Re: [PATCH v9 00/13] riscv: Add support for xtheadvector

Conor Dooley
2024-08-09T22:31:34Z

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On Tue, Aug 06, 2024 at 05:31:36PM -0700, Charlie Jenkins wrote:
> xtheadvector is a custom extension that is based upon riscv vector
> version 0.7.1 [1]. All of the vector routines have been modified to
> support this alternative vector version based upon whether xtheadvector
> was determined to be supported at boot.
>
> vlenb is not supported on the existing xtheadvector hardware, so a
> devicetree property thead,vlenb is added to provide the vlenb to Linux.
>
> There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is
> used to request which thead vendor extensions are supported on the
> current platform. This allows future vendors to allocate hwprobe keys
> for their vendor.
>
> Support for xtheadvector is also added to the vector kselftests.

So uh, since noone seems to have brought it up, in the light of the issues
with thead's vector implementation, (https://ghostwriteattack.com/) do we
want to enable it at all?

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