include: move qemu_msync() to osdep

The implementation depends on the OS. (and longer-term goal is to move
cutils to a common subproject)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-21-marcandre.lureau@redhat.com>

include/qemu/cutils.h

@@ -130,7 +130,6 @@ const char *qemu_strchrnul(const char *s, int c);
 #endif
 time_t mktimegm(struct tm *tm);
 int qemu_fdatasync(int fd);
-int qemu_msync(void *addr, size_t length, int fd);
 int qemu_parse_fd(const char *param);
 int qemu_strtoi(const char *nptr, const char **endptr, int base,
                 int *result);

include/qemu/osdep.h

@@ -641,6 +641,19 @@ static inline void qemu_reset_optind(void)
 #endif
 }
 
+/**
+ * Sync changes made to the memory mapped file back to the backing
+ * storage. For POSIX compliant systems this will fallback
+ * to regular msync call. Otherwise it will trigger whole file sync
+ * (including the metadata case there is no support to skip that otherwise)
+ *
+ * @addr   - start of the memory area to be synced
+ * @length - length of the are to be synced
+ * @fd     - file descriptor for the file to be synced
+ *           (mandatory only for POSIX non-compliant systems)
+ */
+int qemu_msync(void *addr, size_t length, int fd);
+
 /**
  * qemu_get_host_name:
  * @errp: Error object

util/cutils.c

@@ -160,44 +160,6 @@ int qemu_fdatasync(int fd)
 #endif
 }
 
-/**
- * Sync changes made to the memory mapped file back to the backing
- * storage. For POSIX compliant systems this will fallback
- * to regular msync call. Otherwise it will trigger whole file sync
- * (including the metadata case there is no support to skip that otherwise)
- *
- * @addr   - start of the memory area to be synced
- * @length - length of the are to be synced
- * @fd     - file descriptor for the file to be synced
- *           (mandatory only for POSIX non-compliant systems)
- */
-int qemu_msync(void *addr, size_t length, int fd)
-{
-#ifdef CONFIG_POSIX
-    size_t align_mask = ~(qemu_real_host_page_size() - 1);
-
-    /**
-     * There are no strict reqs as per the length of mapping
-     * to be synced. Still the length needs to follow the address
-     * alignment changes. Additionally - round the size to the multiple
-     * of PAGE_SIZE
-     */
-    length += ((uintptr_t)addr & (qemu_real_host_page_size() - 1));
-    length = (length + ~align_mask) & align_mask;
-
-    addr = (void *)((uintptr_t)addr & align_mask);
-
-    return msync(addr, length, MS_SYNC);
-#else /* CONFIG_POSIX */
-    /**
-     * Perform the sync based on the file descriptor
-     * The sync range will most probably be wider than the one
-     * requested - but it will still get the job done
-     */
-    return qemu_fdatasync(fd);
-#endif /* CONFIG_POSIX */
-}
-
 static int64_t suffix_mul(char suffix, int64_t unit)
 {
     switch (qemu_toupper(suffix)) {

util/oslib-posix.c

@@ -950,3 +950,21 @@ int fcntl_setfl(int fd, int flag)
     }
     return 0;
 }
+
+int qemu_msync(void *addr, size_t length, int fd)
+{
+    size_t align_mask = ~(qemu_real_host_page_size() - 1);
+
+    /**
+     * There are no strict reqs as per the length of mapping
+     * to be synced. Still the length needs to follow the address
+     * alignment changes. Additionally - round the size to the multiple
+     * of PAGE_SIZE
+     */
+    length += ((uintptr_t)addr & (qemu_real_host_page_size() - 1));
+    length = (length + ~align_mask) & align_mask;
+
+    addr = (void *)((uintptr_t)addr & align_mask);
+
+    return msync(addr, length, MS_SYNC);
+}

util/oslib-win32.c

@@ -596,3 +596,13 @@ size_t qemu_get_host_physmem(void)
     }
     return 0;
 }
+
+int qemu_msync(void *addr, size_t length, int fd)
+{
+    /**
+     * Perform the sync based on the file descriptor
+     * The sync range will most probably be wider than the one
+     * requested - but it will still get the job done
+     */
+    return qemu_fdatasync(fd);
+}