The change in QEMU 4.0 is only a change in defaults of the machine type, it can be entirely reverted in the VM config with kernel_irqchip=on or <ioapic driver='kvm'/> with libvirt. Using a machine type prior to the q35 4.0 machine type would also avoid it. There are no performance issues with these configurations that would favor using 3.1 over 4.0.
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1826422 Title: Regression: QEMU 4.0 hangs the host (*bisect included*) Status in QEMU: New Bug description: The commit b2fc91db84470a78f8e93f5b5f913c17188792c8 seemingly introduced a regression on my system. When I start QEMU, the guest and the host hang (I need a hard reset to get back to a working system), before anything shows on the guest. I use QEMU with GPU passthrough (which worked perfectly until the commit above). This is the command I use: ``` /path/to/qemu-system-x86_64 -drive if=pflash,format=raw,readonly,file=/path/to/OVMF_CODE.fd -drive if=pflash,format=raw,file=/tmp/OVMF_VARS.fd.tmp -enable-kvm -machine q35,accel=kvm,mem-merge=off -cpu host,kvm=off,hv_vendor_id=vgaptrocks,hv_relaxed,hv_spinlocks=0x1fff,hv_vapic,hv_time -smp 4,cores=4,sockets=1,threads=1 -m 10240 -vga none -rtc base=localtime -serial none -parallel none -usb -device usb-tablet -device vfio-pci,host=01:00.0,multifunction=on -device vfio-pci,host=01:00.1 -device usb-host,vendorid=<vid>,productid=<pid> -device usb-host,vendorid=<vid>,productid=<pid> -device usb-host,vendorid=<vid>,productid=<pid> -device usb-host,vendorid=<vid>,productid=<pid> -device usb-host,vendorid=<vid>,productid=<pid> -device usb-host,vendorid=<vid>,productid=<pid> -device virtio-scsi-pci,id=scsi -drive file=/path/to/guest.img,id=hdd1,format=qcow2,if=none,cache=writeback -device scsi-hd,drive=hdd1 -net nic,model=virtio -net user,smb=/path/to/shared ``` If I run QEMU without GPU passthrough, it runs fine. Some details about my system: - O/S: Mint 19.1 x86-64 (it's based on Ubuntu 18.04) - Kernel: 4.15 - `configure` options: `--target-list=x86_64-softmmu --enable-gtk --enable-spice --audio-drv-list=pa` - EDK2 version: 1a734ed85fda71630c795832e6d24ea560caf739 (20/Apr/2019) - CPU: i7-6700k - Motherboard: ASRock Z170 Gaming-ITX/ac - VGA: Gigabyte GTX 960 Mini-ITX To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1826422/+subscriptions
