Backport Emscripten RAM allocation fix

util/meson.build

@@ -11,7 +11,9 @@ if host_os != 'windows'
   endif
   util_ss.add(files('compatfd.c'))
   util_ss.add(files('event_notifier-posix.c'))
-  util_ss.add(files('mmap-alloc.c'))
+  if host_os != 'emscripten'
+    util_ss.add(files('mmap-alloc.c'))
+  endif
   freebsd_dep = []
   if host_os == 'freebsd'
     freebsd_dep = util

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
@@ -192,14 +193,18 @@ fail_close:
 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared,
                           bool noreserve)
 {
+    size_t align = QEMU_VMALLOC_ALIGN;
+#ifndef EMSCRIPTEN
     const uint32_t qemu_map_flags = (shared ? QEMU_MAP_SHARED : 0) |
                                     (noreserve ? QEMU_MAP_NORESERVE : 0);
-    size_t align = QEMU_VMALLOC_ALIGN;
     void *ptr = qemu_ram_mmap(-1, size, align, qemu_map_flags, 0);
 
     if (ptr == MAP_FAILED) {
         return NULL;
     }
+#else
+    void *ptr = qemu_memalign(align, size);
+#endif
 
     if (alignment) {
         *alignment = align;
@@ -212,7 +217,11 @@ 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_vfree(ptr);
+#endif
 }
 
 void qemu_socket_set_block(int fd)
@@ -573,7 +582,11 @@ 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
+    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;