Reference: this is the call from qemu that I think we see above (on x86) is at [1]. If this time the assumption is correct the kernel place would be at vfio_iommu_type1_ioctl.
For debugging: $ gdb qemu/x86_64-softmmu/qemu-system-x86_64 (gdb) catch syscall 16 (gdb) run -m 131072 -smp 1 -no-user-config -device vfio-pci,host=21:00.1,id=hostdev0,bus=pci.0,addr=0x7 (gdb) continue 22 # Now we are "in front" of the bad call. https://git.qemu.org/?p=qemu.git;a=blob;f=hw/vfio/common.c;h=3e03c495d868f154b26a33c0c2d870273a0b4198;hb=HEAD#l480 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1838575 Title: passthrough devices cause >17min boot delay Status in linux package in Ubuntu: Confirmed Status in qemu package in Ubuntu: Incomplete Bug description: Adding passthrough devices to a guest introduces a boot delay of > 17 minutes. During this time libvirt reports the guest to be "paused". The delay does not seem to scale with the # of hostdevs - that is, 1 hostdev causes about a 17min delay, while 16 only bumps that up to ~18min. Removing all hostdevs avoids the delay. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1838575/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp