Re: [libvirt] [libvirt-tck PATCH] Fix PCI device hotplug tests

On Fri, Oct 24, 2014 at 09:15:42AM -0600, Jim Fehlig wrote: > Eric Blake wrote: > >> On 10/23/2014 03:21 PM, Jim Fehlig wrote: >> >> >>> This patch fixes a few issues noted while enabling the TCK PCI device >>> hotplug tests. >>> >>> First, the call to node device dettach function misses parameters, resulting >>> in the following failure >>> >>> Failed test 'detached device from host OS' >>> at /usr/share/libvirt-tck/tests/domain/250-pci-host-hotplug.t line 90. >>> died: Usage: Sys::Virt::NodeDevice::dettach(dev, driversv, flags=0) >>> at /usr/share/libvirt-tck/tests/domain/250-pci-host-hotplug.t line 90. >>> >>> Trivally fixed by adding the missing parameters when calling node device >>> dettach function. >>> >>> >> That part is fine to fix (note that 'dettach' is a typo but part of the >> API, so we are stuck with it; it's nice to use 'detach' where possible). >> >> >> >>> Second, it appears qemu needs to reach some state of initialization before >>> host device attach/detach works properly. Currently, the test fails when >>> detaching the device from the guest, resetting it, and reattaching it to >>> the host >>> >>> Failed test 'reset the host PCI device' >>> at /usr/share/libvirt-tck/tests/domain/250-pci-host-hotplug.t line 110. >>> died: Sys::Virt::Error (libvirt error code: 1, message: internal error: >>> Not resetting active device 0000:03:00.1) >>> >>> Failed test 'reattached device to host OS' >>> at /usr/share/libvirt-tck/tests/domain/250-pci-host-hotplug.t line 111. >>> died: Sys::Virt::Error (libvirt error code: 55, message: Requested operation >>> is not valid: PCI device 0000:03:00.1 is still in use by driver QEMU, domain >>> tck) >>> >>> I've found that sleeping for a bit after creating the guest allows the >>> tests to pass. >>> >>> >> But that papers over the bug. Ideally, the libvirt API should be >> waiting longer for the guest to relinquish control of the device before >> returning success on the first call, so that the second call cannot hit >> a collision. >> > Even with this delay, the guest has not completely booted when the test > successfully completes. So it is not clear to me how much guest > cooperation is needed. > > >> I'm not so sure that this is the right patch to make to >> TCK, and wonder if we should instead be patching libvirt proper. Or is >> it a case that because detach requires guest cooperation, we need to >> wait long enough for the guest to boot to the point that it can >> cooperate? >> > Perhaps. Maybe acpiphp needs to be loaded in the guest kernel before > this will work. > Yeah, I'm a little fuzzy on just how functiuonal the guest OS has to be. I suspect the kernel mod is sufficient, so whether it finishes booting is probably not important as long as the mod is loaded.