7 +++++++
>   meson.build                   | 25 ++++++++++++++++++++-----
>   meson_options.txt             |  2 +-
>   scripts/meson-buildoptions.sh |  2 +-
>   stubs/meson.build             |  4 ++++
>   6 files changed, 41 insertions(+), 7 deletions(-)
>   create mode 100644 configs/meson/emscripten.txt


> diff --git a/meson.build b/meson.build
> index 41f68d3806..c9aa5016d6 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -50,9 +50,9 @@ genh = []
>   qapi_trace_events = []
>   
>   bsd_oses = ['gnu/kfreebsd', 'freebsd', 'netbsd', 'openbsd', 'dragonfly', 'darwin']
> -supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux']
> +supported_oses = ['windows', 'freebsd', 'netbsd', 'openbsd', 'darwin', 'sunos', 'linux', 'emscripten']
>   supported_cpus = ['ppc', 'ppc64', 's390x', 'riscv32', 'riscv64', 'x86', 'x86_64',
> -  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64']
> +  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64', 'wasm32']
>   
>   cpu = host_machine.cpu_family()
>   
> @@ -353,6 +353,8 @@ foreach lang : all_languages
>         # endif
>         #endif''')
>       # ok
> +  elif compiler.get_id() == 'emscripten'
> +    # ok
>     else
>       error('You either need GCC v7.4 or Clang v10.0 (or XCode Clang v15.0) to compile QEMU')
>     endif
> @@ -470,7 +472,10 @@ endif
>   # instead, we can't add -no-pie because it overrides -shared: the linker then
>   # tries to build an executable instead of a shared library and fails.  So
>   # don't add -no-pie anywhere and cross fingers. :(
> -if not get_option('b_pie')
> +#
> +# Emscripten doesn't support -no-pie but meson can't catch the compiler
> +# warning. So explicitly omit the flag for Emscripten.
> +if not get_option('b_pie') and host_os != 'emscripten'
>     qemu_common_flags += cc.get_supported_arguments('-fno-pie', '-no-pie')
>   endif
>   
> @@ -514,6 +519,8 @@ ucontext_probe = '''
>   supported_backends = []
>   if host_os == 'windows'
>     supported_backends += ['windows']
> +elif host_os == 'emscripten'
> +  supported_backends += ['wasm']
>   else
>     if host_os != 'darwin' and cc.links(ucontext_probe)
>       supported_backends += ['ucontext']
> @@ -2962,7 +2969,9 @@ config_host_data.set('CONFIG_ATOMIC64', cc.links('''
>       return 0;
>     }''', args: qemu_isa_flags))
>   
> -has_int128_type = cc.compiles('''
> +# has_int128_type is set to false on Emscripten to avoid errors by libffi
> +# during runtime.
> +has_int128_type = host_os != 'emscripten' and cc.compiles('''
>     __int128_t a;
>     __uint128_t b;
>     int main(void) { b = a; }''')
> @@ -3774,6 +3783,8 @@ if have_block
>     # os-win32.c does not
>     if host_os == 'windows'
>       system_ss.add(files('os-win32.c'))
> +  elif host_os == 'emscripten'
> +    blockdev_ss.add(files('os-wasm.c'))
>     else
>       blockdev_ss.add(files('os-posix.c'))
>     endif
> @@ -4456,7 +4467,11 @@ subdir('scripts')
>   subdir('tools')
>   subdir('pc-bios')
>   subdir('docs')
> -subdir('tests')
> +# Tests are disabled on emscripten because they rely on host features that aren't
> +# supported by emscripten (e.g. fork and unix socket).
> +if host_os != 'emscripten'
> +  subdir('tests')
> +endif
>   if gtk.found()
>     subdir('po')
>   endif
> diff --git a/meson_options.txt b/meson_options.txt
> index 59d973bca0..45772484cc 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -34,7 +34,7 @@ option('fuzzing_engine', type : 'string', value : '',
>   option('trace_file', type: 'string', value: 'trace',
>          description: 'Trace file prefix for simple backend')
>   option('coroutine_backend', type: 'combo',
> -       choices: ['ucontext', 'sigaltstack', 'windows', 'auto'],
> +       choices: ['ucontext', 'sigaltstack', 'windows', 'wasm', 'auto'],
>          value: 'auto', description: 'coroutine backend to use')

Does wasm depend on TCI at this point (no TCG backend)? If so, should
we check TCI is enabled? (I wonder if configuring with the
--disable-tcg-interpreter option succeed).

Re: [PATCH 17/19] meson: Add wasm build in build scripts

[Kohei Tokunaga]

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Hi Philippe,

> Does wasm depend on TCI at this point (no TCG backend)? If so, should
> we check TCI is enabled? (I wonder if configuring with the
> --disable-tcg-interpreter option succeed).

