Rebase on the latest

.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

.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

.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

MAINTAINERS

@@ -3903,6 +3903,17 @@ F: tcg/tci/
 F: tcg/tci.c
 F: disas/tci.c
 
+WebAssembly TCG target
+M: Kohei Tokunaga <[email protected]>
+S: Maintained
+F: configs/meson/emscripten.txt
+F: hw/9pfs/9p-util-stub.c
+F: tcg/wasm32/
+F: tcg/wasm32.c
+F: tcg/wasm32.h
+F: tests/docker/dockerfiles/emsdk-wasm32-cross.docker
+F: util/coroutine-fiber.c
+
 Block drivers
 -------------
 VMDK

accel/tcg/cputlb.c

@@ -104,13 +104,13 @@ static inline uint64_t tlb_read_idx(const CPUTLBEntry *entry,
 {
     /* Do not rearrange the CPUTLBEntry structure members. */
     QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_read) !=
-                      MMU_DATA_LOAD * sizeof(uintptr_t));
+                      MMU_DATA_LOAD * sizeof(tlb_addr));
     QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_write) !=
-                      MMU_DATA_STORE * sizeof(uintptr_t));
+                      MMU_DATA_STORE * sizeof(tlb_addr));
     QEMU_BUILD_BUG_ON(offsetof(CPUTLBEntry, addr_code) !=
-                      MMU_INST_FETCH * sizeof(uintptr_t));
+                      MMU_INST_FETCH * sizeof(tlb_addr));
 
-    const uintptr_t *ptr = &entry->addr_idx[access_type];
+    const tlb_addr *ptr = &entry->addr_idx[access_type];
     /* ofs might correspond to .addr_write, so use qatomic_read */
     return qatomic_read(ptr);
 }

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
@@ -2011,6 +2015,19 @@ static int handle_aiocb_write_zeroes_unmap(void *opaque)
 }
 
 #ifndef HAVE_COPY_FILE_RANGE
+#ifdef EMSCRIPTEN
+/*
+ * 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;
+}
+#else
 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 +2040,7 @@ 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

configs/meson/emscripten.txt

@@ -0,0 +1,6 @@
+[built-in options]
+c_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
+cpp_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
+objc_args = ['-Wno-unused-command-line-argument','-g','-O3','-pthread']
+c_link_args = ['-Wno-unused-command-line-argument','-g','-O3','-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 = ['-Wno-unused-command-line-argument','-g','-O3','-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']

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" && {

fsdev/file-op-9p.h

@@ -26,6 +26,9 @@
 # include <sys/param.h>
 # include <sys/mount.h>
 #endif
+#ifdef EMSCRIPTEN
+#include <sys/vfs.h>
+#endif
 
 #define SM_LOCAL_MODE_BITS    0600
 #define SM_LOCAL_DIR_MODE_BITS    0700

fsdev/meson.build

@@ -5,6 +5,6 @@ fsdev_ss.add(when: ['CONFIG_FSDEV_9P'], if_true: files(
   '9p-marshal.c',
   'qemu-fsdev.c',
 ), if_false: files('qemu-fsdev-dummy.c'))
-if host_os in ['linux', 'darwin']
+if host_os in ['linux', 'darwin', 'emscripten']
   system_ss.add_all(fsdev_ss)
 endif

hw/9pfs/9p-util-stub.c

@@ -0,0 +1,43 @@
+/*
+ * 9p utilities stub functions
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "9p-util.h"
+
+ssize_t fgetxattrat_nofollow(int dirfd, const char *path, const char *name,
+                             void *value, size_t size)
+{
+    return -1;
+}
+
+ssize_t flistxattrat_nofollow(int dirfd, const char *filename,
+                              char *list, size_t size)
+{
+    return -1;
+}
+
+ssize_t fremovexattrat_nofollow(int dirfd, const char *filename,
+                                const char *name)
+{
+    return -1;
+}
+
+int fsetxattrat_nofollow(int dirfd, const char *path, const char *name,
+                         void *value, size_t size, int flags)
+{
+    return -1;
+
+}
+
+int qemu_mknodat(int dirfd, const char *filename, mode_t mode, dev_t dev)
+{
+    return -1;
+}
+
+ssize_t fgetxattr(int fd, const char *name, void *value, size_t size)
+{
+    return -1;
+}

