** Note: Very different to V1 **
Hi All,
This is target-multi, a system-mode build that can support multiple
cpu-types.
Two architectures are initially converted. Microblaze and ARM. Step
by step conversion in done for each. A microblaze is added to
Xilinx Zynq platform as a test case. This will be elaborted more in
future spins. This use case is valid, as Microblazes can be added (any
number of them!) in Zynq FPGA programmable logic configuration.
The general approach (radically different to approach in V1 RFC) is to build
and prelink an object (arch-obj.o) per-arch containing:
1: target-foo/*
2: All uses of env internals and CPU_GET_ENV
* cputlb, translate-all, cpu-exec
* TCG backend
This means cputlb and friends are compiled multiple times fo each arch. The
symbols for each of these pre-links are then localised to avoid link time name
collisions. This is based on Paolo's suggestion to templatify cputlb and
friends. Just the net of what to multi-compile is widened to incude the TCG
stuff as well now.
Despite being some "major surgery" this approach actually solves many of big
the problems raised in V1. Big problems sovled:
1: With the multi-compile TCG backends there are now multiple tcg_ctx's for
each architecture. This solves the issue PMM raised WRT false positives on TB
hashing as archs no longer share translation context.
2: There is no longer a need to reorder the CPU_COMMON within the ENV or the ENV
within the CPU. This was flagged as a performance issue by multiple people in
V1.
All users of the env internals as well as ENV_GET_CPU are now in multi-compile
code and so multi-arch does not need to define a generic ENV nor does in need to
def the problematic ENV_GET_CPU.
3: With the prelink symbol localisation, link time namespace collision of
helpers from multiple arches is no longer an issue. No need to bloat all the
function names with arch specific prefixes.
4: The architecture specifics used/defined by cpu-defs can now vary from arch to
arch (incl. target_ulong) greatly reducing coversion effort needed. The list
of restrictions for multi-arch capability is much reduced since V1. No
target_long issues anymore.
The approach trades in the big problems of last series for a number of smaller
problems. Some I have decided not to tackle until I have some list uptime. Check
the patches marked HACK, which have commit messages detailing individual
problems (e.g what do we do about TCG profiling with multiple tcg_ctx?).
include/exec/*.h and some of the common code needs some refactoring to setup
this single vs multi compile split. Mostly code movements.
The interface between the multi compile and single compiled files needs to be
virtualised using QOM cpu functions. But this is now a very low footprint
change as most of the virtualised hooks are now in mutli-compiled code (they
only exist as text once). There are more new hooks than before, but the per
target change pattern is reduced.
There is a lot more core code changes and less target-foo changes this time.
Full coversion is looking more feasible for one QEMU that can do everything.
For the implementation of the series, the trickiest part is (still) cpu.h
inclusion management. There are now more than one cpu.h's and different
parts of the tree need a different include scheme. target-multi defines
it's own cpu.h which is bare minimum defs as needed by core code only.
target-foo/cpu.h are mostly the same but refactored to avoid collisions
with other cpu.h's. Inclusion scheme goes something like
this (for the multi-arch build):
*: Core code includes only target-multi/cpu.h
*: target-foo/ implementation code includes target-foo/cpu.h locally
*: System level code (e.g. mach models) can use multiple target-foo/cpu.h's
The hardest unasnwered Q is (still) what to do about bootloading. Currently
each arch has it's own architecture specific bootloading which may assume a
single architecture. I have applied some hacks to at least get this
RFC testable using a -kernel -firmware split but going forward being
able to associate an elf/image with a cpu explictitly needs to be
solved.
No support for KVM, im not sure if a mix of TCG and KVM is supported even for
a single arch? (which would be prerequisite to MA KVM).
Depends (not heavily) on some already on list patches:
memory_mapping: Use qemu_common.h include
configure: Unify arm and aarch64 disas configury
Makefile.target: set master BUILD_DIR
cpus: Change exec_init arg to cpu, not env
cpus: Change tcg_cpu_exec arg to cpu, not env
gdbserver: _fork: Change fn to accept cpu instead of env
translate-all: Change tb_flush env argument to cpu
microblaze: s3adsp: Instantiate CPU using QOM
disas: cris: QOMify target specific disas setup
disas: cris: Fix 0 buffer length case
disas: microblaze: QOMify target specific disas setup
disas: arm: QOMify target specific disas setup
disas: arm-a64: Make printfer and stream variable
disas: QOMify target specific setup
disas: Add print_insn to disassemble info
disas: Remove uses of CPU env
monitor: Split mon_get_cpu fn to remove ENV_GET_CPU
device-tree: Make a common-obj
These deps do not really inhibit at least a high level review of this series.
Regards,
Peter
Changed since v1:
Near total rewrite.
