A number of chardev users where calling qemu_chr_fe_get_driver() which is discouraged as it blocks backend hotswap. As the pattern is common and need for the string is transitory add a helper and keep qemu_chr_fe_get_driver() for those that really need the funkiness of poking around the backend setup. Suggested-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-ID: <20260810153503.2652324-1-alex.bennee@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- v2 - checkpatch fixes - r-b --- include/chardev/char-fe.h | 13 ++++++++++++- backends/cryptodev-vhost-user.c | 8 +------- backends/rng-egd.c | 8 +------- backends/vhost-user.c | 8 +------- hw/char/imx_serial.c | 4 ++-- 5 files changed, 17 insertions(+), 24 deletions(-) diff --git a/include/chardev/char-fe.h b/include/chardev/char-fe.h index 5f8a6df17dc..a82894e1d51 100644 --- a/include/chardev/char-fe.h +++ b/include/chardev/char-fe.h @@ -52,7 +52,8 @@ void qemu_chr_fe_deinit(CharFrontend *c, bool del); * associated Chardev. * Note: avoid this function as the driver should never be accessed directly, * especially by the frontends that support chardevice hotswap. - * Consider qemu_chr_fe_backend_connected() to check for driver existence + * Consider qemu_chr_fe_backend_connected() to check for driver + * existence or qemu_chr_fe_backend_name() if you need the name. */ Chardev *qemu_chr_fe_get_driver(CharFrontend *c); @@ -70,6 +71,16 @@ bool qemu_chr_fe_backend_connected(CharFrontend *c); */ bool qemu_chr_fe_backend_open(CharFrontend *c); +/** + * qemu_chr_fe_backend_name: + * + * Returns: caller freeable string or NULL + */ +static inline char *qemu_chr_fe_backend_name(CharFrontend *c) +{ + return (c->chr && c->chr->label) ? g_strdup(c->chr->label) : NULL; +} + /** * qemu_chr_fe_set_handlers_full: * @c: a CharFrontend diff --git a/backends/cryptodev-vhost-user.c b/backends/cryptodev-vhost-user.c index cc478d9902d..3334e280a27 100644 --- a/backends/cryptodev-vhost-user.c +++ b/backends/cryptodev-vhost-user.c @@ -373,13 +373,7 @@ cryptodev_vhost_user_get_chardev(Object *obj, Error **errp) { CryptoDevBackendVhostUser *s = CRYPTODEV_BACKEND_VHOST_USER(obj); - Chardev *chr = qemu_chr_fe_get_driver(&s->chr); - - if (chr && chr->label) { - return g_strdup(chr->label); - } - - return NULL; + return qemu_chr_fe_backend_name(&s->chr); } static void cryptodev_vhost_user_finalize(Object *obj) diff --git a/backends/rng-egd.c b/backends/rng-egd.c index 1d92bd71cf7..c2207f40c5c 100644 --- a/backends/rng-egd.c +++ b/backends/rng-egd.c @@ -126,13 +126,7 @@ static void rng_egd_set_chardev(Object *obj, const char *value, Error **errp) static char *rng_egd_get_chardev(Object *obj, Error **errp) { RngEgd *s = RNG_EGD(obj); - Chardev *chr = qemu_chr_fe_get_driver(&s->chr); - - if (chr && chr->label) { - return g_strdup(chr->label); - } - - return NULL; + return qemu_chr_fe_backend_name(&s->chr); } static void rng_egd_finalize(Object *obj) diff --git a/backends/vhost-user.c b/backends/vhost-user.c index 380d8250233..46dadb74800 100644 --- a/backends/vhost-user.c +++ b/backends/vhost-user.c @@ -152,13 +152,7 @@ static void set_chardev(Object *obj, const char *value, Error **errp) static char *get_chardev(Object *obj, Error **errp) { VhostUserBackend *b = VHOST_USER_BACKEND(obj); - Chardev *chr = qemu_chr_fe_get_driver(&b->chr); - - if (chr && chr->label) { - return g_strdup(chr->label); - } - - return NULL; + return qemu_chr_fe_backend_name(&b->chr); } static void vhost_user_backend_class_init(ObjectClass *oc, const void *data) diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c index fb41ee2ac50..8ac4efbb5e9 100644 --- a/hw/char/imx_serial.c +++ b/hw/char/imx_serial.c @@ -278,10 +278,10 @@ static void imx_serial_write(void *opaque, hwaddr offset, uint64_t value, unsigned size) { IMXSerialState *s = (IMXSerialState *)opaque; - Chardev *chr = qemu_chr_fe_get_driver(&s->chr); + g_autofree char *label = qemu_chr_fe_backend_name(&s->chr); unsigned char ch; - trace_imx_serial_write(chr ? chr->label : "NODEV", offset, value); + trace_imx_serial_write(label ? label : "NODEV", offset, value); switch (offset >> 2) { case 0x10: /* UTXD */ -- 2.47.3