Den 23.10.2018 20:40, skrev Håkon Alstadheim: > > Den 08. okt. 2018 16:32, skrev Boris Ostrovsky: >> Are these two patches still needed? ISTR they were  written originally >> to deal with guest trying to use device that was previously assigned to >> another guest. But pcistub_put_pci_dev() calls >> __pci_reset_function_locked() which first tries FLR, and it looks like >> it was added relatively recently. >> >> > Sorry for the late reply, but I just now booted xen staging-4.11 > (94fba9f438a2c36ad9bf3a481a6013ddc7cf8cd9), with gentoo-sources-4.19.0 > as dom0. Shut down and started again a VM that has a secondary GPU > passed through, and the whole  machine hung. I haven't had time to look > more closely into this, other than that my old "do_flr" patch no longer > applies to gentoo-sources (i.e. the linux kernel sources) . "do_flr" > worked for me on linux-4.18.? , with appropriate patch to the linux kernel. Without some kind of fix, my whole server (dom0) goes down whenever a domu with pci passed through is re-started. NOTE: I am not a programmer. I have no idea what I am doing. The patch I have as a starting-point does not compile correctly when applied to kernel version 4.19.x. I get implicit declarations of  pci_try_reset_slot() and pci_try_reset_bus(). Replacing those with  pci_reset_bus(dev) gives me the attached patch which applies cleanly to gentoo-sources-4.19.2, compiles without warnings, and works to let me restart a domU with pci-passthrough (modulo changing do_flr to reset in  xen libxl). I hope a dev will adopt these and give them proper care :-) .