Comment 36 for bug 1846427

FWIW, my VMs run with SATA and Virtio SCSI with discard=unmap and detect-zeroes=unmap (among the plethora of options from libvirtd) for maximum space savings. No problems since the fix patches went in and had no bearing on the bug occurence before that.

/usr/bin/qemu-system-x86_64 -name guest=win10,debug-threads=on -machine pc-q35-3.1,accel=kvm,usb=off,vmport=off,dump-guest-core=off -m 4096 -smp 2,sockets=2,cores=1,threads=1 -drive file=win10.qcow2,format=qcow2,if=none,id=drive-sata0-0-2,cache=writeback,discard=unmap,detect-zeroes=unmap -device ide-hd,bus=ide.2,drive=drive-sata0-0-2,id=sata0-0-2,bootindex=1,write-cache=on

/usr/bin/qemu-system-x86_64 -name guest=debian,debug-threads=on -machine pc-q35-4.0.1,accel=kvm,usb=off,vmport=off,dump-guest-core=off capabilities=on,ssbd=on,xsaves=on,pdpe1gb=on,hle=off,rtm=off,mpx=off -m 512 -smp 1,sockets=1,cores=1,threads=1 -device virtio-scsi-pci,id=scsi0,bus=pci.8,addr=0x0 -drive file=debian.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0,cache=writeback,discard=unmap,detect-zeroes=unmap -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,device_id=drive-scsi0-0-0-0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=1,write-cache=on