hw/9pfs/9p-util.h

@@ -84,6 +84,24 @@ static inline int errno_to_dotl(int err) {
     } else if (err == EOPNOTSUPP) {
         err = 95; /* ==EOPNOTSUPP on Linux */
     }
+#elif defined(EMSCRIPTEN)
+    /*
+     * FIXME: Only most important errnos translated here yet, this should be
+     * extended to as many errnos being translated as possible in future.
+     */
+    if (err == ENAMETOOLONG) {
+        err = 36; /* ==ENAMETOOLONG on Linux */
+    } else if (err == ENOTEMPTY) {
+        err = 39; /* ==ENOTEMPTY on Linux */
+    } else if (err == ELOOP) {
+        err = 40; /* ==ELOOP on Linux */
+    } else if (err == ENODATA) {
+        err = 61; /* ==ENODATA on Linux */
+    } else if (err == ENOTSUP) {
+        err = 95; /* ==EOPNOTSUPP on Linux */
+    } else if (err == EOPNOTSUPP) {
+        err = 95; /* ==EOPNOTSUPP on Linux */
+    }
 #else
 #error Missing errno translation to Linux for this host system
 #endif

hw/9pfs/9p.c

@@ -4013,6 +4013,9 @@ static void coroutine_fn v9fs_xattrwalk(void *opaque)
  * Linux guests.
  */
 #define P9_XATTR_SIZE_MAX 65536
+#elif defined(EMSCRIPTEN)
+/* No support for xattr */
+#define P9_XATTR_SIZE_MAX 0
 #else
 #error Missing definition for P9_XATTR_SIZE_MAX for this host system
 #endif

hw/9pfs/coth.h

@@ -19,6 +19,7 @@
 #include "qemu/coroutine-core.h"
 #include "9p.h"
 
+#ifndef EMSCRIPTEN
 /*
  * we want to use bottom half because we want to make sure the below
  * sequence of events.
@@ -57,6 +58,17 @@
         /* re-enter back to qemu thread */                              \
         qemu_coroutine_yield();                                         \
     } while (0)
+#else
+/*
+ * FIXME: implement this on emscripten but emscripten's coroutine
+ * implementation (fiber) doesn't support submitting a coroutine to other
+ * threads.
+ */
+#define v9fs_co_run_in_worker(code_block)                               \
+    do {                                                                \
+        code_block;                                                     \
+    } while (0)
+#endif
 
 void co_run_in_worker_bh(void *);
 int coroutine_fn v9fs_co_readlink(V9fsPDU *, V9fsPath *, V9fsString *);

hw/9pfs/meson.build

@@ -17,6 +17,8 @@ if host_os == 'darwin'
   fs_ss.add(files('9p-util-darwin.c'))
 elif host_os == 'linux'
   fs_ss.add(files('9p-util-linux.c'))
+elif host_os == 'emscripten'
+  fs_ss.add(files('9p-util-stub.c'))
 endif
 fs_ss.add(when: 'CONFIG_XEN_BUS', if_true: files('xen-9p-backend.c'))
 system_ss.add_all(when: 'CONFIG_FSDEV_9P', if_true: fs_ss)

hw/riscv/riscv_hart.c

@@ -102,10 +102,17 @@ static bool csr_qtest_callback(CharBackend *chr, gchar **words)
     return false;
 }
 