Yes, it depends on TCI at this point. Configuring with the
--disable-tcg-interpreter succeeds but leads to a build error. I'll update
the patch to include a check to ensure TCI is enabled.

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[PATCH 18/19] gitlab: Enable CI for wasm build

[Kohei Tokunaga]

Add GitLab CI job that builds QEMU using emscripten. The build runs in the
added Dockerfile that contains dependencies (glib, libffi, pixman, zlib)
compiled by emscripten.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 .gitlab-ci.d/buildtest-template.yml           |  27 ++++
 .gitlab-ci.d/buildtest.yml                    |   9 ++
 .gitlab-ci.d/container-cross.yml              |   5 +
 .../dockerfiles/emsdk-wasm32-cross.docker     | 145 ++++++++++++++++++
 4 files changed, 186 insertions(+)
 create mode 100644 tests/docker/dockerfiles/emsdk-wasm32-cross.docker

diff --git a/.gitlab-ci.d/buildtest-template.yml b/.gitlab-ci.d/buildtest-template.yml
index 39da7698b0..67167d68a5 100644
--- a/.gitlab-ci.d/buildtest-template.yml
+++ b/.gitlab-ci.d/buildtest-template.yml
@@ -126,3 +126,30 @@
     - du -chs ${CI_PROJECT_DIR}/*-cache
   variables:
     QEMU_JOB_AVOCADO: 1
+
+.wasm_build_job_template:
+  extends: .base_job_template
+  stage: build
+  image: $CI_REGISTRY_IMAGE/qemu/$IMAGE:$QEMU_CI_CONTAINER_TAG
+  before_script:
+    - source scripts/ci/gitlab-ci-section
+    - section_start setup "Pre-script setup"
+    - JOBS=$(expr $(nproc) + 1)
+    - section_end setup
+  script:
+    - du -sh .git
+    - mkdir build
+    - cd build
+    - section_start configure "Running configure"
+    - emconfigure ../configure --disable-docs
+          ${TARGETS:+--target-list="$TARGETS"}
+          $CONFIGURE_ARGS ||
+      { cat config.log meson-logs/meson-log.txt && exit 1; }
+    - if test -n "$LD_JOBS";
+      then
+        pyvenv/bin/meson configure . -Dbackend_max_links="$LD_JOBS" ;
+      fi || exit 1;
+    - section_end configure
+    - section_start build "Building QEMU"
+    - emmake make -j"$JOBS"
+    - section_end build
diff --git a/.gitlab-ci.d/buildtest.yml b/.gitlab-ci.d/buildtest.yml
index 00f4bfcd9f..0f92d5313a 100644
--- a/.gitlab-ci.d/buildtest.yml
+++ b/.gitlab-ci.d/buildtest.yml
@@ -801,3 +801,12 @@ coverity:
       when: never
     # Always manual on forks even if $QEMU_CI == "2"
     - when: manual
+
+build-wasm:
+  extends: .wasm_build_job_template
+  timeout: 2h
+  needs:
+    job: wasm-emsdk-cross-container
+  variables:
+    IMAGE: emsdk-wasm32-cross
+    CONFIGURE_ARGS: --static --disable-tools --enable-debug --enable-tcg-interpreter
diff --git a/.gitlab-ci.d/container-cross.yml b/.gitlab-ci.d/container-cross.yml
index 34c0e729ad..3ea4971950 100644
--- a/.gitlab-ci.d/container-cross.yml
+++ b/.gitlab-ci.d/container-cross.yml
@@ -94,3 +94,8 @@ win64-fedora-cross-container:
   extends: .container_job_template
   variables:
     NAME: fedora-win64-cross
+
+wasm-emsdk-cross-container:
+  extends: .container_job_template
+  variables:
+    NAME: emsdk-wasm32-cross
diff --git a/tests/docker/dockerfiles/emsdk-wasm32-cross.docker b/tests/docker/dockerfiles/emsdk-wasm32-cross.docker
new file mode 100644
index 0000000000..60a7d02f56
--- /dev/null
+++ b/tests/docker/dockerfiles/emsdk-wasm32-cross.docker
@@ -0,0 +1,145 @@
+# syntax = docker/dockerfile:1.5
+
+ARG EMSDK_VERSION_QEMU=3.1.50
+ARG ZLIB_VERSION=1.3.1
+ARG GLIB_MINOR_VERSION=2.84
+ARG GLIB_VERSION=${GLIB_MINOR_VERSION}.0
+ARG PIXMAN_VERSION=0.44.2
+ARG FFI_VERSION=v3.4.7
+ARG MESON_VERSION=1.5.0
+
+FROM emscripten/emsdk:$EMSDK_VERSION_QEMU AS build-base
+ARG MESON_VERSION
+ENV TARGET=/builddeps/target
+ENV CPATH="$TARGET/include"
+ENV PKG_CONFIG_PATH="$TARGET/lib/pkgconfig"
+ENV EM_PKG_CONFIG_PATH="$PKG_CONFIG_PATH"
+ENV CFLAGS="-O3 -pthread -DWASM_BIGINT"
+ENV CXXFLAGS="$CFLAGS"
+ENV LDFLAGS="-sWASM_BIGINT -sASYNCIFY=1 -L$TARGET/lib"
+RUN apt-get update && apt-get install -y \
+    autoconf \
