Bug 1017377

Summary: RFE: Give user some indication if PCI assignment won't work
Product: [Community] Virtualization Tools Reporter: Cole Robinson <crobinso>
Component: virt-managerAssignee: Cole Robinson <crobinso>
Status: CLOSED DEFERRED QA Contact:
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Version: unspecifiedCC: berrange, crobinso, gscrivan
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Last Closed: 2019-06-14 21:29:42 UTC Type: Bug
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Description Cole Robinson 2013-10-09 18:11:42 UTC
Right now we basically let the user attempt to assign any PCI device to a guest and hope it works, when there is actually quite a few caveats that we can warn them about. Unfortunately much of this requires info that libvirt doesn't currently expose.

https://bugzilla.redhat.com/show_bug.cgi?id=967231

And the libvirt device assignment default is likely changing to VFIO for libvirt 1.1.4 or soon after, and there are differences between what VFIO and traditional assignment can handle.

Comment 1 Cole Robinson 2013-10-31 20:04:36 UTC
libvirt reports iommuGroup info in the nodedev XML. To support that, we would need to tweak the UI to only allow attaching all devices in the same iommuGroup as one logical block of devices. This won't work for hotplug though so we'd need to make that bit clear.

Comment 2 Cole Robinson 2019-06-14 21:29:42 UTC
libvirt has some reporting here with iommu in capabilities, but in practice this has never really been a problem. If someone shows up with a patch for it I'll accept it but it's not worth explicitly tracking IMO