[libvirt-users] Calling 'virsh' from within a hook script - avoid deadlock?

I'm trying to create a hook that attaches several virtio-scsi disks to a starting vm, and it seems like the hook enters a deadlock while attempting to do so. Is there any workaround around this? Any better way, forking virsh execution somehow? Could anyone explain why this is creating a deadlock in the first place? Isn't libvirt multithreaded? Thanks for the help! Shlomi ### hook script: #!/bin/bash enum_scsi() { scsi_devices=`cd /dev;ls sd[^a]*` } gen_hba_xml() { cat > ./hba.xml << EOF <controller type='scsi' model='virtio-scsi'/> EOF } passthrough_start() { # create virtio-scsi HBA gen_hba_xml virsh attach-device --persistent $domain_name ./hba.xml rm -f ./hba.xml # attache scsi devices to guest enum_scsi for sd in ${scsi_devices[@]} do virsh attach-disk --persistent $domain_name /dev/${sd} ${sd} done } domain_name=$1 domain_event=$2 case $domain_event in start) passthrough_start ;; *) echo "qemu hook called with unexpected options $*" >&2 ;; esac ### starce libvirt: [root@localhost ~]# strace -f -p 14630 Process 14630 attached with 11 threads - interrupt to quit [pid 14640] futex(0xc34ebc, FUTEX_WAIT_PRIVATE, 2303, NULL <unfinished ...> [pid 14638] futex(0xc34ebc, FUTEX_WAIT_PRIVATE, 2303, NULL <unfinished ...> [pid 14637] futex(0xc34ebc, FUTEX_WAIT_PRIVATE, 2303, NULL <unfinished ...> [pid 14636] futex(0xc34ebc, FUTEX_WAIT_PRIVATE, 2303, NULL <unfinished ...> [pid 14635] futex(0x7fcc240ccd80, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...> [pid 14639] futex(0xc34ebc, FUTEX_WAIT_PRIVATE, 2303, NULL <unfinished ...> [pid 14634] futex(0x7fcc240ccd80, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...> [pid 14631] restart_syscall(<... resuming interrupted call ...> <unfinished ...> [pid 14633] futex(0x7fcc240ccd80, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...> [pid 14630] restart_syscall(<... resuming interrupted call ...> <unfinished ...> [pid 14632] futex(0xc34e24, FUTEX_WAIT_PRIVATE, 3091, NULL^C <unfinished ...> ... [pid 14630] poll([{fd=7, events=POLLIN}, {fd=9, events=POLLIN}, {fd=12, events=POLLIN}, {fd=13, events=POLLIN}, {fd=6, events=POLLIN}, {fd=14, events=POLLIN}, {fd=16, events=POLLIN}, {fd=18, events=POLLIN|POLLOUT}, {fd=24, events=POLLIN}], 9, 1927) = 1 ([{fd=18, revents=POLLOUT}]) [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] gettid() = 14630 [pid 14630] write(18, "\0\0\0\34keep\0\0\0\1\0\0\0\1\0\0\0\2\0\0\0\0\0\0\0\0", 28) = 28 ... ### strace bash: [root@localhost ~]# strace -f -p 14783 Process 14783 attached - interrupt to quit wait4(-1, ...