backends: Improve error messages when property can no longer be set

When you try to set virtio-rng property "filename" after the backend
has been completed with user_creatable_complete(), the error message
blames "insufficient permission":

    $ qemu-system-x86_64 -S -display none -nodefaults -monitor stdio -object rng-random,id=rng0 -device virtio-rng,id=vrng0,rng=rng0
    QEMU 7.1.50 monitor - type 'help' for more information
    (qemu) qom-set /objects/rng0 filename /dev/random
    Error: Insufficient permission to perform this operation

This implies it could work with "sufficient permission".  It can't.
Change the error message to:

    Error: Property 'filename' can no longer be set

Same for cryptodev-vhost-user property "chardev", rng-egd property
"chardev", and vhost-user-backend property "chardev".

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221012153801.2604340-3-armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
[Commit message tidied up]
This commit is contained in:
Markus Armbruster 2022-10-12 17:37:59 +02:00
parent 3f7febc937
commit ff92444884
4 changed files with 4 additions and 4 deletions

View File

@ -339,7 +339,7 @@ static void cryptodev_vhost_user_set_chardev(Object *obj,
CRYPTODEV_BACKEND_VHOST_USER(obj);
if (s->opened) {
error_setg(errp, QERR_PERMISSION_DENIED);
error_setg(errp, "Property 'chardev' can no longer be set");
} else {
g_free(s->chr_name);
s->chr_name = g_strdup(value);

View File

@ -116,7 +116,7 @@ static void rng_egd_set_chardev(Object *obj, const char *value, Error **errp)
RngEgd *s = RNG_EGD(b);
if (b->opened) {
error_setg(errp, QERR_PERMISSION_DENIED);
error_setg(errp, "Property 'chardev' can no longer be set");
} else {
g_free(s->chr_name);
s->chr_name = g_strdup(value);

View File

@ -96,7 +96,7 @@ static void rng_random_set_filename(Object *obj, const char *filename,
RngRandom *s = RNG_RANDOM(obj);
if (b->opened) {
error_setg(errp, QERR_PERMISSION_DENIED);
error_setg(errp, "Property 'filename' can no longer be set");
return;
}

View File

@ -141,7 +141,7 @@ static void set_chardev(Object *obj, const char *value, Error **errp)
Chardev *chr;
if (b->completed) {
error_setg(errp, QERR_PERMISSION_DENIED);
error_setg(errp, "Property 'chardev' can no longer be set");
return;
}