[Qemu-devel] [RFC PATCH v1 0/7] Reset and Halting modifications + Zynq SMP

[Peter Crosthwaite]

Hi All. The clock controller module in the Zynq platform has the ability to halt
and reset arbitrary devices, including the CPU. We use this feature to implement
SMP Linux - the kernel halts CPU1 then rewrites the vector table to the
secondary entry point and unhalts.

The clock controller however is reasonable generic, in that in has the ability
to halt and reset any arbitrary device in the Zynq SoC. The interface for doing
this is reasonably consistent. So im looking for unified way to halt and reset
arbitrary devices CPUs included. So given we already have reset() defined on the
TYPE_DEVICE level, i've added halt as well.

This series is based on v3 of the current qom-cpu queue to pick up the move of
cpu halt out of the env. From this I attach the cpu::halted bit to the
Device::(un)halt function.

Next up, CPUs seem to have a different reset path to normal devices. So I have
trivially hooked up CPU::Reset to Device::Reset. This means that anyone who
holds a DeviceState pointer to the CPU can reset it properly without actually
knowing its a CPU.

With the halt API I played with changing an existing device over to use it in
place of the CPU halted bit (sun4m).

I then finally add SMP support to the Zynq machine, and patch the Zynq SLCR
(my clock controller) to have DeviceState pointers to the CPUs. device_reset()
and device_halt() is where the magic happens.

Future work, more devices in Zynq will have halt and reset. My agenda for
abstracting away the fact that attached device is a CPU is to allow for
consistent implementation and a single code path for the clock controlled
devices.


Peter A. G. Crosthwaite (3):
  xilinx_zynq: added smp support
  zynq_slcr: Add links to the CPUs
  zynq_slcr: Implement CPU reset and halting

Peter Crosthwaite (4):
  qdev: Define halting API
  qom/cpu.c: Encapsulate cpu halting
  qom/cpu.c: Hook CPU reset up to device reset
  sun4m: Use halting API to halt/unhalt CPUs

 hw/qdev-core.h   |   17 ++++++++++++++
 hw/qdev.c        |   18 ++++++++++++++
 hw/sun4m.c       |   24 +++++++++---------
 hw/xilinx_zynq.c |   66 ++++++++++++++++++++++++++++++++++++++++++++---------
 hw/zynq_slcr.c   |   30 ++++++++++++++++++++++++
 qom/cpu.c        |   22 ++++++++++++++++++
 6 files changed, 153 insertions(+), 24 deletions(-)