Re: [PATCH 0/6] riscv: RVA22U64 profile support

[Andrea Bolognani]

On Tue, Sep 26, 2023 at 04:49:44PM -0300, Daniel Henrique Barboza wrote:
> Based-on: 20230926183109.165878-1-dbarboza@ventanamicro.com
> ("[PATCH 0/2] riscv: add extension properties for all cpus")
>
> Hi,
>
> These patches implements the base profile support for qemu-riscv and the
> first profile, RVA22U64.
>
> As discussed in this thread [1] we're aiming for a flag that enables all
> mandatory extensions of a profile. Optional extensions were left behind
> and must be enabled by hand if desired. Since this is the first profile
> we're adding, we'll need to add the base framework as well.
>
> The RVA22U64 profile was chosen because qemu-riscv implements all its
> extensions, both mandatory and optional. That includes 'zicntr' and
> 'zihpm', which we support for awhile but aren't adverting to userspace.
>
> Other design decisions made:
>
> - disabling a profile flag does nothing, i.e. we won't mass disable
>   mandatory extensions of the rva22U64 profile if the user sets
>   rva22u64=false;

Wouldn't it make more sense to error out when this is requested?

Silently ignoring an explicit request made by the user is pretty much
never a good idea in my experience.

-- 
Andrea Bolognani / Red Hat / Virtualization