The series is a first attempt at enabling Multi-Threaded TCG on PowerPC.
Changes that were needed to enable PowerPC are pretty simple;
Patch 01: Take a iothread lock during hcall, as hcall can generate io requests
02: For TCG, we were harcoding smt as 1, this gets rid of the limitation
03: Use atomic_cmpxchg in store conditional
04: With more threads, flush the entry from each cpu.
This can be optimized further.
The patches are based on the Alex Bennee's base enabling patches for
MTTCG[1] and Emilios's cmpxchg atomics. The consolidated tree of the
above patches is here:
https://github.com/stsquad/qemu/tree/mttcg/base-patches-v4-with-cmpxchg-atomics-v2
Apart from the above, PPC patches are based out of ppc-for-2.8 and
load/store consolidation patches [2]
Series with all dependent patches available here:
https://github.com/nikunjad/qemu/tree/ppc_mttcg_v1
Testing:
========
-smp 4,cores=1,threads=4 -accel tcg,thread=multi
TODO
====
Implement msgsndp instructions(door-bell), newer kernels enable it
depending on the PVR. I have been using following workaround to boot.
https://github.com/nikunjad/qemu/commit/2c10052c5f93418a6b920e6ba3ce1813fcf50bc4
[1] https://www.mail-archive.com/qemu-devel@nongnu.org/msg391966.html
[2] https://lists.gnu.org/archive/html/qemu-ppc/2016-08/msg00265.html
Nikunj A Dadhania (4):
spapr-hcall: take iothread lock during handler call
target-ppc: with MTTCG report more threads
target-ppc: use atomic_cmpxchg for ld/st reservation
target-ppc: flush tlb from all the cpu
cputlb.c | 15 +++++++++++++++
hw/ppc/spapr_hcall.c | 11 +++++++++--
include/exec/exec-all.h | 2 ++
target-ppc/kvm.c | 2 +-
target-ppc/kvm_ppc.h | 2 +-
target-ppc/mmu-hash64.c | 2 +-
target-ppc/translate.c | 24 +++++++++++++++++++++---
7 files changed, 50 insertions(+), 8 deletions(-)
--
2.7.4
