diff --git a/.gitlab-ci.d/buildtest.yml b/.gitlab-ci.d/buildtest.yml
index d888a60063715..0dded0418807b 100644
--- a/.gitlab-ci.d/buildtest.yml
+++ b/.gitlab-ci.d/buildtest.yml
@@ -787,11 +787,29 @@ coverity:
     # Always manual on forks even if $QEMU_CI == "2"
     - when: manual
 
-build-wasm:
+build-wasm32:
   extends: .wasm_build_job_template
   timeout: 2h
   needs:
-    job: wasm-emsdk-cross-container
+    job: wasm32-emsdk-cross-container
   variables:
     IMAGE: emsdk-wasm32-cross
-    CONFIGURE_ARGS: --static --disable-tools --enable-debug --enable-tcg-interpreter
+    CONFIGURE_ARGS: --static --cpu=wasm32 --disable-tools --enable-debug --enable-tcg-interpreter
+
+build-wasm-wasm64:
+  extends: .wasm_build_job_template
+  timeout: 2h
+  needs:
+    job: wasm64-emsdk-cross-container
+  variables:
+    IMAGE: emsdk-wasm64-cross
+    CONFIGURE_ARGS: --static --cpu=wasm64 --disable-tools --enable-debug --enable-tcg-interpreter
+
+build-wasm-wasm64l:
+  extends: .wasm_build_job_template
+  timeout: 2h
+  needs:
+    job: wasm64l-emsdk-cross-container
+  variables:
+    IMAGE: emsdk-wasm64l-cross
+    CONFIGURE_ARGS: --static --cpu=wasm64 --wasm64-32bit-address-limit --disable-tools --enable-debug --enable-tcg-interpreter
diff --git a/.gitlab-ci.d/container-cross.yml b/.gitlab-ci.d/container-cross.yml
index 8d3be53b75b23..1bacaff8188d7 100644
--- a/.gitlab-ci.d/container-cross.yml
+++ b/.gitlab-ci.d/container-cross.yml
@@ -92,7 +92,23 @@ win64-fedora-cross-container:
   variables:
     NAME: fedora-win64-cross
 
-wasm-emsdk-cross-container:
+wasm32-emsdk-cross-container:
   extends: .container_job_template
   variables:
     NAME: emsdk-wasm32-cross
+    BUILD_ARGS: --build-arg TARGET_CPU=wasm32
+    DOCKERFILE: emsdk-wasm-cross
+
+wasm64-emsdk-cross-container:
+  extends: .container_job_template
+  variables:
+    NAME: emsdk-wasm64-cross
+    BUILD_ARGS: --build-arg TARGET_CPU=wasm64 --build-arg WASM64_MEMORY64=1
+    DOCKERFILE: emsdk-wasm-cross
+
+wasm64l-emsdk-cross-container:
+  extends: .container_job_template
+  variables:
+    NAME: emsdk-wasm64l-cross
+    BUILD_ARGS: --build-arg TARGET_CPU=wasm64 --build-arg WASM64_MEMORY64=2
+    DOCKERFILE: emsdk-wasm-cross
diff --git a/.gitlab-ci.d/container-template.yml b/.gitlab-ci.d/container-template.yml
index 4eec72f383dd7..01ca8404136fb 100644
--- a/.gitlab-ci.d/container-template.yml
+++ b/.gitlab-ci.d/container-template.yml
@@ -10,12 +10,14 @@
     - export COMMON_TAG="$CI_REGISTRY/qemu-project/qemu/qemu/$NAME:latest"
     - docker login $CI_REGISTRY -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD"
     - until docker info; do sleep 1; done
+    - export DOCKERFILE_NAME=${DOCKERFILE:-$NAME}
   script:
     - echo "TAG:$TAG"
     - echo "COMMON_TAG:$COMMON_TAG"
     - docker build --tag "$TAG" --cache-from "$TAG" --cache-from "$COMMON_TAG"
       --build-arg BUILDKIT_INLINE_CACHE=1
-      -f "tests/docker/dockerfiles/$NAME.docker" "."
+      $BUILD_ARGS
+      -f "tests/docker/dockerfiles/$DOCKERFILE_NAME.docker" "."
     - docker push "$TAG"
   after_script:
     - docker logout
diff --git a/MAINTAINERS b/MAINTAINERS
index 28cea342718db..47b35bae47e5c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -647,7 +647,7 @@ 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
+F: tests/docker/dockerfiles/emsdk-wasm-cross.docker
 
 Alpha Machines
 --------------
diff --git a/configure b/configure
index 825057ebf1551..0587577da985d 100755
--- a/configure
+++ b/configure
@@ -182,6 +182,10 @@ EXTRA_CXXFLAGS=""
 EXTRA_OBJCFLAGS=""
 EXTRA_LDFLAGS=""
 
+# The value is propagated to Emscripten's "-sMEMORY64" flag.
+# https://emscripten.org/docs/tools_reference/settings_reference.html#memory64
+wasm64_memory64=1
+
 # Default value for a variable defining feature "foo".
 #  * foo="no"  feature will only be used if --enable-foo arg is given
 #  * foo=""    feature will be searched for, and if found, will be used
@@ -239,6 +243,8 @@ for opt do
   ;;
   --without-default-features) default_feature="no"
   ;;
+  --wasm64-32bit-address-limit) wasm64_memory64="2"
+  ;;
   esac
 done
 
