Re: [Qemu-devel] [PATCH v3 0/2] VT-d migration support

[Peter Xu]

On Mon, Jan 09, 2017 at 10:18:45AM +0800, Peter Xu wrote:
> On Fri, Jan 06, 2017 at 01:27:38PM +0000, Dr. David Alan Gilbert wrote:
> 
> [...]
> 
> > > (P.S. I found that split irqchip cannot work well with migration. Is
> > >  this an known issue?)
> > 
> > How did it fail?
> 
> The keyboard hangs after migration.
> 
> Command line for reference:
> 
> $qemu -M q35,kernel-irqchip=split -enable-kvm \
>       -netdev user,id=net0 \
>       -device e1000,netdev=net0 \
>       -m 512M -monitor stdio \
>       $incoming /var/lib/libvirt/images/vm1.qcow2
> 
> Here $incoming is "" for init vm, and "-incoming tcp:0:6666" for the
> dest side. Not sure whether this is reproducable issue. Looks like
> some EOI ack is missing.
> 
> Host: 4.10.0-rc1+ (I should also tried 4.6.4-301.fc24)
> Qemu: latest master
> 
> Looking into it.

The problem is that we didn't setup the first 24 gsi routing entries
(which is used by the userspace ioapic) in kernel after the migration.
Will post a fix for it later.

-- peterx