Peter Xu <pet...@redhat.com> wrote: > Migration is silently broken now with x2apic config like this: > > -smp 200,maxcpus=288,sockets=2,cores=72,threads=2 \ > -device intel-iommu,intremap=on,eim=on > > After migration, the guest kernel could hang at anything, due to > x2apic bit not migrated correctly in IA32_APIC_BASE on some vcpus, so > any operations related to x2apic could be broken then (e.g., RDMSR on > x2apic MSRs could fail because KVM would think that the vcpu hasn't > enabled x2apic at all). > > The issue is that the x2apic bit was never applied correctly for vcpus > whose ID > 255 when migrate completes, and that's because when we > migrate APIC we use the APICCommonState.id as instance ID of the > migration stream, while that's too short for x2apic. > > Let's use the newly introduced initial_apic_id for that. > > Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Juan Quintela <quint...@redhat.com>