+    build-essential \
+    libglib2.0-dev \
+    libtool \
+    pkgconf \
+    ninja-build \
+    python3-pip
+RUN pip3 install meson==${MESON_VERSION} tomli
+RUN mkdir /build
+WORKDIR /build
+RUN mkdir -p $TARGET
+RUN <<EOF
+cat <<EOT > /cross.meson
+[host_machine]
+system = 'emscripten'
+cpu_family = 'wasm32'
+cpu = 'wasm32'
+endian = 'little'
+
+[binaries]
+c = 'emcc'
+cpp = 'em++'
+ar = 'emar'
+ranlib = 'emranlib'
+pkgconfig = ['pkg-config', '--static']
+EOT
+EOF
+
+FROM build-base AS zlib-dev
+ARG ZLIB_VERSION
+RUN mkdir -p /zlib
+RUN curl -Ls https://zlib.net/zlib-$ZLIB_VERSION.tar.xz | \
+    tar xJC /zlib --strip-components=1
+WORKDIR /zlib
+RUN emconfigure ./configure --prefix=$TARGET --static
+RUN emmake make install -j$(nproc)
+
+FROM build-base AS libffi-dev
+ARG FFI_VERSION
+RUN mkdir -p /libffi
+RUN git clone https://github.com/libffi/libffi /libffi
+WORKDIR /libffi
+RUN git checkout $FFI_VERSION
+RUN autoreconf -fiv
+RUN emconfigure ./configure --host=wasm32-unknown-linux \
+    --prefix=$TARGET --enable-static \
+    --disable-shared --disable-dependency-tracking \
+    --disable-builddir --disable-multi-os-directory \
+    --disable-raw-api --disable-docs
+RUN emmake make install SUBDIRS='include' -j$(nproc)
+
+FROM build-base AS pixman-dev
+ARG PIXMAN_VERSION
+RUN mkdir /pixman/
+RUN git clone  https://gitlab.freedesktop.org/pixman/pixman /pixman/
+WORKDIR /pixman
+RUN git checkout pixman-$PIXMAN_VERSION
+RUN <<EOF
+cat <<EOT >> /cross.meson
+[built-in options]
+c_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+cpp_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+objc_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+c_link_args = [$(printf "'%s', " $LDFLAGS | sed 's/, $//')]
+cpp_link_args = [$(printf "'%s', " $LDFLAGS | sed 's/, $//')]
+EOT
+EOF
+RUN meson setup _build --prefix=$TARGET --cross-file=/cross.meson \
+    --default-library=static \
+    --buildtype=release -Dtests=disabled -Ddemos=disabled
+RUN meson install -C _build
+
+FROM build-base AS glib-dev
+ARG GLIB_VERSION
+ARG GLIB_MINOR_VERSION
+RUN mkdir -p /stub
+WORKDIR /stub
+RUN <<EOF
+cat <<'EOT' > res_query.c
+#include <netdb.h>
+int res_query(const char *name, int class,
+              int type, unsigned char *dest, int len)
+{
+    h_errno = HOST_NOT_FOUND;
+    return -1;
+}
+EOT
+EOF
+RUN emcc ${CFLAGS} -c res_query.c -fPIC -o libresolv.o
+RUN ar rcs libresolv.a libresolv.o
+RUN mkdir -p $TARGET/lib/
+RUN cp libresolv.a $TARGET/lib/
+
+RUN mkdir -p /glib
+RUN curl -Lks https://download.gnome.org/sources/glib/${GLIB_MINOR_VERSION}/glib-$GLIB_VERSION.tar.xz | \
+    tar xJC /glib --strip-components=1
+
+COPY --link --from=zlib-dev /builddeps/ /builddeps/
+COPY --link --from=libffi-dev /builddeps/ /builddeps/
+
+WORKDIR /glib
+RUN <<EOF
+CFLAGS="$CFLAGS -Wno-incompatible-function-pointer-types" ;
+cat <<EOT >> /cross.meson
+[built-in options]
+c_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+cpp_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+objc_args = [$(printf "'%s', " $CFLAGS | sed 's/, $//')]
+c_link_args = [$(printf "'%s', " $LDFLAGS | sed 's/, $//')]
+cpp_link_args = [$(printf "'%s', " $LDFLAGS | sed 's/, $//')]
+EOT
+EOF
+RUN meson setup _build --prefix=$TARGET --cross-file=/cross.meson \
+    --default-library=static --buildtype=release --force-fallback-for=pcre2 \
+    -Dselinux=disabled -Dxattr=false -Dlibmount=disabled -Dnls=disabled \
+    -Dtests=false -Dglib_debug=disabled -Dglib_assert=false -Dglib_checks=false
+# FIXME: emscripten doesn't provide some pthread functions in the final link,
+#        which isn't detected during meson setup.
+RUN sed -i -E "/#define HAVE_POSIX_SPAWN 1/d" ./_build/config.h
+RUN sed -i -E "/#define HAVE_PTHREAD_GETNAME_NP 1/d" ./_build/config.h
+RUN meson install -C _build
+
+FROM build-base
+COPY --link --from=glib-dev /builddeps/ /builddeps/
+COPY --link --from=pixman-dev /builddeps/ /builddeps/
-- 
2.25.1

