Each qemu (version) is slightly different in the road to this, but then seems to behave.
This one is slightly better to get "in front" of the slow call to map all the memory. $ virsh nodedev-detach pci_0000_21_00_1 --driver vfio $ gdb /usr/bin/qemu-system-x86_64 (gdb) b vfio_dma_map (gdb) command 1 Type commands for breakpoint(s) 1, one per line. End with a line saying just "end". >silent >if size != 134217728000 >cont >end >end (gdb) run -m 131072 -smp 1 -no-user-config -device vfio-pci,host=21:00.1,id=hostdev0,bus=pci.0,addr=0x7 -enable-kvm (gdb) catch syscall 16 (gdb) c Also correct the link to qemu - it is the one from vfio_listener_region_add: https://git.qemu.org/?p=qemu.git;a=blob;f=hw/vfio/common.c;h=3e03c495d868f154b26a33c0c2d870273a0b4198;hb=HEAD#l664 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1838575 Title: passthrough devices cause >17min boot delay To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1838575/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs