Qemu 4.0.0 is out!

Great news, but for some, this might have caused some headaches in their existing Windows 10 configuration! Including me! No reason to panic though, as with some small modifications you are good to go again!

Windows 10 Issues

Some typical issues someone can encounter is:

Qemu 4.0.0 hangs the host and Windows 10 client, e.g. see here
Qemu 4.0.0 and NVIDIA card issue, e.g. see here
Qemu 4.0.0 sound issues

All of those issues can be fixed! No worries!

Fix the sound configuration!

The major edit in your configuration is regarding the sound. The QEMU_AUDIO_ environment variables and -audio-help are now deprecated. Use -audiodev instead!

So start by removing all QEMU_AUDIO_ environment variables!
An example configuration using Intel HD Audio would be:
qemu-system-x86_64 […] -soundhw hda -audiodev id=pa,driver=pa,server=/run/user/$(id -u $USER)/pulse/native.
– Use $(id -u $SUDO_USER) if you are running the command with sudo. Basically you want the ID of the current user and not root.

For a list of sound-hardware you can use:

qemu-system-x86_64 -soundhw -help

qemu-system-x86_64: -soundhw -help: Unknown sound card name `-help'
Valid sound card names (comma separated):
sb16        Creative Sound Blaster 16
es1370      ENSONIQ AudioPCI ES1370
ac97        Intel 82801AA AC97 Audio
adlib       Yamaha YM3812 (OPL2)
gus         Gravis Ultrasound GF1
cs4231a     CS4231A
hda         Intel HD Audio
pcspk       PC speaker

-soundhw all will enable all of the above

Fix the machine configuration!

In case you are using -machine type=q35, this will now basically default to -machine type=pc-q35-4.0.

I suggest switching back to using -machine type=pc-q35-3.1 or if you insist,
you can use -machine type=pc-q35-4.0 but add -machine type=pc-q35-4.0,kernel_irqchip=on as suggested in the bug report.

For a list of possible machine configurations use:

qemu-system-x86_64 -machine help             

Supported machines are:
pc                   Standard PC (i440FX + PIIX, 1996) (alias of pc-i440fx-4.0)
pc-i440fx-4.0        Standard PC (i440FX + PIIX, 1996) (default)
pc-i440fx-3.1        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-3.0        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.9        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.8        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.7        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.6        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.5        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.4        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.3        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.2        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.12       Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.11       Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.10       Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.1        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-2.0        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-1.7        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-1.6        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-1.5        Standard PC (i440FX + PIIX, 1996)
pc-i440fx-1.4        Standard PC (i440FX + PIIX, 1996)
pc-1.3               Standard PC (i440FX + PIIX, 1996)
pc-1.2               Standard PC (i440FX + PIIX, 1996)
pc-1.1               Standard PC (i440FX + PIIX, 1996)
pc-1.0               Standard PC (i440FX + PIIX, 1996)
pc-0.15              Standard PC (i440FX + PIIX, 1996) (deprecated)
pc-0.14              Standard PC (i440FX + PIIX, 1996) (deprecated)
pc-0.13              Standard PC (i440FX + PIIX, 1996) (deprecated)
pc-0.12              Standard PC (i440FX + PIIX, 1996) (deprecated)
q35                  Standard PC (Q35 + ICH9, 2009) (alias of pc-q35-4.0)
pc-q35-4.0           Standard PC (Q35 + ICH9, 2009)
pc-q35-3.1           Standard PC (Q35 + ICH9, 2009)
pc-q35-3.0           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.9           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.8           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.7           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.6           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.5           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.4           Standard PC (Q35 + ICH9, 2009)
pc-q35-2.12          Standard PC (Q35 + ICH9, 2009)
pc-q35-2.11          Standard PC (Q35 + ICH9, 2009)
pc-q35-2.10          Standard PC (Q35 + ICH9, 2009)
isapc                ISA-only PC
none                 empty machine

That’s it! If you make these small changes in your configuration, your setup should be up and running again! 🙂