You say that hot-add failare is reasonable after hot-remove? I think it is a clear issue.
>Hi
On Sat, Nov 6, 2021 at 10:41 PM ???????????? <787738581@qq.com> wrote:
>
> We have found that qemu cannot plug in the previously unplugged device.
> start qemu with the following command:
> ./qemu-system-x86_64 -enable-kvm -m 8192 -smp 16 \
> -object memory-backend-file,id=mem,size=8192M,mem-path=/dev/hugepages,share=on \
> -numa node,memdev=mem -mem-prealloc \
> ...
> -chardev socket,id=drive-virtio-disk1,path=/var/run/spdk/vhost_blk_socket-30dcf467-486a-45cf-b754-093bf5cf24d1,reconnect=10 \
> -device vhost-user-blk-pci,chardev=drive-virtio-disk1,num-queues=1,bus=pci.0,addr=0x5,id=virtio-disk1 \
> ...
>
> (qemu) info chardev
> serial0: filename=pty:/dev/pts/0
> drive-virtio-disk1: filename=unix:
> charmonitor:
> filename=unix:/usr/local/var/lib/libvirt/qemu/domain-55-e59039db-d576-40db-a/monitor.sock,server
> (qemu) device_del virtio-disk1
> (qemu) chardev-remove drive-virtio-disk1
> (qemu) info chardev
> serial0: filename=pty:/dev/pts/0
> charmonitor:
> filename=unix:/usr/local/var/lib/libvirt/qemu/domain-55-e59039db-d576-40db-a/monitor.sock,server
> (qemu) chardev-add socket,id=drive-virtio-disk1,path=/var/run/spdk/vhost_blk_socket-30dcf467-486a-45cf-b754-093bf5cf24d1,reconnect=10
> device failed: Duplicate ID 'drive-virtio-disk1' for chardev Error: Parsing chardev args failed
>
> The root cause of this issue is that the QemuOpts is still reserved in vm_config_groups list,
> so qemu_opts_create will fail with the error above. So the QemuOpts should be removed when
> invoking qmp_chardev_remove.
>
>
> Signed-off-by: Zhoujian Yu <windyu@tencent.com>
> Reviewed-by: Lei Wang <kaierwang@tencent.com>
> Reviewed-by: Xun Ni <richardni@tencent.com>
> Reviewed-by: Zhigang Lu <tonnylu@tencent.com>
> ---
> chardev/char.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/chardev/char.c b/chardev/char.c
> index 398f09d..d2087bd 100644
> --- a/chardev/char.c
> +++ b/chardev/char.c
> @@ -37,6 +37,7 @@
> #include "qemu/help_option.h"
> #include "qemu/module.h"
> #include "qemu/option.h"
> +#include "qemu/option_int.h"
> #include "qemu/id.h"
> #include "qemu/coroutine.h"
> #include "qemu/yank.h"
> @@ -1159,6 +1160,7 @@ ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
> void qmp_chardev_remove(const char *id, Error **errp)
> {
> Chardev *chr;
> + QemuOpts *opts;
>
> chr = qemu_chr_find(id);
> if (chr == NULL) {
> @@ -1175,6 +1177,10 @@ void qmp_chardev_remove(const char *id, Error **errp)
> return;
> }
> object_unparent(OBJECT(chr));
> + /* delete the opts reserved in vm_config_groups list. */
> + opts = qemu_opts_find(qemu_find_opts("chardev"), id);
> + if (opts)
> + qemu_opts_del(opts);
That seems reasonable to me,
Reviewed-by: Marc-Andr?? Lureau <marcandre.lureau@redhat.com>
> }
>
> void qmp_chardev_send_break(const char *id, Error **errp)
> --
> 1.8.3.1