* Marcel Apfelbaum (mar...@redhat.com) wrote: > On 04/01/2016 06:54 PM, Dr. David Alan Gilbert wrote: > >* Dr. David Alan Gilbert (dgilb...@redhat.com) wrote: > >>* Dr. David Alan Gilbert (dgilb...@redhat.com) wrote: > >>>Hi, > >>> I'm seeing a breakage on q35 migration on head (and possibly older > >>>but certainly head; it's also on a 2.5.0 world I've got with a bunch > >>>of patches but I've not tried a clean 2.5.0 yet). > >>> > >>>It looks like some type of interrupt screwup; with a virtio-net device > >>>I get a: > >>> BUG: soft lockup - CPU#0 stuck for 22s! > >>> ... virtnet_config_changed_work > >>> > >>>but if I swap that out for an e1000 I get: > >>> Disabling IRQ #22 > >>> > >>> and various timeouts on e1000 and cdrom (scsi). > >>>The guest kind of limps along with an existing terminal scrolling dmesg -w > >>>output. > >>> > >>>This is an f23 guest on a rhel7.2-ish host; with the guest sitting an idle > >>>(MATE) Gui. > >> > >>Also broken with 2.4.1 and 2.5.1 (with pc-q35-2.4 machine type); > >>see a screen shot attached; note: > >> a) The large count on irq 22 (enp2s1) on cpu1 > >> b) The large count on virtio2-config on cpu1 > >> c) The count of 'Deferred Error APIC interrupts'. > > > >OK, this seems to be the i82801b11-bridge; if I remove it from the config > >it all works. > > > >My minimum config that fails so far is: > >/opt/qemu-head/bin/qemu-system-x86_64 -nographic -machine > >pc-q35-2.6,accel=kvm,usb=off,vmport=off -cpu SandyBridge -m 4096 -realtime > >mlock=off -smp 4,sockets=4,cores=1,threads=1 \ > > -device i82801b11-bridge,id=pci.1,bus=pcie.0,addr=0x1e \ > > -drive id=image,file=/home/vms/f23-serial.qcow2,if=none,cache=none \ > > -device > > virtio-blk-pci,scsi=off,bus=pci.1,addr=0x5,drive=image,id=virtio-disk0,bootindex=1 > > \ > > $* > > > >if I flip the i82801b11-bridge for a pci-bridge then it works. > > Hi Dave, > That's good news. I see we don't have a vmstate for this bridge, but we do > have one for the regular pci-bridge. > Maybe this is the problem?
Yeh that's one of my suspicions; but how do device classes work? If a i82801b11-bridge is a subclass of pci-bridge should it just pick up the vmstate of the subclass magically? Dave P.S. I've filed this as RH bz 1323273 > > Thanks, > Marcel > > > > >Dave > > > >-- > >Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK