[Qemu-ppc] [PATCH 00/10] spapr: option vector re-work and memory unplug support

[Michael Roth]

This series is based on David's ppc-for-2.8 branch, and is also available from:

  https://github.com/mdroth/qemu/commits/spapr-hotplug-event-update

Changes since RFC:
  * Submit as v1 now that PAPR Hotplug ACR is accepted
  * Rebase on latest ppc-for-2.8 (with device-tree refactoring)
  * address Patchew warnings
  * add comments to clarify spapr->ov5/ov5_cas usage. (David)
  * revise comment to clarify intent when setting spapr->ov5
    OV5_HP_EVT bit. (Bharata)
  * drop internal usage of spapr_ovec_from_bitmap() in favor of
    directly assigning bitmap to sPAPROptionVector instances. (David)
  * standardize meaning of 'vector_len' variable through spapr_ovec_*
    functions to be the byte-wise length of option vectors entries,
    and not including the preceeding length byte itself. (David)
  * fix spapr_ovec_populate_dt() to parse up to OV_MAXBITS bits
    rather than OV_MAXBITS - 1. (David)
  * fix spapr_ovec_populate_dt() encode the minimum of 1 option
    vector byte instead of the max of OV_MAXBYTES in cases where
    no option bits are set. (David)
  * add some comments to spapr_ovec_populate_dt() to clarify what
    is being encoded into length byte of ibm,architecture-vec-5
  * switch 'legacy-hotplug-events' option to
    'modern-hotplug-events' (David)
  * modify rtas_event_log_to_source() to check for OV5_HP_EVT
    option rather than relying on whether the hotplug source is
    specifically enabled. Assert the latter in cases where
    OV5_HP_EVT is set. (Bharata)
  * drop global EventSource list in favor of an sPAPREventSource
    list field within sPAPRMachineState (David)
  * add CPU unplug hook in mc->unplug_request (Bharata)


Patches 1-4 address various deficiencies in how we currently handle option
vectors via ibm,client-architecture-support. This is done here in preparation
for a new option vector bit introduced later in this series, as well as a
number of future option vector bits related to other features, but I can
break this out into a separate series if preferred.

Patches 5-7 add support for an updated event format for hotplug events,
which includes a new way to specify a range of DRCs/LMBs to hotplug/unplug
using a starting position and count, which is necessary for memory unplug.
The format for this new event format is still in draft form, but slated
for inclusion in the PAPR/LoPAPR.

Patches 8-10 add support for memory unplug using the new event format.

In addition to kernel 4.8 or later, there are a number of patches required
to enable support on the guest kernel side. I've including the minimum set
of patches in my branch here:

   https://github.com/mdroth/linux/commits/spapr-hotplug-event-update

   *powerpc/pseries: advertise Hot Plug Event support to firmware
   powerpc/pseries: Implement indexed-count hotplug memory remove
   powerpc/pseries: Implement indexed-count hotplug memory add

Note that there is currently an issue that arises when attempting to
offline an LMB that was onlined using a guest kernel's auto-onlining
mechanism, which can prevent full completion of memory unplug requests.
This is being investigated, but for the purposes of testing this can
be worked around currently by disabling auto-onlining in guests via:

  "echo offline >/sys/devices/system/memory/auto_online_blocks"

and instead onlining the blocks manually or via udev.

 docs/specs/ppc-spapr-hotplug.txt |  55 +++++++++++++++++++++-----
 hw/ppc/Makefile.objs             |   2 +-
 hw/ppc/spapr.c                   | 243 
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 hw/ppc/spapr_drc.c               |  17 ++++++++
 hw/ppc/spapr_events.c            | 278 
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------
 hw/ppc/spapr_hcall.c             |  70 ++++++++++++++-------------------
 hw/ppc/spapr_ovec.c              | 242 
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/ppc/spapr.h           |  17 ++++++--
 include/hw/ppc/spapr_ovec.h      |  67 ++++++++++++++++++++++++++++++++
 9 files changed, 868 insertions(+), 123 deletions(-)