Peter Crosthwaite (34):
cpu-defs: Move CPU_TEMP_BUF_NLONGS to tcg
cpu-exec: Purge all uses of CPU_GET_ENV
Makefile.target: Introduce arch-obj
cpu-exec: Migrate some generic fns to cpus.c
translate: Listify tcg_exec_init
cpu-common: Define tb_page_addr_t for everyone
exec-all: Move cpu_can_do_io to qom/cpu.h
translate-all: Move tcg_handle_interrupt to -common
include/exec: Move standard exceptions to cpu-all.h
include/exec: Split target_long def to new header
include/exec: Move cputlb exec.c defs out
include/exec: Move tb hash functions out
cpu-defs: Move out TB_JMP defines
cpu-defs: Allow multiple inclusions
HACK: monitor: Comment out TCG profile ops
HACK: Disable list_cpus
HACK: globalise TCG page size variables
HACK: monitor: uninclude cpu_ldst
HACK: disas: Defeature print_target_address
HACK: exec: comment out use of cpu_get_tb_cpu_from_state
core: virtualise CPU interfaces completely
microblaze: enable multi-arch
arm: cpu: static inline cpu_arm_init
target-arm: Split cp helper API to new C file
arm: enable multi-arch
core: Introduce multi-arch build
hw: arm: Explicitly include cpu.h for consumers
arm: Remove ELF_MACHINE from cpu.h
hw: mb: Explicitly include cpu.h for consumers
mb: Remove ELF_MACHINE from cpu.h
arm: boot: Don't assume all CPUs are ARM
arm: xilinx_zynq: Add a Microblaze
HACK: mb: boot: Assume using -firmware for mb software
HACK: mb: boot: Disable dtb load in multi-arch
Makefile.objs | 1 +
Makefile.target | 34 +++-
arch_init.c | 4 +-
configure | 39 ++++-
cpu-exec.c | 101 ++++--------
cpus.c | 54 ++++++-
cputlb.c | 40 +++--
default-configs/multi-softmmu.mak | 2 +
disas.c | 12 +-
exec.c | 40 +++--
gdbstub.c | 2 +-
hw/arm/armv7m.c | 2 +-
hw/arm/boot.c | 8 +-
hw/arm/strongarm.h | 2 +
hw/arm/xilinx_zynq.c | 15 ++
hw/microblaze/boot.c | 12 +-
hw/microblaze/boot.h | 2 +
include/exec/cpu-all.h | 6 +
include/exec/cpu-common.h | 4 +
include/exec/cpu-defs.h | 50 ++----
include/exec/cputlb.h | 16 --
include/exec/exec-all.h | 73 ++-------
include/exec/target-long.h | 52 ++++++
include/exec/tb-hash.h | 51 ++++++
include/hw/arm/arm.h | 3 +
include/hw/arm/digic.h | 2 +
include/hw/arm/exynos4210.h | 2 +
include/hw/arm/omap.h | 2 +
include/hw/arm/pxa.h | 2 +
include/qemu-common.h | 5 +
include/qom/cpu.h | 84 ++++++++++
include/sysemu/arch_init.h | 1 +
linux-user/elfload.c | 3 +
monitor.c | 5 +-
qom/cpu.c | 1 +
stubs/Makefile.objs | 1 +
stubs/cpu-qom.c | 76 +++++++++
target-arm/Makefile.objs | 24 +--
target-arm/cpu-qom.h | 2 +
target-arm/cpu.c | 1 +
target-arm/cpu.h | 70 +++++++-
target-arm/helper.c | 331 --------------------------------------
target-arm/hw/Makefile.objs | 1 +
target-arm/hw/cp.c | 330 +++++++++++++++++++++++++++++++++++++
target-microblaze/Makefile.objs | 6 +-
target-microblaze/cpu-qom.h | 2 +
target-microblaze/cpu.c | 1 +
target-microblaze/cpu.h | 44 ++++-
target-multi/cpu.h | 16 ++
target-multi/helper.h | 1 +
tcg/tcg.h | 7 +-
tcg/tci/tcg-target.h | 3 +-
tci.c | 2 +-
translate-all.c | 45 +-----
translate-all.h | 2 -
translate-common.c | 89 ++++++++++
56 files changed, 1131 insertions(+), 655 deletions(-)
create mode 100644 default-configs/multi-softmmu.mak
create mode 100644 include/exec/target-long.h
create mode 100644 include/exec/tb-hash.h
create mode 100644 stubs/cpu-qom.c
create mode 100644 target-arm/hw/Makefile.objs
create mode 100644 target-arm/hw/cp.c
create mode 100644 target-multi/cpu.h
create mode 100644 target-multi/helper.h
create mode 100644 translate-common.c
--
1.9.1
