diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index f265501eac1d..52bbf4f1b37c 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -292,12 +292,11 @@ static int v9fs_receive_status(V9fsProxy *proxy,
 /*
  * Proxy->header and proxy->request written to socket by QEMU process.
  * This request read by proxy helper process
  * returns 0 on success and -errno on error
  */
-static int v9fs_request(V9fsProxy *proxy, int type,
-                        void *response, const char *fmt, ...)
+static int v9fs_request(V9fsProxy *proxy, int type, void *response, ...)
 {
     dev_t rdev;
     va_list ap;
     int size = 0;
     int retval = 0;
@@ -315,11 +314,11 @@ static int v9fs_request(V9fsProxy *proxy, int type,
         retval = -EIO;
         goto err_out;
     }
     iovec = &proxy->out_iovec;
     reply = &proxy->in_iovec;
-    va_start(ap, fmt);
+    va_start(ap, response);
     switch (type) {
     case T_OPEN:
         path = va_arg(ap, V9fsString *);
         flags = va_arg(ap, int);
         retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, flags);
@@ -603,11 +602,11 @@ close_error:
 }
 
 static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, "s", fs_path);
+    retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, fs_path);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return retval;
@@ -615,12 +614,11 @@ static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
 
 static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
                               char *buf, size_t bufsz)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
-                          fs_path, bufsz);
+    retval = v9fs_request(fs_ctx->private, T_READLINK, buf, fs_path, bufsz);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return strlen(buf);
@@ -637,11 +635,11 @@ static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs)
 }
 
 static int proxy_open(FsContext *ctx, V9fsPath *fs_path,
                       int flags, V9fsFidOpenState *fs)
 {
-    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, flags);
+    fs->fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, flags);
     if (fs->fd < 0) {
         errno = -fs->fd;
         fs->fd = -1;
     }
     return fs->fd;
@@ -651,11 +649,11 @@ static int proxy_opendir(FsContext *ctx,
                          V9fsPath *fs_path, V9fsFidOpenState *fs)
 {
     int serrno, fd;
 
     fs->dir.stream = NULL;
-    fd = v9fs_request(ctx->private, T_OPEN, NULL, "sd", fs_path, O_DIRECTORY);
+    fd = v9fs_request(ctx->private, T_OPEN, NULL, fs_path, O_DIRECTORY);
     if (fd < 0) {
         errno = -fd;
         return -1;
     }
     fs->dir.stream = fdopendir(fd);
@@ -733,12 +731,12 @@ static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
 }
 
 static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, "sd",
-                          fs_path, credp->fc_mode);
+    retval = v9fs_request(fs_ctx->private, T_CHMOD, NULL, fs_path,
+                          credp->fc_mode);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
@@ -750,12 +748,12 @@ static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, "sdqdd",
-                          &fullname, credp->fc_mode, credp->fc_rdev,
+    retval = v9fs_request(fs_ctx->private, T_MKNOD, NULL, &fullname,
+                          credp->fc_mode, credp->fc_rdev,
                           credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -770,11 +768,11 @@ static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, "sddd", &fullname,
+    retval = v9fs_request(fs_ctx->private, T_MKDIR, NULL, &fullname,
                           credp->fc_mode, credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -802,13 +800,12 @@ static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
     V9fsString fullname;
 
     v9fs_string_init(&fullname);
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
 
-    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, "sdddd",
-                          &fullname, flags, credp->fc_mode,
-                          credp->fc_uid, credp->fc_gid);
+    fs->fd = v9fs_request(fs_ctx->private, T_CREATE, NULL, &fullname, flags,
+                          credp->fc_mode, credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     if (fs->fd < 0) {
         errno = -fs->fd;
         fs->fd = -1;
     }
@@ -825,12 +822,12 @@ static int proxy_symlink(FsContext *fs_ctx, const char *oldpath,
     v9fs_string_init(&target);
 
     v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name);
     v9fs_string_sprintf(&target, "%s", oldpath);
 
-    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, "ssdd",
-                          &target, &fullname, credp->fc_uid, credp->fc_gid);
+    retval = v9fs_request(fs_ctx->private, T_SYMLINK, NULL, &target, &fullname,
+                          credp->fc_uid, credp->fc_gid);
     v9fs_string_free(&fullname);
     v9fs_string_free(&target);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
@@ -845,11 +842,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
     V9fsString newpath;
 
     v9fs_string_init(&newpath);
     v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
 
-    retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
+    retval = v9fs_request(ctx->private, T_LINK, NULL, oldpath, &newpath);
     v9fs_string_free(&newpath);
     if (retval < 0) {
         errno = -retval;
         retval = -1;
     }
@@ -858,11 +855,11 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
 
 static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
 {
     int retval;
 
