Looks similar to https://bugs.launchpad.net/qemu/+bug/1879175
-- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1882784 Title: Legacy IGD passthrough in QEMU 5 disabled Status in QEMU: New Bug description: Bug with tag v5.0.0, or commit fdd76fecdde1ad444ff4deb7f1c4f7e4a1ef97d6 As of QEMU 5 Legacy IGD PT is no longer working. Host is a Xeon E3-1226 v3 and my method to test is to run the following: ./qemu-system-x86_64 \ -device 'pci-bridge,id=pci.1,chassis_nr=1,bus=pci.0,addr=0x1f' \ -device 'vfio-pci,host=00:02.0,addr=02.0' \ -L '/usr/share/kvm' \ -nographic \ -vga none \ -nodefaults in the hope of seeing a "IGD device 0000:00:02.0 cannot support legacy mode due to existing devices at address 1f.0" error. The culprit appears to be this commit: https://github.com/qemu/qemu/commit/29d62771c81d8fd244a67c14a1d968c268d3fb19 Specifically the following block in pci-quirks.c: #ifdef CONFIG_VFIO_IGD vfio_probe_igd_bar4_quirk(vdev, nr); #endif as the kconfig variable CONFIG_VFIO_IGD doesn't appear to be available outside of makefiles as described here: https://qemu.weilnetz.de/doc/devel/kconfig.html. I can confirm that the igd code is being pulled in as removing this check, as would defining the variable I presume, makes Legacy IGD PT work again (ie I see the expected "existing devices" error). I first spotted this in Proxmox, but have confirmed the bug by building QEMU sources. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1882784/+subscriptions
