Re: [RFC PATCH V3 00/11] riscv: Add vector ISA support

Greentime Hu
2020-03-10T08:54:34Z

On Mon, Mar 9, 2020 at 6:27 PM LIU Zhiwei <zhiwei_liu@c-sky.com> wrote:
> On 2020/3/9 11:41, Greentime Hu wrote:
> > On Sun, Mar 8, 2020 at 5:50 PM <guoren@kernel.org> wrote:
> >> From: Guo Ren <guoren@linux.alibaba.com>
> >>
> >> The implementation follow the RISC-V "V" Vector Extension draft v0.8 with
> >> 128bit-vlen and it's based on linux-5.6-rc3 and tested with qemu [1].
> >>
> >> The patch implement basic context switch, sigcontext save/restore and
> >> ptrace interface with a new regset NT_RISCV_VECTOR. Only fixed 128bit-vlen
> >> is implemented. We need to discuss about vlen-size for libc sigcontext and
> >> ptrace (the maximum size of vlen is unlimited in spec).
> >>
> >> Puzzle:
> >> Dave Martin has talked "Growing CPU register state without breaking ABI" [2]
> >> before, and riscv also met vlen size problem. Let's discuss the common issue
> >> for all architectures and we need a better solution for unlimited vlen.
> >>
> >> Any help are welcomed :)
> >>
> >> 1: https://github.com/romanheros/qemu.git branch:vector-upstream-v3
> > Hi Guo,
> >
> > Thanks for your patch.
> > It seems the qemu repo doesn't have this branch?
> Hi Greentime,
>
> It's a promise from me. Now it's ready. You can turn on vector by
> "qemu-system-riscv64 -cpu rv64,v=true,vext_spec=v0.7.1".
>
> Zhiwei
>
>

Hi Zhiwei,

Thank you, I see the branch in the repo now. I will give it a try and
let you know if I have any problem. :)