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

[Alistair Francis <alistair23@gmail.com>]

On Mon, Jun 24, 2019 at 2:33 AM Palmer Dabbelt <palmer@sifive.com> wrote:
>
> 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
> >
> > 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(-)
>
> Aside from the comments on 3 and 9
>
> Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
>
> I've got these, along with my proposed modifications, queued up.  LMK if that's
> a problem, particularly the two-patch replacement for 9 needs a review as it's
> entirely new code.

I haven't looked at the new code yet, but it all passes my tests so LGTM.

Alistair