install

https://computingforgeeks.com/install-kvm-qemu-virt-manager-arch-manjar/

sudo pacman -S qemu virt-manager virt-viewer libguestfs # dnsmasq vde2 bridge-utils openbsd-netcat
# see virt-sandbox
sudo systemctl enable libvirtd.service
sudo systemctl start libvirtd.service
systemctl status libvirtd.service

conf

file=/etc/libvirt/libvirtd.conf
sudo cp -a $file $file$(date +%s)
sudo sed -i 's|^#\?\(unix_sock_group =\).*$|\1 "libvirt"|' $file
sudo sed -i 's|^#\?\(unix_sock_rw_perms =\).*$|\1 "0770"|' $file
sudo usermod -a -G libvirt $USER
sudo systemctl restart libvirtd.service

mod=$(lsmod|awk '/^kvm_/ {print $1}')
sudo modprobe -r $mod
sudo modprobe $mod nested=1
echo "options ${mod/_/-} nested=1" | sudo tee /etc/modprobe.d/${mod/_/-}.conf
systool -m ${mod} -v | grep nested

share

host

hostpath=/vms/share
sudo mkdir $hostpath

#sudo usermod -G libvirtd -a $USER
sudo usermod -G libvirt-qemu -a $USER
hostpath=/vms/share
#sudo chown -R libvirt-qemu:libvirt-qemu $hostpath
sudo setfacl -d -Rm g:libvirt-qemu:rwx $hostpath

virt-manager

hostshare

<filesystem type="mount" accessmode="mapped" fmode="0660" dmode="0770">
  <source dir="/vms/share"/>
  <target dir="/hostshare"/>
  <address type="pci" domain="0x0000" bus="0x07" slot="0x00" function="0x0"/>
</filesystem>

guest

guestpath=/share
#sudo chmod -R 777 $guestpath
sudo chown -R $USER:$USER $guestpath

mount

sudo mount -t 9p -o trans=virtio,rw,version=9p2000.L /hostshare $guestpath

sudo sh -c "echo '
# qemu share
/hostshare                                /share          9p      trans=virtio,version=9p2000.L,rw,noauto              0 0' >> /etc/fstab"

disk

shrink

# linux
sudo dd if=/dev/zero of=/zero bs=4M
sudo rm /zero
# windows
sdelete -z C

qemu-img convert -O qcow2 $file $file2

reduce

qemu-img info $file
qemu-img resize -f qcow2 --shrink $file -10G

expand

qemu-img info $file
qemu-img resize $file +2G

import / export

virsh --connect qemu:///system dumpxml $guest > $guest.xml
virsh --connect qemu:///system define $guest.xml

ova

vm=tsurugi_linux_2022.1_vmdk
mkdir tmp
tar xf ${vm}.ova -C tmp/
qemu-img convert -f vmdk tmp/${vm}.vmdk tmp/${vm}.qcow2
qemu-img convert -O qcow2 tmp/${vm}-disk001.qcow2 ${vm}.qcow2