ktock · ktock · Apr 14, 2025 · Apr 14, 2025 · Apr 14, 2025 · Apr 14, 2025
diff --git a/.gitlab-ci.d/buildtest-template.yml b/.gitlab-ci.d/buildtest-template.yml
@@ -115,3 +115,30 @@
     - du -chs ${CI_PROJECT_DIR}/*-cache
   variables:
     QEMU_JOB_FUNCTIONAL: 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
@@ -792,3 +792,12 @@ 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
@@ -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/MAINTAINERS b/MAINTAINERS
@@ -628,6 +628,15 @@ F: .gitlab-ci.d/cirrus/macos-*
 F: */*.m
 F: scripts/entitlement.sh
 
+WebAssembly
+M: Kohei Tokunaga <[email protected]>
+S: Maintained
+F: include/system/os-wasm.h
+F: os-wasm.c
+F: util/coroutine-wasm.c
+F: configs/meson/emscripten.txt
+F: tests/docker/dockerfiles/emsdk-wasm32-cross.docker
+
 Alpha Machines
 --------------
 M: Richard Henderson <[email protected]>

diff --git a/backends/meson.build b/backends/meson.build
@@ -12,8 +12,10 @@ system_ss.add([files(
 
 if host_os != 'windows'
   system_ss.add(files('rng-random.c'))
-  system_ss.add(files('hostmem-file.c'))
-  system_ss.add([files('hostmem-shm.c'), rt])
+  if host_os != 'emscripten'
+    system_ss.add(files('hostmem-file.c'))
+    system_ss.add([files('hostmem-shm.c'), rt])
+  endif
 endif
 if host_os == 'linux'
   system_ss.add(files('hostmem-memfd.c'))

diff --git 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
@@ -2011,8 +2015,8 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
 }
 
 #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,

diff --git a/configs/meson/emscripten.txt 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
@@ -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/contrib/plugins/cache.c b/contrib/plugins/cache.c
@@ -576,23 +576,23 @@ 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;
 
     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;
 
     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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -71,15 +71,15 @@ 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;
     return ea->totals.reads + ea->totals.writes >
            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/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;

diff --git 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;
@@ -1316,7 +1316,7 @@ 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;

diff --git a/include/glib-compat.h b/include/glib-compat.h
@@ -36,6 +36,13 @@
 #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
+ * instead 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

diff --git a/include/qemu/cacheflush.h b/include/qemu/cacheflush.h
@@ -26,6 +26,13 @@ static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
     /* icache is coherent and does not require flushing. */
 }
 
+#elif defined(EMSCRIPTEN)
+
+static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
+{
+    /* Wasm doesn't have executable region of memory. */
+}
+
 #else
 
 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len);