qemu-system-x86_64: Failed to get "write" lock

[RaghuShankarATX]

Trying set up Swarm-u for first time using Quick Start guide posted here https://vhive-serverless.github.io/vSwarm-u/quick_start/

Completed setup/setup_host.sh with no errors

Now I'm testing downloads
$ make -f test/Makefile all_emu

I get this error "Failed to get write lock" for disk.qcow2 - This is the only process on my system

Running this on Dell laptop with Ubuntu 20.04.5 LTS with 12th Gen Intel Core i7-12800H
$ egrep -c '(vmx|svm)' /proc/cpuinfo
40

DETAILS BELOW:
~/swarm/vSwarm-u-main$ make -f test/Makefile all_emu
make -f /home/raghu/swarm/vSwarm-u-main/test/Makefile build
make[1]: Entering directory '/home/raghu/swarm/vSwarm-u-main'
make[1]: Nothing to be done for 'build'.
make[1]: Leaving directory '/home/raghu/swarm/vSwarm-u-main'
make -f /home/raghu/swarm/vSwarm-u-main/test/Makefile run_emu_test
make[1]: Entering directory '/home/raghu/swarm/vSwarm-u-main'
if [ -f test_dir//test.log ]; then rm test_dir//test.log; fi
make -f /home/raghu/swarm/vSwarm-u-main/test/Makefile create_run_script
make[2]: Entering directory '/home/raghu/swarm/vSwarm-u-main'
cp /home/raghu/swarm/vSwarm-u-main/test/run_emu_test.template.sh test_dir//run.sh
make[2]: Leaving directory '/home/raghu/swarm/vSwarm-u-main'
make -f /home/raghu/swarm/vSwarm-u-main/test/Makefile serve_start
make[2]: Entering directory '/home/raghu/swarm/vSwarm-u-main'
make[2]: Nothing to be done for 'serve_start'.
make[2]: Leaving directory '/home/raghu/swarm/vSwarm-u-main'
make -f /home/raghu/swarm/vSwarm-u-main/test/Makefile run_kvm
make[2]: Entering directory '/home/raghu/swarm/vSwarm-u-main'
sudo qemu-system-x86_64
-nographic
-cpu host -enable-kvm
-smp 2
-m 2G
-drive file=test_dir//disk.qcow2,format=qcow2,if=virtio
-kernel test_dir//kernel
-append 'console=ttyS0 root=/dev/vda2'
[sudo] password for raghu:
qemu-system-x86_64: -drive file=test_dir//disk.qcow2,format=qcow2,if=virtio: Failed to get "write" lock
Is another process using the image [test_dir//disk.qcow2]?
make[2]: *** [/home/raghu/swarm/vSwarm-u-main/test/Makefile:185: run_kvm] Error 1
make[2]: Leaving directory '/home/raghu/swarm/vSwarm-u-main'
make[1]: *** [/home/raghu/swarm/vSwarm-u-main/test/Makefile:232: run_test] Error 2
make[1]: Leaving directory '/home/raghu/swarm/vSwarm-u-main'
make: *** [test/Makefile:60: all_emu] Error 2

[RaghuShankarATX]

Also I've issued the first 2 commands repeatedly to kill any lingering processes & yet I see 3 processes in the lsof command
lslocks command does not show any qemu or qcow2 entries

Help to solve "failed to get write lock error" in above post

$ make -f simulation/Makefile kill_gem5
for p in ; do echo $p; sudo kill $p; don

$ make -f test/Makefile clean
if [ -e test_dir//server.pid ]; then kill cat test_dir//server.pid && rm test_dir//server.pid 2> /dev/null; fi
/bin/sh: 1: kill: No such process
make: *** [test/Makefile:333: serve_stop] Error 1

$ sudo lsof | grep qcow
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1001/gvfs
Output information may be incomplete.
lsof: WARNING: can't stat() fuse file system /run/user/1001/doc
Output information may be incomplete.
qemu-syst 8175 root 10u REG 259,3 6534463488 13768943 /home/raghu/swarm/vSwarm-u-main/test_dir/disk.qcow2
qemu-syst 8175 8176 qemu-syst root 10u REG 259,3 6534463488 13768943 /home/raghu/swarm/vSwarm-u-main/test_dir/disk.qcow2
qemu-syst 8175 8180 qemu-syst root 10u REG 259,3 6534463488 13768943 /home/raghu/swarm/vSwarm-u-main/test_dir/disk.qcow2
qemu-syst 8175 8181 qemu-syst root 10u REG 259,3 6534463488 13768943 /home/raghu/swarm/vSwarm-u-main/test_dir/disk.qcow2

$ lslocks | grep qemu
.. empty set ..