Re: [PATCH 18/19] gitlab: Enable CI for wasm build

[Philippe Mathieu-Daudé]

On 16/4/25 10:14, Kohei Tokunaga wrote:
> Add GitLab CI job that builds QEMU using emscripten. The build runs in the
> added Dockerfile that contains dependencies (glib, libffi, pixman, zlib)
> compiled by emscripten.
> 
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   .gitlab-ci.d/buildtest-template.yml           |  27 ++++
>   .gitlab-ci.d/buildtest.yml                    |   9 ++
>   .gitlab-ci.d/container-cross.yml              |   5 +
>   .../dockerfiles/emsdk-wasm32-cross.docker     | 145 ++++++++++++++++++
>   4 files changed, 186 insertions(+)
>   create mode 100644 tests/docker/dockerfiles/emsdk-wasm32-cross.docker

Probably nitpicking, I'd add the Dockerfile first, then the GitLab job
in another patch.

Re: [PATCH 18/19] gitlab: Enable CI for wasm build

[Kohei Tokunaga]

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Hi Philippe,

> Probably nitpicking, I'd add the Dockerfile first, then the GitLab job
> in another patch.

Thank you for the suggestion. I'll split the patch in the next version.

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[PATCH 19/19] MAINTAINERS: Update MAINTAINERS file for wasm-related files

[Kohei Tokunaga]

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
---
 MAINTAINERS | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index d54b5578f8..74a102c594 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3903,6 +3903,16 @@ F: tcg/tci/
 F: tcg/tci.c
 F: disas/tci.c
 
+WebAssembly TCG target
+M: Kohei Tokunaga <ktokunaga.mail@gmail.com>
+S: Maintained
+F: configs/meson/emscripten.txt
+F: tests/docker/dockerfiles/emsdk-wasm32-cross.docker
+F: util/coroutine-wasm.c
+F: os-wasm.c
+F: include/system/os-wasm.h
+F: stubs/emscripten.c
+
 Block drivers
 -------------
 VMDK
-- 
2.25.1

Re: [PATCH 19/19] MAINTAINERS: Update MAINTAINERS file for wasm-related files

[Philippe Mathieu-Daudé]

On 16/4/25 10:14, Kohei Tokunaga wrote:
> Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> ---
>   MAINTAINERS | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d54b5578f8..74a102c594 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3903,6 +3903,16 @@ F: tcg/tci/
>   F: tcg/tci.c
>   F: disas/tci.c
>   
> +WebAssembly TCG target

Just "WebAssembly target"? (I'd add the future
tcg/wasm/ files in another MAINTAINERS section).

Maybe better to squash with patch 17? Or start adding
the section when you add a new file, then update for
each new file added?

> +M: Kohei Tokunaga <ktokunaga.mail@gmail.com>
> +S: Maintained
> +F: configs/meson/emscripten.txt
> +F: tests/docker/dockerfiles/emsdk-wasm32-cross.docker
> +F: util/coroutine-wasm.c
> +F: os-wasm.c
> +F: include/system/os-wasm.h
> +F: stubs/emscripten.c
> +
>   Block drivers
>   -------------
>   VMDK

Re: [PATCH 19/19] MAINTAINERS: Update MAINTAINERS file for wasm-related files

[Kohei Tokunaga]

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Hi Philippe,

> Just "WebAssembly target"? (I'd add the future
> tcg/wasm/ files in another MAINTAINERS section).
>
> Maybe better to squash with patch 17? Or start adding
> the section when you add a new file, then update for
> each new file added?

Sure, I'll update the patch to follow this approach.

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