[Qemu-devel] [PATCH v3 00/12] spapr: add support for pci hotplug

[Michael Roth <mdroth@linux.vnet.ibm.com>]

These patches are based on ppc-next, and can also be obtained from:

https://github.com/mdroth/qemu/commits/spapr-pci-hotplug-v3-ppc-next

v3:
 * dropped emulation of firmware-managed BAR allocation. this will be
   introduced via a follow-up series via a -machine flag and tied to
   a separate hotplug event to avoid a race condition with guest vs.
   "firmware"-managed BAR allocation, in conjunction with required
   fixes to rpaphp hotplug kernel module to utilize this mode.
 * moved drc_table into sPAPREnvironment (Alexey)
 * moved INDICATOR_* constants and friends into spapr_pci.c (Alexey)
 * use prefixes for global types (DrcEntry/ConfigureConnectorState) (Alexey)
 * updated for new hotplug interface (Alexey)
 * fixed get-power-level to report current power-level rather than
   desired (Alexey)
 * rebased to latest ppc-next

v2:
  * re-ordered patches to fix build bisectability (Alexey)
  * replaced g_warning with DPRINTF in RTAS calls for guest errors (Alexey)
  * replaced g_warning with fprintf for qemu errors (Alexey)
  * updated RTAS calls to use pre-existing error/success macros (Alexey)
  * replaced DR_*/SENSOR_* macros with INDICATOR_* for set-indicator/
    get-sensor-state (Alexey)

OVERVIEW

These patches add support for PCI hotplug for SPAPR guests. We advertise
each PHB as DR-capable (as defined by PAPR 13.5/13.6) with 32 hotpluggable
PCI slots per PHB, which models a standard PCI expansion device for Power
machines where the DRC name/loc-code/index for each slot are generated
based on bus/slot number.

This is compatible with existing guest kernel's via the rpaphp hotplug
module, and existing userspace tools such as drmgr/librtas/rtas_errd for
managing devices, in theory...

NOTES / ADDITIONAL DEPENDENCIES

This series relies on v1.2.19 or later of powerppc-utils (drmgr, rtas_errd,
ppc64-diag, and librtas components, specificially), which will automate
guest-side hotplug setup in response to an EPOW event emitted by QEMU. For
guests with older versions of powerpc-utils, a manual workaround must be
used (documented below).

PATCH LAYOUT

Patches
        1-3   advertise PHBs and associated slots as hotpluggable to guests
        4-7   add RTAS interfaces required for device configuration
        8     fix for ppc (and other) guests that allocate IO bars starting
              at 0x0
        9     enables device_add/device_del for spapr machines and
              guest-driven hotplug
        10-12 define hotplug event structure and emit them in response to
              device_add/device_del

USAGE

For guests with powerpc-utils 1.2.19+:
  hotplug:
    qemu:
      device_add e1000,id=slot0
  unplug:
    qemu:
      device_del slot0

For guests with powerpc-utils prior to 1.2.19:
  hotplug:
    qemu:
      device_add e1000,id=slot0
    guest:
      drmgr -c pci -s "Slot 0" -n -a
      echo 1 >/sys/bus/pci/rescan
  unplug:
    guest:
      drmgr -c pci -s "Slot 0" -n -r
      echo 1 >/sys/bus/pci/devices/0000:00:00.0/remove
    qemu:
      device_del slot0

 hw/pci/pci.c                |   2 +-
 hw/ppc/spapr.c              | 172 +++++++++++++++++++++++++++++++++-
 hw/ppc/spapr_events.c       | 224 ++++++++++++++++++++++++++++++++++++--------
 hw/ppc/spapr_pci.c          | 689 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 include/hw/pci-host/spapr.h |   1 +
 include/hw/ppc/spapr.h      |  46 ++++++++-
 6 files changed, 1083 insertions(+), 51 deletions(-)