Test-qga:Qga write is blocked when the client is no connected, virtio-serial port is throttled.

Hi, I am testing when qga push msg to libvirt, when the vm saved and restore from the memory file, the qga will be hunged in writing. In flush_buf:(gdb) f 4#4 0x55ffc716894a in flush_buf (port=0x55ffc87bf800, buf=, len=) at ../hw/char/virtio-console.c:100100 vcon->watch

Test-qga:Qga write is blocked when the client is no connected, virtio-serial port is throttled.

Hi, I am testing when qga push msg to libvirt, when the vm saved and restore from the memory file, the qga will be hunged in writing. In flush_buf:(gdb) f 4#4 0x55ffc716894a in flush_buf (port=0x55ffc87bf800, buf=, len=) at ../hw/char/virtio-console.c:100100 vcon->watch