[RFC PATCH 0/3] Add API for list cpu extensions

[LIU Zhiwei]

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
    Enable extension:
            
rv64imafdch_zicbom_zicboz_zicsr_zifencei_zihintpause_zawrs_zfa_zba_zbb_zbc_zbs_sstc_svadu
"""

Notice currently this patch is only working for RISC-V system mode.

Thanks Andrew Jones for your suggestion!

Todo:
1) Output all possible user configurable options and all extensions.
2) Add support for RISC-V linux-user mode
3) Add support for other archs


LIU Zhiwei (3):
  cpu: Add new API cpu_type_by_name
  target/riscv: Add API list_cpu_props
  softmmu/vl: Add qemu_cpu_opts QemuOptsList

 cpu.c                     | 39 +++++++++++++++++++++++++++------------
 include/exec/cpu-common.h |  1 +
 include/hw/core/cpu.h     | 11 +++++++++++
 softmmu/vl.c              | 35 +++++++++++++++++++++++++++++++++++
 target/riscv/cpu.c        | 10 ++++++++++
 target/riscv/cpu.h        |  2 ++
 6 files changed, 86 insertions(+), 12 deletions(-)

-- 
2.17.1