+static gpointer g_qtest_set_command_cb(
+    bool (*pc_cb)(CharBackend *chr, gchar **words))
+{
+    qtest_set_command_cb(pc_cb);
+    return NULL;
+}
+
 static void riscv_cpu_register_csr_qtest_callback(void)
 {
     static GOnce once;
-    g_once(&once, (GThreadFunc)qtest_set_command_cb, csr_qtest_callback);
+    g_once(&once, (GThreadFunc)g_qtest_set_command_cb, csr_qtest_callback);
 }
 #endif
 

include/accel/tcg/getpc.h

@@ -13,7 +13,7 @@
 #endif
 
 /* GETPC is the true target of the return instruction that we'll execute.  */
-#ifdef CONFIG_TCG_INTERPRETER
+#if defined(CONFIG_TCG_INTERPRETER) || defined(EMSCRIPTEN)
 extern __thread uintptr_t tci_tb_ptr;
 # define GETPC() tci_tb_ptr
 #else

include/exec/tlb-common.h

@@ -19,14 +19,20 @@
 #ifndef EXEC_TLB_COMMON_H
 #define EXEC_TLB_COMMON_H 1
 
+#ifndef EMSCRIPTEN
 #define CPU_TLB_ENTRY_BITS (HOST_LONG_BITS == 32 ? 4 : 5)
+typedef uintptr_t tlb_addr;
+#else
+#define CPU_TLB_ENTRY_BITS 5
+typedef uint64_t tlb_addr;
+#endif
 
 /* Minimalized TLB entry for use by TCG fast path. */
 typedef union CPUTLBEntry {
     struct {
-        uintptr_t addr_read;
-        uintptr_t addr_write;
-        uintptr_t addr_code;
+        tlb_addr addr_read;
+        tlb_addr addr_write;
+        tlb_addr addr_code;
         /*
          * Addend to virtual address to get host address.  IO accesses
          * use the corresponding iotlb value.
@@ -37,7 +43,7 @@ typedef union CPUTLBEntry {
      * Padding to get a power of two size, as well as index
      * access to addr_{read,write,code}.
      */
-    uintptr_t addr_idx[(1 << CPU_TLB_ENTRY_BITS) / sizeof(uintptr_t)];
+    tlb_addr addr_idx[(1 << CPU_TLB_ENTRY_BITS) / sizeof(tlb_addr)];
 } CPUTLBEntry;
 
 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));

include/exec/vaddr.h

@@ -9,12 +9,23 @@
  * We do not support 64-bit guest on 32-host and detect at configure time.
  * Therefore, a host pointer width will always fit a guest pointer.
  */
+#ifndef EMSCRIPTEN
 typedef uintptr_t vaddr;
 #define VADDR_PRId PRIdPTR
 #define VADDR_PRIu PRIuPTR
 #define VADDR_PRIo PRIoPTR
 #define VADDR_PRIx PRIxPTR
 #define VADDR_PRIX PRIXPTR
 #define VADDR_MAX UINTPTR_MAX
+#else
+/* Explicitly define this as 64bit on emscripten */
+typedef uint64_t vaddr;
+#define VADDR_PRId PRId64
+#define VADDR_PRIu PRIu64
+#define VADDR_PRIo PRIo64
+#define VADDR_PRIx PRIx64
+#define VADDR_PRIX PRIX64
+#define VADDR_MAX UINT64_MAX
+#endif
 
 #endif

include/qemu/atomic.h

@@ -56,13 +56,17 @@
  */
 #define signal_barrier()    __atomic_signal_fence(__ATOMIC_SEQ_CST)
 
+#ifndef EMSCRIPTEN
 /*
  * Sanity check that the size of an atomic operation isn't "overly large".
  * Despite the fact that e.g. i686 has 64-bit atomic operations, we do not
  * want to use them because we ought not need them, and this lets us do a
  * bit of sanity checking that other 32-bit hosts might build.
  */
 #define ATOMIC_REG_SIZE  sizeof(void *)
+#else
+#define ATOMIC_REG_SIZE  8 /* wasm supports 64bit atomics */
+#endif
 
 /* Weak atomic operations prevent the compiler moving other
  * loads/stores past the atomic operation load/store. However there is