[Qemu-devel] [PATCH v4 0/6] spapr/xics: fix migration of older machine types

[Greg Kurz <groug@kaod.org>]

I've provided answers for all comments from the v3 review that I deliberately
don't address in v4.

v4: - some patches from v3 got merged
    - added some more preparatory cleanup in xics (patches 1,2)
    - merge cpu_setup() handler into realize() (patch 4)
    - see individual changelog for patches 3 and 6

v3: - preparatory cleanup in pnv (patch 1)
    - rework ICPState realization and vmstate registration (patches 2,3,4)
    - fix migration using dummy icp/server entries (patch 5)

v2: - some patches from v1 are already merged in ppc-for-2.10
    - added a new fix to a potential memory leak (patch 1)
    - consolidate dt_id computation (patch 3)
    - see individual changelogs for patch 2 and 4

I could successfully do the following on POWER8 host with full cores (SMT8):

1) start a pseries-2.9 machine with QEMU 2.9:
        -smp cores=1,threads=2,maxcpus=8
2) hotplug a core:
        device_add host-spapr-cpu-core,core-id=4
3) migrate to QEMU 2.10 configured with core-id 0,4
4) hotplug another core:
        device_add host-spapr-cpu-core,core-id=2
5) migrate back to QEMU 2.9 configured with core-id 0,4,2
6) hotplug the core in the last available slot:
        device_add host-spapr-cpu-core,core-id=6
7) migrate to QEMU 2.10 configured with core-id 0,4,2,6

I could check that the guest is functional after each migration.

--
Greg

---

Greg Kurz (6):
      xics: introduce macros for ICP/ICS link properties
      xics: pass appropriate types to realize() handlers.
      xics: setup cpu at realize time
      xics: drop ICPStateClass::cpu_setup() handler
      xics: directly register ICPState objects to vmstate
      spapr: fix migration of ICPState objects from/to older QEMU


 hw/intc/xics.c          |   95 ++++++++++++++++++++---------------------------
 hw/intc/xics_kvm.c      |   18 ++++-----
 hw/intc/xics_pnv.c      |    6 +--
 hw/ppc/pnv_core.c       |   17 ++++----
 hw/ppc/pnv_psi.c        |    3 +
 hw/ppc/spapr.c          |   89 +++++++++++++++++++++++++++++++++++++++++++-
 hw/ppc/spapr_cpu_core.c |   22 +++++------
 include/hw/ppc/spapr.h  |    2 +
 include/hw/ppc/xics.h   |   16 ++++----
 9 files changed, 168 insertions(+), 100 deletions(-)