I encountered an issue where vmd terminates unexpectedly when multiple VMs are rebooted at the same time.
[Steps to Reproduce] 0. Environment The issue was reproduced with the following environment on both host and guest: $ uname -a OpenBSD nimbus13.localnet 7.8 GENERIC.MP#54 amd64 $ sysctl kern.version kern.version=OpenBSD 7.8 (GENERIC.MP) #54: Sun Oct 12 12:58:11 MDT 2025 [email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP 1. Prepare four VM images with identical configurations -rw-r--r-- 1 kaw kaw 2147483648 Apr 21 00:08 vm0.img -rw-r--r-- 1 kaw kaw 2147483648 Apr 21 00:08 vm1.img -rw-r--r-- 1 kaw kaw 2147483648 Apr 21 00:08 vm2.img -rw-r--r-- 1 kaw kaw 2147483648 Apr 21 00:08 vm3.img 2. Start each VM in four separate tmux panes using the following script $ cat runvm.sh #!/bin/sh i="$1" case "$i" in [0-9]|[1-9][0-9]) doas vmctl start -c -i 1 -n uplink -m 512M -d vm${i}.img vm78${i};; *) echo "Usage: $0 vm-num";; esac 3. In tmux, enable "set synchronize-panes on" and reboot all four VMs simultaneously Inside each VM: testvm0# reboot syncing disks... done vmmci0: powerdown rebooting... [EOT] host$ [Result] The VMs do not reboot successfully. Pressing ENTER causes cu to exit and return to the host environment. Checking with ps shows that the vmd process is no longer running. The following messages were recorded: in /var/log/messages: Apr 21 00:08:46 nimbus13 vmd[56296]: vmd: proc_dispatch: imsgbuf_write: Bad file descriptor Apr 21 00:08:46 nimbus13 vmd[89452]: failed to remap guest memory Apr 21 00:08:46 nimbus13 vmd[67623]: virtio_dev_launch: failed to receive ready message from 'd' type device Apr 21 00:08:46 nimbus13 vmd[67623]: vm/vm782: failed to launch virtio device in /var/log/daemon: Apr 21 00:08:46 nimbus13 vmd[56296]: vmd: proc_dispatch: imsgbuf_write: Bad file descriptor Apr 21 00:08:46 nimbus13 vmd[59397]: control exiting, pid 59397 Apr 21 00:08:46 nimbus13 vmd[53170]: priv exiting, pid 53170 Apr 21 00:08:46 nimbus13 vmd[61651]: agentx exiting, pid 61651 Apr 21 00:08:46 nimbus13 vmd[28300]: vmm exiting, pid 28300 Apr 21 00:08:46 nimbus13 vmd[89452]: failed to remap guest memory Apr 21 00:08:46 nimbus13 vmd[67623]: virtio_dev_launch: failed to receive ready message from 'd' type device Apr 21 00:08:46 nimbus13 vmd[67623]: vm/vm782: failed to launch virtio device Please let me know if any additional information is required. ---- Yoshihiro Kawamata https://fuguita.org/
