Re: [PATCH] RISC-V: KVM: Allow to downgrade HGATP mode via SATP mode

Andrew Jones
2025-11-24T15:28:00Z

On Sun, Nov 23, 2025 at 10:33:19AM +0800, Guo Ren wrote:
> On Sat, Nov 22, 2025 at 3:50 PM <fangyu.yu@linux.alibaba.com> wrote:
> >
> > From: Fangyu Yu <fangyu.yu@linux.alibaba.com>
> >
> > Currently, HGATP mode uses the maximum value detected by the hardware
> > but often such a wide GPA is unnecessary, just as a host sometimes
> > doesn't need sv57.
> > It's likely that no additional parameters (like no5lvl and no4lvl) are
> > needed, aligning HGATP mode to SATP mode should meet the requirements
> > of most scenarios.
> Yes, no5/4lvl is not clear about satp or hgatp. So, covering HGPATP is
> reasonable.

The documentation should be improved, but I don't think we want to state
that these parameters apply to both s- and g-stage. If we need parameters
to dictate KVM behavior (g-stage management), then we should add KVM
module parameters.

Thanks,
drew