QEMU systemd/SSH

qemu CPU pin

qemu-system-x86_64(16858) threads:
        {qemu-system-x86}(16859): 0-3,24-27
        {IO io1}(16860): 0-3,24-27
        {IO mon_iothread}(16872): 0-3,24-27
        {CPU 0/KVM}(16873): 4
        {CPU 1/KVM}(16874): 28
        {CPU 2/KVM}(16875): 5
        {CPU 3/KVM}(16876): 29
        {CPU 4/KVM}(16877): 6
        {CPU 5/KVM}(16878): 30
        {CPU 6/KVM}(16879): 7
        {CPU 7/KVM}(16880): 31
        {CPU 8/KVM}(16881): 8
        {CPU 9/KVM}(16882): 32
        {CPU 10/KVM}(16883): 9
        {CPU 11/KVM}(16884): 33
        {CPU 12/KVM}(16885): 10
        {CPU 13/KVM}(16886): 34
        {CPU 14/KVM}(16887): 11
        {CPU 15/KVM}(16888): 35
        {worker}(27836): 0-3,24-27
        {worker}(27842): 0-3,24-27
        {worker}(27878): 0-3,24-27
        {worker}(27879): 0-3,24-27
        {worker}(27880): 0-3,24-27
        {worker}(27881): 0-3,24-27
        {worker}(27882): 0-3,24-27

qemu invocation

/usr/sbin/qemu-system-x86_64 \
        -name seat1,debug-threads=on -daemonize -pidfile /run/qemu_seat1.pid -monitor unix:/tmp/seat1.sock,server,nowait -nodefconfig -debugcon file:/var/log/[email protected] -global isa-debugcon.iobase=0x402 \
        -nodefconfig -no-user-config -nodefaults -nographic \
        -machine q35,accel=kvm \
        -enable-kvm -cpu host,kvm=off,hv_spinlocks=0x1fff,hv_relaxed,hv_time,hv_vendor_id=Nvidia43FIX \
        -rtc base=localtime,clock=host,driftfix=slew \
        -mem-path /dev/hugepages \
        -drive file=/tank/fw/active/OVMF-pure-efi.fd,if=pflash,format=raw,unit=0,readonly=on\
        -object iothread,id=io1 \
                -m 8192 \
        -smp cores=8,threads=2,sockets=1 \
        -drive file=/home/adam/win10-OVMF_VARS.fd,if=pflash,format=raw,unit=1 \
        -device virtio-scsi-pci,id=scsi0,ioeventfd=on,iothread=io1,num_queues=4 \
        -drive id=disk0,file=/tank/vm/adam-win10.qcow2,format=qcow2,cache=writeback,readonly=off,if=none \
                -device scsi-hd,drive=disk0,bus=scsi0.0 \
        -netdev bridge,id=netdev0,br=br0 -device virtio-net-pci,netdev=netdev0,mac=52:54:00:12:34:57 \
        -device vfio-pci,host=08:00.0,addr=0x6,multifunction=on -device vfio-pci,host=08:00.1,addr=0x6.0x1 \
        -device vfio-pci,host=03:00.0 -device vfio-pci,host=04:00.0 \
        -drive id=disk2,file=/dev/disk/by-id/ata-Hitachi_HDS723020BLA642_MN1270FA12SE0D,format=raw,readonly=off,if=none,aio=native,cache=none,cache.direct=on \
                -device scsi-hd,drive=disk2,bus=scsi0.0 \
        -drive id=disk3,file="iscsi://192.168.3.1/iqn.2000-01.com.zegelin:adam-win10/0",format=raw,readonly=off,if=none \
                -device scsi-hd,drive=disk3,bus=scsi0.0 \
        -drive id=disk4,file="iscsi://192.168.3.1/iqn.2000-01.com.zegelin:adam-win10/1",format=raw,readonly=off,if=none \
                -device scsi-hd,drive=disk4,bus=scsi0.0 \
        -drive id=disk5,file="iscsi://192.168.3.1/iqn.2000-01.com.zegelin:adam-win10/2",format=raw,readonly=off,if=none \
                -device scsi-hd,drive=disk5,bus=scsi0.0 \
        

[email protected]

[Unit]
Description=QEMU virtual machine (%i)

[Service]
Type=forking
PIDFile=/run/qemu_%i.pid

Environment=QEMU_AUDIO_DRV=pa 
EnvironmentFile=/etc/conf.d/qemu.d/%i/*

ExecStart=/usr/bin/qemu-system-x86_64 -name %i,debug-threads=on -daemonize -pidfile /run/qemu_%i.pid -monitor unix:/tmp/%i.sock,server,nowait -nodefconfig -debugcon file:/var/log/qemu@%i-debugcon.log -global isa-debugcon.iobase=0x402 $common_args $args
ExecStop=/bin/sh -c 'while test -d /proc/$MAINPID; do /usr/bin/echo system_powerdown | /usr/bin/socat - UNIX-CONNECT:/tmp/%i.sock; sleep 60; done'
TimeoutStopSec=1m

[Install]
WantedBy=multi-user.target

[email protected] cpu.conf

[Service]
CPUSchedulingPolicy=rr

ExecStartPost=/bin/sh -c 'exec /usr/bin/qemu-affinity $MAINPID -p 0-3,24-27 -i *:0-3,24-27 -q 0-3,24-27 -w *:0-3,24-27 -k 4 28 5 29 6 30 7 31 8 32 9 33 10 34 11 35'

Regarding the [email protected], I'd like to suggest the following mod:

ExecStop=/bin/sh -c '/usr/bin/echo system_powerdown | /usr/bin/socat - UNIX-CONNECT:/tmp/%i.sock; while test -d /proc/$MAINPID; do sleep 2; done'

I,e,: send the system_powerdown command just once, then keep watching the PID in a "not very tight" loop - just wait for the PID to die, and only then return from the ExecStop action.
In the original version, the loop sends the system_powerdown command and then sleeps no less than a minute, before trying again.

Also, you might wish to increase the TimeoutStopExec to something more than just a minute - some guests may take longer to shut down. But this is probably something that anyone could figure out, eventually.

Thanks for this cool piece. Has saved me quite some time.