diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 55614949740d..930bcc623f8b 100644
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -140,6 +140,7 @@ struct FileOperations
     int (*renameat)(FsContext *ctx, V9fsPath *olddir, const char *old_name,
                     V9fsPath *newdir, const char *new_name);
     int (*unlinkat)(FsContext *ctx, V9fsPath *dir, const char *name, int flags);
+    int (*ftruncate)(FsContext *, int, V9fsFidOpenState *, off_t);
     void *opaque;
 };
 
diff --git a/hw/9pfs/9p-handle.c b/hw/9pfs/9p-handle.c
index 2e741535df24..e48e48a7145d 100644
--- a/hw/9pfs/9p-handle.c
+++ b/hw/9pfs/9p-handle.c
@@ -349,6 +349,20 @@ static int handle_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
     return ret;
 }
 
+static int handle_ftruncate(FsContext *ctx, int fid_type, V9fsFidOpenState *fs,
+                            off_t size)
+{
+    int fd;
+
+    if (fid_type == P9_FID_DIR) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    fd = v9fs_get_fd_fid(fid_type, fs);
+    return ftruncate(fd, size);
+}
+
 static int handle_rename(FsContext *ctx, const char *oldpath,
                          const char *newpath)
 {
@@ -696,4 +710,5 @@ FileOperations handle_ops = {
     .name_to_path = handle_name_to_path,
     .renameat     = handle_renameat,
     .unlinkat     = handle_unlinkat,
+    .ftruncate    = handle_ftruncate,
 };
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 6804c6558b8e..b4c31c49da69 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -874,6 +874,20 @@ static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
     return ret;
 }
 
+static int local_ftruncate(FsContext *ctx, int fid_type, V9fsFidOpenState *fs,
+                           off_t size)
+{
+    int fd;
+
+    if (fid_type == P9_FID_DIR) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    fd = v9fs_get_fd_fid(fid_type, fs);
+    return ftruncate(fd, size);
+}
+
 static int local_rename(FsContext *ctx, const char *oldpath,
                         const char *newpath)
 {
@@ -1275,4 +1289,5 @@ FileOperations local_ops = {
     .name_to_path = local_name_to_path,
     .renameat  = local_renameat,
     .unlinkat = local_unlinkat,
+    .ftruncate = local_ftruncate,
 };
diff --git a/hw/9pfs/9p-proxy.c b/hw/9pfs/9p-proxy.c
index d78ff7b1bd8d..9abcc201bd67 100644
--- a/hw/9pfs/9p-proxy.c
+++ b/hw/9pfs/9p-proxy.c
@@ -864,6 +864,19 @@ static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size)
     return 0;
 }
 
+static int proxy_ftruncate(FsContext *ctx, int fid_type, V9fsFidOpenState *fs,
+                           off_t size)
+{
+    int fd;
+
+    if (fid_type == P9_FID_DIR) {
+        return -EINVAL;
+    }
+
+    fd = v9fs_get_fd_fid(fid_type, fs);
+    return ftruncate(fd, size);
+}
+
 static int proxy_rename(FsContext *ctx, const char *oldpath,
                         const char *newpath)
 {
@@ -1207,4 +1220,5 @@ FileOperations proxy_ops = {
     .name_to_path = proxy_name_to_path,
     .renameat     = proxy_renameat,
     .unlinkat     = proxy_unlinkat,
+    .ftruncate    = proxy_ftruncate,
 };
diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
index 4b6d4e6a3f1c..70c71ce305c9 100644
--- a/hw/9pfs/9p-synth.c
+++ b/hw/9pfs/9p-synth.c
@@ -344,6 +344,13 @@ static int synth_truncate(FsContext *ctx, V9fsPath *path, off_t offset)
     return -1;
 }
 
+static int synth_ftruncate(FsContext *ctx, int fid_type, V9fsFidOpenState *fs,
+                           off_t size)
+{
+    errno = ENOSYS;
+    return -1;
+}
+
 static int synth_chmod(FsContext *fs_ctx, V9fsPath *path, FsCred *credp)
 {
     errno = EPERM;
@@ -566,4 +573,5 @@ FileOperations synth_ops = {
     .name_to_path = synth_name_to_path,
     .renameat     = synth_renameat,
     .unlinkat     = synth_unlinkat,
+    .ftruncate    = synth_ftruncate,
 };
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 3301cef0980d..3aa4c8e22ed9 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1181,6 +1181,19 @@ out_nofid:
     pdu_complete(pdu, retval);
 }
 
+static int v9fs_do_truncate(V9fsPDU *pdu, V9fsFidState *fidp, off_t size)
+{
+    int err;
+
+    if (fid_has_file(fidp)) {
+        err = v9fs_co_ftruncate(pdu, fidp, size);
+    } else {
+        err = v9fs_co_truncate(pdu, &fidp->path, size);
+    }
+
+    return err;
+}
+
 /* Attribute flags */
 #define P9_ATTR_MODE       (1 << 0)
 #define P9_ATTR_UID        (1 << 1)
@@ -1266,7 +1279,7 @@ static void v9fs_setattr(void *opaque)
         }
     }
     if (v9iattr.valid & (P9_ATTR_SIZE)) {
-        err = v9fs_co_truncate(pdu, &fidp->path, v9iattr.size);
+        err = v9fs_do_truncate(pdu, fidp, v9iattr.size);
         if (err < 0) {
             goto out;
         }
@@ -2754,7 +2767,7 @@ static void v9fs_wstat(void *opaque)
         }
     }
     if (v9stat.length != -1) {
-        err = v9fs_co_truncate(pdu, &fidp->path, v9stat.length);
+        err = v9fs_do_truncate(pdu, fidp, v9stat.length);
         if (err < 0) {
             goto out;
         }
diff --git a/hw/9pfs/cofs.c b/hw/9pfs/cofs.c
index 70f584fcbd21..969c24730cb0 100644
--- a/hw/9pfs/cofs.c
+++ b/hw/9pfs/cofs.c
@@ -177,6 +177,24 @@ int v9fs_co_truncate(V9fsPDU *pdu, V9fsPath *path, off_t size)
     return err;
 }
 
+int v9fs_co_ftruncate(V9fsPDU *pdu, V9fsFidState *fidp, off_t size)
+{
+    int err;
+    V9fsState *s = pdu->s;
+
+    if (v9fs_request_cancelled(pdu)) {
+        return -EINTR;
+    }
+    v9fs_co_run_in_worker(
+        {
+            err = s->ops->ftruncate(&s->ctx, fidp->fid_type, &fidp->fs, size);
+            if (err < 0) {
+                err = -errno;
+            }
+        });
+    return err;
+}
+
 int v9fs_co_mknod(V9fsPDU *pdu, V9fsFidState *fidp, V9fsString *name, uid_t uid,
                   gid_t gid, dev_t dev, mode_t mode, struct stat *stbuf)
 {
diff --git a/hw/9pfs/coth.h b/hw/9pfs/coth.h
index 5b02a63ad9fd..4f493ad29ec4 100644
--- a/hw/9pfs/coth.h
+++ b/hw/9pfs/coth.h
@@ -94,5 +94,6 @@ extern int v9fs_co_name_to_path(V9fsPDU *, V9fsPath *,
                                 const char *, V9fsPath *);
 extern int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t,
                           V9fsStatDotl *v9stat);
+extern int v9fs_co_ftruncate(V9fsPDU *, V9fsFidState *, off_t);
 
 #endif