-    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, "sq", fs_path, size);
+    retval = v9fs_request(ctx->private, T_TRUNCATE, NULL, fs_path, size);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return 0;
@@ -877,12 +874,11 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
     v9fs_string_init(&oldname);
     v9fs_string_init(&newname);
 
     v9fs_string_sprintf(&oldname, "%s", oldpath);
     v9fs_string_sprintf(&newname, "%s", newpath);
-    retval = v9fs_request(ctx->private, T_RENAME, NULL, "ss",
-                          &oldname, &newname);
+    retval = v9fs_request(ctx->private, T_RENAME, NULL, &oldname, &newname);
     v9fs_string_free(&oldname);
     v9fs_string_free(&newname);
     if (retval < 0) {
         errno = -retval;
     }
@@ -890,24 +886,23 @@ static int proxy_rename(FsContext *ctx, const char *oldpath,
 }
 
 static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
 {
     int retval;
-    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, "sdd",
-                          fs_path, credp->fc_uid, credp->fc_gid);
+    retval = v9fs_request(fs_ctx->private, T_CHOWN, NULL, fs_path,
+                          credp->fc_uid, credp->fc_gid);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
 
 static int proxy_utimensat(FsContext *s, V9fsPath *fs_path,
                            const struct timespec *buf)
 {
     int retval;
-    retval = v9fs_request(s->private, T_UTIME, NULL, "sqqqq",
-                          fs_path,
+    retval = v9fs_request(s->private, T_UTIME, NULL, fs_path,
                           buf[0].tv_sec, buf[0].tv_nsec,
                           buf[1].tv_sec, buf[1].tv_nsec);
     if (retval < 0) {
         errno = -retval;
     }
@@ -918,11 +913,11 @@ static int proxy_remove(FsContext *ctx, const char *path)
 {
     int retval;
     V9fsString name;
     v9fs_string_init(&name);
     v9fs_string_sprintf(&name, "%s", path);
-    retval = v9fs_request(ctx->private, T_REMOVE, NULL, "s", &name);
+    retval = v9fs_request(ctx->private, T_REMOVE, NULL, &name);
     v9fs_string_free(&name);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -947,11 +942,11 @@ static int proxy_fsync(FsContext *ctx, int fid_type,
 }
 
 static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
 {
     int retval;
-    retval = v9fs_request(s->private, T_STATFS, stbuf, "s", fs_path);
+    retval = v9fs_request(s->private, T_STATFS, stbuf, fs_path);
     if (retval < 0) {
         errno = -retval;
         return -1;
     }
     return retval;
@@ -963,12 +958,12 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
     int retval;
     V9fsString xname;
 
     v9fs_string_init(&xname);
     v9fs_string_sprintf(&xname, "%s", name);
-    retval = v9fs_request(ctx->private, T_LGETXATTR, value, "dss", size,
-                          fs_path, &xname);
+    retval = v9fs_request(ctx->private, T_LGETXATTR, value, size, fs_path,
+                          &xname);
     v9fs_string_free(&xname);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -976,12 +971,11 @@ static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,
 
 static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path,
                                 void *value, size_t size)
 {
     int retval;
-    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, "ds", size,
-                        fs_path);
+    retval = v9fs_request(ctx->private, T_LLISTXATTR, value, size, fs_path);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
 }
@@ -998,12 +992,12 @@ static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name,
     v9fs_string_init(&xvalue);
     xvalue.size = size;
     xvalue.data = g_malloc(size);
     memcpy(xvalue.data, value, size);
 
-    retval = v9fs_request(ctx->private, T_LSETXATTR, value, "sssdd",
-                          fs_path, &xname, &xvalue, size, flags);
+    retval = v9fs_request(ctx->private, T_LSETXATTR, value, fs_path, &xname,
+                          &xvalue, size, flags);
     v9fs_string_free(&xname);
     v9fs_string_free(&xvalue);
     if (retval < 0) {
         errno = -retval;
     }
@@ -1016,12 +1010,11 @@ static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
     int retval;
     V9fsString xname;
 
     v9fs_string_init(&xname);
     v9fs_string_sprintf(&xname, "%s", name);
-    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, "ss",
-                          fs_path, &xname);
+    retval = v9fs_request(ctx->private, T_LREMOVEXATTR, NULL, fs_path, &xname);
     v9fs_string_free(&xname);
     if (retval < 0) {
         errno = -retval;
     }
     return retval;
@@ -1084,11 +1077,11 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, V9fsPath *path,
      */
     if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) {
         errno = ENOTTY;
         return -1;
     }
-    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path);
+    err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, path);
     if (err < 0) {
         errno = -err;
         err = -1;
     }
     return err;
