Update note, i found what prevent my card from running, basically i need to reboot without anything plug into the card and then i can unbind and rebind the card, what that strange behaviour?
2016-01-19 11:35 GMT+01:00 thibaut noah <[email protected]>: > Bumping this, running virsh nodedev-detach pci_0000_xx_yy_z' (with > proper numbers) and/or having managed=yes in the xml file changes nothing > (actually i had this already), ovmf still hangs waiting for i have no idea > what. > Cannot run by unbinding the device through script either, seems that i was > lucky, or maybe i did something that i forgot. > Tried to add nodedev-detach to modprobe but it seems that i did not do it > in the proper way so it wasn't working > > 2016-01-16 11:30 GMT+01:00 thibaut noah <[email protected]>: > >> Didn't know libvirt was capable of unbinding devices on its own, good to >> know, i'm gonna try this and if i manage to make it work i don't have any >> reason to bother myself more with this. (note that i don't use virt-manager >> since you advise me to use libvirt directly) >> Though the usb card will only be use by the vm, i have more than enough >> usb ports on my backpanel. >> >> Tried the gpu method by adding the id of the device in modprobe.d after >> gpu's ids but it didn't work. >> >> I paid it 50euros :( >> Thanks for the explanations alex >> >> >> 2016-01-15 18:59 GMT+01:00 Alex Williamson <[email protected]>: >> >>> A couple comments, first, boot time pre-binding to vfio-pci is really >>> only necessary for devices where the native host drivers behave poorly >>> if you take the device away from them later. This is why we do it for >>> GPUs and their companion sound device, host GPU drivers don't like to >>> give up the device, it plays poorly with any sort of graphics on the >>> host, and sequestering the audio device prevents host tools from >>> getting confused (and there are some bugs in the audio driver limiting >>> number of attach/detach cycles iirc). >>> >>> For anything else, you can dynamically unbind the device from the host >>> driver, bind it to vfio while the VM is running, and give it back to >>> the host on shutdown. libvirt will do this automatically for you if >>> your XML sets managed='yes' for the <hostdev> device. This is the >>> default, so if you use virt-manager to add the device, just select Add >>> Hardware -> PCI Host Device -> select device -> Finish. Done. If for some >>> reason you don't want the device flopping back and forth between host and >>> guest, just run 'virsh nodedev-detach pci_0000_xx_yy_z' at bootup where >>> xx_yy_z is the PCI bus (xx), device (yy), and function (z) numbers, the >>> same as in lspci. You can adopt some of the GPU methods for doing this if >>> you want it to happen earlier as well, there are lots of ways to do this >>> with modprobe.d (install options, softdep, etc..) >>> >>> Finally, yes I've seen OVMF hang with some crappy USB controllers. I'm >>> not sure if it's dependent on the devices attached or the controller >>> itself, but cheaper isn't always better when it comes to selecting >>> devices to use with device assignment. Thanks, >>> >>> Alex >>> >> >> >
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