hello, after some debugging, I am suspecting https://github.com/qemu/qemu/blob/b0ca999a43a22b38158a222233d3f5881648bb4f/hw/block/vhost-user-blk.c#L376 this code creates a watcher which might not be released ( in 4.2.0), if I remove this line, looks like device_del + chardev-remove could correctly release unix link.
On Thu, Feb 10, 2022 at 11:03 AM Jiatong Shen <yshxxsjt...@gmail.com> wrote: > Hello, I figured out I should have executed chardev-remove to disconnect > unix socket connection. It actually works on qemu 6.2.0. > but for qemu 4.2.0 even after delete chardev device, the connection is not > disconnected, My current assumption is that char-socket > object ref count is not 0 after connection_free. > > My question is is there a simple way to track ref count for a specific > object? thank you. > > On Wed, Feb 9, 2022 at 3:07 PM Jiatong Shen <yshxxsjt...@gmail.com> wrote: > >> Hello community, >> >> I am testing vhost-user-blk. the virtual machine is started with the >> following command >> >> ./x86_64-softmmu/qemu-system-x86_64 \ >> --enable-kvm \ >> -smp 2 \ >> -chardev >> socket,id=chr-vu-virtio-disk0,path=/var/lib/nova/volume-04789a9b-21ce-4270-89bd-638700a0e56c,reconnect=10 >> \ >> -device >> vhost-user-blk-pci,bus=pci.0,addr=0x8,chardev=chr-vu-virtio-disk0,id=virtio-disk0 >> \ >> -chardev >> socket,id=chr-vu-virtio-disk1,path=/var/lib/nova/volume-9590b74a-c652-4e97-a88d-f736000b4886,reconnect=10 >> \ >> -device >> vhost-user-blk-pci,bus=pci.0,addr=0x9,chardev=chr-vu-virtio-disk1,id=virtio-disk1 >> \ >> -m 2048 \ >> -overcommit mem-lock=off \ >> -smp 2,sockets=2,dies=1,cores=1,threads=1 \ >> -object >> memory-backend-file,id=ram-node0,mem-path=/dev/hugepages/libvirt/qemu/7-instance-00000005,share=on,prealloc=on,size=2147483648,host-nodes=0,policy=bind >> \ >> -numa node,nodeid=0,cpus=0-1,memdev=ram-node0 \ >> -monitor stdio \ >> -vnc :0 >> >> the two devices are hosted by spdk vhost application >> >> it uses two vhost-user-blk devices. then in the monitor, I execute >> >> device_del virtio-disk1 >> >> the command completed successfully and in the virtual machine the disk is >> gone. >> >> but when I execute spdk vhost_delete_controller, this command will fail >> with spdk vhost application complained >> >> [2022-02-09 14:52:30.487815] vhost.c:1013:vhost_dev_unregister: *ERROR*: >> Controller volume-9590b74a-c652-4e97-a88d-f736000b4 >> >> it looks like qemu does not disconnect unix socket connection even >> though the device is removed. >> >> My question is: is device_del enough? do I need to remove chardev as >> well? thank you. >> >> -- >> >> Best Regards, >> >> Jiatong Shen >> > > > -- > > Best Regards, > > Jiatong Shen > -- Best Regards, Jiatong Shen
