[RFC PATCH v2 0/6] Add API for list cpu extensions

[LIU Zhiwei <zhiwei_liu@linux.alibaba.com>]

Some times we want to know what is the really mean of one cpu option.
For example, in RISC-V, we usually specify a cpu in this way:
-cpu rv64,v=on

If we don't look into the source code, we can't get the ISA extensions
of this -cpu command line.

In this patch set, we add one list_cpu_props API for common cores. It
will output the enabled ISA extensions.

In the near future, I will also list all possible user configurable
options and all possible extensions for this cpu.

In order to reuse the options parse code, I also add a QemuOptsList
for cpu.

After this patch, we can output the extensions for cpu,
"""
./qemu-system-riscv64 -cpu rv64,help
Enabled extensions:
    rv64imafdch_zicbom_zicboz_zicsr_zifencei_zihintpause_zawrs_zfa_zba_zbb_zbc_zbs_sstc_svadu
To get all configuable options for this cpu, use -device rv64-riscv-cpu,help
"""


v1->v2:

1) Give a hint to use -device cpu,help for configualbe options on cpu
2) Support list_cpu_props for linux user mode
3) Add default to some properties to make -device cpu,help output better


Todo:
1) Fix Daniel comments on KVM and cpu option check
2) Add support for other archs
3) Move qdev help function from qdev-monitor to qdev-property

LIU Zhiwei (6):
  cpu: Add new API cpu_type_by_name
  target/riscv: Add API list_cpu_props
  softmmu/vl: Add qemu_cpu_opts QemuOptsList
  target/riscv: Add default value for misa property
  target/riscv: Add defalut value for string property
  linux-user: Move qemu_cpu_opts to cpu.c

 cpu.c                        | 63 +++++++++++++++++++++++++++++-------
 hw/core/qdev-prop-internal.h |  2 ++
 hw/core/qdev-properties.c    |  7 ++++
 include/exec/cpu-common.h    |  3 ++
 include/hw/core/cpu.h        | 11 +++++++
 include/hw/qdev-properties.h |  8 +++++
 linux-user/main.c            | 10 ++++++
 softmmu/vl.c                 | 11 +++++++
 target/riscv/cpu.c           | 30 +++++++++++++----
 target/riscv/cpu.h           |  2 ++
 10 files changed, 128 insertions(+), 19 deletions(-)

-- 
2.17.1