Re: [PATCH 1/5] RISC-V: KVM: Lazy enable hstateen IMSIC & ISEL bit

[Radim Krčmář]

2025-05-05T14:39:26-07:00, Atish Patra <atishp@xxxxxxxxxxxx>:
> Currently, we enable the smstateen bit at vcpu configure time by
> only checking the presence of required ISA extensions.
>
> These bits are not required to be enabled if the guest never uses
> the corresponding architectural state. Enable the smstaeen bits
> at runtime lazily upon first access.

What is the advantage of enabling them lazily?

To make the trap useful, we would have to lazily perform initialization
of the AIA.  I think it would require notable changes to AIA, though...

Thanks.