Re: [Qemu-devel] [PATCH v1 0/9] Update the RISC-V specification versions

[Palmer Dabbelt <palmer@sifive.com>]

On Mon, 17 Jun 2019 18:31:00 PDT (-0700), Alistair Francis wrote:
> Based-on: <cover.1555726824.git.alistair.francis@wdc.com>
>
> Now that the RISC-V spec has started to be ratified let's update our
> QEMU implementation. There are a few things going on here:
>  - Add priv version 1.11.0 to QEMU
>     - This is the ratified version of the Privledge spec
>     - There are almost no changes to 1.10
>  - Mark the 1.09.1 privledge spec as depreated
>      - Let's aim to remove it in two releases
>  - Set priv version 1.11.0 as the default
>  - Remove the user_spec version
>      - This doesn't really mean anything so let's remove it
>  - Add support for the "Counters" extension
>  - Add command line options for Zifencei and Zicsr

Thanks!  I'll look at the code, but I've currently got this queued up behind
your hypervisor patches so it might take a bit.  LMK if you want me to invert
the priority on these.  I'll probably be buried until the start of July.

> We can remove the spec version as it's unused and has never been exposed
> to users. The idea is to match the specs in specifying the version. To
> handle versions in the future we can extend the extension props to
> handle version information.
>
> For example something like this: -cpu rv64,i=2.2,c=2.0,h=0.4,priv_spec=1.11
>
> NOTE: This isn't supported today as we only have one of each version.
>
> This will be a future change if we decide to support multiple versions
> of extensions.
>
> The "priv_spec" string doesn't really match, but I don't have a better
> way to say "Machine ISA" and "Supervisor ISA" which is what is included
> in "priv_spec".
>
> For completeness I have also added the Counters, Zifencei and Zicsr
> extensions.
>
> Everything else seems to match the spec names/style.
>
> Please let me know if I'm missing something. QEMU 4.1 is the first
> release to support the extensions from the command line, so we can
> easily change it until then. After that it'll take more work to change
> the command line interface.
>
> Alistair Francis (9):
>   target/riscv: Restructure deprecatd CPUs
>   target/riscv: Add the privledge spec version 1.11.0
>   target/riscv: Comment in the mcountinhibit CSR
>   target/riscv: Set privledge spec 1.11.0 as default
>   qemu-deprecated.texi: Deprecate the RISC-V privledge spec 1.09.1
>   target/riscv: Require either I or E base extension
>   target/riscv: Remove user version information
>   target/riscv: Add support for disabling/enabling Counters
>   target/riscv: Add Zifencei and Zicsr as command line options
>
>  qemu-deprecated.texi                          |  8 +++
>  target/riscv/cpu.c                            | 72 ++++++++++---------
>  target/riscv/cpu.h                            | 19 ++---
>  target/riscv/cpu_bits.h                       |  1 +
>  target/riscv/csr.c                            | 13 +++-
>  .../riscv/insn_trans/trans_privileged.inc.c   |  2 +-
>  6 files changed, 71 insertions(+), 44 deletions(-)