@@ -365,7 +371,6 @@ 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
@@ -425,6 +430,8 @@ elif check_define __aarch64__ ; then
   cpu="aarch64"
 elif check_define __loongarch64 ; then
   cpu="loongarch64"
+elif check_define EMSCRIPTEN ; then
+  error_exit "wasm32 or wasm64 must be specified to the cpu flag"
 else
   # Using uname is really broken, but it is just a fallback for architectures
   # that are going to use TCI anyway
@@ -535,6 +542,9 @@ case "$cpu" in
   wasm32)
     CPU_CFLAGS="-m32"
     ;;
+  wasm64)
+    CPU_CFLAGS="-m64 -sMEMORY64=$wasm64_memory64"
+    ;;
 esac
 
 if test -n "$host_arch" && {
@@ -791,6 +801,8 @@ for opt do
   ;;
   --disable-rust) rust=disabled
   ;;
+  --wasm64-32bit-address-limit)
+  ;;
   # everything else has the same name in configure and meson
   --*) meson_option_parse "$opt" "$optarg"
   ;;
@@ -916,6 +928,8 @@ Advanced options (experts only):
   --disable-containers     don't use containers for cross-building
   --container-engine=TYPE  which container engine to use [$container_engine]
   --gdb=GDB-path           gdb to use for gdbstub tests [$gdb_bin]
+  --wasm64-32bit-address-limit Restrict wasm64 address space to 32-bit (default
+                               is to use the whole 64-bit range).
 EOF
   meson_options_help
 cat << EOF
diff --git a/meson.build b/meson.build
index e53cd5b413847..291fe3f0d0320 100644
--- a/meson.build
+++ b/meson.build
@@ -52,7 +52,7 @@ qapi_trace_events = []
 bsd_oses = ['gnu/kfreebsd', 'freebsd', 'netbsd', 'openbsd', 'dragonfly', 'darwin']
 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', 'wasm32']
+  'arm', 'aarch64', 'loongarch64', 'mips', 'mips64', 'sparc64', 'wasm32', 'wasm64']
 
 cpu = host_machine.cpu_family()
 
@@ -916,7 +916,7 @@ if have_tcg
     if not get_option('tcg_interpreter')
       error('Unsupported CPU @0@, try --enable-tcg-interpreter'.format(cpu))
     endif
-  elif host_arch == 'wasm32'
+  elif host_arch == 'wasm32' or host_arch == 'wasm64'
     if not get_option('tcg_interpreter')
       error('WebAssembly host requires --enable-tcg-interpreter')
     endif
diff --git a/tests/docker/dockerfiles/emsdk-wasm32-cross.docker b/tests/docker/dockerfiles/emsdk-wasm-cross.docker
similarity index 85%
rename from tests/docker/dockerfiles/emsdk-wasm32-cross.docker
rename to tests/docker/dockerfiles/emsdk-wasm-cross.docker
index 60a7d02f5613e..4b41be62ab864 100644
--- a/tests/docker/dockerfiles/emsdk-wasm32-cross.docker
+++ b/tests/docker/dockerfiles/emsdk-wasm-cross.docker
@@ -1,14 +1,17 @@
 # syntax = docker/dockerfile:1.5
 
-ARG EMSDK_VERSION_QEMU=3.1.50
+ARG EMSDK_VERSION_QEMU=4.0.10
 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 FFI_VERSION=v3.5.2
 ARG MESON_VERSION=1.5.0
+ARG TARGET_CPU=wasm32
+ARG WASM64_MEMORY64=0
 
-FROM emscripten/emsdk:$EMSDK_VERSION_QEMU AS build-base
+FROM emscripten/emsdk:$EMSDK_VERSION_QEMU AS build-base-common
+ARG TARGET_CPU
 ARG MESON_VERSION
 ENV TARGET=/builddeps/target
 ENV CPATH="$TARGET/include"
@@ -33,8 +36,8 @@ RUN <<EOF
 cat <<EOT > /cross.meson
 [host_machine]
 system = 'emscripten'
-cpu_family = 'wasm32'
-cpu = 'wasm32'
+cpu_family = '${TARGET_CPU}'
+cpu = '${TARGET_CPU}'
 endian = 'little'
 
 [binaries]
@@ -46,6 +49,16 @@ pkgconfig = ['pkg-config', '--static']
 EOT
 EOF
 
+FROM build-base-common AS build-base-wasm32
+
+FROM build-base-common AS build-base-wasm64
+ARG WASM64_MEMORY64
+ENV CFLAGS="$CFLAGS -sMEMORY64=${WASM64_MEMORY64}"
+ENV CXXFLAGS="$CXXFLAGS -sMEMORY64=${WASM64_MEMORY64}"
+ENV LDFLAGS="$LDFLAGS -sMEMORY64=${WASM64_MEMORY64}"
+
+FROM build-base-${TARGET_CPU} AS build-base
+
 FROM build-base AS zlib-dev
 ARG ZLIB_VERSION
 RUN mkdir -p /zlib
@@ -56,17 +69,19 @@ RUN emconfigure ./configure --prefix=$TARGET --static
 RUN emmake make install -j$(nproc)
 
 FROM build-base AS libffi-dev
+ARG TARGET_CPU
+ARG WASM64_MEMORY64
 ARG FFI_VERSION
 RUN mkdir -p /libffi
 RUN git clone https://github.com/libffi/libffi /libffi
 WORKDIR /libffi
 RUN git checkout $FFI_VERSION
 RUN autoreconf -fiv
-RUN emconfigure ./configure --host=wasm32-unknown-linux \
+RUN emconfigure ./configure --host=${TARGET_CPU}-unknown-linux \
     --prefix=$TARGET --enable-static \
     --disable-shared --disable-dependency-tracking \
     --disable-builddir --disable-multi-os-directory \
-    --disable-raw-api --disable-docs
+    --disable-raw-api --disable-docs WASM64_MEMORY64=${WASM64_MEMORY64}
 RUN emmake make install SUBDIRS='include' -j$(nproc)
 
 FROM build-base AS pixman-dev